32O-row CT Combined With D-dimer In Evaluating The Severity Of Pulmonary Embolism And Analysis Of Risk Factors Of PE

Objective:To explore the value of 320-row CT combined with D-dimer.for evaluating the severity of pulmonary embolism,and to analyse clinical risk factors of pulmonary embolism,which may provide evidence for clinical diagnosis,treatment and prognosis.Methods:95 patients with suspected pulmonary embolism in our hospital were collected.Among them,59 patients were diagnosed with pulmonary embolism(observation group)and 36 patients without pulmonary embolism(control group).According to the Qanadli score,pulmonary embolism index(PAOI)were calculated.On this account the observation group were further divided into 3 groups,pulmonary embolism index ?50%as the group A(n = 40),50%?80%as the group B(n = 12),?80%as the group C(n = 7).?The clinical features were recorded to analyse clinical risk factors of PE.?To analyse the ability of PAOI to assess the severity of new pulmonary lesions after pulmonary embolism.?In CTPA,To analyse the differences between the observation group and the control group of the right ventricular function parameters[the right ventricular short axis maximum diameter(RVd),the left ventricular short axis maximum diameter(LVd),the right ventricular/left ventricular short axis maximum diameter ratio(RVd/LVd),the main pulmonary artery(PA)and the superior vena cava(SVC)],and the differences were compared in the observation group.?Twenty patients underwent CT perfusion imaging.Both in perfusion defect area and contralateral normal lung parenchyma,the pulmonary flow PF,bronchial flow BF,and perfusion index[PI=PF/(PF+BF)]were recorded,comparing the differences between the two groups.?To analyse the differences between the observation group and the control group of D-dimer value and arterial oxygen partial pressure,and to evaluate the negative predictive value and positive predictive value of D-dimer in the diagnosis of pulmonary embolism.Datas was analyzed via the SPSS 19.0 statistics software,and for all the tests p<0.05 was considered as statistically significant difference between the data.Results:1.Multivariate logistic regression analysis showed that venous thrombosis of the lower extremities(OR=4.323;95%CI:1.050?17.801;P=0.043),age(OR=1.065;95%CI:1.023?1.109;P=0.002),and gender(OR = 3.101;95%CI:1.077?8.930;P=0.036))are the clinical risk factors for PE.2.New pulmonary lesions after pulmonary embolism appeared in 23 patients,and venous thrombosis in the lower extremities as the underlying disease took the largest proportion,which accounted 19 cases(82.61%).There were 13 cases(32.50%)of new lung lesions and 0 cases(0%)of pulmonary infarction in group A,4 cases(33.33%)of new lung lesions and 3 cases(25.00%)of pulmonary infarction in group B,6 cases(85.71%)of new lung lesions and 3 cases of pulmonary infarction(42.86%)in group C;By ROC curve analysis,when PAOI1>36.25%,the sensitivity and specificity in evaluation pulmonary lesions after pulmonary artery embolization were the highest,which were 85.7%and 43.3%respectively,and the AUC was 0.716,P<0.01;when PAOI2>68.75%,the sensitivity and specificity in evaluation pulmonary infarction were the highest,which were 85.7%and 90.0%respectively,and the AUC was 0.898,P<0.01.3.In the observation group,patients with bilateral pulmonary arteries embolism took the majority part(41 cases);23 patients appeared new pulmonary lesions after pulmonary embolism,including 19 patients with bilateral pulmonary arteries embolism(15 cases left and right pulmonary artery trunk involved,4 cases the following pulmonary trunk involvded);6 patients with pulmonary infarction had the left and the right pulmonary artery trunk involvded.4.The assessment of right ventricular function parameters:The RVd,LVd,RVd/LVd,and PA in the observation group were higher than those in the control group,and the difference was statistically significant(P<0.01).The differences of RVd and RVd/LVd among observation group were statistically significant(P<0.01),and the difference of LVd and PA between group A and group C was statistically significant(P<0.05).The other indicators had no significantly difference among the groups(P>0.05);Spearman correlation analysis showed that there was a significant correlation between RVd/LVd and pulmonary embolism index,and the correlation coefficient was 0.649(P<0.01);The results of ROC curve analysis showed the area under the ROC curve of RVd/LVd was the largest,0.877(P<0.01).When the value of RVd/LVd was taken as 1.01,diagnosing the severity of pulmonary embolism was the highest,the sensitivity 76.5%and the specificity 95.8%(P<0.01).5.Compared with the parameters of pulmonary embolism perfusion defect area and contralateral normal perfusion area,PF in these two areas had statistically significant difference(P<0.05).BF and PI in these two areas had no significant difference(P>0.05);There was no linear correlation between PF and PAOI in pulmonary embolism perfusion defect area(P>0.05).6.Using CT pulmonary artery imaging and CT perfusion imaging as reference standards,the negative predictive value of D-dimer was 100%and the positive predictive value was 89.39%.There was no correlation between D-dimer and PAOI in observation group(P>0.05).7.The oxygen partial pressure(PO2)of the observation group was lower than that of the control group,and the difference was statistically significant(P<0.01).Conclusion:1.320-row CT combined with D-dimer values contribute to increase the diagnostic rate of pulmonary embolism and assessment of severity.2.The clinical risk factors of pulmonary embolism are lower extremity venous thrombosis,age and sex.