FIGURE A1.

(a) T2‐weighted image of the diffusion phantom showing the inner and outer ring of vials labeled as (1) and (2), respectively. Each ring contains six vials with the concentration of polyvinylpyrrolidone (PVP) varying from 0% to 50%. White dot represents location of isocenter. The distance between the isocenter and the inner ring is approximately 35 mm. The distance between the isocenter and the outer ring is approximately 60 mm. (b) Apparent diffusion coefficient (ADC) map acquired with single‐shot EPI and imaging parameters listed in manuscript. (c) ADC map acquired with Cartesian spin‐echo and imaging parameters listed in manuscript