Diagnostic Value Of Dual Energy CT Lungperfusion Imaging Combined With CT Pulmonary Angiography In Patients With Pulmonary Embolism

Objective: To investigate the diagnostic value of dual energy CT lung perfusionimaging (DEPI) combined with CT pulmonary angiography(CTPA) in patients withpulmonary embolism.Methods:130consecutive patients suspected of having PE underwent CT pulmonaryarteriography with dual-energy technique on the dual source CT scanner CT pulmonaryarteriography(CTPA) and perfusion blood volume (PBV)images after post-processing ofthe raw data were obtained.Evaluation of the PBV image quality and typing of PE wereperformed by two radiologists as well as to observe the presence, location, extent of PE.The PBV appearances and its relationship with CTPA images as well as pulmonaryparenchyma abnormities were analyzed, The consistency of the2observers in evaluatingthe PBV image quality and typing were examined by Kappa value. The sensiticity,specificity, positive predictive value (PPV) and negative predictive value (NPV) of PBVimages for the diagnosis of PE were calculated.Result: The ranking of PBV inage quality and typing showed very good agreementbetween two observers, the K value was0.79and0.82, respectively (P<0.05)。Thesensitivity, specificity, PPV and NPV of PBV for the diagnosis of PE were90.0%,9.1%,15.3%and83.3%. Most of the complete filling defedts in segmental andsubsegmental pulmonary arteries in CTPA associated with perfusion defects in CTpurfusion map. While partial filling defects in CTPA often coincided with partialperfusion defects in DEPI and segmental perfusion defects in DEPI without filling defectbecause of lung disease.Conclusion: Abnormalities caused by pulmonary blood flow changes induced by PE could be displayed by PBV with dual energy pulmonary perfusion imaging on dual sourceCT. The combination of CTPA and DEPI will offer more information in the diagnosis ofthe pulmonary embolism.