Fast T₁ mapping MRI in preclinical and clinical settings using subspace-constrained joint-domain reconstructions

This work aims to develop fast T₁ mapping methods for preclinical and clinical scanners based on subspace-constrained reconstructions. Two sequences are explored for rapid T₁ characterizations: 1) Interleaved spatiotemporal encoding incorporating variable repetition times. 2) Inversion recovery gradient echo with random sampling of the phase-encoding (PE) dimension. For both sequences, the subspace reconstruction of the signal recovery was applied, to jointly reconstruct the down-sampled images while characterizing the T₁ relaxation. In vivo scans on human brains and abdomens confirmed the efficiency of the proposed methods, including compatibility with breath-holding. In addition, Scans on animals with abdominal tumors and dynamic contrast-enhanced T₁ mapping on kidneys support the applicability of the proposed methods also in preclinical settings.