Combining magnetic resonance late gadolinium enhanced and Look-Locker sequences for myocardial scar characterization

Characterization of myocardial scar has important diagnostic and prognostic value for treatment of post-infarction patients. Late gadolinium enhanced (LGE) MR visualizes myocardial scar as regions of hyper-enhanced signal intensity, however, the accuracy and reproducibility of scar characterization is impaired by the lack of an absolute measure in this imaging modality. We propose a new method to calibrate the signal intensity of LGE MR using the accompanying Look-Locker (LL) MR sequence which measures the absolute tissue T1 relaxation properties. The calibrated LGE MR results in accurate scar characterization, as demonstrated by comparison with high-density electroanatomic voltage mapping (EAVM) data acquired during a ventricular tachycardia (VT) ablation procedure in a group of 15 post-infarction patients.