Department of Soil Science, College of Agriculture and Bioresources, 7235University of Saskatchewan, Saskatoon, Canada.
Interdisciplinary Plant Group, Division of Plant Sciences, Department of Chemistry, Missouri Research Reactor Center, 14716University of Missouri, Columbia, MO, USA.
Mol Imaging. 2020 Jan-Dec;19:1536012120966405. doi: 10.1177/1536012120966405.
Positron-emitting nuclides have long been used as imaging agents in medical science to spatially trace processes non-invasively, allowing for real-time molecular imaging using low tracer concentrations. This ability to non-destructively visualize processes in real time also makes positron imaging uniquely suitable for probing various processes in plants and porous environmental media, such as soils and sediments. Here, we provide an overview of historical and current applications of positron imaging in environmental research. We highlight plant physiological research, where positron imaging has been used extensively to image dynamics of macronutrients, signalling molecules, trace elements, and contaminant metals under various conditions and perturbations. We describe how positron imaging is used in porous soils and sediments to visualize transport, flow, and microbial metabolic processes. We also address the interface between positron imaging and other imaging approaches, and present accompanying chemical analysis of labelled compounds for reviewed topics, highlighting the bridge between positron imaging and complementary techniques across scales. Finally, we discuss possible future applications of positron imaging and its potential as a nexus of interdisciplinary biogeochemical research.
正电子放射性核素长期以来一直被用作医学科学中的成像剂，以非侵入性的方式在空间上追踪过程，允许使用低示踪剂浓度进行实时分子成像。这种实时无损可视化过程的能力也使正电子成像特别适合探测植物和多孔环境介质（如土壤和沉积物）中的各种过程。在这里，我们提供了正电子成像在环境研究中的历史和当前应用的概述。我们重点介绍了植物生理学研究，其中正电子成像已被广泛用于在各种条件和干扰下对大量营养素、信号分子、微量元素和污染物金属的动态进行成像。我们描述了正电子成像如何用于多孔土壤和沉积物中，以可视化运输、流动和微生物代谢过程。我们还讨论了正电子成像与其他成像方法之间的接口，并为所审查的主题提供了标记化合物的伴随化学分析，突出了正电子成像与跨尺度互补技术之间的桥梁。最后，我们讨论了正电子成像的可能未来应用及其作为跨学科生物地球化学研究的纽带的潜力。
