¹⁸Fluorodeoxyglucose Accumulation in Arterial Tissues Determined by PET Signal Analysis

Area of Science:

• Cardiovascular Imaging
• Molecular Imaging
• Atherosclerosis Research

Background:

• Arterial 18fluorodeoxyglucose (FDG) positron emission tomography (PET) is a tool for assessing atherosclerotic plaque macrophages and disease activity.
• The precise distribution of FDG within different arterial cell types remains unclear.

Purpose of the Study:

• To investigate FDG uptake patterns in various arterial tissues.
• To determine the contribution of different tissues to the overall PET signal in normal and atherosclerotic arteries.

Main Methods:

• Atherosclerosis was induced in Yucatan minipigs using a high-fat, high-cholesterol diet.
• FDG-PET and CT scans were performed, followed by histological analysis of arterial tissues.
• FDG distribution was quantified using in vivo PET signal modeling and confirmed with direct autoradiography.

Main Results:

• FDG-PET imaging in minipigs closely resembled human imaging findings.
• Quantitative modeling demonstrated comparable FDG accumulation in macrophages and other arterial tissues, including smooth muscle cells.
• Autoradiography validated these findings in both normal and atherosclerotic arteries.

Conclusions:

• FDG uptake is not selective to macrophages in arterial tissues.
• This finding provides a mechanistic explanation for clinical observations that previously seemed inconsistent with macrophage-selective FDG uptake in atherosclerosis.