Divgi Chaitanya R
Nuclear Medicine Clinical Molecular Imaging, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.
Proc Am Thorac Soc. 2009 Aug 15;6(5):464-8. doi: 10.1513/pats.200902-005AW.
Molecular imaging (MI) may be defined as imaging in vivo using molecules that report on biologic function. This review will focus on the clinical use of radioactive tracers (nonpharmacologic amounts of compounds labeled with a radioactive substance) that permit external imaging using single photon emission computed tomography (planar, SPECT) or positron emission tomography (PET) imaging. Imaging of lung cancer has been revolutionized with the use of fluorine-18-labeled fluorodeoxyglucose (18F-FDG), an analog of glucose that can be imaged using PET. The ability to carry out whole body imaging after intravenous injection of 18F-FDG allows accurate staging of disease, helping to determine regional and distant nodal and other parenchymal involvement. Glycolysis is increased in nonmalignant conditions, including inflammation (e.g., sarcoidosis), and 18F-FDG PET is a sensitive method for evaluation of active inflammatory disease. Inflammatory disease has been imaged, even before the advent of PET, with planar and SPECT imaging using gallium-67, a radiometal that binds to transferrin. Metabolic alteration in pulmonary pathology is currently being studied, largely in lung cancer, primarily with PET, with a variety of other radiotracers. Prominent among these is thymidine; fluorine-18-labeled thymidine PET is being increasingly used to evaluate proliferation rate in lung and other cancers. This overview will focus on the clinical utility of 18F-FDG PET in the staging and therapy evaluation of lung cancer as well as in imaging of nonmalignant pulmonary conditions. PET and SPECT imaging with other radiotracers of interest will also be reviewed. Future directions in PET imaging of pulmonary pathophysiology will also be explored.
分子成像（MI）可定义为利用报告生物功能的分子进行体内成像。本综述将聚焦于放射性示踪剂（非药理剂量的用放射性物质标记的化合物）的临床应用，这些示踪剂可通过单光子发射计算机断层扫描（平面、SPECT）或正电子发射断层扫描（PET）成像进行外部成像。氟-18标记的氟脱氧葡萄糖（18F-FDG）的应用彻底改变了肺癌成像，18F-FDG是一种葡萄糖类似物，可通过PET成像。静脉注射18F-FDG后进行全身成像的能力可实现疾病的准确分期，有助于确定区域和远处淋巴结及其他实质受累情况。在包括炎症（如结节病）在内的非恶性疾病中，糖酵解会增加，18F-FDG PET是评估活动性炎症性疾病的一种敏感方法。甚至在PET出现之前，炎症性疾病就已通过使用与转铁蛋白结合的放射性金属镓-67进行平面和SPECT成像。目前正在对肺部病理学中的代谢改变进行研究，主要是针对肺癌，主要使用PET及多种其他放射性示踪剂。其中突出的是胸腺嘧啶核苷；氟-18标记的胸腺嘧啶核苷PET越来越多地用于评估肺癌和其他癌症的增殖率。本综述将聚焦于18F-FDG PET在肺癌分期和治疗评估以及非恶性肺部疾病成像中的临床应用。还将综述使用其他感兴趣的放射性示踪剂进行的PET和SPECT成像。也将探索肺部病理生理学PET成像的未来发展方向。
