Purpose: To evaluate the accuracy of Cardiac MRI (CMR) in differentiating between intra cardiac tumors and thrombi.
Materials and Methods: Retrospective analysis of a prospectively maintained database (2004-2013) was performed. This included all patients referred for the evaluation of intra-cardiac tumors versus thrombi. MRI sequences included: T2, gradient echo, T1 before and after Gadolinium (Gd) administration, first pass perfusion and delayed enhancement. The MRI findings were compared to the definitive diagnosis of the intra cardiac - mass established either by pathology and /or clinical and echocardiographic follow up, when available. Accuracy, sensitivity and positive predictive volume (PPV) of CMR for differentiating between tumor and thrombus were calculated, accordingly.
Results: Of the 150 patients referred for CMR, intra cardiac masses were detected at in 111 patients. At CMR cardiac tumors were diagnosed in 72 patients, thrombi in 28 patients; 11 masses were inconclusive. Definitive diagnosis was available in 66 patients including 49 tumors and 17 thrombi. CMR correctly diagnosed 48 out of 49 tumors; sensitivity PPV and NPV were 97%, 97% and 92%, respectively. Thrombi were correctly diagnosed at CMR in 14 out of 17 scans; sensitivity PPV and NPV were 82%, 93% and 80%, respectively. The overall accuracy in differentiating intra-cardiac tumors from thrombi was 94%. Of the 11 inconclusive lesions detected, 5 were smaller than 1 cm.
Conclusions: The different CMR sequences allow reliable tissue characterization, thus enabling an accurate differentiation between intra cardiac tumors and thrombi. This high diagnostic potential is limited in lesion smaller than 1 cm.
