Background:

Femoroacetabular impingement syndrome (FAIS) is a common disorder of the hip resulting in groin pain and ultimately osteoarthritis. Radiologic assessment of FAI morphologies, which may present with overlapping radiologic features of hip dysplasia, often requires the use of computed tomography (CT) for evaluation of osseous abnormality, owing to the difficulty of direct visualization of cortical and subchondral bone with conventional magnetic resonance imaging (MRI). The use of a zero echo time (ZTE) MRI pulse sequence may obviate the need for CT by rendering bone directly from MRI.

Purpose/Hypothesis:

The purpose was to explore the application of ZTE MRI to the assessment of osseous FAI and dysplasia morphologies of the hip. It was hypothesized that angular measurements from ZTE images would show significant agreement with measurements obtained from CT images.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

Thirty-eight hips from 23 patients were imaged with ZTE MRI and CT. Clinically relevant angular measurements of hip morphology were made in both modalities and compared to assess agreement. Measurements included coronal and sagittal center-edge angles, femoral neck-shaft angle, acetabular version (at 1-, 2-, and 3-o’clock positions), Tönnis angle, alpha angle, and modified-beta angle. Interrater agreement was assessed for a subset of 10 hips by 2 raters. Intermodal agreement was assessed on the complete cohort and a single rater.

Results:

Interrater agreement was demonstrated in both CT and ZTE, with intraclass correlation coefficient values ranging from 0.636 to 0.990 for ZTE and 0.747 to 0.983 for CT, indicating “good” to “excellent” agreement. Intermodal agreement was also shown to be significant, with intraclass correlation coefficients ranging from 0.618 to 0.904.

Conclusion:

Significant agreement of angular measurements for hip morphology exists between ZTE MRI and CT imaging. ZTE MRI may be an effective method to quantitatively evaluate osseous hip morphology.

中文翻译：

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使用零回波时间磁共振成像评估髋骨的骨形态。

背景：

髋臼前冲综合征（FAIS）是常见的髋关节疾病，导致腹股沟疼痛，最终导致骨关节炎。FAI形态的放射学评估可能表现出髋关节发育不良的重叠放射学特征，由于常规磁共振成像难以直接显示皮层和软骨下骨，因此通常需要使用计算机断层扫描（CT）来评估骨异常。 （MRI）。通过直接从MRI渲染骨骼，使用零回波时间（ZTE）MRI脉冲序列可以消除对CT的需求。

目的/假设：

目的是探讨中兴磁共振成像技术在评估髋骨骨固定和不典型增生形态方面的应用。假设从ZTE图像获得的角度测量结果将与从CT图像获得的测量结果显着吻合。

学习规划：

队列研究（诊断）；证据水平2。

方法：

通过ZTE MRI和CT对23例患者的38个髋部进行了成像。在两种方式中均进行了髋部形态的临床相关角度测量，并进行了比较以评估一致性。测量包括冠状和矢状中心边缘角度，股骨颈轴角度，髋臼版本（在1点，2点和3点钟位置），Tönnis角，α角和修正的β角。由2位评估者评估了10个髋关节的评估者之间的评估者之间的一致性。对完整的队列和单个评分者评估了多式联运协议。

结果：

在CT和ZTE中都显示出评分者之间的一致性，对于ZTE，组内相关系数值在0.636到0.990之间，对于CT则是0.747到0.983，表明“良好”到“优秀”一致性。联运协议也很重要，组内相关系数从0.618到0.904。

结论：

在ZTE MRI和CT成像之间，对于髋部形态的角度测量存在显着一致性。中兴核磁共振成像可能是一种有效的方法来定量评估骨性髋骨形态。