Trends in use and yield of chest computed tomography with angiography for diagnosis of pulmonary embolism in a Connecticut hospital emergency department.

Rationale: We hypothesize that the ready availability of chest computed tomography (CT) scan, with angiography (CTA), for pulmonary embolism (PE) has resulted in its increased use in the emergency department (ED) with an associated decrease in positive studies.

Results: CTA for diagnosis of PE increased over 13-fold from 2000 to 2005. The diagnostic yield of CTA for PE decreased from 14% in 2000 to a mean (SD) of 7.2 (.91)% during subsequent years (P =.007). No significant change in yield occurred after 2001 (P = 0.51). Significantly more segmental and subsegmental embolisms were observed with the 16-slice CT in years 2004-2005 when compared to the single-slice CT used in years 2000-2003.

Conclusions: CTA for PE in our hospital ED has a low-positive yield rate, suggesting overutilization. However, the positive-yield rate remained steady despite increasing numbers of CTA, suggesting increased detection of PE and/or false-positive CTA.