TY - JOUR
T1 - Development of a phantom compatible for MRI and hyperthermia using carrageenan gel - Relationship between T1 and T2 values and NaCl concentration
AU - Yoshida, A.
AU - Kato, H.
AU - Kuroda, M.
AU - Hanamoto, K.
AU - Yoshimura, K.
AU - Shibuya, K.
AU - Kawasaki, S.
AU - Tsunoda, M.
AU - Kanazawa, S.
AU - Hiraki, Y.
N1 - Funding Information:
This work was supported in part by Grants-in-Aid for Scientific Research (#13670942, #14370278, #15209063) and Exploratory Research (#138770141) from the Ministry of Education, Culture, Sports, Science and Technology, Japan.
PY - 2004/12
Y1 - 2004/12
N2 - The authors developed a phantom, designated as the CAGN phantom, compatible for MRI and hyperthermia that is useful in the fundamental studies of non-invasive MR thermometry. The ingredients of this phantom are carrageenan, GdCl3 as a T1, modifier, agarose as a T2 modifier, NaCl as a conductivity modifier, NaN3 as an antiseptic and distilled water. Another phantom that was developed, the CAG phantom, has relaxation times that are adjustable to those of any human tissue. To use this phantom for electromagnetic heating, NaCl was added to change the conductivity of the phantom and clarified the relationship between the conductivity and NaCl concentration. This study examined the relationship between relaxation times and NaCl concentration of the CAGN phantom. The results showed that both T1, and T2 values were affected by NaCl and the experimental results led to the empirical formulae expressing the relationship between the relaxation rates (1/T1, 1/T2) and the concentrations of GdCl3, agarose and NaCl. The appropriate concentrations of T1, and T2 modifiers were calculated from these empirical formulae when making a specified phantom that has the required relaxation times and NaCl concentration.
AB - The authors developed a phantom, designated as the CAGN phantom, compatible for MRI and hyperthermia that is useful in the fundamental studies of non-invasive MR thermometry. The ingredients of this phantom are carrageenan, GdCl3 as a T1, modifier, agarose as a T2 modifier, NaCl as a conductivity modifier, NaN3 as an antiseptic and distilled water. Another phantom that was developed, the CAG phantom, has relaxation times that are adjustable to those of any human tissue. To use this phantom for electromagnetic heating, NaCl was added to change the conductivity of the phantom and clarified the relationship between the conductivity and NaCl concentration. This study examined the relationship between relaxation times and NaCl concentration of the CAGN phantom. The results showed that both T1, and T2 values were affected by NaCl and the experimental results led to the empirical formulae expressing the relationship between the relaxation rates (1/T1, 1/T2) and the concentrations of GdCl3, agarose and NaCl. The appropriate concentrations of T1, and T2 modifiers were calculated from these empirical formulae when making a specified phantom that has the required relaxation times and NaCl concentration.
KW - Carrageenan
KW - Hyperthermia
KW - MRI
KW - NaCl
KW - Phantom
KW - Tissue-equivalent
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U2 - 10.1080/0265673042000199268
DO - 10.1080/0265673042000199268
M3 - Article
C2 - 15764343
AN - SCOPUS:9744268862
VL - 20
SP - 803
EP - 814
JO - International Journal of Hyperthermia
JF - International Journal of Hyperthermia
SN - 0265-6736
IS - 8
ER -