Sequential MRIs of the right pectoralis major muscle demonstrates an extensive partial thickness tear (arrows) commencing from the lower aspect of the muscle, almost involving its entire length.
An axial scan through the same area demonstrates fluid consistent with haemorrhage in the muscle defect. Importantly, the tendon inserting onto the humerus (orange arrow) is intact.
These injuries commonly occur during bench pressing, wrestling and football, with surgery required for extensive partial or full thickness tears if function and strength is to be preserved.
MRI is the best imaging modality that can determine the location and extent of the injury, as can ultrasound in experienced hands (1).
- Connell DA, Sherman MF, Wickiewicz TL. Injuries of the pectoralis major muscle: evaluation with MR imaging. Radiology. 210(3):785-91, 1999