Time-dependent diffusion MRI could distinguish between functioning and non-functioning pituitary adenoma

Motivation: Differentiation between functioning and non-functioning pituitary adenoma (PA) is clinically relevant. Feasibility of their microstructural differentiation is undetermined. Goal(s): To investigate whether the time-dependent diffusion MRI can distinguish functioning from non-functioning PA. Approach: Twenty-four patients with functioning and 30 with non-functioning PA were examined. Pituitary DWI was performed using inner FOV EPI based on 2D-selective radiofrequency excitations with oscillating (diffusion time=7.1ms) and pulsed (36.3ms) gradient preparations. ADC change (cADC) and relative ADC change (rcADC) between two diffusion-times were calculated. Results: cADC was significantly higher in functioning than in non-functioning PAs (P=0.012), showing that time-dependent diffusion MRI can distinguish them. Impact: Our results clarified that there are microstructural differences between functional and non-functional pituitary adenomas. Time-dependent diffusion MRI of the pituitary gland can detect their microstructural characteristics, providing clues as to their imaging differentiation.