Female 23 years old with history of septic shock, unknown source, evaluate for abscess versus tissue necrosis in gluteal region, PET scan demonstrates bilateral right greater than left decreased activity within the gluteal musculature with peripheral increased activity Diffuse edema with increased T2 signal throughout the gluteal musculature and soft tissues bilaterally. A fluid collection is noted measuring up to 14 x 48 mm in the area of the right gluteus minimus/maximus muscles (601/29).Bilateral iliacus and iliopsoas muscle enhancement as well as diffuse and heterogeneous enhancement of the gluteal muscles, which appears more severe on the right, with central areas of decreased enhancement measuring up to 47 x 99 mm on the right (901/20) and 36 x 61 mm on the left (901/22). These regions correspond to areas of decreased FDG uptake on recent PET and are consistent with necrosis. Surrounding subcentimeter necrotic areas with rim enhancement are also noted within the gluteal musculature and to a lesser extent along the coccyx.Decreased T1 signal within the marrow of the iliac bones, right greater than left, with corresponding increased T2 signal. Additional areas of decreased T1 signal along the greater trochanters and lateral aspects of the bilateral femoral heads are also noted.Small bilateral hip effusions noted. Rectal tube in place. Distended bladder containing foci of gas.
1. Diffuse soft tissue edema with heterogeneous enhancement of the bilateral gluteal, iliacus, and iliopsoas muscles. Large central areas of necrosis within the gluteal muscles are noted bilaterally with multiple surrounding subcentimeter abscesses. An additional 1.5 x 5 cm fluid collection is also noted within the right gluteal musculature.2. Underlying osseous involvement of the iliac bones, right greater than left, suspicious for osteomyelitis. The greater trochanters and lateral aspects of the femoral heads are also involved to a lesser extent.