Use of computed tomographic pulmonary angiography for the diagnosis of pulmonary embolism; are we overdoing it?

Background: computed tomographic pulmonary angiography (ctpa) is a gold standard test for the diagnosis of pulmonary embolism (pe),but is reported to be over prescribed. we performed this study to determine over prescription of ctpas at a district general hospital (dgh) in the united kingdom. our secondary aim was to establish a cause of its over-prescription.methods: we retrospectively reviewed clinical data of all patients who underwent ctpas during january 2011 to july 2013. collected data included ctpa findings,clinical probability score,d-dimer results,chest x-ray (cxr) findings and patient's demographic data. a calculation of overall clinical probability (including initial and post ctpa values) and its cross analysis with d-dimer,ctpa and cxr findings was made.results: pulmonary embolism was positive in 5 (11.6%) cases. an initial probability score was available in 16 (37.20%),and a d-dimer result was available in 33 (76.7%). chest x-ray (cxr) was abnormal in 8 (18.6%). a coupling of total probability score with d-dimer results (cppd) identified 10 (22.2%) potential over prescriptions. a further analysis of cppd with cxr revealed a definite over prescription of 8 (18.6%),whereas it increased the number of an overall possible over prescription to 14 (32.6%).conclusion: the ctpas are being over prescribed and the main reasons behind it are poor utilization of probability scoring systems,d-dimer rule and lack of interpretation of alternative diagnosis on cxrs.