49-year-old female with spontaneous hemorrhage of the thenar muscles. Evaluate for intramuscular hemangioma. Best seen on the T2-weighted images, is mild increased signal intensity, suggesting mild edema within the thenar musculature, suggesting a strain injury. There is also minimal enhancement along the deep fibers of the thenar musculature, but we see no hematoma or mass to suggest an underlying vascular malformation. There is also enhancement along the volar aspect of the first metacarpal phalangeal joint, which may reflect a capsular sprain, but we see no discrete ligamentous tear or fracture. There is also a small amount of fluid and enhancement within the first metacarpophalangeal joint which may reflect a mild synovitis. The flexor pollicis longus tendon appears intact. The remaining of the visualized bones and soft tissues are normal.
Mild edema and enhancement along the thenar musculature and volar aspect of the first metacarpal phalangeal joint may reflect a mild muscle strain and capsular sprain, respectively. We see no hematoma or underlying mass, such as a vascular malformation.