Development of a new hybrid gel phantom using carrageenan and gellan gum for visualizing three-dimensional temperature distribution during hyperthermia and radiofrequency ablation.
We developed a new hybrid gel phantom using carrageenan and gellan gum for the purpose of visualizing three-dimensional temperature distribution. The phantom, which contains carrageenan, gellan gum, non-ionic surface active agent, potassium chloride, n-butanol, sodium azide, and water, shows good transparency at room temperature, and has the advantage that the heated region becomes white and opaque due to segregation of the surface active agent. Carrageenan and gellan gum were added to improve the transparency and fragility of the hybrid gel. Potassium chloride was used to adjust the electrical conductivity of the gel to a range of 5-130 MHz, so that it would be equivalent to that of muscle tissue for each frequency used by electromagnetic heating devices. N-butanol was used to adjust the clouding temperature to a range between 45 and 55 degrees C. In the present study we clarified the important properties of the new phantom, and developed formulae for easy determination of the amounts of ingredients necessary for the desired clouding temperature and electric conductivity. The characteristics of this phantom are: a) a solid form to avoid convection by heat conduction; b) sufficient strength without fragility to form a torso without the use of a reinforcing agent; c) high transparency at room temperature and visualization of the heating area as a white turbidity; d) time-lapse and accurate visualization of the changing temperature area without thermal hysteresis; e) electrical properties similar to those of human tissues; f) ease of production; and g) low cost and good safety. This phantom might assist oncologists in their routine checking and study of the performance of electromagnetic heating devices for hyperthermia and radiofrequency ablation.
Kuroda
Masahiro
M
Department of Radiology, Okayama University Medical School, Japan. kurodamd@cc.okayama-u.ac.jp
Kato
Hirokazu
H
Hanamoto
Katsumi
K
Shimamura
Kaoru
K
Uchida
Tetsuya
T
Wang
Yadi
Y
Akaki
Shiro
S
Asaumi
Jun-Ichi
J
Himei
Kengo
K
Takemoto
Mitsuhiro
M
Kanazawa
Susumu
S
Shibuya
Koichi
K
Kawasaki
Shoji
S
Hiraki
Yoshio
Y
D020001:1-Butanol / Q000737:chemistry; D002351:Carrageenan / Q000737:chemistry*; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D003470:Culture Media / Q000494:pharmacology; D004553:Electric Conductivity; D005782:Gels; D006801:Humans; D006979:Hyperthermia, Induced / Q000295:instrumentation* / Q000379:methods; D007202:Indicators and Reagents / Q000494:pharmacology; D009369:Neoplasms / Q000532:radiotherapy*; D019047:Phantoms, Imaging; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D011189:Potassium Chloride / Q000737:chemistry / Q000494:pharmacology; D019810:Sodium Azide / Q000737:chemistry; D013696:Temperature; D013814:Thermal Conductivity
D003470:Culture Media; D005782:Gels; D007202:Indicators and Reagents; D011135:Polysaccharides, Bacterial; D011189:Potassium Chloride; C048288:gellan gum; D020001:1-Butanol; D002351:Carrageenan; D019810:Sodium Azide