A Study On Multi-slice Spiral CT Angiography In The Diagnosis Of Pulmonary Embolism And Deep Venvous Thrombosis Of Lower Extremities

Background and purpose:Pulmonary embolism(PE) is a common disorder associated with substantial morbidity and mortality.In America,PE is the third most common acute cardiovascular disease,after myocardial infarction and stroke.It was once thought that PE is a rare disease in China.However,it's not true by a series of autopsies over the last years,furthermore,it has a tendency to increase year by year.The mortality rate in untreated cases is 30% or so,whereas the mortality rate in treated cases decreases to 2%~8%.So,prompt and accurate diagnosis of PE greatly influences patient outcome.Being short of specific clinical manifestation it is notoriously difficult for PE to be detected earlier and treated in time.Actually,PE is not an isolated disease,but the most severe complication of deep venous thrombosis (DVT) of lower limbs,and the primary risk factor for recurrent PE is the presence of residual proximal venous thrombosis.Earlier diagnosis and timely treatment of DVT is the main method to prevent PE.Accurate diagnosis of PE and DVT of lower limbs depends on imaging tests.Historically,all clinically applicable imaging tests for thromboembolic disease examine the pulmonary arterial system separately from the lower limb veins,so a comprehensive evaluation of pulmonary embolism and deep venous thrombosis requires two separate examinations.It is especially inconvenient for dangerous period patients.Clinically,it is difficult to acquire PE and DVT imaging information at the same time.Combined CT venography and pulmonary angiography(CTVPA) can solve this problem effectively.Plasma D-dimer is sensitive to thromboembolic disease.The negative predictive value is...