Incidental findings seen in almost a third of CT scans in emergency departments

Incidental findings seen on a CT scan in emergency departments are present in almost a third of cases, according to a systemic review

The presence of incidental findings (IF) occurs in about a third of all computed tomography (CT) scans undertaken with emergency departments according to the results of a systematic review by a group of US researchers.

The term “incidentaloma” refers to a mass or lesion discovered accidentally, detected by imaging and which was made for an unrelated reason.. Such incidental findings are not uncommon, especially among CT scans of trauma patients with a study revealing how findings were present in 15% of trauma CT scans. Although the presence of FI does not affect or alter the current diagnostic workup of the emergency department clinician, it is important that these findings be communicated to patients to ensure that, if necessary, further testing and a appropriate follow-ups are initiated. However, in non-trauma patients, little is known about the level of incidental findings among CT scans performed in emergency departments. For the present study, the US team sought to estimate the prevalence of radiological IF in patients visiting an emergency department and having undergone a CT scan. A secondary objective was to examine how hospitals manage and stratify the risks associated with abnormal outcomes.

Undertaking a comprehensive literature search, the authors searched for studies including terms such as ‘incidentaloma’ without restriction on the type of study design and which included those that were retrospective, cross-sectional or prospective in nature. The primary outcome of the systematic review was the prevalence of IF on a CT scan.

Prevalence of incidental findings on CT scans

A total of 69 studies representing 147,763 emergency department visits or radiology reports, with a median sample size of 882 patients, were included in the analysis. The majority of studies were cross-sectional in design (82.6%), with the remainder comprising a cohort (7.2%) and those with a pre- and post-intervention design. Just over half of the studies (50.7%) involved trauma patients and 63.8% of the studies included some form of IF risk stratification.

The pooled prevalence of any incidental finding on CT scan was 31.3% (95% CI 24.4% – 39.1%), although there was marked evidence of heterogeneity across studies. The highest prevalence of FI occurred in patients who underwent CT scans for chest pain (36.6%), followed by trauma (34.7%).

In a total of five studies, all based in trauma centers, there were structural interventions designed to improve recognition and notification or follow-up of patients identified with FI on a CT scan. In one such study, for example, following implementation of the IF management strategy, patient reporting increased from 17.7% to 32.4%.

The researchers also found that documentation of FI in patient discharge notes was only present in 20.1% to 47.2% of cases.

In their conclusion, the authors identified the need to establish a comprehensive classification system and a standards-based approach to help clinicians deal with FI. They also called for more flexible care coordination programs to ensure quick follow-up, clear documentation in medical records, and that could easily be implemented in a busy emergency department.

Evans CS et al. Radiology incidental findings in computed tomography studies of emergency department patients: a systematic review and meta-analysis Ann Emerg Med 2022

Lillian L. Pena