Abstract:
Objective To investigate the diagnostic value of X-ray digital tomosynthesis (DTS) imaging in subacromial impingement syndrome (SIS) at supraspinatus exit position.
Methods A retrospective analysis was performed on patients who were admitted to Bayannur Hospital from July 2017 to January 2020. The clinical and imaging data of 93 SIS patients with shoulder joint discomfort who were diagnosed by clinical physical examination and MRI examination were included. The participants included 56 males and 37 females, aged 30−77(55.4±8.2) years. All patients underwent digital radiography (DR) and DTS imaging within 7 days after MRI examination to determine whether acromioplasty or rotator cuff reconstruction was necessary. Nonparametric rank sum test was used to compare the morphological differences of acromion measured by three imaging methods, analysis of variance was used to compare the measured acromio-humeral interval (AHI), and least significant difference (LSD)-t test was used for further pairwise comparison. The area under the curve (AUC), sensitivity and specificity of AHI measured by MRI, DTS and DR were calculated by the receiver operator characteristic (ROC) curve, and the AUCs were compared by Z test.
Results MRI, DR, and DTS imaging methods had no significant difference in the results of acromion morphology examination in SIS patients (χ2=2.84, P>0.05). In the measurement of AHI in SIS patients, there was significant difference in AHI measured by MRI, DR and DTS ((8.37±1.21) mm vs. (8.91±1.50) mm vs. (8.66±1.25) mm, F=3.84, P<0.05). Pairwise comparison of the differences of AHI measured by three examination methods showed that the differences between MRI and DR were statistically significant (t=−2.69, P<0.05), but there were no significant difference between MRI and DTS, DR and DTS (t=−1.60, 1.24; both P>0.05). The sensitivity of MRI, DTS and DR in diagnosing AHI were 96.35%, 96.36% and 86.79% respectively, and the specificity were 72.44%, 58.28% and 54.73% respectively. The AUCs of AHI measured by MRI, DTS and DR were 0.906, 0.808 and 0.677 respectively, the 95%CI were 0.839−0.951, 0.727−0.874 and 0.586−0.760 respectively, and the difference between them was statistically significant (Z=3.01, P<0.05).
Conclusion Supraspinatus exit position DTS is a relatively economical and practical imaging method for diagnosis of SIS, and it can be used as a screening method for patients with shoulder discomfort.