ABSTRACT
Objective To evaluate the correlation between CT perfusion blood volume (Lung PBV)and the degree of pulmonary embolism by CT pulmonary angiography (CTPA).Methods 1 65 patients with suspected pulmonary embolism underwent dual-ener-gy CT angiography,then the Lung PBV iodine distribution was analyzed by using a software algorithm.Consistent CTPA results evaluated by two experienced radiologists were taken as standard reference.After two months,the CTPA images were assessed by other two radiologists at random.The position and the number of perfusion defects,and (or)hypoperfusion were recorded.Results Of all 1 65 suspected patients,41 were diagnosed as pulmonary embolism with involved 1 64 segment arteries including part occlusion in 56 and complete occlusion in 108.Lung PBV showed perfusion defect in 141 pulmonary segment including 42 in patients with part occlusion and 99 in ones with complete occlusion.1 7 pulmonary segments were misdiagnosed with part occlusion in 9 and complete ones in 8.23 segments were misdiagnosed including part occlusion in 14 and complete ones in 9.The perfusion defect of Lung PBV was correlated to CTPA moderately or well (to part occlusion with r =0.508 and P =0.022;to complete ones with r =0.905 and P =0.000).Conclusion Dual-energy lung perfusion imaging is helpful for accurate assessment of abnormal blood flow distribution caused by pulmonary embolism,and improve the diagnosis.