Clinical Value Of CT Pulmonary Angiography Combined With Plasma D-dimer Detection In Diagnosis Of Pulmonary Embolism

Objective: To investigate the clinical value of CTPA combined with plasma D-dimer level in the diagnosis of pulmonary embolism.Methods: 492 patients with suspected pulmonary embolism were selected and underwent CTPA examination in our hospital from August 2017 to August 2018.The CTPA images were analyzed and divided into pulmonary embolism group and non-pulmonary embolism group according to the diagnostic criteria of CTPA.The pulmonary embolism group was further divided into massive pulmonary embolism group and Non-massive pulmonary embolism group according to the scope of embolism.All patients underwent plasma D-dimer test at the same time and recorded the results.Independent sample t-test was used to compare the difference of plasma D-dimer values between CTPA groups and those of other groups.The sensitivity,specificity,positive predictive value and negative predictive value of D-dimer in the diagnosis of pulmonary embolism were evaluated with CTPA as the golden standard.Results: 200 patients in 492 patients were diagnosed as pulmonary embolism by CTPA and 1081 pulmonary arteries were involved,including 204 complete filling defects and 877 incomplete filling defects;159 patients with pulmonary embolism had plasma D-dimer value > 0.5ug/mL;and 113 patients without pulmonary embolism had plasma D-dimer value > 0.5ug/mL.2.There were significant differences in plasma D-dimer values between patients with pulmonary embolism and patients without pulmonary embolism diagnosed by CTPA(3.26±1.54)ug/mL and(1.38±0.94)ug/mL,t=-2.804,P =0.005].There were no significant differences in plasma D-dimer values between Massive pulmonary embolism group and non-massive pulmonary embolism group(5.77 ± 2.52)ug/mL and(1.38 ± 1.17)ug/mL,t = 2.64,P = 0.095].3.Thesensitivity,specificity,positive predictive value and negative predictive value of D-dimer in the diagnosis of pulmonary embolism were 79%,61%,50% and 81% respectively.Conclusion: CTPA combined with plasma D-dimer can improve the early diagnosis rate of pulmonary embolism and also reduces the rate of misdiagnosis or missed diagnosis.