Development of a human‐tissue‐like phantom for 3.0‐T MRI

Purpose: A 3.0‐T MRI phantom having human‐tissue‐equivalent relaxation times was developed.Methods: The ingredients of the phantom are carrageenan (for gelatinization), GdCl 3 (as a T 1 ‐relaxation modifier), agarose (as a T 2 ‐relaxation modifier), and NaN 3 (as an antiseptic agent). Numerous samples with varying concentrations of GdCl 3 and agarose were prepared, and T 1 and T 2 were measured using 3.0‐T MRI.Results: Relaxation times of the phantom samples ranged from 395 to 2601 ms for T 1 values and 29 to 334 ms for T 2 values. Based on the measured results, empirical formulae were devised to express the relationships between the concentrations of relaxation modifiers and relaxation times.Conclusions: Adjustment of GdCl 3 and agarose concentrations allows arbitrary setting of relaxation times, and the creation of a phantom that can mimic relaxation times of human‐tissue. Carrageenan is considered the most suitable as a gelling agent for an MRI phantom, as it permits the relatively easy and inexpensive production of a large phantom such as for the human torso, and which can be easily shaped with a knife.