The Clinical Relevance of Magnetic Resonance Imaging İncluding Subacromial Volume in Subacromial Impingement Syndrome: An MRI-Based Prospective Study.

Abstract

This prospective observational single-center study aims to investigate the relationship between magnetic resonance imaging (MRI) findings, including subacromial volume, with shoulder pain and function in patients with subacromial impingement syndrome (SIS). The study included patients aged 18-65 diagnosed with SIS and persistent complaints for at least six weeks. Pain intensity was measured using the Visual Analog Scale, and shoulder function was assessed with the Shoulder Pain and Disability Index (SPADI). MRI scans were reviewed by an experienced radiologist, analyzing tendon conditions, the critical shoulder angle, acromiohumeral distance (AHD), and subacromial bursa. Three-dimensional software was used to calculate subacromial volume, which was defined as the space between the inferior surface of the acromion and the humeral head cartilage, segmented manually across consecutive sagittal images. There were no significant correlations between MRI findings, including subacromial volume, and demographic factors, symptom duration, pain, or functional scores. Patients with diabetes mellitus (DM) had significantly lower subacromial volume (<i>p</i> = 0.011). Infraspinatus tendinopathy showed higher SPADI pain scores and shorter symptom duration. A statistically significant positive correlation was observed between subacromial volume and AHD (<i>p</i> < 0.001). A statistically significant negative correlation was observed between subacromial volume and acromial spur (<i>p</i> = 0.035). There was no correlation between subacromial volume and other MRI parameters. Our study revealed no correlation between subacromial volume and clinical symptoms or function, supporting the notion that MRI may have limited value in routine SIS evaluation. Subacromial volume was significantly lower in DM individuals, which may suggest a specific subgroup worth further investigation.