The Evaluation Value Of CTPA Combined With D-dimer For The Severity Of Acute Pulmonary Embolism

ObjectiveTo evaluate the severity of acute pulmonary embolism(APE)by multi-slice spiral CT pulmonary angiography(CTPA)and plasma D-dimer.Methods174 patients with pulmonary embolism diagnosed by CT pulmonary angiography from January 2016 to June 2018 were collected.The patients who were suffering from lung mass or basic lung diseases were excluded from.At the same time,plasma D-dimer was measured before thrombolytictherapy,and the corresponding added value was calculated.A total of 149 cases accorded with the results.On CT pulmonary angiography,right ventricular/left ventricular diameter ratio(Rvd/Lvd)was calculated and divided into right ventricular remodeling negative group(n=95)and positive group(n=54)according to whether the value was more than 1.Pulmonary artery obstruction index(PAOI)was calculated by Philips post-processing workstation and Mastora score method to observe the location and degree of acute pulmonary embolism.ResultThe age range of 149 subjects ranged from 26 to 86 years with an average age of65.27±13.04 years,including 71 males and 78 females,132 over 50 years old and 17 under50 years old.1430 embolized arteries were analyzed and 1069 segmental arteries were found,of which 162,166,111,184 and 446 were embolized in 1-5,237 were involved in lobar arteries,of which 57,33,24,40 and 83 were embolized in 1-5 and 124 were involved in mediastinal arteries,of which 57,22,22,6 and 17 were embolized in 1-5.The plasma D-dimer concentration ranged from 0.70 mg/d L to 42.44 mg/d L with a median of 5.56mg/d L,and the corresponding increment ranged from 0.02 mg/d L to 41.78 mg/d L with a median of 3.88 mg/d L.PAOI ranged from 1% to 72%,with a median of 14%.The correlation analysis showed that the increase of plasma D-dimer concentration,pulmonary artery obstruction index and right ventricular/left ventricular diameter ratio were correlated(rs =0.210,P≤ 0.05;rs=0.562,P≤0.001);the increase of plasma D-dimer concentration was correlated with pulmonary embolism index(rs=0.408,P<0.001).There were signifycant differences in pulmonary artery occlusion index and plasma D-dimer concentration between positive and negative groups of right ventricular remodeling(Z=-7.978,P=0.000<0.05;Z=-2.549,P=0.011<0.05).Pulmonary embolism index and plasma D-dimer concentration in negative group of right ventricular remodeling were lower than those in negative group.When plasma D-dimer concentration increased by 1.58 mg/d L,the diagnostic sensitivity and specificity of right ventricular remodeling were 90.7% and 33.7%respectively.When the pulmonary artery occlusion index was 18%,the diagnostic sensitivity and specificity of right ventricular remodeling were 85.2% and 77.9%,respe-ctively.Conclusion256-slice CT pulmonary angiography can directly show the location and area of pulmonary embolism and the embolic area of each branch of blood vessel.It can reflect the severity of pulmonary embolism by measuring the ratio of the maximum diameter of right ventricle to left ventricle.At the same time,the pulmonary embolism index and the increase of plasma D-dimer concentration can also reflect the severity of pulmonary embolism.Therefore,the combination of plasma D-dimer concentration and CT pulmonary angiogramphy in the diagnosis of pulmonary embolism has higher sensitivity and accuracy,and can early reflect the severity of pulmonary embolism,providing more evidence for clinical treatment.