Enhanced respiratory motion compensation in free-breathing dynamic contrast-enhanced MRI with GROG-facilitated bunch phase encoding and Golden angle radial sampling.

Respiratory motion poses a persistent challenge in dynamic contrast-enhanced (DCE) MRI, by introducing blurring and ghosting artifacts that reduce image quality and affect reliable clinical interpretation. XD-GRASP method has emerged as an effective motion compensation technique that employs Golden Angle Radial (GAR) acquisitions combined with motion-resolved compressed sensing reconstruction to separate respiratory phases and reduce motion artifacts. Building upon these advancements, this paper proposes a novel framework to reduce the respiratory motion artifacts in free-breathing Dynamic Contrast-Enhanced (DCE) MRI through GAR acquisitions, binning and the integration of GROG-facilitated Bunch Phase Encoding (GROG-BPE). By merging the strengths of BPE with motion-resolved compressed sensing, our approach optimizes motion compensation without losing temporal resolution. The proposed method has been tested on in-vivo DCE liver and abdominal datasets across two different types of amplitude based binning techniques including uniform and adaptive binning. Performance of the proposed method has been quantitatively evaluated on the basis of signal-to-noise ratio and contrast-to-noise ratio, and qualitatively by expert radiologists. Experimental results reveal that the proposed method yields superior performance both quantitatively and qualitatively, in comparison with the contemporary DCE-MRI techniques.