Characterisation and management of expected and unexpected urgent findings from positron emission tomography with 18F-fluorodeoxyglucose integrated with computed tomography in cardiovascular disease.

BACKGROUND:Cardiac 18F-fluorodeoxyglucose (FDG)-PET-CT plays an important role in the assessment of cardiovascular diseases. Effective management of urgent scan findings facilitates optimal patient care. METHODS:We characterised the management of urgent, expected and unexpected findings in patients referred for cardiac [18F]fluorodeoxyglucose integrated with computed tomography (FDG-PET-CT) at the Royal Brompton Hospital (United Kingdom). Urgent findings are escalated by the reporting physicians/radiologists raising RadAlert notifications to the referring clinician. We characterised the indications and time to management (TTM) between the RadAlert and the resulting management. As controls, we characterised the TTM of 33 urgent findings identified before the RadAlert system was implemented. RESULTS:Of the 1497 consecutive FDG-PET-CT scans screened (April 2021 to February 2023), 93 RadAlerts were suitable for analysis (TTM 7 days [interquartile range: 2-14]). Expected urgent findings included active cardiac sarcoidosis (56%; TTM 8 days [5-18]), heart transplant rejection (12%; 6 ± 4 days), infective endocarditis (9%; 2 days [1-12]), cardiac device infections (5%; 1 day [0-2]), acute myocarditis (2%; 5 and 14 days) and epicardial mass (1%; 1 day). TTM did not differ significantly between indications (P = 0.06). RadAlert cases had significantly shorter TTM than controls without RadAlert, P = 0.001. After the RadAlerts, 81% of patients had clinical reviews, and 55% had escalation of medical/surgical therapies. Unexpected findings (total N = 45; median TTM 6 days [1-10]) included malignancies (N = 3), infections (N = 2), pneumothorax (N = 1), benign diagnosis (N = 30), unclear diagnosis (N = 5) and 4 findings disappeared on repeat imaging. CONCLUSIONS:Cardiac FDG-PET-CT identifies expected and unexpected findings in a range of cardiovascular diseases. Serious, unexpected findings are rare and can be effectively escalated by the RadAlert system.