OBJECTIVETo evaluate the clinical value of radionuclide bone scintigraphy in diagnosis of avascular osteonecrosis in patients with severe acute respiratory syndrome (SARS) in convalescence.

METHODSWe performed three-phase bone scintigraphy of femoral head regions and whole-body bone scan in SARS patients 4-6 months after they recovered from the syndrome, and then compared the results with simultaneous MRI.

RESULTSTypical avascular necrosis at different stages and severities was found on bone scintigraphy at 31 femoral heads of 16 SARS patients, 97% of which were MRI positive. Suspicious necrosis was found at 42 femoral heads of 23 patients, 67% of which were MRI negative. Among 30 patients with normal three-phase scintigraphic results, 10% of whom were suspicious on MRI. In addition, abnormal distributions of radioactivity were observed in other bones on the whole-body bone scans of 29 patients, including osteonecrosis of knees in 15 patients.

CONCLUSIONSRadionuclide bone scintigraphy is valuable in early diagnosis of osteonecrosis in SARS patients in convalescence. It provides a mutually supplementary tool for MRI.