OBJECTIVES This study was conducted in order to investigate whether there is a correlation between the time-to-enhancement (TTE) in ultrafast MRI and histopathological characteristics of breast cancers. METHODS Between January and August 2017, 274 consecutive breast cancer patients (mean age, 53.5 years; range, 25-80 years) who underwent ultrafast MRI and subsequent surgery were included for analysis. Ultrafast MRI scans were acquired using TWIST-VIBE or 4D TRAK-3D TFE sequences. TTE and maximum slope (MS) were derived from the ultrafast MRI. The repeated measures ANOVA, Mann-Whitney U test and Kruskal-Wallis H test were performed to compare the median TTE, MS and SER according to histologic type, histologic grade, ER/PR/HER2 positivity, level of Ki-67 and tumour subtype. For TTE calculation, intraclass correlation coefficient (ICC) was used to evaluate interobserver variability. RESULTS The median TTE of invasive cancers was shorter than that of in situ cancers (p < 0.001). In invasive cancers, large tumours showed shorter TTE than small tumours (p = 0.001). High histologic/nuclear grade cancers had shorter TTE than low to intermediate grade cancers (p < 0.001 and p < 0.001). HER2-positive cancers showed shorter TTE than HER2-negative cancers (p = 0.001). The median TTE of cancers with high Ki-67 was shorter than that of cancers with low Ki-67 (p < 0.001). ICC between two readers showed moderate agreement (0.516). No difference was found in the median MS or SER values according to the clinicopathologic features. CONCLUSIONS The median TTE of breast cancer in ultrafast MRI was shorter in invasive or aggressive tumours than in in situ cancer or less aggressive tumours, respectively. KEY POINTS • Invasive breast tumours show a shorter TTE in ultrafast DCE-MRI than in situ cancers. • A shorter TTE in ultrafast DCE-MRI is associated with breast tumours of a large size, high histologic or nuclear grade, PR negativity, HER2 positivity and high Ki-67 level.

中文翻译：

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超快乳腺DCE-MRI的增强时间：肿瘤侵袭性的潜在成像生物标志物。

目的进行这项研究是为了研究超快MRI的增强时间（TTE）与乳腺癌的组织病理学特征之间是否存在相关性。方法纳入2017年1月至2017年8月之间连续接受274例乳腺癌患者（平均年龄53.5岁;范围25-80岁）的患者，这些患者接受了超快MRI和随后的手术治疗。使用TWIST-VIBE或4D TRAK-3D TFE序列进行超快MRI扫描。TTE和最大斜率（MS）来自超快MRI。根据组织学类型，组织学等级，ER / PR / HER2阳性，Ki-67水平和肿瘤亚型，重复进行ANOVA，Mann-Whitney U检验和Kruskal-Wallis H检验以比较中位TTE，MS和SER。 。对于TTE计算，组内相关系数（ICC）用于评估观察者间的变异性。结果浸润性癌症的中位TTE短于原位癌（p <0.001）。在浸润性癌症中，大肿瘤的TTE比小肿瘤短（p = 0.001）。高组织学/核级癌症的TTE短于低至中级癌（p <0.001和p <0.001）。HER2阳性癌症的TTE比HER2阴性癌症短（p = 0.001）。Ki-67高的癌症的中位TTE比Ki-67低的癌症的中位TTE短（p <0.001）。两名读者之间的ICC表现出中等程度的一致性（0.516）。根据临床病理特征，中位MS或SER值无差异。结论在侵袭性或侵袭性肿瘤中，超快MRI中乳腺癌的中位TTE分别比在原位癌或侵袭性肿瘤中更短。要点•超快DCE-MRI中浸润性乳腺肿瘤的TTE短于原位癌。•超快DCE-MRI中较短的TTE与大尺寸，组织学或核分级高，PR阴性，HER2阳性和Ki-67水平高的乳腺肿瘤有关。