Objective: To compare the diagnostic accuracy of supraspinatus muscle outlet X-ray film, oblique sagittal multislice helical CT (MSCT), and oblique sagittal MRI in the diagnosis of subacromial impingement syndrome (SIS).
Methods: A retrospective analysis was conducted on the imaging data of 106 patients diagnosed with SIS between January 2023 and December 2024. The cohort consisted of 32 males and 74 females, with ages ranging from 43 to 70 years (mean, 60.19 years). All patients underwent supraspinatus muscle outlet X-ray film, MSCT, and MRI scans, with MSCT further subjected to three-dimensional reconstruction. Two experienced radiologists independently evaluated the acromion morphology in each imaging modality using the Bigliani classification system. Inter-observer reliability was assessed via Kappa statistics. The CT three-dimensional reconstructions were used as the "gold standard". The overall consistency, Kappa values, sensitivity, and specificity of the three imaging modalities were calculated. Receiver operating characteristic (ROC) curves were plotted, and the area under the curve (AUC) was computed.
Results: The inter-observer reliability for supraspinatus muscle outlet X-ray film, oblique sagittal MSCT, and oblique sagittal MRI was moderate, with Kappa values of 0.62, 0.63, and 0.55, respectively. When compared to the CT three-dimensional reconstructions as the "gold standard", the overall consistency was 88.7% (94/106), 62.3% (66/106), and 58.5% (62/106), respectively. The supraspinatus muscle outlet X-ray film showed excellent consistency (Kappa=0.77), whereas the consistency of MSCT and MRI was lower (Kappa=0.34 and 0.29, respectively). In terms of diagnostic sensitivity and specificity, the supraspinatus muscle outlet X-ray film outperformed oblique sagittal MSCT and oblique sagittal MRI in distinguishing various acromion types. ROC analysis demonstrated that the AUC for the supraspinatus muscle outlet X-ray film was consistently higher than for oblique sagittal MSCT and oblique sagittal MRI, with the highest diagnostic performance observed for type Ⅲ hooked acromion (AUC=0.939).
Conclusion: Supraspinatus muscle outlet X-ray film provides the highest diagnostic accuracy for acromion classification in SIS patients, particularly in identifying type Ⅲ hooked acromion, which is strongly associated with SIS. Given its superior sensitivity and consistency, it should be considered the primary screening tool. MSCT and MRI serve as valuable supplementary modalities for complex cases and preoperative evaluation.
目的: 比较冈上肌出口位X线片、多层螺旋CT（multislice helical CT，MSCT）斜矢状位及MRI斜矢状位3种影像学检查方法对肩峰下撞击综合征（subacromial impingement syndrome，SIS）患者肩峰形态分型诊断的准确性。.
方法: 回顾性分析2023年1月—2024年12月就诊并经影像学及临床诊断为SIS的106例患者影像学资料，其中男32例，女74例；年龄43～70岁，平均60.19岁。所有患者均完成了冈上肌出口位X线片、MSCT及MRI检查，利用MSCT进一步进行了三维重建。由2名经验丰富的医师独立评估3种影像中肩峰形态（参考Bigliani分型标准进行肩峰形态分型），分析观察者间一致性（Kappa值）。以CT三维重建诊断的肩峰形态分型作为“金标准”，计算3种影像学方法的总体一致性、Kappa值、敏感度和特异度；并绘制受试者工作特征（receiver operating characteristic，ROC）曲线，计算曲线下面积（area under the curve，AUC）。.
结果: 2位医师对冈上肌出口位X线片、MSCT斜矢状位、MRI斜矢状位肩峰分型的判读一致性均为中等，Kappa值分别为0.62、0.63、0.55。以CT三维重建图像作为“金标准”，冈上肌出口位X线片、MSCT斜矢状位、MRI斜矢状位与CT三维重建的总体一致性分别为88.7%（94/106）、62.3%（66/106）、58.5%（62/106）；冈上肌出口位X线片判读一致性极好（Kappa值为0.77），MSCT斜矢状位、MRI斜矢状位判读一致性较差（Kappa值分别为0.34、0.29）。在分型敏感度和特异度方面，冈上肌出口位X线片在各分型肩峰的判别中均优于MSCT斜矢状位和MRI斜矢状位。3种影像学方法对肩峰分型诊断的ROC曲线显示，冈上肌出口位X线片的AUC均高于MSCT斜矢状位和MRI斜矢状位，其中冈上肌出口位X线片对Ⅲ型肩峰的诊断效能最强（AUC=0.939）。.
结论: 冈上肌出口位X线片在SIS患者肩峰分型诊断中具有最高准确性，尤其在识别与SIS高度相关的Ⅲ型钩状肩峰方面表现出极高的敏感性和一致性，可作为首选筛查工具；MSCT和MRI作为补充手段，适用于复杂病例的诊断与术前评估。.
Keywords: CT three-dimensional reconstruction; MRI; Subacromial impingement syndrome; acromial morphology; multislice helical CT; supraspinatus muscle outlet X-ray film.