Voxel-based Three-dimensional Segmentation of the Capsulo-synovium from Contrast-enhanced MRI Can Represent Clinical Impairments in Adhesive Capsulitis.

The purposes were to calculate total voxel volume of the entire capsulo-synovial enhanced portion on contrast-enhanced (CE) MRI in adhesive capsulitis, and to investigate its association with glenohumeral joint volume and passive range of motions (ROMs), which are a well-known diagnostic reference standard and clinical hallmark of this condition. Medical records of 169 consecutive patients who underwent ultrasound-guided intraarticular injection with adhesive capsulitis and CE-MRI to exclude other mimicking shoulder diseases were retrospectively reviewed. To calculate total voxel volume of entire capsulo-synovial enhanced portion on CE-MRI, voxel-based 3-dimensional (3D) segmentation was obtained semi-automatically using Fiji, an open-source image processing software. Pearson's correlation coefficients were analyzed. Sixty patients who met eligibility criteria were included. Total voxel volume showed a significant inverse correlation with the glenohumeral joint volume (r = -0.528, P < 0.001), forward elevation, external rotation, and abduction (r = -0.407, P = 0.001; r = -0.342, P = 0.007; r = -0.275, P = 0.034, respectively). Intra-observer and inter-observer reliabilities, measured by intraclass correlation coefficients (ICC), were excellent (ICC = 0.87 and 0.77, respectively). This study's results indicate that voxel-based 3D segmentation of entire capsulo-synovial enhanced portion from CE-MRI can represent the severity of clinical impairments, such as obliterated joint volume and limited passive ROMs in adhesive capsulitis.