ABSTRACT
Objective To analyze the causes and manifestations of non-pulmonary embolism induced perfusion defects (PDs) on dual-energy perfusion imaging (DEPI) using dual source CT.Methods Consecutive 208 patients without pulmonary embolism who underwent DEPI were reviewed retrospectively.The causes of PDs were analyzed by two radiologists, the pulmonary segment numbers, the proportion and the perfusion patterns of each case were recorded and analyzed respectively.Results 1 118 of 3 716 pulmonary segments showed the PDs.Among them, 752(67.26%), 36(3.22%), 308(27.55%) and 22(1.97%) pulmonary segments had PDs due to intra-pulmonary lesions, vascular diseases, artifacts and unidentifiable causes, respectively.In PDs resulted from intra-pulmonary lesions, vascular diseases and unidentifiable causes, three patterns (wedge-shaped, heterogeneous and regionally homogeneous) were identified,and most of those PDs were heterogeneous and regionally homogeneous, which were largely in accordance with the lesions showed on non-contrast enhanced scans.Artifacts included the beam hardening artifacts and artifacts caused by heart beat or diaphragmatic movement.The PDs caused by artifacts usually had particular locations and shapes.Conclusion Understanding of the manifestations and causes of PDs in patients without pulmonary embolism can improve the diagnosis accuracy of pulmonary embolism on DEPI.