3D Cardiac T1p Mapping using XD-GRASP Reconstruction: Initial Evaluation in Patients with Ischemic and Non-ischemic Cardiomyopathy

Motivation: T1ρ mapping is an emerging non-contrast pulse sequence for measuring cardiac fibrosis, but current techniques suffer from lack of coverage, poor spatial resolution, and long scan time. Goal(s): We aimed to develop an accelerated, free-breathing 3D cardiac T1ρ mapping pulse sequence using XD-GRASP reconstruction extended to include both respiratory and spin-locking time dimensions. Approach: Our 3D T1ρ sequence was tested in 12 patients undergoing clinically indicated cardiac MRI to compare T1ρ with extracellular volume fraction (ECV) and late gadolinium enhancement (LGE). Results: Myocardial T1ρ correlates with ECV of non-ischemic myocardium but not with a mixture of acute and chronic ischemic myocardium. Impact: 3D T1ρ mapping achieves robust image quality and T1ρ values that agree with literature. 3D T1ρ could be used for measuring fibrosis in patients where contrast should be avoided, after further research into the nature of T1ρ in focal scar.