Incidental extracardiac findings at cardiac CT angiography: Comparison of prevalence and clinical significance between precontrast low-dose whole thoracic scan and postcontrast retrospective ECG-gated cardiac scan

Purpose: To compare the prevalence and clinical significance of incidental extracardiac findings at cardiac CT angiography (CCTA) with precontrast low-dose whole thoracic scan (LDCT) and ECG-gated CCTA. Materials and Methods: We reviewed 254 patients who underwent CCTA. All participants first underwent LDCT to determine a range for CCTA and to screen unrecognized extracardiac lesions. CCTA was reconstructed with a small field of view of the heart. Clinically significant extracardiac findings were defined as abnormalities requiring further diagnostic work up, therapeutic intervention, or follow-up. Results: On LDCT, 285 extracardiac findings were detected in 62.6% patients; on CCTA, 18 findings in 7% patients. Among these, 66 findings in 20.4% patients were considered clinically significant on LDCT, and 4 findings in 1.6% patients on CCTA. Conclusion: Clinically significant extracardiac findings are common in patients undergoing CCTA with a considerable number of extracardiac findings being detected only on LDCT. We advise performing whole thorax LDCT prior to CCTA.