An acetone-based phantom for quantitative diffusion MRI

Purpose: To propose and evaluate an acetone-D₂ O phantom that has an extended range of apparent diffusion coefficient (ADC) for quantitative diffusion magnetic resonance imaging (MRI), as well as to compare its properties to previously described water-based phantoms.

Materials and methods: The proposed acetone-D₂ O, and previously described sucrose water solution and polyvinylpyrrolidone (PVP) water solution phantoms, were constructed in a number of concentrations between 0% and 50%. At 1.5T field strength, diffusion-weighted MR spectroscopy (DW-MRS), based on a point-resolved spectroscopy (PRESS) acquisition, nondiffusion-weighted stimulated echo acquisition mode (STEAM)-MRS, and diffusion-weighted echo-planar imaging (DW-EPI) were used to evaluate each phantom. The MR spectra, diffusion-weighted signal decay pattern, tunability of ADC, and ADC range of each phantom were all evaluated.

Results: When placed in an ice-water bath, all phantoms provided desirable signal properties, including single-peak signal with Gaussian diffusion and tunable ADC. At 0°C, however, water-based phantoms had ADC limited to less than 1.1·10^-3 mm² ·s^-1 (0.2-1.1·10^-3 mm² ·s^-1 ), while the proposed acetone-based phantom had ADC values spanning a wider range (0.6-3.5·10^-3 mm² ·s^-1 ).

Conclusion: The proposed acetone-D₂ O phantom provided desirable signal properties over a wide range of ADCs with temperature controlled using an ice-water bath.

Level of evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1683-1692.