Calibration-free Highly Accelerated Multi-slice MRI via Alternating Phase Encoding Directions and Low-rank Tensor Completion Reconstruction

Abstract

2D multi-slice MR data share strong correlations in coil sensitivities and image contents over adjacent slices. Here we’ve developed a new acquisition and reconstruction strategy for calibration-free multi-slice MRI. In brief, k-space data for each slice are uniformly undersampled along one phase encoding direction, while undersampled data for next adjacent slice are acquired with phase encoding along an orthogonal direction. Multiple images are then jointly reconstructed using a low-rank Hankel tensor completion approach. This method maximizes the incoherence of aliasing artifacts, and utilizes the coil sensitivity and image content correlations across adjacent slices, leading to high accelerations with uniform undersampling.