24 year old woman presents with right shoulder and left knee pain, without known trauma.
Right shoulder radiographs:
Left knee radiographs:
Radiograph Findings:
- Ephiphyseal curvilinear areas of sclerosis in the right humeral head, left distal femur, and left proximal tibia
- Left suprapatellar joint effusion
- No fracture or articular collapse
Bone Scan Findings:
- Increased peripheral radiotracer uptake in the distal femurs, proximal tibias, and right greater than left humeral heads
- Heterogeneous uptake throughout the long bones, especially the femurs and tibias
- Photopenic defects at bilateral femoral heads compatible with prior hip arthroplasty (with left greater than right reactive uptake at the acetabula)
- Round radiotracer activity in the left upper abdomen, compatible with splenic uptake
These are examples of classic findings in a patient with sickle cell disease, with prior episodes of avascular necrosis (resulting in sclerotic lesions and hip arthroplasty) and splenic infarctions (resulting in radiotracer uptake presumed due to associated microcalcification). This patient’s pain was believed to be due to recurrent avascular necrosis.
Avascular necrosis or osteonecrosis is one of the most common vaso-occlusive complications in patients with sickle cell disease. Imaging characteristics vary based on time of injury:
Immediate (onset – 48 hours):
- Tc99m sulfur colloid: photopenic defect in bone marrow
- Radiographs, Tc99m bone scan, and MRI are normal
Early stage (48 hours – 1 week):
- Radiographs: typically normal (with possible nonspecific osteopenia)
- Tc99m bone scan: photopenic defect
- MRI: bone marrow edema
Late stage (1-2 weeks onward):
- Radiographs: curvilinear sclerosis, “crescent sign” of subchondral lucency (denotes impending collapse)
- Tc99m bone scan: increased uptake peripherally and at the site of infarct
- MRI: “double line sign” of curvilinear hypointensity (sclerosis) and adjacent hyperintensity (edema/granulation tissue) on T2
Cerci SS, et al. Ann Nucl Med 2007;21:311-314.
Ziessman HA, O’Malley JP, Thrall JH, eds. Nuclear Medicine, the Requisites, 4th ed. Philadelphia: Elsevier, 2014.
Manaster BJ, May DA, Disler DG, ed. Musculoskeletal Imaging, the Requisites, 4th ed. Philadelphia: Elsevier, 2013.