Baldock C, Rintoul L, Keevil S F, Pope J M, George G A
Centre for Medical and Health Physics, Queensland University of Technology, Brisbane, Australia.
Phys Med Biol. 1998 Dec;43(12):3617-27. doi: 10.1088/0031-9155/43/12/017.
Polyacrylamide gels (PAGs) are used for magnetic resonance imaging radiation dosimetry. Fourier transform (FT) Raman spectroscopy studies were undertaken to investigate cross-linking changes during the copolymerization of polyacrylamide gels in the spectral range of 200-3500 cm(-1). Vibrational bands of 1285 cm(-1) and 1256 cm(-1) were assigned to acrylamide and bis-acrylamide single CH2 deltaCH2 binding modes. Bands were found to decrease in amplitude with increasing absorbed radiation dose as a result of copolymerization. Principal component regression was performed on FT-Raman spectra of PAG samples irradiated to 50 Gy. Two components were found to be sufficient to account for 98.7% of the variance in the data. Cross validation was used to establish the absorbed radiation dose of an unknown PAG sample from the FT-Raman spectra. The calculated correlation coefficient between measured and predictive samples was 0.997 with a standard error of estimate of 0.976 and a standard error of prediction of 1.140. Results demonstrate the potential of FT-Raman spectroscopy for ionizing radiation dosimetry using polyacrylamide gels.
聚丙烯酰胺凝胶（PAGs）用于磁共振成像辐射剂量测定。进行了傅里叶变换（FT）拉曼光谱研究，以调查聚丙烯酰胺凝胶在200 - 3500 cm(-1)光谱范围内共聚过程中的交联变化。1285 cm(-1)和1256 cm(-1)的振动带被指定为丙烯酰胺和双丙烯酰胺的单个CH2δCH2结合模式。由于共聚作用，发现这些带的振幅随着吸收辐射剂量的增加而降低。对辐照至50 Gy的PAG样品的FT - 拉曼光谱进行主成分回归。发现两个成分足以解释数据中98.7%的方差。使用交叉验证从FT - 拉曼光谱确定未知PAG样品的吸收辐射剂量。测量样品与预测样品之间计算的相关系数为0.997，估计标准误差为0.976，预测标准误差为1.140。结果证明了FT - 拉曼光谱在使用聚丙烯酰胺凝胶进行电离辐射剂量测定方面的潜力。
