Value of CMR for the Differential Diagnosis of Cardiac Masses
What is the value of cardiac magnetic resonance (CMR) for the differentiation of cardiac tumors from thrombi?
The authors conducted a retrospective analysis of CMR scans from 116 patients with definite cardiac masses, evaluating size, mobility, heterogeneity, T1, T2, first-pass perfusion, and late gadolinium enhancement (LGE) characteristics.
The authors found that several CMR parameters had value for differentiation of cardiac tumors from thrombi. Of these, the highest diagnostic accuracy for identification of thrombi was with a characteristic pattern of LGE with hyperintensity/isointensity with short post-contrast inversion (TI) times and hypointensity with long TI times (sensitivity 94%, specificity 98%, positive predictive value 98%, negative predictive value 91%, accuracy 95%). Other accurate parameters included area (accuracy 86%), absence of LGE (accuracy 87%), absence of first-pass perfusion (accuracy 85%), and homogeneity (accuracy 84%). Approximately 91% of thrombi had the typical LGE pattern and absent LGE and absent first-pass perfusion. The accuracy for differentiation of benign versus malignant tumors was more modest for evaluated CMR characteristics (accuracy 69-79%).
The authors concluded that CMR is an accurate noninvasive method for differentiation of thrombi from cardiac tumors.
This study adds to the body of literature highlighting the ability of CMR to differentiate thrombi from tumors. The finding of a typical LGE pattern extends and supports prior work in this field. Of concern, however, is that nearly 10% of thrombi either had first-pass perfusion or had LGE in a pattern atypical for thrombi. The authors propose that this could be due to neovascularization in the late chronic stage of thrombi. However, in many cases, thrombi may be commingled with tumor cells in patients with known malignancies, and internal vascularization may also be a sign that thrombus is malignant rather than benign. Thus, given the clinical importance of the differentiation of tumor from thrombus, this may not be sufficient in some clinical scenarios, and providers should integrate CMR findings with clinical suspicion.
Keywords: Thrombosis, Sensitivity and Specificity, Gadolinium, Magnetic Resonance Spectroscopy, Heart Neoplasms, Neovascularization, Pathologic
< Back to Listings