Tumor Microstructural Measurement at Time-Dependent Diffusion MRI Mapping for Predicting Lymphovascular Invasion in Rectal Cancer

Motivation: Early prediction of lymphovascular invasion (LVI) in rectal cancer is crucial for treatment planning. Current imaging methods lack sufficient ability for detecting LVI-related microstructural changes, warranting advanced MRI biomarkers for improved assessment. Goal(s): This study evaluates the correlation between microstructural parameters obtained from time-dependent diffusion MRI (td-dMRI), ADC measurements and LVI to identify optimal predictive indicators. Approach: Eighty-four patients rectal cancer underwent td-dMRI using OGSE and PGSE sequences. Four microstructural parameters and eight ADC measurements were assessed. Results: Combination of intracellular volume fraction (ICVF), cellularity, and MRI-reported extramural venous invasion (EMVI) achieved the highest predictive performance for LVI. Impact: The intracellular volume fraction (ICVF) from td-dMRI shows promise as a biomarker for LVI in rectal cancer. Combining ICVF and cellularity with MRI-reported EMVI enhances predictive performance, supporting clinicians in identifying high-risk patients for targeted treatment strategies.