Time-Dependent Diffusion MRI-Based Microstructural Mapping for Characterization of Cribriform and Intraductal Carcinoma Morphologies in Prostate Cancer: A Preliminary Study

Background: Intraductal carcinoma (IDC) and invasive cribriform (Cr) histologic patterns are important adverse morphologies in prostate cancer (PCa) and may influence pretreatment risk stratification. This study evaluated the feasibility of time-dependent diffusion magnetic resonance imaging (td-dMRI)-based microstructural mapping for preoperative characterization of these aggressive morphologies. Methods: This retrospective study included 95 men with pathologically confirmed PCa on radical prostatectomy specimens from March 2023 to March 2025. Td-dMRI was performed using pulsed and oscillating gradient diffusion sequences. Microstructural parameters, including extracellular diffusivity (Dex), cell diameter (d), intracellular volume fraction (fin), cellularity, and diffusivities at 0, 17, and 33 Hz (ADC0Hz, ADC17Hz, and ADC33Hz), were estimated using a two-compartment model. Conventional apparent diffusion coefficient (ADCDWI) values were obtained from standard diffusion-weighted imaging. Parameters were compared between tumors with and without Cr/IDC patterns, and diagnostic performance was assessed using receiver operating characteristic analysis. Pairwise comparisons of AUCs were performed using the DeLong test. Results: Among 95 participants, 62 (65.3%) had Cr/IDC patterns. Compared with Cr/IDC-negative tumors, Cr/IDC-positive tumors showed higher fin and cellularity (both p < 0.001) and lower ADCDWI, ADC0Hz, ADC17Hz, and ADC33Hz values (all p < 0.05). Dex and d did not differ significantly between groups. Among td-dMRI-derived parameters, fin showed the highest diagnostic performance (AUC = 0.757; 95% CI, 0.654–0.860). Conclusions: Td-dMRI-based microstructural mapping demonstrates promise for characterizing the Cr/IDC morphologies in PCa.