16 week old male with swelling and pain and elevated inflammatory markers. Evaluate for myositis versus osteomyelitis. Again the proximal femoral metaphysis is noted to be displaced laterally from the acetabulum. This is moderate-sized intermediate T1 and T2 signal left hip joint effusion measuring at least 2.2 x 1.7 cm (series 1001, image 11) with synovial enhancement.Mildly increased focal T2 signal involving the distal left femoral metaphysis as noted on coronal STIR series 401, image 23; this region does not demonstrate abnormal enhancement and the overlying cortex is intact. There is extensive T2/STIR signal within the left gluteal and left thigh musculature compatible with inflammation/edema. The left thigh musculature and the left gluteal musculature demonstrates extensive enhancement compatible with myositis. In addition, there are multiple T1 hypointense and T2 hyperintense collections throughout the inferior gluteus medius, gluteus minimus, proximal hamstrings, and proximal anterior thigh musculature which demonstrate peripheral enhancement compatible with abscesses. The largest of these is in the gluteus medius and measures approximately 1.4 x 1.1 cm (cranial caudal and AP dimension as seen on series 1001, image 12).
1.Extensive left gluteal and thigh musculature myositis. No definite evidence of osteomyelitis. 2.Findings compatible with multiple abscesses in the left gluteal and proximal thigh musculature as detailed.3.Moderate sized complex appearing left hip joint effusion concerning for septic arthritis.