Diagnostic Accuracy of an Integrated Multimodality Imaging Approach in Patients With Cardiac Masses

Background: Multimodality imaging plays a central role in the evaluation of cardiac masses (CMs), yet the comparative performance of integrated imaging strategies including cardiac magnetic resonance (CMR), cardiac computed tomography (CCT), and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) remains incompletely defined. Objectives: This study sought to compare the diagnostic accuracy of multiparametric scores derived from echocardiography, CMR, CCT, and 18F-FDG PET, individually and in combination, for identifying malignant CMs using histology as the reference standard. Methods: In this prospective study, patients with suspected CMs underwent echocardiography, CCT, CMR, and 18F-FDG PET within 2 months of first medical contact. Final diagnosis was established by histology or radiological resolution after anticoagulation therapy for thrombi. Diagnostic performance was assessed using receiver-operating characteristic curves, and the areas under the curve (AUCs) were compared with the DeLong test, applying Bonferroni correction for multiple comparisons. CART (Classification And Regression Tree) analysis assessed the incremental value of PET following CMR or CCT. Results: Among 142 patients, 54% had malignant CMs. Echocardiography showed the lowest diagnostic accuracy (AUC: 0.77). CMR demonstrated the highest standalone performance (AUC: 0.94), outperforming CCT and 18F-FDG PET (both AUCs: 0.85). The combination of CMR and 18F-FDG PET was associated with high diagnostic accuracy (AUC: 0.97; positive predictive value 95.1%; negative predictive value 100%), whereas CCT combined with 18F-FDG PET achieved an AUC of 0.92. The addition of PET after CMR or CCT was associated with improved diagnostic classification in selected cases, as supported by CART analysis. Conclusions: CMR provides the highest standalone accuracy for malignancy detection. In inconclusive cases, adding 18F-FDG PET further improves diagnostic performance, while CCT combined with 18F-FDG PET represents a reliable alternative.