CT scanning of the chest, abdomen and pelvis (CT-CAP) is often used by neurologists to identify underlying disease processes such as malignancy or sarcoidosis. However, the utility of CT-CAP, and the rate of incidental findings, remains uncertain.

This retrospective study investigated all CT-CAP requests by the neurology department in Edinburgh over a 5-year period (n=261), combining CT-CAP reports with electronic patient records. Incidental findings were classified by need for further investigations. Category 1 findings required further investigations (e.g. pulmonary nodule >4 mm). Category 2 findings required extra tests depending on clinical context (e.g. dilated biliary tract; liver function and surgical history determining need for further investigations). Category 3 findings did not require further investigations (e.g. simple diverticular disease).

20% (n=51) of CT-CAP scans were reported as showing an underlying malignancy, with half (n=26) confirmed as cancer by subsequent investigations. CT-CAP identified three cases of sarcoidosis and one of tuberculosis. There were 191 category 3 incidental findings, 57 category 2 incidental findings, and 27 category 1 findings.

Overall, CT-CAP shows an underlying cause of neurology symptoms in 11.5% of cases. The proportion of patients needing further tests due to category 1 or concerning category 2 incidental findings (12/57) was higher at 14.9%.