The bilateral iliac bones, proximal femurs, ischii , and right sacral ala are markedly abnormal with diffuse abnormal marrow signal intensity, sparing the pubic bones. The involved osseous structures demonstrate heterogeneously hyperintense fluid-sensitive signal intensity with heterogeneously avid enhancement on postcontrast imaging.
There is a moderate-sized effusion within the left femoroacetabular joint, and mild effusion on the right. There is enhancement of these effusions with contrast.
The muscles about the left hip demonstrate enhancement and fluid signal intensity involving the anterior compartment musculature, adductors, gluteal muscles and iliacus muscle.
A well circumscribed mass measuring 2.8 x 1.5 cm is observed between the right iliac bone
and right iliacus muscle on the large field of view coronal images. This mass is isointense to skeletal muscle on T1, hyperintense on T2, and demonstrates avid contrast enhancement. There is also a soft tissue mass measuring 3.1 x 2.2 cm located posterior to the left femur, centered with the adductor compartment of the left hip which demonstrates increased STIR signal intensity and mild enhancement.