Abstract: Objective To explore the value of multi-slice spiral CT (MSCT) combined with magnetic resonance imaging (MRI) in the diagnosis and severity determination of shoulder joint injury. 
 Methods A total of 120 patients with suspected shoulder joint injury were selected to analyze the value of MSCT and MRI in diagnosing shoulder joint injury. 
 Results Eighty-nine patients with shoulder joint injury were diagnosed through arthroscopy. The sensitivity, accuracy, and negative predictive values of MSCT combined with MRI in the diagnosis of shoulder joint injury were 89.89%, 88.33%, and 74.29%, respectively, which were significantly higher than those of MSCT and MRI alone (P＜0.05). The consistency between MSCT combined with MRI in determining the severity of injury and arthroscopic examination results was high (Kappa value=0.864, P＜0.05), and the accuracy of MSCT combined with MRI in determining the severity of injury was 93.75%. Patients with shoulder joint injury had significantly shorter head to shoulder distance and smaller angle of the acromioclavicular joint and acromial angle measured by MRI compared to patients without shoulder joint injury (P＜0.05). The head to shoulder distance measured by MRI on the affected side was significantly shorter than that on the healthy side and that measured by MSCT (P＜0.05). The distance between the acromial and coronoid processes measured by MRI on the affected side was significantly greater than that on the healthy side (P＜0.05). The angle of the acromioclavicular joint measured by MSCT and MRI on the affected side was significantly smaller than that on the healthy side, and the acromial angle was significantly greater than that on the healthy side (P＜0.05). 
 Conclusion The combination of MSCT and MRI has good application value in the diagnosis and determination of shoulder joint injuries, and is worthy of clinical promotion and application. 

Key words: shoulder injuries, multi-detector computed tomography, magnetic resonance imaging