Dose Reduction in Pediatric Molecular Imaging

描述（由申请人提供）：医学成像造成的辐射暴露已经成为一个公共安全问题。减少儿科患者的剂量尤其重要，因为这些患者由于其组织的放射敏感性增强以及随机辐射效应可能显现的时间较长而面临更高的风险。本提案的目的是开发和验证可用于在不影响图像诊断质量的情况下将接受分子成像手术的儿科患者的辐射暴露降至最低的技术。本提案的假设是，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受的吸收剂量：(1)个体化给药活动量和图像采集时间，以更好地考虑患者特定的身体大小和形状可能对检测器计数率密度的影响；(2)调整采集参数，以适应儿童成像中较小的视场；(3)改进图像重建方法，使这些低计数、小视场图像能够生成图像。在目前的临床实践中，儿科分子成像的剂量集中在经验法则上，以确定不同成像程序对儿童进行的活动。通过使用最先进的模拟、图像质量评估和辐射剂量测量工具，本拨款申请中提出的工作将以更严格和科学验证的方式研究剂量减少方法。这种方法将导致儿科（以及潜在的成人）分子成像的临床可实施的剂量减少技术，与国家在儿童和成人CT和透视引导干预中减少剂量的努力相当，而不会对图像的诊断质量产生不利影响。

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.