Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3723_Библиотеки_им_академика_М_И_Перельмана

Initial studies in molecular CAD imaging were conducted with the glucose analog FDG.FDG is a positron-emitting radionuclide that has been widely used in molecular imaging for the assess­ment of inammatory and neoplastic processes utilizing PET.After intravenous injection, FDG is absorbed by cells using glucose transporter pro­teins (primarily GLUT-1) and is phosphorylated by hexokinase to its nal metabolite form, FDG­phosphate, which cannot be metabolized and thus remains trapped in cells. Thus, FDG serves as a marker for glucose metabolism and can label tis­sues with increased metabolic activity [7]. The exact cells responsible for FDG increase in ath­erosclerosis remain ill-dened. In vitro analyses of glucose utilization and metabolism in ather­oma-bound cell populations showed that direct inammatory activation by cytokines does not increase FDG metabolism inlocal macrophages, but rather in vascular smooth muscles and endo­thelial cells [8]. Moreover, cell studies simulating a hypoxic environment increased glucose trans­port, and thus FDG uptake, in macrophages [8]. Further studies are needed to dissect the cell types and pathways leading to increased GLUT-1 expression and FDG uptake in atherosclerotic lesions. Despite the incompletely understood biology, and due to its correlation with the relative increase inlocal macrophage metabolic activity, FDG-PET imaging quickly gained interest in applications for labeling atherosclerotic disease with active inammation. The potential of FDG­PET to non-invasively detect highly metabolic macrophages and (likely) highly glycolytic smooth muscles very early in the atherosclerotic disease process offered a vital tool for CAD risk assessment [4, 9–16]. Additional investigations demonstrated FDG uptake in atherosclerotic plaques to be directly correlated with macrophage density and inammation [14, 17, 18].