Coronal T1-weighted MRI of the pelvis demonstrating bilateral osteonecrosis (avascular necrosis) of the femoral heads. The image reveals heterogeneous signal intensity and irregular morphology within both femoral heads. White arrows highlight areas of subchondral collapse, which is most pronounced on the left side, where there is a clear loss of the normal spherical contour of the femoral head. These findings are consistent with advanced-stage osteonecrosis leading to articular surface fragmentation and secondary degenerative joint disease (osteoarthritis) of the hip. The pelvic girdle, including the acetabula and surrounding soft tissues, shows signs of chronic remodeling associated with altered joint mechanics. This diagnostic image serves as a clinical example of the progression from bone marrow ischemia to structural joint failure in a patient with systemic risk factors such as hemochromatosis.

This diagnostic image is a coronal view Magnetic Resonance Imaging (MRI) of the pelvis, primarily demonstrating bilateral avascular necrosis (AVN) of the femoral heads. Both femoral heads exhibit characteristic serpiginous, low-signal intensity lines circumscribing the infarcted areas, consistent with late-stage osteonecrosis. There is evidence of significant structural progression, including an advanced loss of joint space and articular cartilage bilaterally. A yellow arrow points specifically to a subchondral collapse at the superolateral aspect of the left femoral head, indicating secondary osteoarthritis and joint surface irregularity. Surrounding soft tissues show evidence of complex effusions and synovial thickening, potentially indicating secondary synovial osteochondromatosis. Additionally, the image displays diffuse muscular oedema and atrophy of the surrounding pelvic and proximal thigh musculature, most notably in the right rectus muscle. This visual material is clinically relevant for orthopedic surgical planning, such as total hip arthroplasty, and for teaching the radiological hallmarks of Stage IV/V avascular necrosis using the Ficat or Steinberg classification systems.

This composite of three Magnetic Resonance Imaging (MRI) scans—comprising coronal (A), axial (B), and sagittal (C) views—demonstrates bilateral avascular necrosis (AVN) of the femoral heads at varying stages. The right femoral head (indicated by white arrows) exhibits features consistent with Grade 3 AVN, characterized by significant low-signal intensity (sclerosis) in the weight-bearing region, subchondral collapse, and subtle flattening of the articular contour. In contrast, the left femoral head demonstrates Grade 2 AVN, showing focal areas of marrow signal alteration and a well-defined 'double-line sign' or sclerotic rim, but with a relatively preserved spherical shape and no evidence of articular surface depression. These images illustrate the radiological progression of osteonecrosis of the hip, highlighting the transition from early marrow edema and focal lesions to mechanical subchondral failure. The series serves as an educational tool for differentiating Ficat and Arlet or Steinberg stages of femoral head necrosis using multi-planar cross-sectional imaging.