Conventional PET imaging has usually been limited to a single tracer per scan. We propose a new technique for multi-tracer PET imaging that uses dynamic imaging and multi-tracer compartment modeling including an explicitly derived arterial input function (AIF) for each tracer using blood sampling spectroscopy. For that purpose, at least one of the co-injected tracers must be based on a non-pure positron emitter. The proposed technique was validated in vivo by performing cardiac PET/CT studies on three healthy pigs injected with 18FDG (viability) and 68Ga-DOTA (myocardial blood flow and extracellular volume fraction) during the same acquisition. Blood samples were collected during the PET scan, and separated AIF for each tracer was obtained by spectroscopic analysis. A multi-tracer compartment model was applied to the myocardium in order to obtain the distribution of each tracer at the end of the PET scan. Relative activities of both tracers and tracer uptake were obtained and compared with the values obtained by ex vivo analysis of excised myocardial tissue segments. A high correlation was obtained between multi-tracer PET results, and those obtained from ex vivo analysis (18FDG relative activity: r = 0.95, p < 0.0001; SUV: r = 0.98, p < 0.0001). The proposed technique allows performing PET scans with two tracers during the same acquisition obtaining separate information for each tracer.

中文翻译：

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使用血液采样光谱显式测量PET成像的多示踪动脉输入功能。

常规的PET成像通常仅限于每次扫描使用单个示踪剂。我们提出了一种用于多示踪PET成像的新技术，该技术使用动态成像和多示踪隔室建模，包括使用血液采样光谱学为每个示踪剂显式导出的动脉输入函数（AIF）。为此，至少一个共注入示踪剂必须基于非纯正电子发射体。通过在同一采集期间对注射18FDG（生存力）和68Ga-DOTA（心肌血流量和细胞外体积分数）的三只健康猪进行心脏PET / CT研究，对所提出的技术进行了体内验证。在PET扫描期间收集血液样本，并通过光谱分析获得每种示踪剂的分离AIF。将多示踪剂室模型应用于心肌，以便在PET扫描结束时获得每个示踪剂的分布。获得示踪剂和示踪剂摄取的相对活性，并将其与通过离体心肌组织节段的离体分析获得的值进行比较。多示踪PET结果与离体分析结果之间具有高度相关性（18FDG相对活性：r = 0.95，p <0.0001； SUV：r = 0.98，p <0.0001）。所提出的技术允许在同一采集期间使用两个示踪剂执行PET扫描，从而为每个示踪剂获得单独的信息。获得示踪剂和示踪剂摄取的相对活性，并将其与通过离体分析的心肌组织片段的离体分析获得的值进行比较。多示踪PET结果与离体分析结果之间具有高度相关性（18FDG相对活性：r = 0.95，p <0.0001； SUV：r = 0.98，p <0.0001）。所提出的技术允许在同一采集过程中使用两个示踪剂执行PET扫描，从而获得每个示踪剂的单独信息。获得示踪剂和示踪剂摄取的相对活性，并将其与通过离体分析的心肌组织片段的离体分析获得的值进行比较。多示踪PET结果与离体分析结果之间具有高度相关性（18FDG相对活性：r = 0.95，p <0.0001； SUV：r = 0.98，p <0.0001）。所提出的技术允许在同一采集过程中使用两个示踪剂执行PET扫描，从而获得每个示踪剂的单独信息。