Prevalence, taxonomy, and outcomes of inpatient imaging incidental findings

Objective: Incidental findings, including masses, anatomic abnormalities, medical conditions, and foreign bodies, are an increasingly common medical phenomenon. We sought to categorize and determine the risk and prevalence of incidental findings in an inpatient setting as well as the appropriateness of follow-up and clinical outcomes. Methods: We performed a cross sectional study of 210 patients admitted to the hospital medicine service between January 1, 2018, and May 31, 2018. Incidental findings were identified and categorized into anatomic abnormalities, masses, medical conditions and foreign bodies. They were assigned harm scores ranging from 1 to 5 with 1 representing potential for catastrophic harm and 5 representing no potential for harm. Appropriate follow-up and adverse events were determined. Results: We identified 235 incidental findings of which 179 (76.2%) had a harm score of 4 (20.0%) or 5 (56.2%). 43 (18.3%) incidental findings had a harm score of 3. None had a harm score of 1 and 13 (5.5%) had a harm score of 2. 79 (33.6%) were anatomic abnormalities, 40 (17%) were masses, 115 (48.9%) were medical conditions, and 1 (0.4%) was a foreign body. Of the 13 incidental findings with a harm score 2, only 2 (15.4%) were addressed during the hospital stay or within 2 months of hospitalization. There were 29 studies with a radiologist's recommendation for follow-up, 41.3% of the recommended follow-ups were completed in the suggested timeframe. Five (2.1%) of the incidental findings without recommended follow-up progressed. None resulted in deaths. Conclusions: Incidental findings are common among hospitalized patients undergoing imaging studies. Most incidental findings are low-risk and are not specifically addressed in the discharge plan or in follow-up. The high prevalence of low-risk incidental findings may contribute to limited adverse clinical outcomes for the rare, high-risk incidental findings.