title: [Report on the investigation of lower extremity osteonecrosis with magnetic resonance imaging in recovered severe acute respiratory syndrome in Guangzhou].
abstract: OBJECTIVE
  To report the occurrence of lower extremity avascular abnormalities in 124 cases of recovered severe acute respiratory syndrome (SARS) health care workers of four hospitals in Guangzhou and preliminary investigate the correlation with the treatment of steroid.
  
  
  METHODS
  124 health care workers with recovered SARS from four hospitals in Guangzhou were examined with MR imaging of the lower extremity including bilateral hips and knees. In 124 health care workers, 38 cases have not treated with steroid, while 86 cases have treated with varied dosage. The imaging protocol was consisted of screening and full examination. Coronal T1-weighted imaging and short tau inversion recovery sequence were defined as the screening examination. The full examination was defined as images from the screening examination plus three additional imaging sequences: transverse and coronal T2-weighted imaging and short tau inversion recovery sequence.
  
  
  RESULTS
  In 86 health care workers, 5 cases were found positive in the lower extremity. Osteonecrosis was found in 3 cases. One was involved in bilateral femoral head, and another was unilateral femoral head, and the remaining one was bilateral femoral heads and unilateral femoral condyle and tibial condyle. Bilateral femoral and tibial marrow edema were found in one case. Femoral infarction with significant calcification occurred in one health care worker. Logistic regression analysis indicated that the presence of avascular abnormalities was related with maximum daily dosage.
  
  
  CONCLUSIONS
  Osteonecrosis definitely exists in the minority of health care workers with recovered SARS in Guangzhou, who had treated with steroid. The maximum daily dosage of steroid may significantly influence on the occurrence of avascular abnormalities.
authors.affiliation: Department of Radiology, 2nd Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Shen
authors.forename: Bi-ling
authors.initials: BL
authors.lastname: Liang
authors.forename: Qing-si
authors.initials: QS
authors.lastname: Zeng
authors.forename: Jian-yu
authors.initials: JY
authors.lastname: Chen
authors.forename: Qing-yu
authors.initials: QY
authors.lastname: Liu
authors.forename: Rong-chang
authors.initials: RC
authors.lastname: Chen
authors.forename: Nan-shan
authors.initials: NS
authors.lastname: Zhong
mesh_terms: D000293:Adolescent; D000328:Adult; D002681:China / Q000453:epidemiology; D003289:Convalescence; D005260:Female; D005271:Femur Head Necrosis / Q000139:chemically induced / Q000453:epidemiology / Q000517:prevention & control; D006801:Humans; D035002:Lower Extremity; D008279:Magnetic Resonance Imaging; D008297:Male; D008403:Mass Screening; D008775:Methylprednisolone / Q000009:adverse effects*; D008875:Middle Aged; D010020:Osteonecrosis / Q000139:chemically induced* / Q000453:epidemiology* / Q000517:prevention & control; D045169:Severe Acute Respiratory Syndrome / Q000188:drug therapy*
chemical_list: D008775:Methylprednisolone