Diagnostic Accuracy of Cardiac Computed Tomography and 18 F-Fluorodeoxyglucose With Positron Emission Tomography in Cardiac Masses.

OBJECTIVES: This study sought to assess the diagnostic accuracy of cardiac computed tomography (CT) and 18 F-fluorodeoxyglucose (18 F-FDG) with positron emission tomography/computed tomography (PET/CT) in defining the nature of cardiac masses.

BACKGROUND: The diagnostic accuracy of cardiac CT and 18 F-FDG PET/CT in identifying the nature of cardiac masses has been analyzed to date only in small samples.

METHODS: Of 223 patients with echocardiographically diagnosed cardiac masses, a cohort of 60 cases who underwent cardiac CT and 18 F-FDG PET/CT was selected. All masses had histological confirmation, except for a minority of thrombotic formations. For each mass, 8 morphological CT signs, standardized uptake value (SUVmax , SUVmean ), metabolic tumor volume, and total lesion glycolysis in 18 F-FDG PET were used as diagnostic markers.

RESULTS: Irregular tumor margins, pericardial effusion, invasion, solid nature, mass diameter, CT contrast uptake, and pre-contrast characteristics were strongly associated with the malignant nature of masses. The coexistence of at least 5 CT signs perfectly identified malignant masses, whereas the detection of 3 or 4 CT signs did not accurately discriminate the masses' nature. The mean SUVmax , SUVmean , metabolic tumor volume, and total lesion glycolysis values were significantly higher in malignant than in benign masses. The diagnostic accuracy of SUV, metabolic tumor volume, and total lesion glycolysis 18 F-FDG PET/CT parameters was excellent in detecting malignant masses. Among patients with 3 or 4 pathological CT signs, the presence of at least 1 abnormal 18 F-FDG PET/CT parameter significantly increased the identification of malignancies.

CONCLUSIONS: Cardiac CT is a powerful tool to diagnose cardiac masses as the number of abnormal signs was found to correlate with the lesions' nature. Similarly, 18 F-FDG PET/CT accurately identified malignant masses and contributed with additional valuable information in diagnostic uncertainties after cardiac CT. These imaging tools should be performed in specific clinical settings such as involvement of great vessels or for disease-staging purposes.