Iey

FIGURE 4.24. Intraarticular osteoid osteoma. (A) Axial CT scan demonstrates a small intracortical nidus (arrow) surrounded by increased sclerosis. (B) Coronal T2-weighted fat-suppressed image reveals a semicircular focus of marrow edema in the medial aspect of the femoral neck. (C) Axial proton density fat-suppressed image demonstrates the small nidus (arrow) surrounded by marrow edema in the medial femoral neck.

FIGURE 4.25. Synovial osteochondromatosis. Axial Tl-weighted image from a low-field-strength scanner demonstrates multiple small low-signal loose bodies (arrows) in the medial joint.

FIGURE 4.24. Intraarticular osteoid osteoma. (A) Axial CT scan demonstrates a small intracortical nidus (arrow) surrounded by increased sclerosis. (B) Coronal T2-weighted fat-suppressed image reveals a semicircular focus of marrow edema in the medial aspect of the femoral neck. (C) Axial proton density fat-suppressed image demonstrates the small nidus (arrow) surrounded by marrow edema in the medial femoral neck.

FIGURE 4.25. Synovial osteochondromatosis. Axial Tl-weighted image from a low-field-strength scanner demonstrates multiple small low-signal loose bodies (arrows) in the medial joint.

Pigmented villonodular synovitis primarily occurs in adults and is typically a monoarticular process that is characterized by masslike proliferation of the synovium with associated elements of chronic or acute hemorrhage. Often, the disorder is associated with secondary erosive change in underlying bone or bone cyst formation. In the hip, erosive changes typically occur at the junction of the femoral head and neck (Figure 4.26) or acetabulum.72 Plain radiographs may demonstrate a joint effusion or paraarticular mass and erosive or cystic changes in the proximal femur or acetabulum. MR typically reveals paraarticular soft tissue masses that are commonly associated with bone erosions (Figure 4.26) and contain hemosiderin (decreased signal on Tl- and T2-weighted images).

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

Get My Free Ebook


Post a comment