MRI2Qmap: multi-parametric quantitative mapping with MRI-driven denoising priors

Abstract

Magnetic Resonance Fingerprinting (MRF) and other highly accelerated transient-state parameter mapping techniques enable simultaneous quantification of multiple tissue properties, but often suffer from aliasing artifacts due to compressed sampling. Incorporating spatial image priors can mitigate these artifacts, and deep learning has shown strong potential when large training datasets are available. However, extending this paradigm to MRF-type sequences remains challenging due to the scarcity of quantitative imaging data for training. Can this limitation be overcome by leveraging sources of training data from clinically-routine weighted MRI images? To this end, we introduce MRI2Qmap, a plug-and-play quantitative reconstruction framework that integrates the physical acquisition model with priors learned from deep denoising autoencoders pretrained on large multimodal weighted-MRI datasets. MRI2Qmap demonstrates that spatial-domain structural priors learned from independently acquired datasets of routine weighted-MRI images can be effectively used for quantitative MRI reconstruction. The proposed method is validated on highly accelerated 3D whole-brain MRF data from both in-vivo and simulated acquisitions, achieving competitive or superior performance relative to existing baselines without requiring ground-truth quantitative imaging data for training. By decoupling quantitative reconstruction from the need for ground-truth MRF training data, this framework points toward a scalable paradigm for quantitative MRI that can capitalize on the large and growing repositories of routine clinical MRI.

Figures (11)

• Figure 1: MRI2Qmap vs. an ADMM reconstruction without spatial regularization. Quantitative T1/T2 maps and synthesized T1w, T2w, and PDw images are shown (electronic zoom recommended). By leveraging MRI-driven denoising priors, MRI2Qmap suppresses aliasing artifacts in synthesized contrasts and the underlying quantitative maps.
• Figure 2: Reconstructed T1 and T2 maps at $R=8$ acceleration. Relative to baselines ($^*$indicates MRF-trained), MRI2Qmap exhibits reduced artifacts and improved anatomical delineation e.g. for deep brain structures (axial views) and the cerebellum (coronal views). Electronic zoom in boxed regions is recommended.
• Figure 3: TSMI magnitudes across $s=5$ compressed coefficient channels (rows) for the subject in Fig.\ref{['fig:vivo-maps']}, reconstructed by MRI2Qmap and baselines (columns). CG/init $\mathbf{x}_\text{init}$ initializes MRI2Qmap; ARNet was trained with MRF ground-truth data.
• Figure 4: Reconstructed T1/T2 maps for additional in-vivo subjects: MRI2Qmap vs. representative baselines (LRTV/ARNet).
• Figure 5: T1/T2 maps and synthesized MRIs (columns) from MRI2Qmap with one denoising modality prior disabled (rows); most affected images in each row are highlighted.