Appleby A, Christman E A, Leghrouz A
Med Phys. 1987 May-Jun;14(3):382-4. doi: 10.1118/1.596052.
Radiation dose distributions are conventionally measured using ionization chambers or diodes in liquid phantoms, or in two dimensions using film. This work describes a new application of magnetic resonance imaging to radiation dose planning. Agarose gels containing ferrous sulfate, sulfuric acid, and benzoic acid have been irradiated with 137Cs gamma rays and 6-14 MeV electrons, to doses of up to 20 Gy. The dose distributions have been imaged by magnetic resonance, making use of the effect on the T1 proton relaxation times of the radiolytic Fe3+. The image intensity was proportional to doses of up to 10 Gy, and images were stable for at least 24 h postirradiation. The G value for Fe3+ production was about 100 (molecules per 100 eV absorbed).
传统上，辐射剂量分布是通过在液体模体中使用电离室或二极管来测量的，或者在二维空间中使用胶片进行测量。这项工作描述了磁共振成像在辐射剂量规划中的一种新应用。含有硫酸亚铁、硫酸和苯甲酸的琼脂糖凝胶已用137Cs伽马射线和6 - 14兆电子伏特电子进行照射，剂量高达20戈瑞。利用辐射分解产生的Fe3+对T1质子弛豫时间的影响，通过磁共振对剂量分布进行成像。图像强度与高达10戈瑞的剂量成正比，并且在辐照后至少24小时内图像保持稳定。Fe3+产生的G值约为100（每吸收100电子伏特产生的分子数）。
