The Diagnostic Valuation Of I-MRAR In The Subacromial Impingement Syndrome

Objective:Through analysis and summarize the image characteristics of shoulder in patients by unenhanced MR and indirect magnetic resonance arthrography (I-MRAR), we evaluate the diagnostic value of MRI and I-MRAR in subacromial impingement syndrome to make secondary evaluation for clinical diagnose and provide imaging support for selection of clinical treatment.Methods:30patients with suspected shoulder injury in our hospital were selected. All the patients had shoulder pain, shoulder mobility or dysfunction, aged38to82years, mean age of58.6years. Before shoulder arthroscopy, all the patients had MRI and I-MRAR examination. The MRI and I-MRAR performances of shoulder bone structure and soft tissue structure were analyzed and diagnosed by two experienced radiologists. If there was disagreement, they negotiated and ultimately reach consensus diagnosis. Clinical diagnosis and arthroscopic shoulder surgery were used as the gold standard. Sensitivity, specificity and diagnostic accuracy of MRI and I-MRAR were calculated in subacromial impingement syndrome. Then compared the diagnostic value in subacromial impingement syndrome between them.Results:(1) There was significant statistical difference (Sensitivity of P-value<0.05, Accuracy of P-value<0.05) when MRI and I-MRAR were used in the diagnosis of partial rotator cuff tear. There was no significant statistical difference (Sensitivity of P value>0.05) when MRI and I-MRAR were used in the diagnosis of in the diagnosis of full-thickness rotator cuff tear and tendinitis.(2) There was no statistical difference in the diagnosis of indirect signs of SAIS between MRI and I-MRAR(P>0.05). MRI and I-MRAR had higher diagnostic sensitivity to indirect sign of SAIS, however with less specificity.(3) There was significant difference in the diagnosis of labral tear between MRI and I-MRAR (P<0.05). However, no significant difference was detected in supraspinatus muscle and deltoid muscle atrophy. Both MRI and I-MRAR can make the correct diagnosis of supraspinatus muscle and deltoid muscle atrophy. I-MRAR had more sensitivity in the diagnosis of labral tear.(4) There was no significant difference in the diagnosis of SAIS etiology between MRI and I-MRAR (P>0.05). Both MRI and I-MRAR can make the correct diagnosis of shoulder morphology and subacromial channel narrow.Conclusion:Unenhanced MRI could make correct diagnosis in most subacromial impingement syndrome, but it had limited effect in diagnosis for partial tear of the supraspinatus tendon and joint labrum tear caused by shoulder impingement. However, I-MRAR had important diagnostic value in partial tear of the supraspinatus tendon and joint labrum tear. The diagnosis can be determined. It may help to make secondary evaluation for clinical diagnose and provide imaging support for selection of clinical treatment.