Cardiac thrombus: can T1 and T2 mapping replace contrast enhanced images?

The aim of the study was to evaluate and compare contrast-to-noise ratios (CNRs) and signal-to-noise ratios (SNRs) of pre- and postcontrast T1 maps, T2 maps, early and late gadolinium images in terms of visual assessment of cardiac thrombus, to see if maps can replace contrast-enhanced images for detection of cardiac thrombus.

T1, T2 maps, and postcontrast images of 22 patients with cardiac thrombus were retrospectively evaluated for SNR and CNR. SNR and CNR values of thrombus, blood pool, and myocardium measured at maps and contrast-enhanced images were compared with each other.

The distinguishability of thrombus from blood pool and myocardium was better on early gadolinium images (EGE) and late gadolinium enhanced (LGE) images than T1 and T2 mapping. The mean CNRs calculated to be the highest on EGE, followed by LGE and then maps.

Native mapping sequences may have a potential in detecting cardiac thrombus, but contrast-enhanced images are superior. In future studies, the optimal mapping sequence for evaluation of thrombus in noncontrast images can be determined by using different modified Look-Locker inversion recovery schemes or other T1 and T2 mapping methods.

CNR values of EGE and LGE remained higher than mapping sequences.