Vascular Inflammation in Subclinical Atherosclerosis Detected by Hybrid PET/MRI

J Am Coll Cardiol. 2019 Apr 2;73(12):1371-1382. doi: 10.1016/j.jacc.2018.12.075.

Abstract

Background: Atherosclerosis is a chronic inflammatory disease, but data on arterial inflammation at early stages is limited.

Objectives: The purpose of this study was to characterize vascular inflammation by hybrid 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/magnetic resonance imaging (PET/MRI).

Methods: Carotid, aortic, and ilio-femoral 18F-FDG PET/MRI was performed in 755 individuals (age 40 to 54 years; 83.7% men) with known plaques detected by 2-/3-dimensional vascular ultrasound and/or coronary calcification in the PESA (Progression of Early Subclinical Atherosclerosis) study. The authors evaluated the presence, distribution, and number of arterial inflammatory foci (increased 18F-FDG uptake) and plaques with or without inflammation (coincident 18F-FDG uptake).

Results: Arterial inflammation was present in 48.2% of individuals (24.4% femorals, 19.3% aorta, 15.8% carotids, and 9.3% iliacs) and plaques in 90.1% (73.9% femorals, 55.8% iliacs, and 53.1% carotids). 18F-FDG arterial uptakes and plaques significantly increased with cardiovascular risk factors (p < 0.01). Coincident 18F-FDG uptakes were present in 287 of 2,605 (11%) plaques, and most uptakes were detected in plaque-free arterial segments (459 of 746; 61.5%). Plaque burden, defined by plaque presence, number, and volume, was significantly higher in individuals with arterial inflammation than in those without (p < 0.01). The number of plaques and 18F-FDG uptakes showed a positive albeit weak correlation (r = 0.25; p < 0.001).

Conclusions: Arterial inflammation is highly prevalent in middle-aged individuals with known subclinical atherosclerosis. Large-scale multiterritorial PET/MRI allows characterization of atherosclerosis-related arterial inflammation and demonstrates 18F-FDG uptake in plaque-free arterial segments and, less frequently, within plaques. These findings suggest an arterial inflammatory state at early stages of atherosclerosis. (Progression of Early Subclinical Atherosclerosis [PESA]; NCT01410318).

Keywords: (18)F-FDG PET/MRI; arterial inflammation; plaque inflammation; subclinical atherosclerosis.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Arteries* / diagnostic imaging
  • Arteries* / immunology
  • Asymptomatic Diseases
  • Atherosclerosis / diagnosis*
  • Calcinosis / diagnosis
  • Disease Progression
  • Early Diagnosis
  • Female
  • Fluorodeoxyglucose F18 / pharmacology
  • Humans
  • Inflammation / diagnosis
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Multimodal Imaging / methods
  • Plaque, Atherosclerotic* / diagnostic imaging
  • Plaque, Atherosclerotic* / immunology
  • Positron-Emission Tomography / methods*
  • Radiopharmaceuticals / pharmacology
  • Tomography, X-Ray Computed / methods

Substances

  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18

Associated data

  • ClinicalTrials.gov/NCT01410318