38-year-old male with MRSA bacteremia, recurrent fever, MRI pelvis (4/20) noted 3.0 x 1.8 cm abscess in the right obturator internus muscle, and MRI LS-spine (4/20) without evidence of discitis or osteomyelitis. BONE MARROW: There is edema type signal with enhancement of the right iliac bone extending to the acetabulum.SOFT TISSUE: There is marked abnormal T2 hyperintense signal and T1 intermediate signal throughout the course of the right obturator internus muscle extending from its origin to the insertion about the greater trochanter of the femur with rim enhancement. This signal intensity pattern immediately abuts the right iliac bone throughout its course. The collection is difficult to measure in its entirety given the irregular contour however for reference the largest component measures 6.1 cm x 3.5 cm and spans approximately 10 cm in craniocaudal dimension. There is surrounding soft tissue edema in the right hemipelvis as well as stranding within the proximal musculature of the right thigh.JOINTS: The hip joints appear within normal limits bilaterally. The sacroiliac joints are unremarkable.ADDITIONAL
Findings most compatible with an abscess within the right obturator internus muscle with high suspicion for osteomyelitis affecting the right iliac bone. Other findings as described above.