This study investigates temperature and concentration dependence of apparent diffusion coefficient (ADC) for aqueous solutions of polyvinylpyrrolidone (PVP). Our objective is to report accurate diffusion values for PVP in the scanner room temperature range. We performed ADC measurements of PVP (0-50% concentration) with K40 polymer moiety at multiple room temperatures while simultaneously measuring internal phantom temperature using an MRI-compatible optical thermometer. To reduce measurement bias, we also performed “gradient calibration” of each physical gradient channel using water ADC at 0oC. Our results are consistent with Arrhenius model for water ADC dependence on temperature and PVP concentration.