Multi-coil multi-contrast joint reconstruction with protection from hallucination: Application to low-field MRI

Motivation: In clinical MR imaging workflows, multiple contrast weightings of the same anatomy —sharing significant mutual information —are acquired sequentially. Harnessing this mutual information effectively while avoiding hallucination would enable substantial acceleration in MR acquisition without compromising image quality. Goal(s): To evaluate the efficacy of a projection-guidance in multi-coil, multi-contrast MR image reconstruction. Approach: Refinement block is projected onto the subspace spanned by the trailing right singular vectors of the forward operator, allowing disambiguation of potential solutions without undermining data consistency. Results: Joint reconstruction of three contrasts reduces the clinical workflow from 13 minutes to just 1 minute, maintaining high image quality and outperforming relevant baselines. Impact: MR images from different contrast weightings share substantial information. When this shared information is rigorously leveraged, high acceleration levels can be achieved, even in low-field settings, enabling efficient workflows and facilitating broader adoption.