Incidence of pulmonary emboli on chest computed tomography angiography based upon referral patterns.

Pulmonary embolism (PE) is a potentially lethal condition, and the diagnosis of PE can be difficult. The purpose of this study is to evaluate the incidence of PE on chest computed tomography angiography (CTA) studies ordered in the inpatient, outpatient, and emergency department (ED) settings and further segregated based on the adult and pediatric populations, and by the ordering clinician (attending physicians, resident physicians, or physician extenders). A retrospective review of chest CTA examinations performed between July 1,2009 and June 30, 2010 was performed. Of 5848 adult CTA studies, PE was diagnosed in 594 (10.1 %). Of these positive studies, 315 (53 %) were inpatient, 234 (39.4 %) were ED patients, and 45 (7.6 %) were outpatient. Four hundred sixty-four of 4445 (10.4 %) CTA examinations ordered by attending physicians were positive for PE. Seventy-four of the 801 (9.2 %) CTA examinations ordered by resident physicians were positive for PE. Fifty-six of the 608 CTA examinations ordered by physician extenders were positive for PE. Thirty-three pediatric CTA studies for PE met criteria and none of them indicated PE. There is no significant difference in the incidence of PE in chest CTA based on setting or ordering clinician.