Zonal anatomy of the prostate using magnetic resonance imaging, morphometrics, and radiomic features: impact of age-related changes

Objective: To evaluate the impact of age on the zonal anatomy of the prostate by MRI using morphometric and textural analysis. Methods: A total of 154 men (mean age: 63 years) who underwent MRI due to a high prostate-specific antigen (PSA) level were included retrospectively. At each MRI examination the following variables were measured: overall dimensions of the prostate (whole gland (WG), transitional zone (TZ), and peripheral zone (PZ)), and thickness of the anterior fibromuscular stroma (AFMS) and the periprostatic venous plexus (PPVP) on T-2 weighted images. Identical regions of interest (ROIs) were delineated on the apparent diffusion coefficient (ADC) map on the anterior (horn) and posterior part of the PZ. Textural (TexRAC) parameter differences between TZ and PZ ROIs on T-2 weighted images were analyzed by linear regression. Results were correlated with age (distributed into five decades from 22 to 89 years). Results: Age was positively correlated with PSA level and glandular volumes (WG, TZ, and TZ/WG ratio; p < 0.0001) and was negatively correlated with AFSM and PPVP thickness (p < 0.0001). There was a positive correlation between ADC values of the PZ and age (p 0.003) and between entropy of the TZ and PZ and age (p < 0.001). Conclusion: Gradual variations in morphologic and textural features of the prostate were observed with age, mainly due to the increase in TZ volume while PZ volume tended to decrease. These modifications resulted in textural changes mainly at the expense of entropy. Advances in knowledge: Entropy could be relevant for studying the process of aging of the prostate.