Highly Accelerated Inner-volume selective 3D GRASE CEST Imaging with Temporal Random Walk Sampling – Application to a Brain Tumor Patient at 3 T

Motivation: To overcome the limitations of traditional 2D CEST imaging, such as partial volume effects and limited spatial coverage, which hinder accurate tumor boundary delineation. Goal(s): To develop and validate a 3D GRASE CEST imaging sequence with inner-volume selection for enhanced spatial resolution and tumor visualization. Approach: The proposed method integrates variable-density CAIPI sampling and a temporal random walk pattern, tested through phantom and patient studies to ensure effective imaging protocols. Results: The 3D GRASE CEST sequence achieved consistent CEST effects across partitions, with reliable MTR asymmetric values that distinguish tumor from normal tissue. Impact: This technique offers a promising tool for efficient, high-resolution CEST imaging, with potential applications in clinical neuro-oncology for precise tumor assessment.