Utilization of Lutetium Background Radiation for Quantitative Total-Body PET Imaging

利用镥背景辐射进行定量全身 PET 成像

• 批准号: 10532720
• 负责人: Negar Omidvari
• 金额: $ 7.99万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10532720
• 关键词: Address; Adolescent; Adopted; Affect; Anatomy; Attention; Background Radiation; Beds; Body Regions; Cardiology; Child; Childhood; Clinical; Compensation; Data; Detection; Diagnosis; Discipline of Nuclear Medicine; Disease; Dose; Elements; Ensure; Event; Generations; Health; Human; Image; Infant; Inflammatory; Length; Lesion; Lutetium; Maps; Methodology; Methods; Monte Carlo Method; Motion; Neurology; Noise; Oncology; Patients; Photons; Population; Positioning Attribute; Positron-Emission Tomography; Process; Prognosis; Protocols documentation; Radiation Dose Unit; Research; Scanning; Signal Transduction; Source; Speed; System; Technology; Time; Translating; Vision; X-Ray Computed Tomography; attenuation; clinical application; data exchange; deep learning; denoising; detector; image reconstruction; image registration; improved; prevent; radiotracer; reconstruction; research study; tool; transmission process; treatment planning; trend; uptake

Project Summary/Abstract Positron emission tomography (PET) is widely used as a clinical and research tool for diagnosis, prognosis, and treatment planning in oncology, while increasingly being adopted in other fields such as cardiology, neurology, and inflammatory disorders. The latest generation of PET scanners offer significant enhancements in sensitivity with an increased axial imaging extent. The sensitivity gain in these scanners directly translates into improved image quality in standard imaging protocols and enables use of new scan protocols with ultrashort time frames or ultralow-dose scans. The long axial-field-of-view (AFOV) in these systems offers unique opportunities and challenges in addressing quantification barriers in PET. Among a wide range of factors affecting the quantitative accuracy of PET, the effects from attenuation, scatter, and human motion are common and predominant. In this project, we aim to utilize the lutetium (Lu) background radiation present in these scanners: first, for attenuation correction (AC) and scatter correction (SC), and second, for motion correction (MC), with particular attention on ultralow-dose PET scans. AC and SC are usually performed using the attenuation maps (μ-maps) obtained from a computed tomography (CT) scan performed prior to PET. As ultralow-dose PET scans are now made possible with long-AFOV PET scanners, it is desirable to further reduce the radiation dose by estimating the μ-maps from the Lu background radiation, when an additional CT scan can be avoided. We will primarily study our methodology with the uEXPLORER scanner, which is the world’s first total-body PET scanner that can simultaneously image the entire body, and will employ the Lu background data together with the PET emission data in maximum likelihood reconstruction of attenuation and activity (MLAA). We expect to achieve improved quantitative accuracy compared to prior studies as the high sensitivity and increased flux of background radiation originating from the large volume of Lu-based detectors in long-AFOV PET scanners, in addition to the ability of scanning the entire body in a single bed position, enables more efficient utilization of the Lu background. Finally, as human motion causes quantification bias by introducing image blurring and attenuation-emission mismatches, we will use a data-driven total-body MC framework to correct both the Lu-background-based μ-maps and the PET images. We will study the effects of different types of motion on PET quantification in two cases: first, when PET emission data is used for motion-estimation and second, feasibility of utilizing the Lu background data in motion-estimation, particularly in ultralow-dose scans or body regions with low radiotracer uptake, in which standard emission-based data-driven motion estimation methods are prone to error. This is especially important in total-body PET, as motion in one region of body could affect the AC and SC in other regions. We believe this contribution will improve the quantification and diagnosis capability in the new generation of PET scanners and will enable wider clinical and research applications of ultralow-dose PET, particularly in sensitive populations such as infants, children, and adolescents, leading to better understanding of human health.

项目摘要/摘要 正电子发射断层扫描（PET）被广泛用作诊断，预后和预后的临床和研究工具 肿瘤学的治疗计划，同时越来越多地在心脏病学，神经病学等其他领域采用 和炎症性疾病。最新一代的宠物扫描仪可在敏感性方面具有重大增强 轴向成像范围增加。这些扫描仪的灵敏度增益直接转化为改进 标准成像协议中的图像质量，并可以使用具有超短时框的新扫描协议 或超剂量扫描。这些系统中的长轴向视野（AFOV）提供了独特的机会和 解决宠物的定量障碍方面的挑战。在影响定量的广泛因素中 宠物的准确性，衰减，散射和人类运动的影响是普遍的，主要是主导。在这个 项目，我们的目标是利用这些扫描仪中存在的Lutetium（LU）背景辐射：首先，用于衰减 校正（AC）和散射校正（SC），其次进行运动校正（MC），特别注意 超剂量PET扫描。 AC和SC通常使用从衰减图（μ-MAP）进行 在PET之前进行的计算机断层扫描（CT）扫描。由于现在使超级剂量的PET扫描成为可能 使用长期AFOV PET扫描仪，希望通过估计从 可以避免额外的CT扫描时LU背景辐射。我们将主要研究我们的 使用Uexplorer扫描仪的方法，这是世界上第一个可以 类似地，图像整个身体，并将使用LU背景数据以及PET发射 衰减和活动的最大似然重建（MLAA）中的数据。我们希望取得改善 与先前的研究相比，定量精度是高灵敏度和背景辐射的通量增加 除了能力 在单床位置扫描整个身体，可以更有效地利用LU背景。最后， 由于人类运动通过引入模糊和衰减发射不匹配而引起定量偏差，因此 我们将使用数据驱动的总体MC框架来纠正基于Lu-background的μ-MAP和 宠物图像。我们将在两种情况下研究不同类型的运动对PET定量的影响：首先 宠物排放数据用于运动估计，其次，使用LU背景数据的可行性 运动估计，尤其是在超剂量扫描或身体区域，其中放射性示意剂摄取低，其中 基于标准排放的数据驱动运动估计方法容易出错。这尤其重要 在整个身体的宠物中，由于人体一个区域的运动可能会影响其他地区的AC和SC。我们相信这一点 贡献将提高新一代PET扫描仪的数量和诊断能力， 将实现超剂量宠物的更广泛的临床和研究应用，尤其是在敏感人群中 例如婴儿，儿童和青少年，可以更好地了解人类健康。