Incidental findings were detected in 83.9% of patients undergoing whole-body computed tomography for polytrauma, according to a retrospective study proposing a five-level classification system to standardize their reporting and management.

In the study investigators reviewed 1,475 patients who experienced polytrauma and underwent whole-body computed tomography (CT) over a 7-year period at two maximum-care hospitals. The investigators identified 6,277 incidental findings unrelated to trauma. Based on the analysis, the investigators proposed a five-category Incidental Findings–Reporting and Data System (IF-RADS) to classify findings by clinical severity, with recommendations for further evaluation or treatment.

Whole-body CT is the standard procedure for examining severely injured patients and frequently reveals incidental findings unrelated to trauma. However, general recommendations for managing these findings haven't been established, according to the investigators.

Study Findings

Among the 1,475 patients, traumatic injuries were identified in 83.8%, whereas 16.2% had no detectable traumatic injury.

Incidental findings were identified in 1,237 patients, and 84.2% (n = 1,041) of these patients had multiple findings, averaging 5.1 incidental findings per patient.

The incidental findings were most commonly located in the:

• Abdomen: 34.8%

• Thorax: 17.8%

• Head: 14.0%

• Pelvis: 10.5%

• Neck: 5.9%.

The investigators identified 511 distinct types of incidental findings. Many represented normal variants or benign conditions such as accessory spleens (9.6%), azygos lobes (0.9%), and a lusoric artery (0.5%).

Age and sex influenced incidental findings. The patients with incidental findings had a mean age of 49.8 years vs 22.5 years in those without them, and female patients had a median of four findings vs three in male patients.

IF-RADS Classification

The investigators categorized incidental findings into five IF-RADS severity levels ranging from variants (category 1) and benign findings (category 2) to findings requiring monitoring (category 3), further investigation (category 4), or treatment (category 5). Most of the findings fell into the first two categories, whereas 24% of them were classified as categories 3 through 5, indicating the need for follow-up, clarification, or treatment.

Overall, 4.9% (n = 72) of the patients had category 5 findings, which required immediate clarification or treatment. Among these, 45% were suspected of malignant tumors, 20% were acute inflammatory processes such as pneumonia, and 13% were serious vascular findings including thrombosis, pulmonary artery embolisms, or aneurysms.

Study Limitations

The investigators noted several limitations, including the retrospective design and the possibility that some minor findings were omitted. Incidental findings were identified through a retrospective review of reports and imaging data, and some of the findings were detected only during secondary review.

“[W]e propose 'IF-RADS' as the relevant classification of [incidental findings]. This should help to compare [incidental findings] in further studies and to delineate them for clinical purposes,” wrote lead study author Daniela Kildal, MD, of Diagnostic and Interventional Radiology at the University Hospital Ulm in Germany and the Hôpital du Valais in Switzerland, and colleagues.

The authors reported no competing interests.

Source: Insights into Imaging