Model-based reconstruction for simultaneous multi-slice T-1 mapping using single-shot inversion-recovery radial FLASH

Purpose: To develop a single-shot multi-slice (Formula presented.) mapping method by combing simultaneous multi-slice (SMS) excitations, single-shot inversion-recovery (IR) radial fast low-angle shot (FLASH), and a nonlinear model–based reconstruction method. Methods: SMS excitations are combined with a single-shot IR radial FLASH sequence for data acquisition. A previously developed single-slice calibrationless model–based reconstruction is extended to SMS, formulating the estimation of parameter maps and coil sensitivities from all slices as a single nonlinear inverse problem. Joint-sparsity constraints are further applied to the parameter maps to improve (Formula presented.) precision. Validations of the proposed method are performed for a phantom and for the human brain and liver in 6 healthy adult subjects. Results: Phantom results confirm good (Formula presented.) accuracy and precision of the simultaneously acquired multi-slice (Formula presented.) maps in comparison to single-slice references. In vivo human brain studies demonstrate the better performance of SMS acquisitions compared to the conventional spoke-interleaved multi-slice acquisition using model-based reconstruction. Aside from good accuracy and precision, the results of 6 healthy subjects in both brain and abdominal studies confirm good repeatability between scan and re-scans. The proposed method can simultaneously acquire (Formula presented.) maps for 5 slices of a human brain ((Formula presented.) ) or 3 slices of the abdomen ((Formula presented.) ) within 4 seconds. Conclusions: The IR SMS radial FLASH acquisition together with a nonlinear model–based reconstruction enable rapid high-resolution multi-slice (Formula presented.) mapping with good accuracy, precision, and repeatability.