ABSTRACT

Reduction of radiation dose from medical investigations still remains an important strategy. The combined effect of the reduced injected activity of ¹⁸F – FDG, low tube voltage & iodine concentration with iterative reconstruction on image quality, radiation dose, and DNA damage in patients undergoing PET/CT examination were examined. The study includes 16 patients who underwent PET/CT investigation twice using two different protocols; standard & new. A new protocol was followed during follow-up after 4–6 months. All acquisition and reconstruction parameters were the same in both protocols, except administered activity, iodine concentration and CT tube voltage which was reduced. Image quality was assessed using various parameters. Effective dose from PET/CT was assessed using CTDIvol and ICRP coefficients. DNA damage analysis was performed using comet and γ-H2AX assay. No significant difference was noted in quality parameters between two protocols (p > 0.05) except CT noise level (p < 0.05). Mean iodine dose, total radiation dose, mean foci and TM in the new protocol were found significantly lower than standard PET/CT (p < 0.05). There were 26.68% reduction in radiation dose, 10% reduction in contrast load, 20.31% reduction in the number of foci and 17.67% reduction in TM was noted with optimized protocol.

摘要

减少医学研究的辐射剂量仍然是一项重要的战略。¹⁸注射活性降低的综合效果 F – FDG、低管电压和碘浓度，对接受 PET/CT 检查的患者的图像质量、辐射剂量和 DNA 损伤进行迭代重建。该研究包括 16 名使用两种不同方案接受两次 PET/CT 检查的患者；标准和新。在 4-6 个月后的随访期间遵循新的方案。两种方案中的所有采集和重建参数都相同，除了降低的管理活动、碘浓度和 CT 管电压。使用各种参数评估图像质量。使用 CTDIvol 和 ICRP 系数评估来自 PET/CT 的有效剂量。使用彗星和γ-H2AX测定进行DNA损伤分析。两种方案之间的质量参数没有显着差异（p > 0。05) 除了 CT 噪声水平 (p < 0.05)。发现新方案中的平均碘剂量、总辐射剂量、平均病灶和 TM 显着低于标准 PET/CT（p < 0.05）。使用优化方案发现辐射剂量减少 26.68%，造影剂负荷减少 10%，病灶数量减少 20.31%，TM 减少 17.67%。