The diagnostic value of dual energy CT pulmonary perfusion imaging for acute pulmonary embolism

MIAO Na; MENG Fanqi; HUANG Hao; CHEN Shiguang; WEN Zhiyong

doi:10.12122/j.issn.1674-4500.2025.04.10

Abstract：Objective To investigate the qualitative and quantitative diagnostic value of dual-source CT dual-energy pulmonary perfusion imaging(DEPI)for acute pulmonary embolism(APE).Methods A retrospective analysis was conducted on the dual-source CT pulmonary angiogram(CTPA)and DEPI-based reconstructed lung perfusion blood volume(PBV)images of 96 patients with suspected APE treated at our hospital from January 2021 to April 2024.Using expert panel interpretations as the reference standard,the impact of two physicians independently analyzing CTPA images versus combining DEPI with CTPA analysis on thrombus detection,while also the diagnostic consistency between the two physicians were compared and evaluated.Quantitative analyses were performed to compare the differences in perfusion CT and iodine density between normal lung tissues and those with varying severities of peripheral pulmonary embolism.ROC curves were plotted to compare the diagnostic efficiency of quantitative parameters for peripheral APE,and the DeLong test was used to assess differences.Results The retrospective analysis of CTPA and reconstructed Lung PBV images identified more peripheral pulmonary emboli than that of CTPA alone,with statistically significant differences in the detection of subsegmental emboli and the total number of emboli(P<0.05).The mean perfusion CT and iodine density values of fully occluded pulmonary tissues at the segmental and subsegmental levels were lower than those of partially occluded pulmonary tissues;the values for partially and fully occluded pulmonary tissues were both lower than those for normal pulmonary tissues;these pairwise comparisons all exhibited statistically significant differences(P<0.01).The diagnostic consistency between the two physicians was good when analyzing CTPA alone and was excellent when correlations were made with PBV images(Kappa=0.671,0.797).The ROC curve analysis of quantitative parameters showed that mean perfusion CT value and iodine density were two effective diagnostic indicators for APE.The diagnostic threshold for perfusion CT value was≤40 HU,with an AUC of 0.953,sensitivity of 86.16%,specificity of 99.31%,and Youden index of 0.8547.The diagnostic threshold for iodine density was≤1.7 mg/mL,with an AUC of 0.923,sensitivity of 83.74%,specificity of 98.62%,and Youden index of 0.8235.Conclusion The combined use of DEPI and CTPA can help detect more peripheral pulmonary arterial emboli.When DEPI is ordered,the mean perfusion CT and iodine density values of lung tissues can serve as effective diagnostic indicators for APE,with the mean perfusion CT value being more clinically significant in evaluating the condition.