61-year-old male with mass. Evaluate for pseudotumor status post metal on metal hip Metallic artifact reduction protocol was used. Despite this, evaluation of the hip and surrounding tissues is limited by metallic susceptibility artifact from the patient's left total hip arthroplasty. Large collection of near-fluid signal intensity extending from the posterior aspect of the intertrochanteric region of the proximal femur through the soft tissues posterior to the greater trochanter to the lateral skin surface of the hip. The posterior component of this collection measures approximately 13.0 cm x 7.0 cm in transverse dimension and 7.5 cm in craniocaudal dimension. It is surrounded by a low signal intensity rim which could either represent hemosiderin or metal particle deposition. The collection also extends anterior to the hip joint into the iliopsoas muscle forming a collection that is approximately 4.0 cm x 3.5 cm in transverse dimension and 7.5 cm in craniocaudal dimension. There is also a lobulated collection of near fluid signal intensity within the supra-acetabular left ilium measuring approximately 4.0 cm in greatest dimension and correlates to a geographic lucent lesion on prior radiographs. On the fat suppressed T2 weighted images there is thin increased signal intensity within the intertrochanteric region of the femur along the lateral aspect of the femoral component that may represent the same disease process or simply artifact. The gluteus medius and gluteus minimus tendons can be followed to their insertions on the greater trochanter. Severe osteoarthritis affects the right hip and severe degenerative arthritis affects the visualized lumbar spine
Left total hip arthroplasty with adverse soft tissue reaction and focal osteolysis as described above.