作者单位:Univ British Columbia, St Pauls Hosp, Div Radiol, Vancouver, BC V5Z 1M9, Canada[1]Univ Laval, Inst Cardiol & Pneumol Quebec, Quebec Heart & Lung Inst, Quebec City, PQ, Canada[2]Univ British Columbia, St Pauls Hosp, Div Cardiol, Vancouver, BC V5Z 1M9, Canada[3]