MR imaging of the subcoracoid bursa.

Abstract

The subcoracoid bursa, a bursa anterior to the shoulder joint, can be identified on MR images. Awareness of the MR appearance and location of this bursa, which can connect with the subacromial-subdeltoid bursa, enables appropriate diagnosis in patients with shoulder pain. Dictated reports involving all MR imaging of the shoulder (n = 1545) performed at our institution from June 1993 to February 1998 were reviewed from computer archives. Films were reviewed in 16 cases describing a subcoracoid bursa; in nine MR imaging correctly revealed this bursa, whereas in seven MR imaging revealed the subscapular recess, an outpouching of the glenohumeral joint often confused with the subcoracoid bursa. Of the 1545 shoulders examined, MR imaging revealed the subcoracoid bursa in nine (0.6%) patients. Two cases from a teaching file were also included, for a total of 11 cases. In five (45%) of the 11 cases, the subcoracoid bursa contained a small amount of fluid (<1 cm in largest diameter on sagittal images). In the remaining six cases (55%), the subcoracoid bursa contained a moderate (1-2 cm in largest diameter) or a large amount (>2 cm in largest diameter) of fluid. Of the 11 cases, six (55%) also showed connection with the subacromial-subdeltoid bursa. It is important to correctly identify the subcoracoid bursa on MR imaging because it is believed to cause isolated shoulder pain. Fluid in the subcoracoid bursa can also communicate with the subacromial-subdeltoid bursa.