Giaroli Eddie L, Major Nancy M, Lemley Doug E, Lee John
Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC 27710, USA.
AJR Am J Roentgenol. 2006 Jan;186(1):242-6. doi: 10.2214/AJR.04.0830.
The coracohumeral interval previously has been described as predictive of subcoracoid impingement on dynamic screening. The purpose of this study was to determine whether a coracohumeral interval acquired from routinely performed MRI can reliably diagnose subcoracoid impingement.
Preoperative MRI examinations of 19 patients (16 males, three females) with subsequent surgical confirmation of subcoracoid impingement were reviewed retrospectively and compared with MRI studies of 41 control subjects (22 males, 19 females). Axial and oblique sagittal coracohumeral interval measurements were taken. The morphology of the coracoid process and lesser tuberosity was assessed. Postanalysis application of the data to two smaller groups of patients was performed. The first group consisted of nine subjects (three males, six females) for whom subcoracoid impingement was diagnosed prospectively on the basis of abnormalities found by MRI. The second group consisted of seven patients (two males, five females) who were referred for MRI evaluation because of clinically suspected subcoracoid impingement.
The average coracohumeral interval for females was 3 mm smaller than that for males. Using sex-adjusted data, we found a statistically significant difference between individuals with or without subcoracoid impingement in the axial coracohumeral interval (p = 0.01). This value, however, was poorly predictive (area under the receiver operating characteristic curve, 0.73). An 11.5-mm axial coracohumeral interval had 84% sensitivity but only 44% specificity. A 10.5-mm axial coracohumeral interval had 79% sensitivity and 59% specificity. The shoulder morphologic features assessed and intraarticular contrast use were not statistically significantly related to the coracohumeral interval. In postanalysis application of data, in the group of nine subjects without clinical diagnosis of subcoracoid impingement, all prospective MRI subcoracoid impingement diagnoses were falsely positive. However, if subcoracoid impingement was the referring diagnosis, prospective MRI evaluation more often was correct (n = 7 [three true-negatives, two true-positives, two false-negatives]).
A sex-adjusted coracohumeral interval of 10.5-11.5 mm, although statistically significantly related to subcoracoid impingement, is poorly predictive of this diagnosis when acquired via routinely performed MRI. Subcoracoid impingement is primarily a clinical diagnosis that may be supported, but not established, by this means.
喙肱间隙先前已被描述为动态筛查时喙突下撞击的预测指标。本研究的目的是确定从常规MRI获得的喙肱间隙是否能可靠地诊断喙突下撞击。
回顾性分析19例（16例男性，3例女性）经手术证实为喙突下撞击患者的术前MRI检查，并与41例对照者（22例男性，19例女性）的MRI研究进行比较。测量轴向和斜矢状面的喙肱间隙。评估喙突和小结节的形态。对数据进行分析后应用于两组较小的患者。第一组由9名受试者（3名男性，6名女性）组成，他们基于MRI发现的异常被前瞻性诊断为喙突下撞击。第二组由7名患者（2名男性，5名女性）组成，他们因临床怀疑喙突下撞击而被转诊进行MRI评估。
女性的平均喙肱间隙比男性小3mm。使用性别调整后的数据，我们发现轴向喙肱间隙中有无喙突下撞击的个体之间存在统计学显著差异（p = 0.01）。然而，该值的预测性较差（受试者工作特征曲线下面积为0.73）。轴向喙肱间隙为11.5mm时，敏感性为84%，但特异性仅为44%。轴向喙肱间隙为10.5mm时，敏感性为79%，特异性为59%。评估的肩部形态特征和关节内造影剂的使用与喙肱间隙无统计学显著相关性。在数据的分析后应用中，在9名未临床诊断为喙突下撞击的受试者组中，所有前瞻性MRI对喙突下撞击的诊断均为假阳性。然而，如果喙突下撞击是转诊诊断，前瞻性MRI评估更常是正确的（n = 7 [3例假阴性，2例假阳性，2例真阳性]）。
经性别调整的喙肱间隙为10.5 - 11.5mm，虽然与喙突下撞击在统计学上有显著相关性，但通过常规MRI获得时，对该诊断的预测性较差。喙突下撞击主要是一种临床诊断，通过这种方法可能得到支持，但不能确诊。
