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  • Methadone-induced encephalopathy: a case series and literature review
    BMC Med. Imaging (IF 1.622) Pub Date : 2020-01-17
    Maryam Haghighi-Morad; Zahra Naseri; Nazila Jamshidi; Hossein Hassanian-Moghaddam; Nasim Zamani; Leila Ahmad-Molaei

    Accidental ingestion or consumption of supra-therapeutic doses of methadone can result in neurological sequelae in humans. We aimed to determine the neurological deficits of methadone-poisoned patients admitted to a referral poisoning hospital using brain magnetic resonance (MR) and diffusion weighted (DW) imaging. In this retrospective study, brain MRIs of the patients admitted to our referral center due to methadone intoxication were reviewed. Methadone intoxication was confirmed based on history, congruent clinical presentation, and confirmatory urine analysis. Each patient had an MRI with Echo planar T1, T2, FLAIR, and DWI and apparent deficient coefficient (ADC) sequences without contrast media. Abnormalities were recorded and categorized based on their anatomic location and sequence. Ten patients with abnormal MRI findings were identified. Eight had acute- and two had delayed-onset encephalopathy. Imaging findings included bilateral confluent or patchy T2 and FLAIR high signal intensity in cerebral white matter, cerebellar involvement, and bilateral occipito-parietal cortex diffusion restriction in DWI. Internal capsule involvement was identified in two patients while abnormality in globus pallidus and head of caudate nuclei were reported in another. Bilateral cerebral symmetrical confluent white matter signal abnormality with sparing of subcortical U-fibers on T2 and FLAIR sequences were observed in both patients with delayed-onset encephalopathy. Acute- and delayed-onset encephalopathies are two rare adverse events detected in methadone-intoxicated patients. Brain MRI findings can be helpful in detection of methadone-induced encephalopathy.

    更新日期:2020-01-17
  • Dual-energy spectral CT quantitative parameters for the differentiation of Glioma recurrence from treatment-related changes: a preliminary study
    BMC Med. Imaging (IF 1.622) Pub Date : 2020-01-16
    Yanchun Lv; Jian Zhou; Xiaofei Lv; Li Tian; Haoqiang He; Zhigang Liu; Yi Wu; Lujun Han; Meili Sun; Yadi Yang; Chengcheng Guo; Cong Li; Rong Zhang; Chuanmiao Xie; Yinsheng Chen; Zhongping Chen

    Differentiating glioma recurrence from treatment-related changes can be challenging on conventional imaging. We evaluated the efficacy of quantitative parameters measured by dual-energy spectral computed tomographic (CT) for this differentiation. Twenty-eight patients were examined by dual-energy spectral CT. The effective and normalized atomic number (Zeff and Zeff-N, respectively); spectral Hounsfield unit curve (λHU) slope; and iodine and normalized iodine concentration (IC and ICN, respectively) in the post-treatment enhanced areas were calculated. Pathological results or clinicoradiologic follow-up of ≥2 months were used for final diagnosis. Nonparametric and t-tests were used to compare quantitative parameters between glioma recurrence and treatment-related changes. Sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively), and accuracy were calculated using receiver operating characteristic (ROC) curves. Predictive probabilities were used to generate ROC curves to determine the diagnostic value. Examination of pre-contrast λHU, Zeff, Zeff-N, IC, ICN, and venous phase ICN showed no significant differences in quantitative parameters (P > 0.05). Venous phase λHU, Zeff, Zeff-N, and IC in glioma recurrence were higher than in treatment-related changes (P < 0.001). The optimal venous phase threshold was 1.03, 7.75, 1.04, and 2.85 mg/cm3, achieving 66.7, 91.7, 83.3, and 91.7% sensitivity; 100.0, 77.8, 88.9, and 77.8% specificity; 100.0, 73.3, 83.3, and 73.3% PPV; 81.8, 93.3, 88.9, and 93.3% NPV; and 86.7, 83.3, 86.7, and 83.3% accuracy, respectively. The respective areas under the curve (AUCs) were 0.912, 0.912, 0.931, and 0.910 in glioma recurrence and treatment-related changes. Glioma recurrence could be potentially differentiated from treatment-related changes based on quantitative values measured by dual-energy spectral CT imaging.

    更新日期:2020-01-16
  • Preliminary application of 3.0 T magnetic resonance chemical exchange saturation transfer imaging in brain metastasis of lung cancer
    BMC Med. Imaging (IF 1.622) Pub Date : 2020-01-13
    Yonggui Yang; Xiaobo Qu; Yihui Huang; Khan Afsar; Gen Yan; Gang Guo; Shaoyin Duan

    Lung cancer brain metastases are very common and one of the common causes of treatment failure. We aimed to examine the clinical use of chemical exchange saturation transfer (CEST) technology in the evaluation of brain metastases for lung cancer diagnosis and prognosis. We included26 cases of lung cancer brain metastases, 15 cases of gliomas, and 20 cases with normal tests. The magnetization transfer ratio (MTR;3.5 ppm) image from the GRE-EPI-CEST sequence was analyzed using the ASSET technique and APT technology. The MTR values were measured in the lesion-parenchymal, edema, and non-focus regions, and the MTR image was compared with the conventional MRI. ANOVA and t-test were used for statistical analysis. The lesion-parenchymal, edema, and non-focus areas in the metastatic-tumor-group were red-yellow, yellow-green, and green-blue, and the MTR values were 3.29 ± 1.14%,1.28 ± 0.36%,and 1.26 ± 0.31%, respectively. However, in the glioma-group, the corresponding areas were red, red-yellow, and green-blue, and the MTR values were 6.29 ± 1.58%, 2.87 ± 0.65%, and 1.03 ± 0.30%, respectively. The MTR values of the corresponding areas in the normal-group were 1.07 ± 0.22%,1.04 ± 0.23%, and 1.06 ± 0.24%, respectively. Traditional MR images are in black-white contrast and no metabolic information is displayed. The MTRvalues of the three regions were significantly different among the three groups. The values were also significantly different between the parenchymal and edema areas in the metastatic-tumor-group. There were significant differences in the MTR values between the non-lesion and edema regions, but there was no significant difference between the edema and non-focus areas. In the glioma-group, there were significant differences in the MTR values between the parenchymal and edema areas, between the parenchymal and non-focus areas, and between the edema and non-focus areas. CEST reflects the protein metabolism; therefore, early diagnosis of brain metastases and assessment of the prognosis can be achieved using molecular imaging.

    更新日期:2020-01-14
  • Assessing and reducing PET radiotracer infiltration rates: a single center experience in injection quality monitoring methods and quality improvement
    BMC Med. Imaging (IF 1.622) Pub Date : 2020-01-10
    Dustin R. Osborne; Shelley N. Acuff; Michael Fang; Melissa D. Weaver; Yitong Fu

    Successful injection of radiolabeled compounds is critical for positron emission tomography (PET) imaging. A poor quality injection limits the tracer availability in the body and can impact diagnostic results. In this study, we attempt to quantify our infiltration rates, develop an actionable quality improvement plan to reduce potentially compromised injections, and compare injection scoring to PET/CT imaging results. A commercially available system that uses external radiation detectors was used to monitor and score injection quality. This system compares the time activity curves of the bolus relative to a control reading in order to provide a score related to the quality of the injection. These injection scores were used to assess infiltration rates at our facility in order to develop and implement a quality improvement plan for our PET imaging center. Injection scores and PET imaging results were reviewed to determine correlations between image-based assessments of infiltration, such as liver SUVs, and injection scoring, as well as to gather infiltration reporting statistics by physicians. A total of 1033 injections were monitored at our center. The phase 1 infiltration rate was 2.1%. In decision tree analysis, patients < 132.5lbs were associated with infiltrations. Additional analyses suggested patients > 127.5 lbs. with non-antecubital injections were associated with lower quality injections. Our phase 2 infiltration rate was 1.9%. Comparison of injection score to SUV showed no significant correlation and indicated that only 63% of suspected infiltrations were visible on PET/CT imaging. Developing a quality improvement plan and monitoring PET injections can lead to reduced infiltration rates. No significant correlation between reference SUVs and injection score provides evidence that determination of infiltration based on PET images alone may be limited. Results also indicate that the number of infiltrated PET injections is under-reported.

    更新日期:2020-01-11
  • An enhanced adaptive non-local means algorithm for Rician noise reduction in magnetic resonance brain images
    BMC Med. Imaging (IF 1.622) Pub Date : 2020-01-06
    Kaixin Chen; Xiao Lin; Xing Hu; Jiayao Wang; Han Zhong; Linhua Jiang

    The Rician noise formed in magnetic resonance (MR) imaging greatly reduced the accuracy and reliability of subsequent analysis, and most of the existing denoising methods are suitable for Gaussian noise rather than Rician noise. Aiming to solve this problem, we proposed fuzzy c-means and adaptive non-local means (FANLM), which combined the adaptive non-local means (NLM) with fuzzy c-means (FCM), as a novel method to reduce noise in the study. The algorithm chose the optimal size of search window automatically based on the noise variance which was estimated by the improved estimator of the median absolute deviation (MAD) for Rician noise. Meanwhile, it solved the problem that the traditional NLM algorithm had to use a fixed size of search window. Considering the distribution characteristics for each pixel, we designed three types of search window sizes as large, medium and small instead of using a fixed size. In addition, the combination with the FCM algorithm helped to achieve better denoising effect since the improved the FCM algorithm divided the membership degrees of images and introduced the morphological reconstruction to preserve the image details. The experimental results showed that the proposed algorithm (FANLM) can effectively remove the noise. Moreover, it had the highest peak signal-noise ratio (PSNR) and structural similarity (SSIM), compared with other three methods: non-local means (NLM), linear minimum mean square error (LMMSE) and undecimated wavelet transform (UWT). Using the FANLM method, the image details can be well preserved with the noise being mostly removed. Compared with the traditional denoising methods, the experimental results showed that the proposed approach effectively suppressed the noise and the edge details were well retained. However, the FANLM method took an average of 13 s throughout the experiment, and its computational cost was not the shortest. Addressing these can be part of our future research.

    更新日期:2020-01-07
  • Pre-contrast T1 and cartilage thickness as confounding factors in dGEMRIC when evaluating human cartilage adaptation to physical activity
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-31
    Carl Johan Tiderius; Zana K. Hawezi; Lars E. Olsson; Leif E. Dahlberg

    The dGEMRIC (delayed Gadolinium-Enhanced MRI of Cartilage) technique has been used in numerous studies for quantitative in vivo evaluation of the relative glycosaminoglycan (GAG) content in cartilage. The purpose of this study was to determine the influence of pre-contrast T1 and cartilage thickness when assessing knee joint cartilage quality with dGEMRIC. Cartilage thickness and T1 relaxation time were measured in the central part of the femoral condyles before and two hours after intravenous Gd-DTPA2− administration in 17 healthy volunteers from a previous study divided into two groups: 9 sedentary volunteers and 8 exercising elite runners. Results were analyzed in superficial and a deep weight-bearing, as well as in non-weight-bearing regions of interest. In the medial compartment, the cartilage was thicker in the exercising group, in weight-bearing and non-weight-bearing segments. In most of the segments, the T1 pre-contrast value was longer in the exercising group compared to the sedentary group. Both groups had a longer pre-contrast T1 in the superficial cartilage than in the deep cartilage. In the superficial cartilage, the gadolinium concentration was independent of cartilage thickness. In contrast, there was a linear correlation between the gadolinium concentration and cartilage thickness in the deep cartilage region. Cartilage pre-contrast T1 and thickness are sources of error in dGEMRIC that should be considered when analysing bulk values. Our results indicate that differences in cartilage structure due to exercise and weight-bearing may be less pronounced than previously demonstrated.

    更新日期:2020-01-01
  • Automated classification of dense calcium tissues in gray-scale intravascular ultrasound images using a deep belief network
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-30
    Juhwan Lee; Yoo Na Hwang; Ga Young Kim; Ji Yean Kwon; Sung Min Kim

    IVUS is widely used to quantitatively assess coronary artery disease. The purpose of this study was to automatically characterize dense calcium (DC) tissue in the gray scale intravascular ultrasound (IVUS) images using the image textural features. A total of 316 Gy-scale IVUS and corresponding virtual histology images from 26 patients with acute coronary syndrome who underwent IVUS along with X-ray angiography between October 2009 to September 2014 were retrospectively acquired and analyzed. One expert performed all procedures and assessed their IVUS scans. After image acquisition, the DC candidate and corresponding acoustic shadow regions were automatically determined. Then, nine image-base feature groups were extracted from the DC candidates. In order to reduce the dimensionalities, principal component analysis (PCA) was performed, and selected feature sets were utilized as an input for a deep belief network. Classification results were validated using 10-fold cross validation. The dimensionality of the feature map was efficiently reduced by 50% (from 66 to 33) without any performance decrease using PCA method. Sensitivity, specificity, and accuracy of the proposed method were 92.8 ± 0.1%, 85.1 ± 0.1%, and 88.4 ± 0.1%, respectively (p < 0.05). We found that the window size could largely influence the characterization results, and selected the 5 × 5 size as the best condition. We also validated the performance superiority of the proposed method with traditional classification methods. These experimental results suggest that the proposed method has significant clinical applicability for IVUS-based cardiovascular diagnosis.

    更新日期:2019-12-31
  • Reduced regional flow in the left ventricle after anterior acute myocardial infarction: a case control study using 4D flow MRI
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-30
    Philip A. Corrado; Jacob A. Macdonald; Christopher J. François; Niti R. Aggarwal; Jonathan W. Weinsaft; Oliver Wieben

    Acute myocardial infarction (AMI) alters left ventricular (LV) hemodynamics, resulting in decreased global LV ejection fraction and global LV kinetic energy. We hypothesize that anterior AMI effects localized alterations in LV flow and developed a regional approach to analyze these local changes with 4D flow MRI. 4D flow cardiac magnetic resonance (CMR) data was compared between 12 anterior AMI patients (11 males; 66 ± 12yo; prospectively acquired in 2016–2017) and 19 healthy volunteers (10 males; 40 ± 16yo; retrospective from 2010 to 2011 study). The LV cavity was contoured on short axis cine steady-state free procession CMR and partitioned into three regions: base, mid-ventricle, and apex. 4D flow data was registered to the short axis segmentation. Peak systolic and diastolic through-plane flows were compared region-by-region between groups using linear models of flow with age, sex, and heart rate as covariates. Peak systolic flow was reduced in anterior AMI subjects compared to controls in the LV mid-ventricle (fitted reduction = 3.9 L/min; P = 0.01) and apex (fitted reduction = 1.4 L/min; P = 0.02). Peak diastolic flow was also lower in anterior AMI subjects compared to controls in the apex (fitted reduction = 2.4 L/min; P = 0.01). A regional method to analyze 4D LV flow data was applied in anterior AMI patients and controls. Anterior AMI patients had reduced regional flow relative to controls.

    更新日期:2019-12-30
  • Feasibility evaluation of micro-optical coherence tomography (μOCT) for rapid brain tumor type and grade discriminations: μOCT images versus pathology
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-30
    Xiaojun Yu; Chi Hu; Wenfei Zhang; Jie Zhou; Qianshan Ding; M. T. Sadiq; Zeming Fan; Zhaohui Yuan; Linbo Liu

    Precise identification, discrimination and assessment of central nervous system (CNS) tumors is of critical importance to brain neoplasm treatment. Due to the complexity and limited resolutions of the existing diagnostic tools, however, it is difficult to identify the tumors and their boundaries precisely in clinical practice, and thus, the conventional way of brain neoplasm treatment relies mainly on the experiences of neurosurgeons to make resection decisions in the surgery process. The purpose of this study is to explore the potential of Micro-optical coherence tomography (μOCT) as an intraoperative diagnostic imaging tool for identifying and discriminating glioma and meningioma with their microstructure imaging ex vivo, which thus may help neurosurgeons to perform precise surgery with low costs and reduced burdens. Fresh glioma and meningioma samples were resected from patients, and then slices of such samples were excised and imaged instantly ex vivo with a lab-built μOCT, which achieves a spatial resolution of ~ 2.0 μm (μm). The acquired optical coherence tomography (OCT) images were pathologically evaluated and compared to their corresponding histology for both tumor type and tumor grade discriminations in different cases. By using the lab-built μOCT, both the cross-sectional and en face images of glioma and meningioma were acquired ex vivo. Based upon the morphology results, both the glioma and meningioma types as well as the glioma grades were assessed and discriminated. Comparisons between OCT imaging results and histology showed that typical tissue microstructures of glioma and meningioma could be clearly identified and confirmed the type and grade discriminations with satisfactory accuracy. μOCT could provide high-resolution three-dimensional (3D) imaging of the glioma and meningioma tissue microstructures rapidly ex vivo. μOCT imaging results could help discriminate both tumor types and grades, which illustrates the potential of μOCT as an intraoperative diagnostic imaging tool to help neurosurgeons perform their surgery precisely in tumor treatment process.

    更新日期:2019-12-30
  • Association between basilar artery configuration and Vessel Wall features: a prospective high-resolution magnetic resonance imaging study
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-26
    Ziqi Xu; Mingyao Li; Zhikai Hou; Jinhao Lyu; Na Zhang; Xin Lou; Zhongrong Miao; Ning Ma

    The relationship between intracranial vessel configuration and wall features remains poorly investigated. Therefore, we aimed to investigate the relationship between the distal and proximal anatomical configuration of basilar artery (BA) and BA vessel wall features on high-resolution magnetic resonance imaging (HRMRI). From September 2014 to January 2017, patients with suspected symptomatic intracranial arterial stenosis underwent HRMRI. Patients with severe BA stenosis were selected for this prospective study and divided into two groups corresponding to complete and incomplete BA configuration based on characteristics of the bilateral vertebral arteries and posterior cerebral arteries. Culprit blood vessel wall features on HRMRI included plaque enhancement, intraplaque hemorrhage, remodeling patterns, and plaque distribution. Culprit vessel wall features were compared between patients in the complete and incomplete BA configuration groups. Among the 298 consecutively enrolled patients, 34 had severe BA stenosis. Twenty patients had complete anatomical BA configuration and another 14 of them displayed incomplete configuration. There were no significant differences in vessel wall features between the complete and incomplete configuration patient groups. However, the proximal configuration of BA was associated with intraplaque hemorrhage (p = 0.002) while the distal configuration of BA correlated with strong enhancement of BA plaque (p = 0.041). No association was found between the complete and incomplete BA configuration groups and blood vessel wall features. The proximal configuration of BA was related with intraplaque hemorrhage and the distal configuration of BA was associated with strong plaque enhancement. Further studies are warranted to confirm these findings. URL: Unique identifier: NCT02705599 (March 10, 2016).

    更新日期:2019-12-27
  • Comparative evaluation of image registration methods with different interest regions in lung cancer radiotherapy
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-26
    Xiaohui Cao; Ming Liu; Fushan Zhai; Nan Li; Feng Li; Chaoen Bao; Yinliang Liu; Gang Chen

    Lung cancer is a leading cause of morbidity and mortality worldwide. Radiotherapy for lung cancer is beneficial in both the radical and palliative settings, and technologic advances in recent years now afford an opportunity for this treatment to be more targeted than ever before. Although the delivery of more accurate forms of radiotherapy has minimized the risks of side-effects, how to utilize this treatment to optimize outcomes remains questionable. This study aimed to evaluate the accuracy of cone beam computed tomography (CBCT) image registration used in image-guided radiotherapy, providing reasonable guidance for clinic application of CBCT in lung cancer. A total of 53 patients with lung carcinoma including 34 central and 19 peripheral lesions were collected in this study. Varian-IX linear accelerator on-board imaging (OBI) system was used to acquire CBCT scans in three-dimensional (3D) conformal radiotherapy before delivery. Different regions (whole lung/target/vertebrae/ipsilateral structure) were manually registered, and the position deviation and the registration time were analyzed. It was suggested that 34 cases belonged to central type and 19 cases belonged to peripheral type. The volume of left lung and right lung was 1242.98 ± 452.46 cc, 1689.69 ± 574.31 cc, respectively. Tumor size was 6.65 ± 3.87 cm in diameter, and 129.67 ± 136.48 cc in volume. The percentage of left lung and right lung was 6.17 ± 1.24%, 4.74 ± 0.38%, respectively. The position deviation value and absolute value of image registration methods of X, Y and Z axis were not significant (P > 0.05). However, registration time (s) between whole lung registration group, tumor registration group, vertebral body registration group, affected lung registration group, and artificial registration group, was 3.651 ± 0.867 s, 1.144 ± 0.129 s, 1.226 ± 0.126 s, 2.081 ± 0.427 s, 179.491 ± 71.975 s, respectively. The differences were significant (P < 0.05). The registration differences between small tumor group and large tumor group were not statistically significant (P > 0.05). The automatic image matching of OBI is accuracy and high reliability in recognition of offset error. Registering body or ipsilateral structure is recommended to be used in CBCT for lung cancer.

    更新日期:2019-12-27
  • Time-lapse angiography of the ocular fundus: a new video-angiography
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-19
    Chufeng Gu; Jili Chen; Tong Su; Qinghua Qiu

    Ocular fundus angiography is an indispensable component of the tests utilized for fundus diseases. Dynamic angiography results can provide additional information; however, many difficulties remain. In this study, we introduce a modified method, time-lapse angiography (TLA), to dynamically present imaging results. TLA, combining time-lapse photography and fundus angiography (using Heidelberg retina angiography II, Germany), includes pre-photographing and post- photosynthesis and ultimately produces a video that is approximately 15 s in length. Four typical videos in the article showed the characteristics of TLA, including a short and rapid but continuous and integral presentation, highly valid information, high definition, etc. TLA is beneficial for the diagnosis of diseases and the assessment of progression and is convenient for peer communication, patient interpretation, and student education. The application of time-lapse photography in ocular fundus angiography is a monumental and innovative attempt.

    更新日期:2019-12-19
  • Inter and intra-reliability of ultrasonography for the measurement of abdominal subcutaneous & visceral adipose tissue thickness at 12 weeks gestation
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-17
    Alexandra Cremona; Kevin Hayes; Clodagh S. O’Gorman; Ciara Ní Laighin; Khadijah I. Ismail; Alan E. Donnelly; Jill Hamilton; Amanda Cotter

    Excess abdominal adiposity cause metabolic disturbances, particularly in pregnancy. Methods of accurate measurement are limited in pregnancy due to risks associated with these procedures. This study outlines a non-invasive methodology for the measurement of adipose tissue in pregnancy and determines the intra- and inter-observer reliability of ultrasound (US) measurements of the two components of adipose tissue (subcutaneous (SAT) and visceral adipose tissue (VAT)) within a pregnant population. Thirty pregnant women were recruited at the end of their first trimester, from routine antenatal clinic at the University Maternity Hospital Limerick, Ireland. Measurements of adipose tissue thickness were obtained using a GE Voluson E8 employing a 1–5 MHz curvilinear array transducer. Two observers, employing methodological rigour in US technique, measured thickness of adipose tissue three times, and segmented the US image systematically in order to define measurements of SAT and VAT using specifically pre-defined anatomical landmarks. Intra-observer and inter-observer precision was assessed using Coefficient of Variation (CV). Measurements of SAT and total adipose for both observers were < 5% CV and < 10% CV for VAT in measures by both observers. Inter-observer reliability was assessed by Limits of Agreement (LoA). LoA were determined to be − 0.45 to 0.46 cm for SAT and − 0.34 to 0.53 cm for VAT values. Systematic bias of SAT measurement was 0.01 cm and 0.10 cm for VAT. Inter-observer precision was also assessed by coefficient of variation (CV: SAT, 3.1%; VAT, 7.2%; Total adipose, 3.0%). Intra-observer precision was found to be acceptable for measures of SAT, VAT and total adipose according to anthropometric criterion, with higher precision reported in SAT values than in VAT. Inter-observer reliability assessed by Limits-Of-Agreement (LoA) confirm anthropometrically reliable to 0.5 cm. Systematic bias was minimal for both measures, falling within 95% confidence intervals. These results suggest that US can produce reliable, repeatable and accurate measures of SAT and VAT during pregnancy.

    更新日期:2019-12-18
  • Evaluation of venous pathology of the lower extremities with triggered angiography non-contrast-enhanced magnetic resonance imaging
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-17
    Yao-Kuang Huang; Yuan-Hsi Tseng; Chih-Hung Lin; Yuan-Hsiung Tsai; Yin-Chen Hsu; Shih-Chung Wang; Chien-Wei Chen

    To explore the diagnostic performance of triggered angiography non-contrast-enhanced magnetic resonance imaging (TRANCE-MRI) for the evaluation of venous pathology of the lower extremity. This was a single-centre prospective cohort study of 25 patients with suspected venous disease in the lower extremities. Each patient received Doppler ultrasonography (for venous evaluation) before the scheduled TRANCE-MRI (for venous and arterial evaluations) on a 1.5 T MR scanner (Philips Ingenia, Philips Healthcare, Best, the Netherlands), followed by lymphography and computed tomography angiography that were arranged according to the diagnostic indications. The sensitivity, specificity and accuracy of TRANCE-MRI were 85.7%, 88/9 and 88%, respectively. The inter-rater agreement for deep vein thrombosis (DVT) of the thigh between the ultrasonography and TRANCE-MRI results was substantial agreement (Cohen’s kappa κ, 0.72). In ultrasonography-negative cases, TRANCE-MRI detected four additional cases (16%, 4/25) of DVT; three cases (12%, 3/25) of venous compression caused by pelvic lymphadenopathy, hip prosthesis or knee joint effusion; one case (4%, 1/25) of vena cava anomaly; two cases (8%, 2/25) of occult peripheral artery disease (PAD); and one case (4%, 1/25) of an occluded bypass graft. TRANCE-MRI can be used as an alternative and objective tool for assessing lower extremity diseases, especially suspected venous pathology. Compared with ultrasonography, TRANCE-MRI plays a better role in assessing varicose veins of the lower extremities and deep veins of the pelvis and abdomen. However, false-positive results may occur in the left common iliac vein of elderly patients. Finally, occult PAD rarely occurs in patients with suspected lower extremity venous disease. Therefore, we recommend performing the TRANCE-MRV protocol instead of the full protocol (MRV + MRA) in the clinical setting in patients with venous scenarios.

    更新日期:2019-12-18
  • Diagnostic accuracy of multi-slice computed tomography in children with Abernethy malformation
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-17
    Chen Guo; Yu-Min Zhong; Qian Wang; Li-Wei Hu; Xiao-Hong Gu; Hong Shao; Wei Wu; Jian-Feng Cao; Hai-Sheng Qiu

    Abernethy malformation is a rare congenital abnormality. Imaging examination is an important method for the diagnosis. The purpose of this study was to demonstrate manifestations of multi-slice computed tomography (MSCT) in Abernethy malformation and its diagnostic accuracy. Fourteen children with Abernethy malformation were admitted to our center in China between July 2011 and January 2018. All 14 patients (eight males and six females) received MSCT and digital subtraction angiography (DSA) while eight patients also received ultrasound. The patients’ age ranged from 1 to 14 (median age 8 years old). The clinical records of the patients were retrospectively reviewed. MSCT raw data were transferred to an Advantage Windows 4.2 or 4.6 workstation (General Electric Medical Systems, Waukesha, WI). We compared the findings of MSCT with DSA and surgical results in order to ascertain diagnostic accuracy. Three cases had type Ib Abernethy malformation and eleven cases had type II. Two cases of type II Abernethy malformation were misdiagnosed as type Ib using MSCT. Comparing the findings of MSCT with DSA and surgical results, the accuracy of MSCT was 85.7% (12/14), in which 100.0% (3/3) were type Ib and 81.8% (9/11) were type II. Clinical information included congenital heart disease, pulmonary hypertension, diffuse pulmonary arteriovenous fistula, abnormal liver function, hepatic nodules, elevated blood ammonia, and hepatic encephalopathy. Eleven cases were treated after diagnosis. One patient with Abernethy malformation type Ib (1/3) underwent liver transplantation. Seven patients with Abernethy malformation type II (7/11) were treated by shunt occlusion, received laparoscopy, or were treated with open surgical ligation. Another three patients (3/11) with Abernethy malformation type II were treated by interventional portocaval shunt occlusion under DSA. MSCT attains excellent capability in diagnosing type II Abernethy malformation and further shows the location of the portocaval shunt. DSA can help when it is hard to determine diagnosis between Abernethy type Ib and II using MSCT.

    更新日期:2019-12-18
  • Magnetic resonance imaging findings of idiopathic granulomatous mastitis: can it be an indirect sign of treatment success or fail?
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-12-16
    Ayşegül Altunkeser; Fatma Zeynep Arslan; Mehmet Ali Eryılmaz

    Idiopathic granulomatous mastitis (IGM) is a rare idiopathic benign inflammatory disease of the breast that is characterized by the formation of non-necrotizing granulomas and sterile micro-abscesses [1]. Although several treatment options are available for IGM, there is no well-established treatment algorithm for the disease [2]. Antibiotics, surgical drainage, a partial mastectomy, steroids and methotrexate are among the treatment modalities. Although good results have been achieved with the available modalities in some patients, treatment success has not been achieved in a large number of patients, who then require a mastectomy. To date, only a few studies have investigated magnetic resonance imaging (MRI) findings of IGM [3,4,5]. According to the literature, morphological and contrast-enhancement features on MRI in cases of IGM show great variety, depending on the IGM stages [e.g. inflammatory reactions, abscesses and fibrosis [4, 5]. To the best of our knowledge, no previous studies have investigated the potential importance of MRI findings in predicting treatment success. The aim of the present study was to determine whether MRI findings could play a role in predicting treatment success or guiding the choice of treatment. This retrospective study was conducted in accordance with the ethical guidelines of the Declaration of Helsinki and was approved by the local committee of our hospital. Sixty consecutive female patients who were diagnosed with IGM between 2010 and 2018 were included in the study. The clinical and pathological findings were obtained from a local database in the hospital. All the patients were diagnosed with IGM in our hospital and treated in the general surgery department of our hospital. A core needle biopsy was taken, and the diagnosis of IGM was histopathologically confirmed. Grocott, Periodic acid–Schiff (PAS) and Ziehl–Neelsen staining were negative in all the patients. Patients with other types of granulomatous mastitis [sarcoidosis, tuberculosis etc.] were excluded from the study. All the patients were first evaluated by a general surgeon. After a physical examination and anamnesis, they were referred for sonographic and mammographic evaluations. All of our patients underwent an MRI scan before treatment. A radiologist (AA) experienced in the field of breast imaging performed all the assessments. The lesions were categorized in the light of breast imaging reporting and data system (BI-RADS) lexicon established by the American college of radiology [6]. The involvement of IGM in was grouped as retroareolar region or other quadrant. Mass lesions and non-mass enhancements (NMEs) were noted. Subsequently, morphological features of the mass lesions were identified based on their shapes (irregular, round or oval), margins (irregular, well circumscribed or speculated) and internal enhancement features (heterogeneous, homogeneous or rim). The NMEs were classified depending on their distribution (regional, diffuse, focal, linear, multiple regional or segmental) and internal enhancement patterns (heterogeneous, homogeneous, clumped or clustered). The presence of a fistula clinically detected and also seen on MRI was recorded. The treatment methods were categorized as medical [corticosteroids or non-steroidal anti-inflammatory agents], surgical [segmental mastectomy] and drainage. Antibiotic and nonsteroidal antiinflammatory agents were the basis of our medical treatment. The corticosteroid treatment consisted of prednisolone, which was administered initially at a dose of 60 mg daily in divided doses via the oral route. The doses were tapered slowly, depending on clinical improvements. The asymptomatic cases and BI-RADS 1 and 2 on radiological follow-ups were accepted as clinical and radiological improvement, and those were evaluated as successful treatment. The relationship between the MRI findings, presence of fistula formation and treatment methods with treatment success was investigated. MRI protocol All the examinations were performed using a dedicated 16-channel double breast coil, with 1.5 Tesla MRI (Magnetom Aera; Siemens Healthcare, Erlangen, Germany) equipped with 45-mT m gradients. The patient was placed in the prone position on a table. The imaging protocol was bilateral. The coronal flashed-grappa (TR/TE: 417/11 ms, matrix: 352 × 384, slice thickness: 3 mm, FOV: 180–500 mm), (matrix:352 × 384, slice thickness: 3 mm, FOV: 280–300 mm) T1W started with sequences. Then, the T2W TIRM (TR/TE: 2770/66 ms, matrix: 352 × 384, inversion time: 150 ms, flip angle: 150 degrees, spatial resolution: 0.7 × 0.7 × 2 mm, acquisition time: 3 min 26 s) DWI (TR/TE: 6200/88, long distance resolution: 2.7 × 2.7 × 4 mm, slice thickness: 3 mm, FOV: 258–300 mm, B values 0 and 800 s/mm2, spectral fat saturation and acquisition time: min 47 s). A dynamic study was performed using FLASH (TR/TE: 4.79/1.70 msec, spatial resolution: 0.8 × 0.8 × 1.3 mm, cross-sectional thickness: 1.6 mm, FOV: 318–500 mm). Gadopentetate dimeglumine was intravenously administered at a dose of 0.1 mmol/kg of body weight. Statistical analysis The statistical analysis was performed using SPSS 22 software [IBM Corporation]. The results of the descriptive statistics are presented as mean ± standard deviation [SD] and min-max. The relationship between MRI findings and treatment success was investigated using a chi-square test and univariate logistic regression. P value of < 0.05 was considered statistically significant. In total, 60 IGM patients [62 breast lesions] were re-evaluated retrospectively. The median age of the patients was 35 y (range: 23–65). All the patients were followed up for between 1 and 7 y, with a mean follow up time of 2.32 y. In the study population, 35 of the patients suffered from mastodinia, and rest of them complained from hardness. Two patients were bilaterally affected (Table 1). Seven patients had retroareolar involvement. In these patients, the treatment failed in two cases, and IGM recurred in one patient. In patients with retroareolar regional involvement, treatment success was significantly lower than that of the patients with IGM involving the other quadrants (p < 0.05). MRI revealed a mass lesion in 3 patients, NME in 15 patients and both a mass lesion and NME in 44 patients. Regarding the MRI features of the mass lesions, in 28 cases, the mass was round shaped. In 33 cases, the mass was well circumscribed. The mass enhancement was mostly of the rim type in 41 patients. Abscesses were detected in 39 patients (Fig. 1). In 33 patients, the NME was regional, and the internal enhancement pattern was mostly heterogeneous (n = 31). Thirty six of the lesions were multifocal, 16 were multicentric and 6 were focal based on the findings of non-mass enhancement. There was no statistically significant association between the MRI findings and treatment success (Tables 2 and Table 3). Table 1 General descriptive featuresFull size table Fig. 1 On a T2W TIRM image, b Contrast enhanced subtraction image of 34 year-old patients; multiple abcess formations (arrow), rim-like enhancement and diffuse edeame is seen in the left breastFull size image Table 2 The relationship between MRI findings and the treatment successFull size table Table 3 The association between MRI findings and treatment successFull size table Medical treatment was successful in 18 patients, IGM resolved in 20 patients with drainage, and surgery was successful in 6 patients. IGM recurred in one patient who underwent drainage. Fistulas were observed in 38 patients. There was no statistically significant association between the presence of a fistula and the treatment method or success rate (Table 4). Table 4 The association between the treatment success and treatment methods and fistula formationFull size table Seventeen patients who failed treatment were categorized as BI-RADS 3. Symptoms of 7 patients regressed spontaneously in the follow-up period. Also, one patient developed fistul and than recovered. The remaining 9 patients had pain and swelling. Sonography showed abscess in 5 patients and fistula tract in 1 patient. One of these patients underwent abscess drainage but treatment failed. IGM is a recurrent, resistant chronic inflammatory disease, which shows great variety on MRI. Multiple heterogeneous areas, with ring-like enhanced micro-abscesses, regional NMEs or heterogeneous enhanced masses are the most common findings detected on MRI in cases of IGM [7]. Multiple micro-abscesses, ill defined enhanced masses, skin thickening, parenchymal distortion, oedema, fluid collection, nipple retraction, fistulas and axillary lymphadenopathy may also be seen on MRI [3]. In the present study, most of the patients had NMEs, in addition to abscesses and fistulas. These findings are in accordance with those in the literature [3, 7]. Due to the rarity of IGM and the great variety of its appearance on radiological imaging, the management and treatment of IGM are problematic. There are no standardized and optimal treatment options at present. A recent study on the potential role of sociodemographic factors in treatment failure in IGM reported that a history of pregnancy, breastfeeding, breast infections and smoking were risk factors for treatment failure [8]. The same study reported that current treatment methods did not affect IGM recurrence. Atak et al. found the highest potential for treatment failure in IGM patients with abscesses [9]. Sakurai et al. reported that patients who developed a fistula and an abscess were more difficult to treat [10]. In the present study, in contrast to the literature data, in the majority of patients, there was no association between treatment success and the presence of fistulas. Furthermore, the majority of patients with abscesses were treated successfully, with IGM recurrence in only one patient. As noted earlier, there is limited research on the association between radiological features and treatment failure. In the present study, according to the MRI findings, the affected quadrant was the only predictive factor in treatment success. Lesions located in the retroareolar region were more intractable to treatment, and treatment success was lower in such cases as compared with IGM involving other quadrants. This finding may be explained by the intensity of ductal inflammation in the retroareolar region. Although IGM is not thought to generally affect the retroareolar region, a recent study reported retroareolar involvement in a considerable number of patients with IGM [11]. In our study, retroareolar involvement was noted compatible with the findings of this recent study. At present, the preferred treatment options for IGM are medical treatment [systemic steroids] or surgery. The medical treatment of IGM includes antibiotherapy, steroids and immunosuppressive drugs, such as methotrexate and azathioprine. The surgical treatment consists of abscess drainage, local and wide excision or a mastectomy. Although debate surrounds the most appropriate treatment method, some recent studies concluded that surgical methods were superior to medical methods [9, 12]. In the present study, in terms of the success rate, we found no statistically significant difference in the superiority of surgical versus medical treatment. Aggressive surgical interventions are not recommended as a first-line treatment modality for IGM because of poor cosmetic results. Patients with IGM should be managed on a case-by-case basis. According to a previous study, the addition of steroid therapy to surgical treatment can decrease the recurrence rate of IGM [13]. In the our study, only one patient was managed with steroid therapy, and no recurrence was observed in this patient during a 2-y follow-up. A previous study reported a recurrence rate of between 5 and 50% among all IGM patients, even when broad surgical excision was performed [14]. In the present study, IGM did not recur in any of the patients who received medical or surgical treatment, but it recurred in one patient who underwent drainage. We demonstrated that there was no relationship between MRI findings and the treatment success rate in IGM, except in cases of IGM involving the retroareolar region. The results explain the absence of a standardized treatment regimen for IGM and the difficulty in determining the optimum treatment. The present study has some limitations. First, the data were collected retrospectively. Second, the sample size was relatively small. It is impossible to predict the treatment success or outcome using only MRI findings. However, prospective studies are needed to determine whether MRI findings of IGM can predict treatment success/failure and to improve treatment success of IGM. The treatment of IGM in the retroareolar region may be more failed compared to those in other quadrants. The datasets used and/or analysed during the current study available from the corresponding author on reasonable request. BIRADS: Breast Imaging Reporting and Data System IGM: Idiopathic granulomatous mastitis MRI: Magnetic resonance imaging NMEs: Non-mass enhancements 1. Illman JE, Terra SB, Clapp AJ, Hunt KN, Fazzio RT, Shah SS, Glazebrook KN. Granulomatous diseases of the breast and axilla: radiological findings with pathological correlation. Insights Imaging. 2018;9(1):59–71. Article Google Scholar 2. Altintoprak F, Kivilcim T, Yalkin O, Uzunoglu Y, Kahyaoglu Z, Dilek ON. Topical steroids are effective in the treatment of idiopathic granulomatous mastitis. World J Surg. 2015;39(11):2718–23. Article Google Scholar 3. Poyraz N, Emlik GD, Batur A, Gundes E, Keskin S. Magnetic resonance imaging features of idiopathic granulomatous mastitis: a retrospective analysis. Iran J Radiol. 2016;13(3):e20873. Article Google Scholar 4. Dursun M, Yilmaz S, Yahyayev A, Salmaslioglu A, Yavuz E, Igci A, Acunas G, Tunacı M. Multimodality imaging features of idiopathic granulomatous mastitis: outcome of 12 years of experience. Radiol Med. 2012;117(4):529–38. https://doi.org/10.1007/s11547-011-0733-2 PubMed: 22020426. CAS Article PubMed Google Scholar 5. Kocaoglu M, Somuncu I, Ors F, Bulakbasi N, Tayfun C, Ilkbahar S. Imaging findings in idiopathic granulomatous mastitis. A review with emphasis on magnetic resonance imaging. J Comput Assist Tomogr. 2004;28(5):635–41 PubMed: 15480037. Article Google Scholar 6. American College of Radiology. Breast imaging reporting and datasystem (BI-RADS). 5th ed. Reston: American College of Radiology; 2013. Google Scholar 7. Pluguez-Turull CW, Nanyes JE, Quintero CJ, Alizai H, Mais DD, Kist KA, Dornbluth NC. Idiopathic granulomatous mastitis: manifestations at multimodality imaging and pitfalls. RadioGraphics. 2018;38(2):330–56. Article Google Scholar 8. Uysal E, Soran A, Sezgin E. Factors related to recurrence of idiopathic granulomatous mastitis: what do we learn from a multicentre study? ANZ J Surg. 2018;88(6):635–639. Article Google Scholar 9. Atak T, Sagiroglu J, Eren T, Alimoglu O. Strategies to treat idiopathic granulomatous mastitis: retrospective analysis of 40 patients. Breast Dis. 2015;35(1):19–24. CAS Article Google Scholar 10. Sakurai K, Fuhsaki S, Enomoto K, Amano S, Sugitani M. Evaluation of follow-up strategies for corticosteroid therapy of idiopathic granulomatous mastitis. Surg Today. 2011;41:333–7. CAS Article Google Scholar 11. Aslan H, Pourbagher A, Colakoglu T. Idiopathic granulomatous mastitis: magnetic resonance imaging findings with diffusion MRI. Acta Radiol. 2016;57(7):796–801. https://doi.org/10.1177/0284185115609804. Article PubMed Google Scholar 12. Freeman CM, Xia BT, Wilson GC, Lewis JD, Khan S, Lee SJ, Lower EE, Edwards MJ, Shaughnessy EA. Idiopathic granulomatous mastitis: A diagnostic and therapeutic challenge. Am J Surg. 2017;214(4):701–6. https://doi.org/10.1016/j.amjsurg.2017.07.002. CAS Article PubMed Google Scholar 13. Akcan A, Oz AB, Dogan S, et al. Idiopathic granulomatous mastitis: comparison of wide local excision with or without corticosteroid therapy. Breast Care (Basel). 2014;9:111–5. Article Google Scholar 14. Aghajanzadeh M, Hassanzadeh R, Alizadeh Sefat S, et al. Granulomatous mastitis: presentations, diagnosis, treatment and outcome in 206 patients from the north of Iran. Breast. 2015;24:456. Article Google Scholar Download references None. Funding This study was not funded by any organization. Affiliations Department of Radiology, University of Health Science, Konya Trainning and Research Hospital, Konya, Turkey Ayşegül Altunkeser  & Fatma Zeynep Arslan Department of General Surgery, University of Health Science, Konya Trainning and Research Hospital, Konya, Turkey Mehmet Ali Eryılmaz Authors Search for Ayşegül Altunkeser in: PubMed • Google Scholar Search for Fatma Zeynep Arslan in: PubMed • Google Scholar Search for Mehmet Ali Eryılmaz in: PubMed • Google Scholar Contributions AA planned the study, and participated in its design and coordination and collected of data and drafted the manuscript. AFZ collected of data, drafted the manuscript. and arranged Tables. EM collected of data. All the authors read and approved the final version of the manuscript. Corresponding author Correspondence to Fatma Zeynep Arslan. Ethics approval and consent to participate The study was approved by the Ethics Committee of the Faculty of Medicine, Selçuk University. This retrospective study conducted in accordance with the ethical guidelines of the Declaration of Helsinki was also approved by the local committee of our hospital. The committee waived the need for consent because it is a retrospective study. Consent for publication Not applicable. Competing interests The authors declare that they have no competing interests. Publisher’s Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Reprints and Permissions Cite this article Altunkeser, A., Arslan, F.Z. & Eryılmaz, M.A. Magnetic resonance imaging findings of idiopathic granulomatous mastitis: can it be an indirect sign of treatment success or fail?. BMC Med Imaging 19, 94 (2019) doi:10.1186/s12880-019-0397-2 Download citation Received 22 November 2018 Accepted 03 December 2019 Published 16 December 2019 DOI https://doi.org/10.1186/s12880-019-0397-2

    更新日期:2019-12-17
  • Ultrasound assessment of tensile stress in carotid arteries of healthy human subjects with varying age
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-11-29
    Xianghong Luo; Lianfang Du; Zhaojun Li

    Arterial remodeling is thought to reflect the adaptation of the vessel wall to mechanical and hemodynamic stimuli and contributes to the progression of cardiovascular and cerebrovascular diseases. Tensile stress (TS) is one of the mechanical properties of the artery wall. The purpose of this study was to investigate the tensile stress change (TS) of carotid artery with varying viscoelasticity in healthy subjects within two groups of different ages. Forty-five subjects were recruited and randomly assigned into the group at the age above 50 years and below 50 years. The carotid arteries were examined by ultrasonography, using the techniques of shear wave elastography (SWE), shear wave dispersion (SWD) and radiofrequency (RF) -based ultrasound. The following values, including elastic modulus (SWER) and viscous index (SWDR), as well as the peak and mean TS of the left and right carotid arteries (L-PTS, R-PTS, L-MTS and R-MTS) were measured. The correlations between SWER, SWDR and tensile stress were evaluated. The SWER and SWDR of carotid arteries are lower in the subjects ≥50 years old than the subjects younger than 50 years (SWER, 10.29 ± 9.57 kPa VS 17.24 ± 14.07 kPa; SWDR, 11.99 ± 3.51 (m/s)/kHz VS 13.97 ± 3.71 (m/s)/kHz, P < 0.05). The R-PTS was lower in the group with younger age (P < 0.05). Pearson correlation analysis showed that SWER of carotid artery was positively correlated with the parameters of tensile stress, R-PTS, R-MTS, L-PTS and L-MTS(r = 0.218, r = 0.359, r = 0.209 and r = 0.369, respectively, P < 0.05). However, SWDR of carotid arteries was not significantly associated with TS. Ultrasonic shear wave imaging could be used to quantitatively assess carotid viscoelasticity. The carotid TS was related to its elasticity while little related to its viscosity, suggesting that mechanical properties of the arterial wall might be better revealed. Date of our trial registration: 2018-06-11. Registered with the official website of China Clinical Trial Registration Center (ChiCTR1800016590)

    更新日期:2019-11-30
  • Difference analysis in prevalence of incidental pancreatic cystic lesions between computed tomography and magnetic resonance imaging
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-05-24
    Shuo Zhu; Wen-Tao Wang; Xiao-Sha Shang; Ting Ni; Wen-Chuan Wu; Wen-Hui Lou; Meng-Su Zeng; Sheng-Xiang Rao

    The purpose was to investigate the difference of detection rate of incidental pancreatic cystic lesions (PCLs) with computed tomography (CT) and magnetic resonance imaging (MRI) and to compare the difference between CT and MRI and to explore the effect of this difference on surgical resection. We reviewed the diagnostic reports for incidental PCLs between 2013 and 2016. Images of PCLs would be re-evaluated. Clinical and imaging data were recorded. The chi-square and independent t-test were conducted for categorical and continuous variables. The prevalence of PCLs was 1.91% (1038/54210) and 3.36% (1282/38099) on CT and MRI respectively, and increased with increasing age (P < 0.001). No significant differences were found in the annual prevalence of PCLs on CT (P = 0.796) and MRI (P = 0.213) from 2013 to 2016 while the number of examinations was increasing every year. The annual detection rate of MRI for small PCLs (< 20 mm) was significantly higher than CT (P < 0.001), but was not significantly different for large PCLs (≥20 mm). The rate of surgical resection of PCLs (≥20 mm) in MRI group was higher than CT (55.2% vs. 37.0%, P < 0.001). The detection rate of PCLs on CT and MRI tended to be stable despite increasing scan volumes. Female had a slightly more frequency of PCLs than male. MRI detected more small PCLs(< 20 mm) and had higher impact on surgical resection of large PCL(≥20 mm) compared with CT.

    更新日期:2019-11-28
  • Accurate characterization of 99mTc-MDP uptake in extraosseous neoplasm mimicking bone metastasis on whole-body bone scan: contribution of SPECT/CT
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-05-30
    Linqi Zhang; Qiao He; Tao Zhou; Bing Zhang; Wei Li; Hao Peng; Xi Zhong; Liwu Ma; Rusen Zhang

    99mTc-labelled methylene diphosphonate (99mTc-MDP) uptake can occasionally be identified in extraosseous neoplasms on whole-body scans (WBSs) and may be misinterpreted as bone metastasis. The purpose of our study was to investigate the frequency of 99mTc-MDP uptake in extraosseous neoplasms and to assess the additional value of SPECT/CT for the localization and characterization of this unusual uptake. Data from 7308 patients (SPECT/CT was performed in 2147 patients) with known cancer who underwent WBSs for metastatic work-up between May 2015 and July 2018 were retrospectively reviewed. The locations, numbers, and intensities of extraosseous 99mTc-MDP uptake were evaluated by WBS, and the intratumoural calcification was evaluated by SPECT/CT. The diagnostic accuracy of SPECT/CT in locating 99mTc-MDP uptake in extraosseous neoplasms was compared to that of WBS. A total of 41 patients showed 99mTc-MDP uptake in extraosseous neoplasms. Of these patients, 23 patients had uncertain lesions by WBS, and further SPECT/CT was performed. The incidence of 99mTc-MDP uptake in extraosseous neoplasms was observed to be 0.6% by WBS and 1.1% (by) SPECT/CT. During imaging analysis, WBS had an accuracy of only 35% (14/40), whereas SPECT/CT correctly located and diagnosed all 40 lesion sites in the 23 patients. Twenty-three lesion sites (57.5%, 23/40) showed moderate or high intensity of extraosseous 99mTc-MDP uptake. Of the 23 patients, 17 patients (73.9%, 18/23) with 31 lesion sites (77.5%, 31/40) presented with intratumoural calcification. 99mTc-MDP uptake in extraosseous neoplasms can be observed as 0.6% on WBS and is usually localized to the breast, liver, and lung. Nuclear physicians should be familiar with such extraosseous uptake when interpreting WBSs. SPECT/CT offers better accuracy than WBS alone for locating the majority of lesions present with intratumoural calcification.

    更新日期:2019-11-28
  • Quantifying cervical spondylosis: reliability testing of a coherent CT-based scoring system
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-05-30
    Eric Rydman; Sara Bankler; Sari Ponzer; Hans Järnbert-Pettersson

    Grading of degeneration of the cervical spine is of great clinical value, considering the vast amount of radiological investigations that are being done with this query. Despite the fact that Computed Tomography (CT) is frequently used in clinical practice there is today no user-friendly and reliable scoring system for assessment of cervical spondylosis on CT-scans available. The aim of this study was to establish a scoring system for cervical spondylosis based on CT-scans and to test it for reliability. Twenty adult patients undergoing CT of the cervical spine due to neck pain following a motor vehicle accident were included in the study. Three independent raters, i.e. one orthopedic surgeon and two radiologists, assessed their CT-scans. Two of the raters repeated the assessments after three months. A radiographic-based scoring system for cervical disc degeneration, addressing disc height, osteophytes and endplate sclerosis, was applied on CT and tested for reliability. A pre-existing, reliable CT-based scoring system for facet joint degeneration, considering joint space narrowing, osteophytes and irregularity of the articular surface was modified and reevaluated. This in order to develop a coherent CT-based total degeneration score for cervical spondylosis. The scoring systems for cervical disc degeneration and facet joint degeneration both exhibited an acceptable or better level of strength of agreement regarding intra- and interrater agreement. The total disc degeneration score showed a moderate level of inter-rater reliability with a kappa-value of 0.47 and a good intra-rater agreement with intra-class correlation coefficients (ICC) of 0.67 and 0.60 for the two raters performing the assessments. The total facet joint degeneration score showed a moderate level of inter-rater reliability (kappa 0.54) and an excellent intra-rater agreement with ICC 0.75 for one of the raters and fair for the other rater (ICC 0.54). When the total disc and facet joint degeneration score were classified into a three-point total degeneration score the inter-rater agreement was 0.695 and the ICC 0.82 and 0.73 respectively. This coherent scoring system assessing both disc degeneration and facet joint degeneration on CT-scans of the cervical spine was shown to meet the standards of reliability.

    更新日期:2019-11-28
  • Comparison of different registration methods and landmarks for image-guided radiation therapy of pulmonary tumors
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-05-31
    Xiaohui Cao; Ming Liu; Fushan Zhai; Nan Li; Chaoen Bao; Yinliang Liu; Gang Chen

    To compare the accuracy, advantages and disadvantages of automatic registration methods at different anatomical-sites for thoracic image-guided radiation therapy (IGRT). The Varian-IX IGRT system was used to perform a manual registration of the images collected on the first fraction of 60 patients with lung cancer (42 cases central location and 18 cases of peripheral). The registered images were used as reference images. Offline registration was performed for computed tomography-CBCT images using four methods: whole image registration, ipsilateral registration, soft tissue tumor registration, and vertebral body registration. Time taken to complete and deviation value were analyzed between the different methods. There were significant differences in absolute deviation value of all the three directions (P < 0.001) and the time consumption (P < 0.001) between 4 methods. The Z direction had significant differences in deviation value of 4 methods (0.023 ± 0.128 mm, − 0.030 ± 0.175 mm, − 0.010 ± 0.238 mm, − 0.075 ± 0.137 mm, P = 0.011). The difference was significant in the X direction of the ipsilateral registration method between central and peripheral lung cancer (0.033 ± 0.053 mm vs. 0.067 ± 0.067 mm, P = 0.045). The whole lung or affected side registration methods could be recommended to be used in the automatic registration function of the Varian-IX’s On-Board Imaging (OBI) system.

    更新日期:2019-11-28
  • Ultrasound versus temporal artery biopsy in patients with Giant cell arteritis: a prospective cohort study
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-06-06
    Quan Zou; Sumei Ma; Xinghu Zhou

    Diagnosis of giant cell arteritis by temporal artery biopsy is time-consuming and visual loss lies in the first week after its diagnosis. The purpose of the study was to test the hypothesis that ultrasound can reduce the risk of overdiagnosis and overtreatment in giant cell arteritis. Data regarding physical/ clinical features examinations, temporal artery biopsy examinations, ultrasound findings, and magnetic resonance imaging examinations of 980 suspected patients for giant cell arteritis were included in the study. Decision curve analysis was applied to get a beneficial score for selected diagnostic modalities. Cost analysis was performed for each patient. Fewer numbers of false positive giant cell arteritis results were reported under physical/ clinical features examinations following ultrasound detection than physical/clinical features examinations following temporal artery biopsy examinations (45 vs. 127, p < 0.0001). The working area that detects giant cell arteritis at least one time for physical/ clinical features examinations following ultrasound detection and physical/ clinical features examinations following temporal artery biopsy examinations were 0–91% and 0–86%. No significant difference for true negative results between magnetic resonance imaging and physical and clinical features examinations following ultrasound detection (p = 0.007). Physical and clinical features examinations following ultrasound detection were less expensive method than physical/ clinical features examinations following temporal artery biopsy examinations (14,023 ± 982 ¥/patient vs. 18,551 ± 1231 ¥/patient, p < 0.0001) and MRI. Physical and clinical features examinations following ultrasound are recommended for diagnosis of patients with suspected giant cell arteritis.

    更新日期:2019-11-28
  • A potential field segmentation based method for tumor segmentation on multi-parametric MRI of glioma cancer patients
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-06-17
    Ranran Sun; Keqiang Wang; Lu Guo; Chengwen Yang; Jie Chen; Yalin Ti; Yu Sa

    Accurate segmentation of brain tumors is vital for the gross tumor volume (GTV) definition in radiotherapy. Functional MR images like apparent diffusion constant (ADC) and fractional anisotropy (FA) images can provide more comprehensive information for sensitive detection of the GTV. We synthesize anatomical and functional MRI for accurate and semi-automatic segmentation of GTVs and improvement of clinical efficiency. Four MR image sets including T1-weighted contrast-enhanced (T1C), T2-weighted (T2), apparent diffusion constant (ADC) and fractional anisotropy (FA) images of 5 glioma patients were acquired and registered. A new potential field segmentation (PFS) method was proposed based on the concept of potential field in physics. For T1C, T2 and ADC images, global potential field segmentation (global-PFS) was used on user defined region of interest (ROI) for rough segmentation and then morphologically processed for accurate delineation of the GTV. For FA images, white matter (WM) was removed using local potential field segmentation (local-PFS), and then tumor extent was delineated with region growing and morphological methods. The individual segmentations of multi-parametric images were ensembled into a fused segmentation, considered as final GTV. GTVs were compared with manually delineated ground truth and evaluated with segmentation quality measure (Q), Dice’s similarity coefficient (DSC) and Sensitivity and Specificity. Experimental study with the five patients’ data and new method showed that, the mean values of Q, DSC, Sensitivity and Specificity were 0.80 (±0.07), 0.88 (±0.04), 0.92 (±0.01) and 0.88 (±0.05) respectively. The global-PFS used on ROIs of T1C, T2 and ADC images can avoid interferences from skull and other non-tumor areas. Similarity to local-PFS on FA images, it can also reduce the time complexity as compared with the global-PFS on whole image sets. Efficient and semi-automatic segmentation of the GTV can be achieved with the new method. Combination of anatomical and functional MR images has the potential to provide new methods and ideas for target definition in radiotherapy.

    更新日期:2019-11-28
  • Magnetic resonance imaging indicator of the causes of optic neuropathy in IgG4-related ophthalmic disease
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-06-18
    Jing Li; Yan Zhang; Hang Zhou; Lei Wang; Zhenchang Wang; Hongyang Li

    The following study investigates the involvement of optic neuropathy in IgG4-related ophthalmic diseases (IgG4-ROD) based on the magnetic resonance imaging (MRI) data, and different imaging features of IgG4-ROD related optic neuropathy related to other orbital diseases. This retrospective study included 225 patients with IgG4-RD admitted at two ophthalmology centers between January 2014 and December 2017. Twenty-six patients had both pre-therapeutic orbital MRI and optic never injury. The causes of optic neuropathy were analyzed, and the special sign in MRI to diagnose IgG4-ROD was also evaluated. Twelve cases had inflammation of the optic nerve sheath, while 14 cases had compression due to extraocular muscles and pseudo tumor masses. Two cases had hypertrophic cranial pachymeningitis, while one case had hypophysis involving optic chiasma. The most common causes of optic nerve injury in IgG-4 ROD are inflammation of optic nerve sheath, compression of extraocular muscles, pseudo tumor mass and hypertrophic cranial pachymeningitis, and hypophysis involving optic chiasma.

    更新日期:2019-11-28
  • Ethiodized poppyseed oil versus ioversol for image quality and adverse events in hysterosalpingography: a prospective cohort study
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-06-24
    Yiqing Tan; Shilin Zheng; Wenfeng Lei; Fuhua Wang; Shengpan Jiang; Ting Zeng; Bei Zhou; Fan Hong

    This study aimed to investigate the image quality and adverse events (AEs) of ethiodized poppyseed oil (EPO) compared with ioversol as contrast agents in hysterosalpingography (HSG). Two hundred twenty-eight patients underwent HSG were consecutively recruited in this prospective cohort study, and were accordingly divided into EPO group (N = 165) and ioversol group (N = 63). The quality of image was assessed according to the European Guidelines on quality criteria for diagnostic radiographic images. AEs during, within 2 h and at 1-month post-HSG were recorded. EPO displayed elevated image quality compared with ioversol including the total image quality score (P < 0.001), the cervical canal display score (P < 0.001), shape and outline of uterus score (P < 0.01), cervical mucosa or folds score (P < 0.001), oviduct isthmus score (P < 0.001), ampulla and fimbriae of oviduct score (P < 0.001) and celiac diffuse image score (P < 0.001). Multivariate linear regression displayed that EPO (P < 0.001) was an independent predictive factor for increased total image quality score. AEs were similar between EPO group and ioversol group during and within 2 h post-HSG (all P > 0.05). However, at 1-month post-HSG, the number of patients had unchanged and faded menstrual blood color decreased but the proportion of patients with deepened menstrual color increased in EPO group compared with ioversol group (P = 0.007). In addition, the number of patients had iodine residue in uterine cavity was elevated in EPO group compared with ioversol group (P < 0.001). EPO is more efficient in image quality and equally tolerant compared to ioversol as contrast agents in HSG.

    更新日期:2019-11-28
  • An experimental study on breast lesion detection and classification from ultrasound images using deep learning architectures
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-07-01
    Zhantao Cao; Lixin Duan; Guowu Yang; Ting Yue; Qin Chen

    Computer-aided diagnosis (CAD) in the medical field has received more and more attention in recent years. One important CAD application is to detect and classify breast lesions in ultrasound images. Traditionally, the process of CAD for breast lesions classification is mainly composed of two separated steps: i) locate the lesion region of interests (ROI); ii) classify the located region of interests (ROI) to see if they are benign or not. However, due to the complex structure of breast and the existence of noise in the ultrasound images, traditional handcrafted feature based methods usually can not achieve satisfactory result. With the recent advance of deep learning, the performance of object detection and classification has been boosted to a great extent. In this paper, we aim to systematically evaluate the performance of several existing state-of-the-art object detection and classification methods for breast lesions CAD. To achieve that, we have collected a new dataset consisting of 579 benign and 464 malignant lesion cases with the corresponding ultrasound images manually annotated by experienced clinicians. We evaluate different deep learning architectures and conduct comprehensive experiments on our newly collected dataset. For the lesion regions detecting task, Single Shot MultiBox Detector with the input size as 300×300 (SSD300) achieves the best performance in terms of average precision rate (APR), average recall rate (ARR) and F1 score. For the classification task, DenseNet is more suitable for our problems. Our experiments reveal that better and more efficient detection and convolutional neural network (CNN) frameworks is one important factor for better performance of detecting and classification task of the breast lesion. Another significant factor for improving the performance of detecting and classification task, which is transfer learning from the large-scale annotated ImageNet to classify breast lesion.

    更新日期:2019-11-28
  • Ratio and difference of the cross-sectional area of median nerve to ulnar nerve in diagnosing carpal tunnel syndrome: a case control study
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-07-04
    Yi-Wei Chang; Tsung-Cheng Hsieh; I-Shiang Tzeng; Valeria Chiu; Pei-Jung Huang; Yi-Shiung Horng

    To evaluate the diagnostic accuracy of the median-to-ulnar nerve ratio (MUR) and the median-to-ulnar nerve difference (MUD) in patients with carpal tunnel syndrome (CTS). In this study, 32 patients with CTS and 32 healthy volunteers were evaluated. All participants received a series of tests and ultrasound examination for the evaluation of the following criteria: cross-sectional area of the median nerve at the pisiform level (CSA-P), swelling ratio (SR), MUR, MUD, and flattening ratio (FR). CSA-P, SR, MUR, and MUD were all significantly larger in the patients with CTS than in the healthy volunteers. The areas under the receiver operator characteristic curves of MUD, MUR, CSA-P, and SR were 0.78, 0.75, 0.70, and 0.61 respectively. MUD had higher sensitivity (84%) than MUR, CSA-P, and SR (sensitivity: 63, 63, and 53%, respectively). By using the ulnar nerve area at the pisiform level as an internal control parameter, the MUD and MUR methods showed higher diagnostic accuracy than SR in patients with CTS. Further application of these methods in research and clinical settings is recommended. Clinicaltrial.gov NCT03033173. Registered 18 January 2017. Retrospectively registered.

    更新日期:2019-11-28
  • Ultrasound measurements versus invasive intracranial pressure measurement method in patients with brain injury: a retrospective study
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-07-05
    Jing Zhou; Jing Li; Tiantian Ye; Yanrong Zeng

    The invasive method for intracranial pressure measurement is ‘gold standard’ but not always feasible because the intraventricular catheter/ intraparenchymal micro transducer used in the measurement of intracranial pressure measurement may cause complications. Imaging modalities with clinical examination protocol have a lack of specificity and accuracy. The objective of the study was to compare the accuracy of diagnostic parameters of ultrasound measurements in patients with brain injury underwent invasive intracranial pressure measurement method. Data of invasive intracranial pressure measurement method and ultrasound measurements of 185 patients with brain injury who required admission diagnosis were included in the analysis. Pearson correlation was tested for diagnostic parameters. Logistical regression analysis was performed for diagnostic parameters of death patients to evaluate independent parameter of mortality. Straight sinus flow velocities, middle cerebral artery flow velocities, and optic nerve sheath diameter were correlated with intracranial pressure (p < 0.0001 for all). Arterial blood pressure (p = 0.127) and middle cerebral artery pulsatility index (p = 0.06) were not correlated with intracranial pressure. A total of 47 patients died during the study period. Intracranial pressure (p = 0.015) and optic nerve sheath diameter (p = 0.035) were found to be independent predictor of mortality. Ultrasound measurement especially optic nerve sheath diameter can be successfully used instead of invasive intracranial pressure measurement method in patients with brain injury. III.

    更新日期:2019-11-28
  • Velopharyngeal closure analysis using four-dimensional computed tomography: a pilot study of healthy volunteers and adult patients with cleft palate
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-07-08
    Yoshikazu Kobayashi; Daisuke Kanamori; Naoko Fujii; Yumi Kataoka; Emiko Hirai; Satoshi Yoshioka; Koji Satoh; Hiroshi Toyama; Kensei Naito; Koichiro Matsuo

    Nasopharyngoscopy is a common method to evaluate velopharyngeal closure in patients with cleft palate. However, insertion of a fiberoptic nasopharyngoscope causes discomfort in patients. The aim of this study was to estimate the reliability of short-time exposure images obtained using 320-row area detector computed tomography (320-ADCT) as a novel evaluation method for the assessment of velopharyngeal function. We evaluated five healthy adult volunteers and five postoperative adult patients with cleft palate. During a 3.3-s imaging exposure, the participants were asked to perform two tasks: nasal inspiration and subsequent oral expiration through a catheter into a water-filled cup. The movement of the velopharyngeal structures was recorded during each examination, and the presence of velopharyngeal insufficiency (VPI) and velopharyngeal closure (VPC) patterns were estimated. If VPI was detected, the cross-sectional area was also calculated. Cohen’s kappa and weighted kappa coefficients were used to evaluate the concordance of nasopharyngoscopy and 320-ADCT evaluation. Speech pathology evaluation did not reveal hypernasality in any study participant. Micro-VPI was detected by nasopharyngoscopy in one healthy volunteer and two patients. 320-ADCT detected micro-VPI in two more patients. The cross-sectional area of the VPI in these subjects ranged from 2.53 to 16.28 mm2. Nasopharyngoscopy and 320-ADCT were concordant in detecting VPI in eight participants (κ = 0.6) and in assessing VPC patterns in nine (κ = 0.82). Moreover, images obtained using 320-ADCT allowed for reduced dead angle and, thus, easy detection of micro-VPI and Passavant’s ridges. Although the radiation exposure cannot be ignored, our novel evaluation method using 320-ADCT enables more detailed evaluation of VPC than nasopharyngoscopy. Future studies should investigate the relationship between 320-ADCT findings and speech pathology evaluations.

    更新日期:2019-11-28
  • Effect of region of interest on ADC and interobserver variability in thyroid nodules
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-07-12
    Xiang Zhou; Chao Ma; Zhi Wang; Jia-ling Liu; Yuan-peng Rui; Yue-hua Li; Yi-feng Peng

    To determine the effect of region of interest (ROI) on tumor’s apparent diffusion coefficient (ADC) and interobserver variability in thyroid nodules. Thirty-three individuals with 45 pathologically-confirmed thyroid nodules were assessed by preoperative diffusion-weighted imaging (DWI) with b values of 0 and 400 s/mm2, respectively. Two readers evaluated the ADC values of lesions based on three ROI techniques: whole-volume, single-slice and small solid-sample groups. Interobserver variability was analyzed for all ROI techniques, and the mean ADCs of benign and cancerous thyroid nodules were compared. For the mean ADCs of non-cancerous thyroid nodules, average differences and limits of agreement (LOAs) between readers were 0.00 [− 0.17–0.17] × 10− 3 mm2/s for whole-volume ROI (ICC = 0.967), 0.00 [− 0.26–0.26] × 10− 3 mm2/s for single-slice ROI (ICC = 0.932) and − 0.02 [− 0.38–0.41] × 10− 3 mm2/s for small solid-sample ROI (ICC = 0.823). For the mean ADCs of cancerous thyroid nodules, average differences and LOAs between readers were − 0.05 [− 0.23–0.13] × 10− 3 mm2/s (ICC = 0.885), 0.01 [− 0.23–0.25] × 10− 3 mm2/s (ICC = 0.839) and − 0.07 [− 0.52–0.39] × 10− 3 mm2/s (ICC = 0.579) for the three ROI methods, respectively. The mean ADC values were more scattered in the small solid-sample ROI group in comparison with the whole-volume and single-slice groups, in noncancerous and cancerous specimens. Of all three ROI techniques, whole-volume ROI-determined ADC had the highest combined sensitivity (80.0%), specificity (88.3%) and Youden index (0.683), with a cut-off of 1.84 × 10− 3 mm2/s. The ROI method overtly affects ADC measurements in benign and cancerous thyroid nodules. Small solid-sample ROI yielded the worst interobserver variability of average ADC measurements.

    更新日期:2019-11-28
  • Drivers to adopting B-flow ultrasonography:contextualizing the integrated technology acceptance model
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-07-12
    Gulsah Hancerliogullari Koksalmis

    Ovarian torsion is an unprecedented gynecological crisis that regularly influences ladies of regenerative age. Its signs and indications are like those of other abdominal conditions, which make its differential determination testing. B-flow ultrasonography (B-flow USG), which is utilized for the differential determination of ovarian torsion, is the highest quality level non-intrusive indicative instrument in the early period of an ovarian torsion. The aim of this paper is to investigate and incorporate variety of factors affecting physicians’ actual use of B-flow USG. Drawing from technology acceptance model (TAM), five variables – actual use, behavioral intention to use, attitude toward use, perceived ease of use and perceived usefulness – are integrated with social influence and knowledge to propose a theoretical model. The data was collected from the medical doctors including radiologists, urologists, gynecologists, pediatric surgeons between June and October 2018. The sample size is N = 512 hence, structural equation modeling (SEM) methodology has been implemented to study the relationship between explanatory factors and actual use of B-flow USG. SmartPLS 3.2.7 software was used for the data analysis and testing of the validity of the eight hypotheses. The results indicate that actual use of B-flow USG is positively affected by knowledge, social influence, perceived ease of use, perceived usefulness, attitude toward use and behavioral intention to use. It is discovered that perceived usefulness mediates the relationship between perceived ease of use and attitude toward use, and attitude toward use mediates the relationship between perceived usefulness and behavioral intention to use B-flow USG. The implications of the outcomes are discussed, and suggestions for future research are made.

    更新日期:2019-11-28
  • Evaluation of a shortened cardiac MRI protocol for left ventricular examinations: diagnostic performance of T1-mapping and myocardial function analysis
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-07-24
    Jonathan Nadjiri; Anna-Lena Zaschka; Alexandra S. Straeter; Andreas Sauter; Maximilian Englmaier; Florian Weis; Karl-Ludwig Laugwitz; Ernst J. Rummeny; Daniela Pfeiffer; Michael Rasper

    In this study we sought to retrospectively evaluate whether a very brief cardiac magnetic resonance imaging (CMR) protocol sufficiently distinguishes patients with relevant myocardial changes with need for further examination from healthy subjects. Patients with clinical indication for CMR (n = 160) were included in the study. Patients were categorized into two groups depending on presence of left ventricular (LV) dysfunction. ROC-analysis was done for results of T1-, T2- mapping and extracellular volume evaluation in patients without LV dysfunction. Binary endpoint was correctly depicted pathology of the conventional qualitative CMR techniques and report. In the patient cohort without LV dysfunction (49%), AUC for T1 mapping was 82% (p < 0.001), 60% for T2 mapping (p = 0.1) and 79% for ECV (p < 0.001). T1 mapping was significantly superior to T2 mapping to rule out left ventricular pathology (p = 0.012). Sensitivity for the combined use of T1 mapping and sBTFE cine imaging was 98%; the negative predictive value was 90%. In 49 patients (30%) full protocol CMR did not provide any additional information; T1 mapping correctly detected 57% of the subjects from this group who would not benefit from additional CMR. A shortened CMR protocol comprising T1 mapping and LV-function analysis seems suitable to rule out myocardial alterations. Every third patient of the study population did not benefit from full contrast enhanced CMR. The shortened protocol correctly identified every fifth patient who would not benefit but no relevant pathologic findings with the obligation for treatment were missed.

    更新日期:2019-11-28
  • Quantification of porcine myocardial perfusion with modified dual bolus MRI – a prospective study with a PET reference
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-07-26
    Minna Husso; Mikko J. Nissi; Antti Kuivanen; Paavo Halonen; Miikka Tarkia; Jarmo Teuho; Virva Saunavaara; Pauli Vainio; Petri Sipola; Hannu Manninen; Seppo Ylä-Herttuala; Juhani Knuuti; Juha Töyräs

    The reliable quantification of myocardial blood flow (MBF) with MRI, necessitates the correction of errors in arterial input function (AIF) caused by the T1 saturation effect. The aim of this study was to compare MBF determined by a traditional dual bolus method against a modified dual bolus approach and to evaluate both methods against PET in a porcine model of myocardial ischemia. Local myocardial ischemia was induced in five pigs, which were subsequently examined with contrast enhanced MRI (gadoteric acid) and PET (O-15 water). In the determination of MBF, the initial high concentration AIF was corrected using the ratio of low and high contrast AIF areas, normalized according to the corresponding heart rates. MBF was determined from the MRI, during stress and at rest, using the dual bolus and the modified dual bolus methods in 24 segments of the myocardium (total of 240 segments, five pigs in stress and rest). Due to image artifacts and technical problems 53% of the segments had to be rejected from further analyses. These two estimates were later compared against respective rest and stress PET-based MBF measurements. Values of MBF were determined for 112/240 regions. Correlations for MBF between the modified dual bolus method and PET was rs = 0.84, and between the traditional dual bolus method and PET rs = 0.79. The intraclass correlation was very good (ICC = 0.85) between the modified dual bolus method and PET, but poor between the traditional dual bolus method and PET (ICC = 0.07). The modified dual bolus method showed a better agreement with PET than the traditional dual bolus method. The modified dual bolus method was found to be more reliable than the traditional dual bolus method, especially when there was variation in the heart rate. However, the difference between the MBF values estimated with either of the two MRI-based dual-bolus methods and those estimated with the gold-standard PET method were statistically significant.

    更新日期:2019-11-28
  • T1- and ECV-mapping in clinical routine at 3 T: differences between MOLLI, ShMOLLI and SASHA
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-01
    Julius F. Heidenreich; Andreas M. Weng; Julian Donhauser; Andreas Greiser; Kelvin Chow; Peter Nordbeck; Thorsten A. Bley; Herbert Köstler

    T1 mapping sequences such as MOLLI, ShMOLLI and SASHA make use of different technical approaches, bearing strengths and weaknesses. It is well known that obtained T1 relaxation times differ between the sequence techniques as well as between different hardware. Yet, T1 quantification is a promising tool for myocardial tissue characterization, disregarding the absence of established reference values. The purpose of this study was to evaluate the feasibility of native and post-contrast T1 mapping methods as well as ECV maps and its diagnostic benefits in a clinical environment when scanning patients with various cardiac diseases at 3 T. Native and post-contrast T1 mapping data acquired on a 3 T full-body scanner using the three pulse sequences 5(3)3 MOLLI, ShMOLLI and SASHA in 19 patients with clinical indication for contrast enhanced MRI were compared. We analyzed global and segmental T1 relaxation times as well as respective extracellular volumes and compared the emerged differences between the used pulse sequences. T1 times acquired with MOLLI and ShMOLLI exhibited systematic T1 deviation compared to SASHA. Myocardial MOLLI T1 times were 19% lower and ShMOLLI T1 times 25% lower compared to SASHA. Native blood T1 times from MOLLI were 13% lower than SASHA, while post-contrast MOLLI T1-times were only 5% lower. ECV values exhibited comparably biased estimation with MOLLI and ShMOLLI compared to SASHA in good agreement with results reported in literature. Pathology-suspect segments were clearly differentiated from remote myocardium with all three sequences. Myocardial T1 mapping yields systematically biased pre- and post-contrast T1 times depending on the applied pulse sequence. Additionally calculating ECV attenuates this bias, making MOLLI, ShMOLLI and SASHA better comparable. Therefore, myocardial T1 mapping is a powerful clinical tool for classification of soft tissue abnormalities in spite of the absence of established reference values.

    更新日期:2019-11-28
  • The routes of infection spread in central skull-base osteomyelitis and the diagnostic role of CT and MRI scans
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-01
    J. Mejzlik; M. Cerny; L. Zeinerova; J. Dedkova; J. Kopriva; K. Zadrobilek; J. Adamkov; V. Chrobok; V. Pellantova

    Central skull-base osteomyelitis (CSBO) represents a life-threatening complication of external ear canal infection. Computed tomography (CT) and magnetic resonance imaging (MRI) play key roles in assessment of CSBO progression. Twelve patients with CSBO were included in a retrospective clinical study. In total, 62 scans (30 CTs and 32 MRIs) were performed to evaluate the extent of inflammatory changes. The scans were read independently by two radiologists specialised in imaging of the head and neck. The regions under the skull base were specified using the online Anatomy Atlas of the skull base. To clarify the timeline, the time period was divided into four parts, and inflammatory changes in the skull-base regions were tracked. Data were statistically analysed. In early stages of the disease, CT scan detects inflammatory changes closely related to the stylomastoid foramen and medially to the posterior belly of the digastric muscle, changes which have been proved to be crucial for the diagnosis of CSBO. Later the infection spreads to the contralateral side causing demineralisation of the bones. Imaging methods play a crucial role not only in establishing the diagnosis, but also in anticipating the direction of infection spread underneath the skull base.

    更新日期:2019-11-28
  • The benefits of radiological imaging for postoperative orthostatic headache: a case report
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-07
    Mu-Jung Lee; Chih-Jen Hung

    Traditionally, the diagnosis of post-dural puncture headache (PDPH) relied upon the patient’s history regarding dural puncture and symptoms, such as orthostatic headache. However, such evidence may not always be reliable or specific. We report an unexpected diagnosis with spontaneous intracranial hypotension (SIH), which was confirmed upon examination of Magnetic Resonance (MR) images in a patient who was initially suspected to have PDPH because he had recently undergone a uncertain dural puncture. A 45-year-old man had undergone a thoracic epidural catheter insertion for perioperative analgesia prior to general anesthesia induction. Due to intermittent dripping of fluid while the epidural needle was being advanced, a dural puncture was suspected. The patient complained of an orthostatic headache after recovery from surgery, therefore a PDPH was suspected. MR images revealed signs of SIH: dural sinus engorgement, contrast enhancement along the neural sleeves of the left C6–7, bilateral C7-T1, T1–2, T2–3, T3–4, T4–5, and T5–6. Computed tomography-guided epidural blood patching (EBP) was performed the following day, with the patient experiencing immediate relief of the headache. The benefits of radiological imaging in this case included confirming the correct diagnosis, guiding the accurate level and proper approach of EBP, distinguishing the epidural space from the intrathecal space, and ultimately increasing the likelihood of successful EBP.

    更新日期:2019-11-28
  • Assessment the reliability of ultrasonography in the imaging of the plantar fascia: a comparative study
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-07
    Jing Wu; Yuan-zhi Zhang; Yang Gao; Tian-you Luo

    Imaging methods for the plantar fascia have included radiography, ultrasound and magnetic resonance imaging (MRI), all of which have provided valuable information. This study assessed the reliability of ultrasonography examinations of the plantar fascia using a comparative study. Fifty healthy adult volunteers (25 males and 25 females, mean age 31.6 ± 3.5 years) were included in this study. Images of the plantar fascia from 100 ft were acquired with ultrasonography, CT and MRI. Ultrasound was used to measure the thickness of the plantar fascia. Imaging data from CT and MRI in a DICOM format were transformed into the Materialise Mimics Innovation Suite 16.0 software for digital analysis. SPSS software (SPSS, USA) was used for statistical analysis. The reliability was established by a t-test. Moreover, 42 patients with unilateral plantar fasciitis were examined by ultrasonography. There were no significant differences between the three imaging modalities for patients of the same sex (P > 0.05). There were no statistically significant differences between the left and right sides for patients of the same sex (P > 0.05), but the difference between males and females was statistically significant (P < 0.01). There were no significant differences between US, CT and MRI in the normal group, but there were significant differences in the plantar fasciitis group evaluated with ultrasound. The plantar fascii of normal male subjects are significantly thicker than those of the normal female. Ultrasonography can be a relatively simple and reliable method for the measurement of plantar fascia thickness.

    更新日期:2019-11-28
  • Computed tomography-based predictive nomogram for differentiating primary progressive pulmonary tuberculosis from community-acquired pneumonia in children
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-08
    Bei Wang; Min Li; He Ma; Fangfang Han; Yan Wang; Shunying Zhao; Zhimin Liu; Tong Yu; Jie Tian; Di Dong; Yun Peng

    To investigate the value of predictive nomogram in optimizing computed tomography (CT)-based differential diagnosis of primary progressive pulmonary tuberculosis (TB) from community-acquired pneumonia (CAP) in children. This retrospective study included 53 patients with clinically confirmed pulmonary TB and 62 patients with CAP. Patients were grouped at random according to a 3:1 ratio (primary cohort n = 86, validation cohort n = 29). A total of 970 radiomic features were extracted from CT images and key features were screened out to build radiomic signatures using the least absolute shrinkage and selection operator algorithm. A predictive nomogram was developed based on the signatures and clinical factors, and its performance was assessed by the receiver operating characteristic curve, calibration curve, and decision curve analysis. Initially, 5 and 6 key features were selected to establish a radiomic signature from the pulmonary consolidation region (RS1) and a signature from lymph node region (RS2), respectively. A predictive nomogram was built combining RS1, RS2, and a clinical factor (duration of fever). Its classification performance (AUC = 0.971, 95% confidence interval [CI]: 0.912–1) was better than the senior radiologist’s clinical judgment (AUC = 0.791, 95% CI: 0.636-0.946), the clinical factor (AUC = 0.832, 95% CI: 0.677–0.987), and the combination of RS1 and RS2 (AUC = 0.957, 95% CI: 0.889–1). The calibration curves indicated a good consistency of the nomogram. Decision curve analysis demonstrated that the nomogram was useful in clinical settings. A CT-based predictive nomogram was proposed and could be conveniently used to differentiate pulmonary TB from CAP in children.

    更新日期:2019-11-28
  • Image quality and pathology assessment in CT Urography: when is the low-dose series sufficient?
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-09
    Bharti Kataria; Jonas Nilsson Althén; Örjan Smedby; Anders Persson; Hannibal Sökjer; Michael Sandborg

    Our aim was to compare CT images from native, nephrographic and excretory phases using image quality criteria as well as the detection of positive pathological findings in CT Urography, to explore if the radiation burden to the younger group of patients or patients with negative outcomes can be reduced. This is a retrospective study of 40 patients who underwent a CT Urography examination on a 192-slice dual source scanner. Image quality was assessed for four specific renal image criteria from the European guidelines, together with pathological assessment in three categories: renal, other abdominal, and incidental findings without clinical significance. Each phase was assessed individually by three radiologists with varying experience using a graded scale. Certainty scores were derived based on the graded assessments. Statistical analysis was performed using visual grading regression (VGR). The limit for significance was set at p = 0.05. For visual reproduction of the renal parenchyma and renal arteries, the image quality was judged better for the nephrogram phase (p < 0.001), whereas renal pelvis/calyces and proximal ureters were better reproduced in the excretory phase compared to the native phase (p < 0.001). Similarly, significantly higher certainty scores were obtained in the nephrogram phase for renal parenchyma and renal arteries, but in the excretory phase for renal pelvis/calyxes and proximal ureters. Assessment of pathology in the three categories showed no statistically significant differences between the three phases. Certainty scores for assessment of pathology, however, showed a significantly higher certainty for renal pathology when comparing the native phase to nephrogram and excretory phase and a significantly higher score for nephrographic phase but only for incidental findings. Visualisation of renal anatomy was as expected with each post-contrast phase showing favourable scores compared to the native phase. No statistically significant differences in the assessment of pathology were found between the three phases. The low-dose CT (LDCT) seems to be sufficient in differentiating between normal and pathological examinations. To reduce the radiation burden in certain patient groups, the LDCT could be considered a suitable alternative as a first line imaging method. However, radiologists should be aware of its limitations.

    更新日期:2019-11-28
  • Unenhanced multidetector computed tomography findings in acute central pulmonary embolism
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-14
    Chiao-Hsuan Chien; Fu-Chieh Shih; Chin-Yu Chen; Chia-Hui Chen; Wan-Ling Wu; Chee-Wai Mak

    Computed tomography pulmonary angiography (CTPA) is the gold standard for the diagnosis of pulmonary embolism (PE). However, contrast is contraindicated in some patients. The purpose of this study was to determine the diagnostic accuracy of unenhanced multidetector CT (MDCT) for diagnosis of central PE using CTPA as the gold standard. The records of patients with suspected PE seen between 2010 and 2013 were retrospectively reviewed. Inclusion criteria were an acute, central PE confirmed by CTPA and non-enhanced MDCT before contrast injection. Patients with a PE ruled out by CTPA served as a control group. MDCT findings studied were high-attenuation emboli in pulmonary artery (PA), main PA dilatation > 33.2 mm, and peripheral wedge-shaped consolidation. Receiver operating characteristic (ROC) analysis was used to determine the sensitivity and specificity of unenhanced MDCT to detect PE. Wells score of all patients were calculated using data extracted from medical records prior to imaging analysis. Thirty-two patients with a PE confirmed by CTPA and 32 with a PE ruled out by CTPA were included. Among the three main MDCT findings, high-attenuation emboli in the PA showed best diagnostic performance (Sensitivity 72.9%; Specificity 100%), followed by main PA dilatation > 33.2 mm (sensitivity 46.9%; specificity 90.6%), and peripheral wedge-shaped consolidation (sensitivity 43.8%; specificity 78.1%). Given any one or more positive findings on unenhanced MDCT, the sensitivity was 96.9% and specificity was 71.9% for a diagnosis of PE in patients. The area under the curve (AUC) of a composite measure of unenhanced MDCT findings (0.909) was significantly higher than that of the Wells score (0.688), indicating unenhanced MDCT was reliable for detecting PE than Wells score. Unenhanced MDCT is an alternative for the diagnosis of acute central PE when CTPA is not available.

    更新日期:2019-11-28
  • Evaluation of an optimized metal artifact reduction algorithm for flat-detector angiography compared to DSA imaging in follow-up after neurovascular procedures
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-14
    Nadine Amelung; Volker Maus; Daniel Behme; Ismini E. Papageorgiou; Johanna Rosemarie Leyhe; Michael Knauth; Marios Nikos Psychogios

    Flat detector CT – angiography (FDCTA) has become a valuable imaging tool in post- and peri-interventional imaging after neurovascular procedures. Metal artifacts produced by radiopaque implants like clips or coils still impair image quality. FDCTA was performed in periprocedural or follow-up imaging of 21 patients, who had received neurovascular treatment. Raw data was sent to a dedicated workstation and subsequently a metal artifact reduction algorithm (MARA) was applied. Two neuroradiologists examined the images. Application of MARA improved image appearance and led to a significant reduction of metal artifacts. After application of MARA only 8 datasets (34% of the images) were rated as having many or extensive artifacts, before MARA 15 (65%) of the images had extensive or many artifacts. Twenty percent more cases of reperfusion were diagnosed after application of MARA, congruent to the results of digital subtraction angiography (DSA) imaging. Also 3 (13% of datasets) images, which could not be evaluated before application of MARA, could be analyzed after metal artifact reduction and reperfusion could be excluded. Application of MARA improved image evaluation, reduced the extent of metal artifacts, and more cases of reperfusion could be detected or excluded, congruent to DSA imaging.

    更新日期:2019-11-28
  • Radiomic features from MRI distinguish myxomas from myxofibrosarcomas
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-15
    Teresa Martin-Carreras; Hongming Li; Kumarasen Cooper; Yong Fan; Ronnie Sebro

    Myxoid tumors pose diagnostic challenges for radiologists and pathologists. All myxoid tumors can be differentiated from each other using fluorescent in-situ hybridization (FISH) or immunohistochemical markers, except for myxomas and myxofibrosarcomas. Myxomas and myxofibrosarcomas are rare tumors. Myxomas are benign and histologically bland, whereas myxofibrosarcomas are malignant and histologically heterogenous. Because of the histological heterogeneity, low grade myxofibrosarcomas may be mistaken for myxomas on core needle biopsies. We evaluated the performance of T1-weighted signal intensity (T1SI), tumor volume, and radiomic features extracted from magnetic resonance imaging (MRI) to differentiate myxomas from myxofibrosarcomas. The MRIs of 56 patients (29 with myxomas, 27 with myxofibrosarcomas) were analyzed. We extracted 89 radiomic features. Random forests based classifiers using the T1SI, volume features, and radiomic features were used to differentiate myxomas from myxofibrosarcomas. The classifiers were validated using a leave-one-out cross-validation. The performances of the classifiers were then compared. Myxomas had lower normalized T1SI than myxofibrosaromas (p = 0.006) and the AUC using the T1SI was 0.713. However, the classification model using radiomic features had an AUC of 0.885 (accuracy = 0.839, sensitivity = 0.852, specificity = 0.828), and outperformed the classification models using T1SI (AUC = 0.713) and tumor volume (AUC = 0.838). The classification model using radiomic features was significantly better than the classifier using T1SI values (p = 0.039). Myxofibrosarcomas are on average higher in T1-weighted signal intensity than myxomas. Myxofibrosarcomas are larger and have shape differences compared to myxomas. Radiomic features performed best for differentiating myxomas from myxofibrosarcomas compared to T1-weighted signal intensity and tumor volume features.

    更新日期:2019-11-28
  • Non-contrast-enhanced magnetic resonance angiography of facial arteries for pre-operative evaluation of vascularized submental lymph node flaps
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-16
    Ming-Chen Wu; Ming-Yi Hsu; Ren-Fu Shie; Ming-Huei Cheng; Fang-I Chu; Chien-Yuan Lin; Yui-Ping Fan; Sung-Yu Chu

    The aim of this study was to compare non-contrast-enhanced 3D phase contrast magnetic resonance angiography (3D PC-MRA) and conventional intravenous administration of contrast media, i.e., contrast-enhanced MRA (CE-MRA), to evaluate the courses of facial arteries for the preparation of vascularized submental lymph node flap (VSLN flap) transfer. The head and neck regions of 20 patients with limb lymphedema were imaged using a 3 T MRI scanner. To improve the evaluation of facial artery courses, MRA was fused with anatomical structures generated by high-resolution T1-weighted imaging. The diagnostic and image qualities of facial arteries for VSLN flap planning were independently rated by two radiologists. Interobserver agreement was evaluated using Cohen’s kappa. Differences between 3D PC-MRA and CE-MRA in terms of the diagnostic quality of facial arteries were evaluated using McNemar’s test. Cohen’s kappa indicated fair to good interobserver agreement for the diagnostic and image qualities of the bilateral facial arteries. No significant difference in terms of the diagnostic quality of the left and right facial arteries between 3D PC-MRA and CE-MRA, respectively, was identified. Non-contrast 3D PC-MRA is a reliable method for the evaluation of facial artery courses prior to VSLN flap transfer and could serve as an alternative to CE-MRA for patients with renal insufficiency or severe adverse reactions to contrast media.

    更新日期:2019-11-28
  • Assessment of peripheral muscle thickness and architecture in healthy volunteers using hand-held ultrasound devices; a comparison study with standard ultrasound
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-19
    Peter Turton; Richard Hay; Ingeborg Welters

    Pocket-sized ultrasound devices are increasingly used in a variety of clinical situations, and perform well against standard ultrasound machines. We sought to investigate if a pocket-sized ultrasound device can assess muscle thickness and architecture in healthy volunteers. Healthy male volunteers (n = 21) across a range of ages were recruited to the study. Laying supine, ultrasound images were taken from the right anterior and lateral thigh. Thickness of the rectus femoris (RFMT), vastus intermedius (VIMT), and the two combined (anterior thigh, AMT) were measured, along with thickness of vastus lateralis (VLMT), pennation angle (VLPA) and derived fascicle length (VLFL). These scans were performed initially using a pocket-sized ultrasound (VScan) and then using a standard device (Telemed Echoblaster 128). In all six variables, there was no significant difference between the two sets of measurements. Intra-class correlation co-efficients (ICC) for VLMT, VLPA, and AMT were all excellent (0.93, 0.89, 0.90 respectively) with the derived value of VLFL having an ICC of 0.84. All ICC values were statistically significant. Regression analysis demonstrated no evidence of proportional bias in any of the measured or derived variables. A pocket-sized ultrasound device gives similar measurements of lower limb muscle thickness and architecture as a standard device in healthy volunteers.

    更新日期:2019-11-28
  • Diagnostic value of whole-body MRI in Opsoclonus-myoclonus syndrome: a clinical case series (3 case reports)
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-20
    Corinna Storz; Roland Bares; Martin Ebinger; Rupert Handgretinger; Ilias Tsiflikas; Jürgen F. Schäfer

    Opsoclonus-myoclonus syndrome (OMS) is a rare clinical disorder and typically occurs in association with occult neuroblastic tumor in pediatric patients. I-123 metaiodobenzylguanidine (mIBG) scintigraphy is widely adopted as screening procedure in patients with suspected neuroblastic tumor. Also, contrast-enhanced magnetic resonance imaging (MRI) or computed tomography (CT) are involved in the imaging workup, primarily for the assessment of the primary tumor region. However, the diagnostic value of whole-body MRI (WB-MRI) for the detection of occult neuroblastic tumor in pediatric patients presenting with OMS remains unknown. We present three cases of patients with OMS, in whom WB-MRI revealed occult neuroblastic tumor masses, whereas scintigraphy was inconclusive: In a 17 months old girl with OMS, WB-MRI revealed a paravertebral mass. After thoracoscopic resection, histopathology revealed a ganglioneuroblastoma. A 13 months old boy presenting with OMS WB-MRI detected a tumor of the left adrenal gland; histopathology demonstrated a ganglioneuroblastoma after adrenalectomy. In a 2 year old boy with OMS, immunoscintigraphy at the time of diagnosis was inconclusive. At the age of 13 years, a WB-MRI was performed due to persistent neurological symptoms, revealing a paravertebral retroperitoneal mass, which was classified as ganglioneuroblastoma. In OMS, particularly in the setting of inconclusive scintigraphy, WB-MRI may be considered as a valuable alternative in the early phase of diagnostic work-up.

    更新日期:2019-11-28
  • Quantitative margin assessment of radiofrequency ablation of a solitary colorectal hepatic metastasis using MIRADA RTx on CT scans: a feasibility study
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-20
    B. G. Sibinga Mulder; P. Hendriks; T. R. Baetens; A. R. van Erkel; C. S. P. van Rijswijk; R. W. van der Meer; C. J. H. van de Velde; A. L. Vahrmeijer; J. S. D. Mieog; M. C. Burgmans

    Compared to surgery, radiofrequency ablation(RFA) for colorectal liver metastasis(CRLM) is associated with higher local recurrence(LR) rates. A wide margin (at least 5 mm) is generally recommended to prevent LR, but the optimal method to assess ablation margins is yet to be established. The aim of our study was to evaluate the feasibility and reproducibility of CT-CT co-registration, using MIRADA software, in order to assess ablation margins of patients with CRLM. In this retrospective study, pre- and post-ablation contrast-enhanced CT scans of 29 patients, treated with percutaneous RFA for a solitary CRLM, were co-registered. Co-registration was performed by two independent radiologist, based on venous structures in proximity to the tumor. Feasibility of CT-CT co-registration and inter-observer agreement for reproducibility and ablation margins was determined. Furthermore, the minimal ablation margin was compared with the occurrence of LR during follow-up. Co-registration was considered feasible in 18 patients (61% male, 63.1(±10.9) year), with a perfect inter-observer agreement for completeness of ablation: κ = 1.0(p < 0.001). And substantial inter-observer agreement for measurement of the minimal margin (≤ 0 mm, 1-5 mm, ≥ 5 mm): κ = 0.723(p-value < 0.001). LR occurred in eight of nine(88.9%) incompletely ablated CRLM and in one of the nine completely ablated CRLM(11.1%). Co-registration using MIRADA is reproducible and potentially a valuable tool in defining technical success. Feasibility of co-registration of pre- and post-ablation CT scans is suboptimal if scans are not acquired concordantly. Co-registration may potentially aid in the prediction of LR after percutaneous ablation.

    更新日期:2019-11-28
  • Sonographic estimation of gestational age from 20 to 40 weeks by fetal kidney lengths’ measurements among pregnant women in Portharcourt, Nigeria
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-22
    Everistus Obinna Abonyi; Charles Ugwoke Eze; Kennedy Kenechukwu Agwuna; Warric Sobechukwu Onwuzu

    Ultrasonography has become an indispensible tool in the management of obstetric patients. Accurate determination of fetal gestational age (FGA) has posed great challenge to patient management as the accuracy of traditional biometric parameters decreases with advance in gestation age. Accuracy of fetal kidney length (FKL) in the determination of FGA at third trimester has been documented in other population. This study is aimed to create baseline reference values of fetal kidney lengths in a Nigerian population as previous studies show population specific variations. This prospective cross sectional study was carried out on 534 pregnant women between 20 and 40 weeks of gestation who met the inclusion criteria at Diamond Biomedical Services Ltd. A pilot study was conducted on 20 patients to determine the reproducibility and reliability of ultrasound measurement of FKL. Fetal kidney lengths were calculated as mean of three separate measurements. The 5th, 50th and 95th percentiles were calculated using least squared regression analysis. Third polynomial regression models were used to establish the relationship between right and left FKL and FGA. Both FKL measurements are highly reproducible with excellent correlation and agreement within and between sonographers. It correlates strongly with gestational age while the relationships between right and left kidney lengths with gestational age were established using the following regression equations: RKL = − 11.18 + 1.193 × FGA − 0.0350 × FGA2 + 0.00037 × FGA3 and LKL = − 12.57 + 1.332 × FGA − 0.0390 × FGA2 + 0.00040 × FGA3 for right and left kidneys respectively. Nigerian population specific baseline reference values of FKLs for the estimation of FGA should be adopted rather than relying on the Caucasians values as universal patterns.

    更新日期:2019-11-28
  • Automatic glioma segmentation based on adaptive superpixel
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-23
    Yaping Wu; Zhe Zhao; Weiguo Wu; Yusong Lin; Meiyun Wang

    The automatic glioma segmentation is of great significance for clinical practice. This study aims to propose an automatic method based on superpixel for glioma segmentation from the T2 weighted Magnetic Resonance Imaging. The proposed method mainly includes three steps. First, we propose an adaptive superpixel generation algorithm based on simple linear iterative clustering version with 0 parameter (ASLIC0). This algorithm can acquire a superpixel image with fewer superpixels and better fit the boundary of region of interest (ROI) by automatically selecting the optimal number of superpixels. Second, we compose a training set by calculating the statistical, texture, curvature and fractal features for each superpixel. Third, Support Vector Machine (SVM) is used to train classification model based on the features of the second step. The experimental results on Multimodal Brain Tumor Image Segmentation Benchmark 2017 (BraTS2017) show that the proposed method has good segmentation performance. The average Dice, Hausdorff distance, sensitivity, and specificity for the segmented tumor against the ground truth are 0.8492, 3.4697 pixels, 81.47, and 99.64%, respectively. The proposed method shows good stability on high- and low-grade glioma samples. Comparative experimental results show that the proposed method has superior performance. This provides a close match to expert delineation across all grades of glioma, leading to a fast and reproducible method of glioma segmentation.

    更新日期:2019-11-28
  • Relation between carotid vulnerable plaques and peripheral leukocyte: a case-control study of comparison utilizing multi-parametric contrast-enhanced ultrasound
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-23
    Xianghong Luo; Wanbin Li; Yun Bai; Lianfang Du; Rong Wu; Zhaojun Li

    This study evaluates carotid vulnerable plaques using contrast-enhanced ultrasound (CEUS) and explores the relationship between vulnerable plaques and leukocytes. Sixty-two symptomatic and 54 asymptomatic patients underwent CEUS. The images were analyzed using time-intensity and fitting curves, and peak (PTIC), mean (MTIC), peak (PFC), sharpness (SFC), and area under the curve (AUCFC) were obtained. The relations between CEUS parameters and leukocytes were analyzed. In the symptomatic group, total leukocytes and neutrophils were higher, while lymphocyte was decreased; PTIC, MTIC, PFC, SFC, and AUCFC were significantly higher; MTIC and AUCFC were negatively correlated with lymphocytes, and MTIC was positively correlated with neutrophils. Classification and regression tree analysis showed that MTIC at a cutoff of 20.8 and AUCFC at a cutoff of 8.8 resulted in a predictive of acute cerebral infarction, accuracy of 84.3%, sensitivity of 87.1%, and specificity of 81.5%. The variation in the perivascular leucocyte is significantly related to intraplaque inflammatory activities, CEUS is a feasible monitor of intraplaque neovascularization, so CEUS combined with perivascular leucocyte could be helpful as a warning for vulnerable plaques.

    更新日期:2019-11-28
  • Perfusion imaging with 320-slice spiral computed tomography and color-coded digital subtraction angiography for assessing acute skeletal muscle ischemia-reperfusion injury in a rabbit model
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-28
    Chengzhi Li; Xingyi Liu; Huimin You; Hong Zhang; Yuqi Liu; Yan Zhang

    In recent years, skeletal muscle-related ischemia-reperfusion injury (IRI) has become more common. IRI can lead to severe limb injuries, multiple organ failure, and even death in some cases. However, there is still a lack of rapid and sensitive detection methods for IRI in skeletal muscle. This study aims to explore the value of computed tomography perfusion imaging (CTPI) and color-coded digital subtraction angiography (DSA) in assessing acute IRI of skeletal muscle in a rabbit model. Fifty New Zealand white rabbits were randomly assigned to the ischemia-reperfusion (IR) group (n = 40) or sham group (n = 10). After 3 h of surgically-induced hindlimb ischemia, the IR group underwent reperfusion and CTPI and color-coded DSA were taken to assess the skeletal muscle at 0, 6, 12, or 24 h post-reperfusion. The data from CTPI and DSA in the right and left hindlimbs, blood flow (AF-R/L), blood volume (BV-R/L), contrast clearance rate (C-R/L) and the maximum contrast enhancement values (peak-R/L) were obtained. Serum superoxide dismutase (SOD), creatine kinase (CK), lactic dehydrogenase (LDH) and malondialdehyde (MDA) were measured. The statistical correlation between the above parameters (CTPI, color-coded DSA, and biochemical markers) was analyzed. The mean value of AF-R/L, BV-R/L, C-R/L and peak-R/L decreased linearly from 1.07 ± 0.08 to 0.75 ± 0.11, 1.03 ± 0.06 to 0.85 ± 0.14, 0.93 ± 0.15 to 0.71 ± 0.18, and 1.07 ± 0.01 to 0.47 ± 0.04, respectively. The correlation coefficients between AF-R/L and SOD, CK, LDH and MDA were 0.57, − 0.44, − 0.60, and − 0.62, respectively (p < 0.001). The correlation coefficients between Peak-R/L and SOD, CK, LDH, MDA were 0.59, 0.68, 0.71 and 0.66, respectively (p < 0.001). The correlation coefficient between AF-R/L and Peak-R/L was 0.70 (p < 0.001). Both CTPI and color-coded DSA could dynamically assess skeletal muscle IRI in rabbits.

    更新日期:2019-11-28
  • Value of virtual monochromatic spectral image of dual-layer spectral detector CT with noise reduction algorithm for image quality improvement in obese simulated body phantom
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-08-28
    Hyo-Jin Kang; Jeong Min Lee; Sang Min Lee; Hyun Kyung Yang; Ri Hyeon Kim; Ju Gang Nam; Aruna Karnawat; Joon Koo Han

    Dual-layer spectral detector CT (SDCT) may provide several theoretical advantages over pre-existing DECT approaches in terms of adjustment-free sampling number and dose modulation, beam hardening correction, and production spectral images by post-processing. In addition, by adopting noise reduction algorithm, high contrast resolution was expected even in low keV level. We surmised that this improvement would be beneficial to obese people. Therefore, our aim of study is to compare image quality of virtual monochromatic spectral images (VMI) and polychromatic images reconstructed from SDCT with different body size and radiation dose using anthropomorphic liver phantom. One small and one large size of body phantoms, each containing eight (four high- and four low-contrast) simulated focal liver lesions (FLLs) were scanned by SDCT (at 120 kVp) using different Dose Right Indexes (DRIs). VMI were reconstructed from spectral base images from 40 keV to 200 keV. Hybrid iterative reconstruction (iDose4) was used for polychromatic image reconstruction. Image noise and contrast to noise ratio (CNR) were compared. Five radiologists independently rated lesion conspicuity, diagnostic acceptability and subjective noise level in every image sets, and determined optimal keV level in VMI. Compare with conventional polychromatic images, VMI showed superior CNR at low keV level regardless of phantom size at every examined DRIs (Ps < 0.05). As body size increased, VMI had more gradual CNR decrease and noise increase than conventional polychromatic images. For low contrast FLLs in large phantom, lesion conspicuities at low radiation dose levels (DRI 16 and 19) were significantly increased in VMI (Ps < 0.05). Subjective image noise and diagnostic acceptabilities were significantly improved at VMI in both phantom size. VMI of dual-layer spectral detector CT with noise reduction algorithm provides improved CNR, noise reduction, and better subjective image quality in imaging of obese simulated liver phantom compared with polychromatic images. This may hold promise for improving detection of liver lesions and improved imaging of obese patients.

    更新日期:2019-11-28
  • Combination of CEUS and MRI for the diagnosis of periampullary space-occupying lesions: a retrospective analysis
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-09-02
    Xin-Pei Chen; Jiang Liu; Jing Zhou; Peng-Cheng Zhou; Jian Shu; Lu-Lu Xu; Bo Li; Song Su

    The value of magnetic resonance imaging (MRI), contrast-enhanced ultrasound (CEUS), and the combination of CEUS and MRI (CCWM) for the diagnosis of periampullary space-occupying lesions (PSOL) was investigated. A total of 102 patients diagnosed with PSOLs by surgery or biopsy were recruited retrospectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MRI, CEUS, and CCWM were analyzed. MRI, CEUS, and CCWM allowed for the accurate detection of 91.17, 92.15, and 99.01% of PSOLs, respectively. The specificity, PPV, and accuracy of CCWM were significantly different from MRI and CEUS (p < 0.05). However, there the sensitivity and NPV were not significantly different among the three diagnostic technologies. In addition, the specificity, PPV, and accuracy were not significantly different between MRI and CEUS (all p > 0.05). CCWM is valuable for differentiating benign and malignant PSOL, which provides important guiding significances for the clinic.

    更新日期:2019-11-28
  • Development of a novel radioligand for imaging 18-kD translocator protein (TSPO) in a rat model of Parkinson’s disease
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-09-18
    Chun-Yi Wu; Yang-Yi Chen; Jia-Jia Lin; Jui-Ping Li; Jen-Kun Chen; Te-Chun Hsieh; Chia-Hung Kao

    The inflammation reaction in the brain may stimulate damage repair or possibly lead to secondary brain injury. It is often associated with activated microglia, which would overexpress 18-kDa translocator protein (TSPO). In this study, we successfully developed a new TSPO radioligand, [18F]-2-(4-fluoro-2-(p-tolyloxy)phenyl)-1,2-dihydroisoquinolin-3(4H)-one ([18F]FTPQ), and evaluate its potential to noninvasively detect brain changes in a rat model of Parkinson’s disease (PD). The precursor (8) for [18F]FTPQ preparation was synthesized via six steps. Radiofluorination was carried out in the presence of a copper catalyst, and the crude product was purified by high-performance liquid chromatography (HPLC) to give the desired [18F]FTPQ. The rat model of PD was established by the injection of 6-OHDA into the right hemisphere of male 8-week-old Sprague-Dawley rats. MicroPET/CT imaging and immunohistochemistry (IHC) were performed to characterize the biological properties of [18F]FTPQ. The overall chemical yield for the precursor (8) was around 14% after multi-step synthesis. The radiofluorination efficiency of [18F]FTPQ was 60 ± 5%. After HPLC purification, the radiochemical purity was higher than 98%. The overall radiochemical yield was approximately 19%. The microPET/CT images demonstrated apparent striatum accumulation in the brains of PD rats at the first 30 min after intravenous injection of [18F]FTPQ. Besides, longitudinal imaging found the uptake of [18F]FTPQ in the brain may reflect the severity of PD. The radioactivity accumulated in the ipsilateral hemisphere of PD rats at 1, 2, and 3 weeks after 6-OHDA administration was 1.84 ± 0.26, 3.43 ± 0.45, and 5.58 ± 0.72%ID/mL, respectively. IHC revealed that an accumulation of microglia/macrophages and astrocytes in the 6-OHDA-injected hemisphere. In this study, we have successfully synthesized [18F]FTPQ with acceptable radiochemical yield and demonstrated the feasibility of [18F]FTPQ as a TSPO radioligand for the noninvasive monitoring the disease progression of PD.

    更新日期:2019-11-28
  • Ataxia as the main manifestation of tumor-like primary angiitis of the central nervous system: a case report and literature review
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-10-15
    Yu-Jing Huang; Li Zhang; Ying Mao; Guang-Xian Nan

    Primary angiitis of the central nervous system (PACNS) is a rare disease, and tumor-like primary angiitis of the central nervous system is even rarer. Histopathology is the gold standard for tumor-mimicking PACNS. However, pathological diagnosis is relatively limited due to fewer biopsy opportunities. A 68-year-old male presented with ataxia, and was diagnosed with tumor-like primary angiitis of the central nervous system. The patient underwent Intravenous drip glucocorticoid therapy (10 mg of dexamethasone, daily). After 10 days, the symptoms of the patient were completely relieved. Radiology revealed that the low density lesion in the right cerebellar hemisphere obviously narrowed. Cyclophosphamide therapy was not initiated. It is crucial for clinicians to be aware of changes in radiology that indicate PACNS, since the diagnosis of tumor-like PACNS remains quite challenging. Glucocorticoid therapy is an effective therapy in this condition, and the prognosis can be favorable.

    更新日期:2019-11-28
  • Half-body MRI volumetry of abdominal adipose tissue in patients with obesity
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-10-22
    Nicolas Linder; Kilian Solty; Anna Hartmann; Tobias Eggebrecht; Matthias Blüher; Roland Stange; Harald Busse

    The purpose of this study was to determine to what extent the whole volumes of abdominal subcutaneous (ASAT) and visceral adipose tissue (VAT) of patients with obesity can be predicted by using data of one body half only. Such a workaround has already been reported for dual-energy x-ray absorption (DEXA) scans and becomes feasible whenever the field of view of an imaging technique is not large enough. Full-body abdominal MRI data of 26 patients from an obesity treatment center (13 females and 13 males, BMI range 30.8–41.2 kg/m2, 32.6–61.5 years old) were used as reference (REF). MRI was performed with IRB approval on a clinical 1.5 T MRI (Achieva dStream, Philips Healthcare, Best, Netherlands). Segmentation of adipose tissue was performed with a custom-made Matlab software tool. Statistical measures of agreement were the coefficient of determination R2 of a linear fit. Mean ASATREF was 12,976 (7812–24,161) cm3 and mean VATREF was 4068 (1137–7518) cm3. Mean half-body volumes relative to the whole-body values were 50.8% (48.2–53.7%) for ASATL and 49.2% (46.3–51.8%) for ASATR. Corresponding volume fractions were 56.4% (51.4–65.9%) for VATL and 43.6% (34.1–48.6%) for VATR. Correlations of ASATREF with ASATL as well as with ASATR were both excellent (R2 > 0.99, p < 0.01). Corresponding correlations of VATREF were marginally lower (R2 = 0.98 for VATL, p < 0.01, and R2 = 0.97 for VATR, p < 0.01). In conclusion, abdominal fat volumes can be reliably assessed by half-body MRI data, in particular the subcutaneous fat compartment.

    更新日期:2019-11-28
  • Comparison of conventional and Si-photomultiplier-based PET systems for image quality and diagnostic performance
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-10-22
    Jenny Oddstig; Sigrid Leide Svegborn; Helen Almquist; Ulrika Bitzén; Sabine Garpered; Fredrik Hedeer; Cecilia Hindorf; Jonas Jögi; Lena Jönsson; David Minarik; Richard Petersson; Annika Welinder; Per Wollmer; Elin Trägårdh

    A new generation of positron emission tomography with computed tomography (PET-CT) was recently introduced using silicon (Si) photomultiplier (PM)-based technology. Our aim was to compare the image quality and diagnostic performance of a SiPM-based PET-CT (Discovery MI; GE Healthcare, Milwaukee, WI, USA) with a time-of-flight PET-CT scanner with a conventional PM detector (Gemini TF; Philips Healthcare, Cleveland, OH, USA), including reconstruction algorithms per vendor’s recommendations. Imaging of the National Electrical Manufacturers Association IEC body phantom and 16 patients was carried out using 1.5 min/bed for the Discovery MI PET-CT and 2 min/bed for the Gemini TF PET-CT. Images were analysed for recovery coefficients for the phantom, signal-to-noise ratio in the liver, standardized uptake values (SUV) in lesions, number of lesions and metabolic TNM classifications in patients. In phantom, the correct (> 90%) activity level was measured for spheres ≥17 mm for Discovery MI, whereas the Gemini TF reached a correct measured activity level for the 37-mm sphere. In patient studies, metabolic TNM classification was worse using images obtained from the Discovery MI compared those obtained from the Gemini TF in 4 of 15 patients. A trend toward more malignant, inflammatory and unclear lesions was found using images acquired with the Discovery MI compared with the Gemini TF, but this was not statistically significant. Lesion-to-blood-pool SUV ratios were significantly higher in images from the Discovery MI compared with the Gemini TF for lesions smaller than 1 cm (p < 0.001), but this was not the case for larger lesions (p = 0.053). The signal-to-noise ratio in the liver was similar between platforms (p = 0.52). Also, shorter acquisition times were possible using the Discovery MI, with preserved signal-to-noise ratio in the liver. Image quality was better with Discovery MI compared to conventional Gemini TF. Although no gold standard was available, the results indicate that the new PET-CT generation will provide potentially better diagnostic performance.

    更新日期:2019-11-28
  • The use of non-contrast-enhanced MRI to evaluate serial changes in endoleaks after aortic stenting: a case report
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-10-22
    Yu-Li Lee; Yao-Kuang Huang; Li-Sheng Hsu; Pang-Yen Chen; Chien-Wei Chen

    Aortic dissection is a life-threatening syndrome that sometimes requires emergency intervention, and endovascular aortic aneurysm repair (EVAR) is a treatment option. Long-term image follow-up is also required for patients after EVAR due to possible complications. We present the case of a 73-year-old male with underlying chronic renal disease diagnosed with a type A aortic dissection who underwent EVAR. Four-dimensional (three spatial dimensions combined with time) phase-contrast magnetic resonance imaging (4D PC-MRI) was performed during regular follow-up in preference to contrast-enhanced computed tomography or simple MRI while taking his poor renal function into consideration. We considered this preferable given his issues with renal function.

    更新日期:2019-11-28
  • Potential use of a diluted high-relaxivity gadolinium-based intra-articular contrast agent for magnetic resonance arthrography: an in-vitro study
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-10-25
    Carmelo Messina; Domenico Albano; Davide Orlandi; Vito Chianca; Angelo Corazza; Federica Ferrari; Salvatore Gitto; Luca Maria Sconfienza

    Magnetic resonance arthrography (MRA) requires intra-articular injection of gadolinium-based diluted paramagnetic contrast material. To our knowledge, gadobenate dimeglumine (Gd-BOPTA) has never been used for intra-articular applications. Our aim was to test in vitro different concentrations of Gd-BOPTA to be potentially used to perform MRA. Gd-BOPTA was diluted in saline (NaCl 0.9%) to achieve different concentrations (4 mmol/l; 2 mmol/l; 1 mmol/l; 0.67 mmol/l; 0.5 mmol/l). Six sets of five sterile pipes were prepared with 5 ml of each solution, five sets added with 0.5 ml of fresh synovial fluid. Two separate pipes were prepared with 5 ml of gadopentetate dimeglumine (Gd-DTPA) at 2 mmol/l, one pipe added with 0.5 ml of synovial fluid. Pipes were imaged using a T1-weighted sequence at 1.5 T. For each pipe, signal intensity (SI) in arbitrary units (au) was measured. SI reproducibility range was 86–99%. Mean Gd-BOPTA SI in pipes containing synovial fluid increased from 1236 ± 8au (0.5 mmol/l) up to 1610 ± 44au (1 mmol/l) and down to 1405 ± 33au (4 mmol/l). Mean Gd-BOPTA SI in pipes without synovial fluid increased from 1184 ± 29au (0.5 mmol/l) up to 1530 ± 38au (1 mmol/l), and down to 1347 ± 39au (4 mmol/l). SI of pipes without synovial fluid was lower than that of pipes with synovial fluid for both Gd-BOPTA and Gd-DTPA (P ≤ 0.002). Regarding pipes with synovial fluid, mean Gd-DTPA SI at 2 mmol/l was 1246 ± 27au. Compared with Gd-BOPTA, SI was not different at 0.5 mmol/l (− 0.2%, P = 0.587) while it was higher (P < 0.001) at all other concentrations (range + 13.3%[4 mmol/l] − + 28.3%[1 mmol/l]). Regarding pipes without synovial fluid, mean Gd-DTPA SI at 2 mmol/l was 1275 ± 56au. Compared with Gd-BOPTA, SI was lower at 0.5 mmol/l (− 6.8%,P < 0.001), while it was higher (P < 0.001) at all other concentrations (range + 6.1%[4 mmol/l] − + 19.6% [1 mmol/l]). In vitro, Gd-BOPTA at 1 mmol/ had a + 28% SI increase in comparison to Gd-DTPA 2 mmol/l. SI similar to Gd-DTPA can be obtained using one fourth concentration of Gd-BOPTA.

    更新日期:2019-11-28
  • Comparing complications of urethral stricture across various ages: a retrospective analysis of findings from retrograde urethrogram and voiding cysto-urethrogram over 10 years
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-10-29
    Ikenna I. Nnabugwu; Augustine C. Onuh; Solomon K. Anyimba; Samuel O. Mgbor

    To determine the rate and the distribution of the structural defects in the urinary bladder complicating urethral stricture in men, and to compare the complications observed in the younger patients to those observed in the older patients. Retrospectively, case files of patients diagnosed of urethral stricture using retrograde urethrogram (RUG) and voiding cysto-urethrogram (VCUG) from February 2009 to August 2018 were analyzed. Stricture characteristics were outlined. In addition, complicating structural defects in the lower urinary tract proximal to the stricture site were documented. The complicating defects identified in the patients were segregated according to age for any observable associations. Logistic regression analysis was used to define the nature of the association of patient age, stricture site, number and length, with distribution of complicating structural defects. Analyses were done using SPSS® version 20. Within the 10-year review period, 257 of 421 suspected cases of urethral stricture were confirmed. Patients are between 1 and 104 years of age (mean: 50.1 ± 19.1 years; median: 51.0 years IQR 35.0–65.0). Bulbar (34.2%); short segment (62.6%); partial (73.9%) strictures are prevalent. Forty-seven (18.3%) of 257 patients presented with 1 or more complications. Bladder diverticulum (8.6%) and urethra-cutaneous fistula (6.6%) are prevalent complications. The distribution of complications does not vary with age, or with stricture characteristics. Presentation with complications is not uncommon. The distribution of these complications does not vary with age or with stricture characteristics.

    更新日期:2019-11-28
  • Evaluating the performance of convolutional neural networks with direct acyclic graph architectures in automatic segmentation of breast lesion in US images
    BMC Med. Imaging (IF 1.622) Pub Date : 2019-11-08
    Marly Guimarães Fernandes Costa; João Paulo Mendes Campos; Gustavo de Aquino e Aquino; Wagner Coelho de Albuquerque Pereira; Cícero Ferreira Fernandes Costa Filho

    Outlining lesion contours in Ultra Sound (US) breast images is an important step in breast cancer diagnosis. Malignant lesions infiltrate the surrounding tissue, generating irregular contours, with spiculation and angulated margins, whereas benign lesions produce contours with a smooth outline and elliptical shape. In breast imaging, the majority of the existing publications in the literature focus on using Convolutional Neural Networks (CNNs) for segmentation and classification of lesions in mammographic images. In this study our main objective is to assess the ability of CNNs in detecting contour irregularities in breast lesions in US images. In this study we compare the performance of two CNNs with Direct Acyclic Graph (DAG) architecture and one CNN with a series architecture for breast lesion segmentation in US images. DAG and series architectures are both feedforward networks. The difference is that a DAG architecture could have more than one path between the first layer and end layer, whereas a series architecture has only one path from the beginning layer to the end layer. The CNN architectures were evaluated with two datasets. With the more complex DAG architecture, the following mean values were obtained for the metrics used to evaluate the segmented contours: global accuracy: 0.956; IOU: 0.876; F measure: 68.77%; Dice coefficient: 0.892. The CNN DAG architecture shows the best metric values used for quantitatively evaluating the segmented contours compared with the gold-standard contours. The segmented contours obtained with this architecture also have more details and irregularities, like the gold-standard contours.

    更新日期:2019-11-28
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