Evaluation of the Short- and Long-Term Stability of Apparent Diffusion Coefficient Using the Commercial Product Pseudo-Blood®

The current study aimed to investigate the feasibility of using the pseudo-blood^®, adjusted to equal specific gravity of beads and solution, as a phantom for diffusion-weighted imaging (DWI) evaluation. The pseudo-blood^® with bead concentrations was adjusted to 0%, 9.8%, 28.1%, and 48.5% and was used as phantoms. Approximately 3-min of DWI was performed 15 times at 10-min intervals. The same experiment was conducted after 30, 60, and 90 days. The coefficients of variation of the obtained intra- and inter-day apparent diffusion coefficient (ADC) values were calculated. The ADC values significantly decreased with increasing bead concentrations in the pseudo-blood^®, with ADC values of 0.789 ± 0.002, 0.753 ± 0.001, 0.709 ± 0.003, and 0.685 ± 0.003 × 10⁻³ mm² s⁻¹ at bead concentrations of 0%, 9.8%, 28.1%, and 48.5% (Day 0), respectively. The intra- and inter-day coefficients of variation and repeatability coefficient were < 5% and < 5 × 10⁻⁵ mm² s⁻¹ for all phantoms. Therefore, the pseudo-blood^® can be used as a phantom for DWI evaluation.