Incidental findings on emergency CT scans: predictive factors and medico-economic impact

Abstract Purpose The main objective was to evaluate types and predictive factors of incidental findings (IFs) on multidetector computed tomographies (MDCTs) performed for an emergency department (ED). The secondary aim was to analyze additional investigations, their benefits, side effects, costs and the final diagnoses. Method One thousand consecutive patients over 18 years old who underwent an MDCT in the ED of our institution from January 2011 to November 2011 were retrospectively included, accounting for 300 head MDCTs and 700 other MDCTs. The following criteria were collected in patient electronic medical records: IFs (divided into low and high clinical significance), body areas covered, availability of a prior imaging, radiologist’s experience and subspecialty, additional investigations, their outcomes and costs. Results Among the 1000 included patients, 232 had at least one IF and 122 had at least one IF of high clinical significance (IFCS). There were 340 IFs and 150 IFCSs. A significant association with the presence of at least one IF was noted for older patients, less-experienced radiologists, no subspecialty of the radiologist, the abdominopelvic area, and the absence of prior imaging. Eighteen IFs generated additional investigations in our institution, including five invasive samplings and three surgical operations, with two diagnoses of malignancy (a gastrointestinal stromal tumor and a Bosniak IV cystic renal lesion). One benign iatrogenic complication occurred. Total cost of these investigations was €41,247 (with an average of €2292 per IF investigated). Conclusion IFs on emergency MDCTs were frequent, rarely severe, rarely iatrogenic and relatively expensive.