Physical principles and technology of clinical PET imaging.
Physical principles and technology of clinical PET imaging.
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DOI：
10.47102/annals-acadmedsg.v33n2p133
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发表时间：
2004-03
期刊：
影响因子：
--
通讯作者：
David W. Townsend
中科院分区：
文献类型：
--
作者：
David W. Townsend
正电子放射核素分子成像在恶性疾病的诊断和分期以及监测治疗反应方面发挥着越来越重要的作用。为了应对这一挑战，近年来在成像技术的性能方面取得了重大进展。这种发展受到正电子发射断层扫描（PET）物理学的限制，设计或改进PET扫描仪的主要目标是实现高空间分辨率和灵敏度，同时最大限度地提高相对于噪声过程贡献的真实巧合计数率。PET中的噪声贡献不仅包括与光子计数相关的统计效应，还包括散射和随机巧合等背景过程。最近，用于PET探测器的新型、更快的闪烁体和电子设备的发展，以及基于统计的算法，可以在几分钟内重建全三维（3D） PET图像，大大减少了临床成像时间，同时提高了图像质量。最近的一项进展是，在PET/CT扫描仪中结合功能成像和计算机断层扫描（CT），通过消除冗长的PET传输扫描和提供准确的功能异常解剖定位，进一步缩短了研究时间。PET成像技术现在已经改进到可以在不到10分钟的时间内完成解剖和功能临床研究，尽管利用这种高通量潜力将对诊断成像部门的患者管理提出挑战。本文回顾了PET的物理原理，并总结了PET扫描仪技术的最新发展，从新的PET探测器的引入到PET/CT组合扫描仪的发展。
Molecular imaging with positron-emitting radionuclides is playing an increasingly important role in the diagnosis and staging of malignant disease and in monitoring response to therapy. To meet this challenge, significant improvements in the performance of the imaging technology have been achieved in recent years. Such developments are subject to the constraints imposed by the physics of positron emission tomography (PET) and the main objectives in designing or improving PET scanners are to achieve high spatial resolution and sensitivity while maximising the true coincidence count rate relative to contributions from noise processes. Noise contributions in PET include not only statistical effects associated with photon counting but also background processes such as scatter and random coincidences. The recent developments of new, faster scintillators and electronics for PET detectors, as well as statistically-based algorithms that reconstruct fully three-dimensional (3D) PET images in minutes, have dramatically reduced clinical imaging times while improving image quality. A recent advance, the combination of functional imaging and computed tomography (CT) in the PET/CT scanner has further reduced the study duration by eliminating the lengthy PET transmission scan and providing accurate anatomical localisation of functional abnormalities. PET imaging technology has now improved to where a combined anatomical and functional clinical study can be completed in less than 10 minutes--although taking advantage of such high throughput potential will challenge patient management in diagnostic imaging departments. This paper reviews the physical principles underlying PET and summarises the recent developments in PET scanner technology, from the introduction of new PET detectors to the development of the combined PET/CT scanner.