Dynamic glucose enhanced imaging using direct water saturation.

Area of Science:

• Magnetic Resonance Imaging
• Biomedical Engineering
• Medical Physics

Background:

• Dynamic glucose enhanced (DGE) MRI methods like CEST and CESL are used to study glucose uptake but suffer from low effect size and motion sensitivity.
• Existing DGE MRI techniques require improvement in sensitivity and robustness for clinical applications.

Purpose of the Study:

• To introduce and evaluate a novel DS-DGE MRI technique utilizing exchange-based linewidth broadening for improved glucose uptake assessment.
• To overcome the limitations of current DGE MRI methods by enhancing effect size and motion sensitivity.

Main Methods:

• Simulations using Bloch-McConnell equations estimated glucose-infusion-induced linewidth (LW) changes (ΔLW) in various tissues.
• Whole-brain DS-DGE imaging was performed at 3 T with dynamic Z-spectral acquisitions.
• A deep learning-based Lorentzian fitting approach assessed voxel-based ΔLW, and area-under-the-curve (AUC) images were generated and compared to perfusion-weighted imaging.

Main Results:

• Simulations predicted varying ΔLW across tissues, with significant values in malignant tumor tissue (7.5%) and CSF (13%).
• In vivo results demonstrated substantial ΔLW in brain tumor tissues (5-20%) and CSF (40%), with approximately 1% in GM/WM.
• Generated DS-DGE AUC maps effectively delineated lesion areas, showing clear enhancement.

Conclusions:

• DS-DGE MRI is a promising technique for evaluating D-glucose uptake, offering high-quality visualization of glucose-induced line broadening.
• Initial patient studies indicate that DS-DGE MRI provides lesion enhancement maps comparable or complementary to perfusion-weighted imaging.
• The developed DS-DGE MRI method shows potential for improved assessment of glucose metabolism in brain tumors.