Magnetic resonance imaging findings in patients with polymyalgia rheumatica

To describe the prevalence of magnetic resonance imaging (MRI) findings in patients with the clinical diagnosis of polymyalgia rheumatica (PMR).

Sixteen consecutive patients with untreated PMR, meeting the American College of Rheumatology criteria, underwent MRI examinations of the shoulder(s), hip(s), or both, depending on clinical complaints. Six patients also underwent MRI of the spine.

We evaluated 24 shoulders, among which we identified subacromial-subdeltoid bursitis in 21 (87.5%), glenohumeral joint effusion in 17 (70.8%), and fluid distention of the long head of the biceps tendon sheath in 15 (62.5%). Peritendinitis and capsular edema were observed in 21 (87.5%) and 17 (70.8%) shoulders, respectively. We also evaluated 17 hips, identifying hip joint effusion in 12 (70.6%), trochanteric bursitis in 11 (64.7%), peritendinitis in 17 (100%), and capsular edema in 14 (82.4%). All six of the patients who underwent MRI of the spine were found to have interspinous bursitis.

Subacromial-subdeltoid bursitis, glenohumeral joint effusion, and hip joint effusion are common findings in patients with PMR. In addition, such patients appear to be highly susceptible to peritendinitis and capsular edema. There is a need for case-control studies to validate our data and to determine the real impact that these findings have on the diagnosis of PMR by MRI.