Pain. Left hamstring avulsion? There is thickening of and branching increased signal intensity within the proximal semimembranosus tendon. Some fibers of the semimembranosus can be followed to their origin high on the superolateral facet of the ischial tuberosity; however, there is new fluid signal intensity/edema partially separating the tendon from the tuberosity and extending down the free semimembranosus tendon and along the medial aspect of the semitendinosus muscle. Edema continues caudally along the semimembranous muscle belly, although I see no frank edema within the muscle itself. Edema also courses laterally from the tendon to surround the sciatic nerve, but the nerve itself appears normal. Additional interfascial edema is noted between the quadratus femoris and proximal adductor magnus muscle. The adductor magnus tendon can be followed to the ischial tuberosity. The conjoined tendon shows intermediate signal intensity suggesting tendinosis but can be followed to its origin on the inferomedial facet of the ischial tuberosity. The sacrotuberous ligament appears intact. The marrow signal intensity of the ischium is normal. There is thickening of the distal tendon of the rectus femoris due to an old injury. The remaining musculature of the proximal left thigh is unremarkable. The left hip joint appears normal for age.On the large field-of-view images, the right hip joint and right hamstring complex appear normal for age. There is a lipoma between the right gracilis muscle and the remaining adductor musculature.
Imaging findings are compatible with with an atypical or "stretching" type strain injury of the posterior thigh, including partial avulsion of the semimembranosus tendon, as described by Askling et. al. (Am J Sports Med, 2007, volume 35, page 1716).I personally reviewed the Images and/or procedure with the Resident/Fellow and agree with this report.