Dose Reduction in Pediatric Molecular Imaging

描述(申请人提供)：医学成像引起的辐射暴露已成为一个公共安全问题。对于儿科患者来说，减少剂量尤其重要，因为这类患者由于其组织对辐射的敏感性增强，以及可能出现随机辐射效应的较长时间段，其风险增加。这项建议的目的是开发和验证可用于最大限度地减少接受分子成像手术的儿科患者的辐射暴露，而不会对图像的诊断质量产生不利影响的技术。该建议的假设是有可能在不影响研究图像质量的情况下减少儿科分子成像患者接收的吸收剂量，方法是：(1)使给药活动量和图像采集时间个体化，以更好地考虑患者特定的身体大小和形状可能对探测器计数率密度的影响；(2)调整采集参数，以考虑到儿科成像中较小的视场；(3)改进图像重建方法，以便能够从这些较低计数、较小视场的图像生成图像。在目前的临床实践中，儿科分子成像的剂量主要集中在经验法则方法上，以识别儿童在不同成像程序中的活动。通过使用最先进的模拟、图像质量评估和辐射剂量测定工具，本赠款申请中提出的工作将以更严格和科学验证的方式审查剂量减少方法。这一方法将为儿童(以及可能的成人)分子成像带来临床上可实施的剂量减少技术，与国家在不影响图像诊断质量的情况下减少儿童和成人CT和透视引导干预的剂量的努力不相上下。

DESCRIPTION (provided by applicant): The radiation exposure resulting from medical imaging has become a public safety concern. Dose reduction for pediatric patients is particularly important since such patients are at increased risk owing to the enhanced radiosensitivity of their tissues and the longer time-period over which stochastic radiation effects may manifest. The objective of this proposal is to develop and validate techniques that can be used to minimize the radiation exposure to pediatric patients undergoing molecular imaging procedures without adversely impacting the diagnostic quality of the images. The hypothesis of this proposal is that it is possible to reduce the absorbed dose received by pediatric molecular imaging patients without compromising the image quality of the study by: (1) individualizing the amount of administered activity and the image acquisition time to better account for the effects that patient-specific body size and shape may have on the detector count-rate density; (2) adjusting acquisition parameters to account for the smaller field of view in pediatric imaging; (3) improving image reconstruction methods to enable image generation from these lower-count, smaller field-of-view images. In current clinical practice, dosing for pediatric molecular imaging has focused on rule-of-thumb approaches to identifying the activity administered to children for different imaging procedures. By using state-of-the-art simulation, image quality evaluation and radiation dosimetry tools, the work proposed in this grant application will examine dose reduction methods in a much more rigorous and, scientifically validated manner. This approach will lead to clinically implementable dose reduction techniques for pediatric (and potentially adult) molecular imaging on par with national efforts to reduce doses in pediatric and adult CT and fluoroscopically guided interventions without adversely impacting the diagnostic quality of the images.