Quantitative microstructural mapping based on time-dependent diffusion MRI for predicting CEA levels in rectal cancer

Motivation: Carcinoembryonic antigen (CEA) levels are an established marker for rectal cancer aggressiveness, yet current imaging methods do not reliably predict CEA status or associated metastatic potential. Goal(s): This study aims to evaluate the use of time-dependent diffusion MRI (td-dMRI) for predicting elevated CEA levels in rectal cancer, offering a non-invasive assessment method. Approach: We applied td-dMRI to quantify microstructural parameters, such as cell diameter and cellularity, in rectal cancer patients, differentiating between CEA-positive and CEA-negative cases. Results: Findings showed that higher cell diameter and lower cellularity are significantly associated with elevated CEA levels, achieving an AUC of 0.760 when combined. Impact: Microstructural parameters based on td-dMRI have the potential to reflect elevated CEA levels, thereby serving as predictors of the proliferative and metastatic capabilities of rectal cancer.