In vivo mapping of vascular inflammation using the translocator protein tracer 18F-FEDAA1106

Mol Imaging. 2014:13. doi: 10.2310/7290.2014.00014.

Abstract

Noninvasive imaging methods are required to monitor the inflammatory content of atherosclerotic plaques. FEDAA1106 (N-(5-fluoro-2-phenoxyphenyl)-N-(2-(2-fluoroethoxy)-5-methoxybenzyl) acetamide) is a selective ligand for TSPO-18kDa (also known as peripheral benzodiazepine receptor), which is expressed by activated macrophages. We compared 18F-FEDAA1106 and 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG, a marker of glucose metabolism) for positron emission tomographic (PET) imaging of vascular inflammation. This was tested using a murine model in which focal inflammation was induced in the carotid artery via placement of a constrictive cuff. Immunostaining revealed CD68-positive cells (macrophages) at a disturbed flow site located downstream from the cuff. Dynamic PET imaging using 18F-FEDAA1106 or 18F-FDG was registered to anatomic data generated by computed tomographic (CT)/CT angiography. Standardized uptake values were significantly increased at cuffed compared to contralateral arteries using either 18F-FEDAA1106 (p < .01) or FDG (p < .05). However, the 18F-FEDAA1106 signal was significantly higher at the inflamed disturbed flow region compared to the noninflamed uniform flow regions, whereas differences in FDG uptake were less distinct. We conclude that 18F-FEDAA1106 can be used in vivo for detection of vascular inflammation. Moreover, the signal pattern of 18F-FEDAA1106 corresponded with vascular inflammation more specifically than FDG uptake.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetamides* / metabolism
  • Animals
  • Carotid Arteries / pathology*
  • Disease Models, Animal
  • Fluorodeoxyglucose F18* / metabolism
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Plaque, Atherosclerotic / diagnosis*
  • Plaque, Atherosclerotic / diagnostic imaging
  • Positron-Emission Tomography
  • Radiopharmaceuticals* / metabolism

Substances

  • Acetamides
  • N-(5-fluoro-2-phenoxyphenyl)-N-(2-fluoroethyl-5-methoxybenzyl)acetamide
  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18