动态肺灌注显像联合常规肺灌注显像结合肺通气显像在急性肺栓塞的初步临床研究

A preliminary study on the diagnostic value of dynamic pulmonary perfusion imaging combined with V/Q scan in acute pulmonary embolism

目的:探讨动态肺灌注显像(DPPI)联合V/Q显像对急性肺栓塞(PE)患者诊断价值的初步研究。方法:回顾性分析2020年6月至2021年6月期间,首次在我科行动态肺灌注显像(DPPI)和肺通气/肺灌注显像断层显像(V/Q SPECT)可疑PE的患者,并排除慢性PE、慢性肺部疾病、既往肺动脉高压的患者,最终107例可疑急性或亚急性PE患者纳入本次研究。在DPPI图像上勾画肺的感兴趣区,计算肺平衡时间(LET)。根据V/Q SPECT评估肺灌注缺损占总肺灌注容积的百分比(PPD%)。经临床诊断将患者最终分为PE组和非PE组。分析比较两组间LET、PPD%。结果:最终43例患者临床确诊为急性PE;64例为非PE。PE组下肢静脉血栓发生率和D-Dimer数值均明显高于非PE组(P<0.05),LET时间明显延长(P=0.003);PPD%明显大于非PE组(P=0.001)。通过ROC曲线获得DPPI诊断肺栓塞的LET的最佳界值为24.5s,以LET<24.5s判断为非PE,以LET≥24.5s为PE。V/Q诊断PE灵敏度88.4%(38/43),特异性75.0%(48/64),准确度为80.4%(86/107),阳性预测值70.4%(38/54),阴性预测值90.6%(48/53)。但V/Q显像有11例患者属于不能明确诊断。应用LET最佳界值判断7例可排除PE,而其余4例判断为PE,V/Q显像联合DPPI后诊断PE的灵敏度93.0%(40/43),特异性71.9%(46/64),准确度为80.4%(86/107),阳性预测值69.0%(40/58),阴性预测值93.8%(46/49)。结论:动态肺灌注显像在传统的V/Q显像的基础上,增加了一项评价肺动脉血流动力学的参数,且没有额外增加患者辐射剂量,在V/Q不能明确诊断时,DPPI能评估患者的血流动力学改变,提高对PE的诊断效能。

Objective:To explore the diagnostic value of dynamic pulmonary perfusion imaging(DPPI)combined with V/Q scan in patients with acute pulmonary embolism(APE).Methods:Patients who underwent DPPI and V/Q SPECT from June 2020 to June 2021 were retrospectively enrolled.Patients with chronic PE,chronic pulmonary diseases,and previous pulmonary hypertension were excluded,and finally a total of 107 patients were included in this study.The lung equilibrium time(LET)was calculated by drawing the region of interest of both lungs on DPPI.The percent of pulmonary perfusion defect(PPD%)was estimated by V/Q SPECT.According to the clinical diagnosis,the patients were divided into PE group and non-PE group.The differences of LET,PPD%and parameters by echocardiography between the two groups were compared.Results:Forty-three patients were clinically diagnosed as PE and 64 patients were non-PE.The D-dimmers and the incidence of lower limb venous thrombosis in the PE group were significantly higher than those in the non-PE group(P<0.05).The LET of the PE group was significantly longer than that of the non-PE group(P<0.003),and the PPD%of the PE group was significantly higher than that of the non-PE group(P<0.001).However,there was no significant difference in echocardiography parameters between the two groups(P>0.05).According to the ROC curve,the best cut-off value of LET for diagnosing PE was 24.5s.LET<24.5s was regarded as non-PE,and LET≥24.5s as PE.The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of V/Q in the diagnosis of PE were 88.4%(38/43),75.0%(48/64),80.4%(86/107),70.4%(38/54),and 90.6%(48/53),respectively.However,there were 11 patients whose were nondiagnostic for PE by V/Q imaging.According to the optimal cut-off value of LET,7 cases could exclude PE,while the other 4 cases could be judged as PE.The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of V/Q combined with DPPI in the diagnosis of PE were 93.0%(40/43),71.9%(46/64),80.4%(86/107),69.0%(40/58),and 93.8%(46/49),respectively.Conclusions:On the basis of V/Q imaging,the LET obtained by dynamic pulmonary perfusion imaging could be a crucial role to comprehensively evaluate the hemodynamic of patients,especially for nondiagnostic patients.And improve the diagnose efficiency of PE,without extra radiation exposition.