Cardiac MRI: A useful tool for differentiating cardiac thrombi from tumors

Background: Correct diagnosis of cardiac masses is a challenge in clinical practice. Accurate identification and differentiation between cardiac thrombi and tumors is crucial because prognosis and appropriate clinical management vary substantially. Objectives: To evaluate the diagnostic performances of cardiac magnetic resonance imaging (CMR) in differentiating between cardiac thrombi and tumors. Methods: A retrospective review of a prospectively maintained database of all CMR scans was performed to distinguish between cardiac thrombi and tumors during a 10 year period in a single academic referral center (2004–2013). Cases with an available standard of reference for a definite diagnosis were included. Correlation of CMR differentiation between thrombi and tumors with an available standard of reference was performed. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy were reported. Results: In this study, 101 consecutive patients underwent CMR for suspicious cardiac masses documented on transthoracic or transesophageal echocardiography. CMR did not detect any cardiac pathology in 17% (17/101), including detection of anatomical variants and benign findings in 18% (15/84). Of the remaining 69 patients, CMR diagnosis was correlated with histopathologic result in 74% (51/69), imaging follow-up in 22% (15/69), and a definite CMR diagnosis (lipoma) in 4% (3/69). For tumors, diagnostic accuracy, sensitivity, specificity, PPV, and NPV were 96.6%, 98%, 86.6%, 96.2%, and 96.6%, respectively. For thrombi, the results were 93.6%, 86.7%, 98.04%, 92.9%, and 97%, respectively. Conclusions: CMR is highly accurate in differentiating cardiac thrombi from tumors and should be included in the routine evaluation of cardiac masses.