Radiological Physics and Technology

, Volume 11, Issue 4, pp 375–381 | Cite as

Influence of magnesium chloride on the dose–response of polyacrylamide-type gel dosimeters

  • Shin-ichiro HayashiEmail author
  • Hiraku Kawamura
  • Shuji Usui
  • Takahiro Tominaga


We investigated the effect of magnesium chloride (MgCl2) on the nuclear magnetic resonance dose–response of polyacrylamide-type (PAGAT, NIPAM, and VIPET) gel dosimeters containing acrylamide, N-isopropylacrylamide, and N-vinylpyrrolidone as a monomer, respectively. The dose-transverse relaxation rates (1/T2 = R2) obtained from magnetic resonance imaging data revealed that a substantial increase in the dose–R2 response occurred as the concentration of MgCl2 in the gel dosimeters increased. The sensitivity of the PAGAT gel with 1.0 M MgCl2 was found to be approximately one order higher than that of the same gel without MgCl2. In addition, the water equivalences of the gels with MgCl2 were evaluated over a wide range of photon energies. The results indicated that MgCl2 acts as a powerful sensitizer to radiation-induced free-radical polymerization in polyacrylamide-type gel dosimeters, but does not interfere with the desirable properties of basic polyacrylamide-type gel dosimeters (i.e., the dose rate and dose integration).


Polymer gel dosimeter PAGAT NIPAM VIPET Magnesium chloride Radiotherapy 


Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

This article does not contain any studies performed with human or animal participants.


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Copyright information

© Japanese Society of Radiological Technology and Japan Society of Medical Physics 2018

Authors and Affiliations

  1. 1.Department of Clinical Radiology, Faculty of Health SciencesHiroshima International UniversityHigashi-HiroshimaJapan
  2. 2.Department of Radiological SciencesIbaraki Prefectural University of Health SciencesIbarakiJapan

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