Multiplanar and multiaxial contrast-enhanced MRI of the right hip confirms an expansile, multiseptated, mixed cystic and solid (fatty) intraosseous lesion within the right quadrilateral plate, posterior acetabulum column extending into the right ischial tuberosity and inferior pubic ramus. There is a peripheral ring-like enhancement relating to the cystic components of the lesion. The solid fatty component is non-enhancing with fibrous septations. There is cortical thinning however no disruption or pathological fracturing. There is no extraskeletal or soft tissue involvement. There is no periosteal reaction.
Incidental bilateral hip effusions. MRI pelvis is otherwise unremarkable.