Carotid plaque inflammation assessed with (18)F-FDG PET/CT is higher in symptomatic compared with asymptomatic patients

Karolina Skagen; Kjersti Johnsrud; Kristin Evensen; Helge Scott; Kirsten Krohg-Sørensen; Frode Reier-Nilsen; Mona-Elisabeth Revheim; Jan Gunnar Fjeld; Mona Skjelland; David Russell

doi:10.1111/ijs.12430

Carotid plaque inflammation assessed with (18)F-FDG PET/CT is higher in symptomatic compared with asymptomatic patients

Int J Stroke. 2015 Jul;10(5):730-6. doi: 10.1111/ijs.12430. Epub 2015 Jan 15.

Affiliations

¹ Department of Neurology, Oslo University Hospital and University of Oslo, Oslo, Norway.
² Department of Radiology and Nuclear Medicine, Oslo University Hospital and University of Oslo, Oslo, Norway.
³ Department of Pathology, Oslo University Hospital and University of Oslo, Oslo, Norway.
⁴ Department of Thoracic Surgery, Oslo University Hospital and University of Oslo, Oslo, Norway.
⁵ Department of Vascular and Thoracic surgery, Akershus University Hospital, Oslo, Norway.
⁶ Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
⁷ Department of Radiology and Nuclear Medicine, Oslo University Hospital and Akershus University College of Applied Sciences, Oslo, Norway.

PMID: 25588553
DOI: 10.1111/ijs.12430

Abstract

Background: Carotid artery plaque inflammation is thought to be an important marker of plaque vulnerability and increased stroke risk.

Aim: The main aim of this study was to assess the level of agreement between 2-deoxy-2-[(18)F] fluoro-D-glucose (18F-FDG) uptake on PET (positron emission tomography) scan in carotid plaques, with cerebrovascular symptoms, carotid plaque ultrasound echogenicity and histological assessments of plaque inflammation.

Methods: Thirty-six patients with ≥70% carotid stenosis scheduled for carotid endarterectomy underwent a Colour Duplex ultrasound, (18)F-FDG PET/CT and blood tests less than 24 h prior to surgery. Plaques were defined as symptomatic when associated with ipsilateral cerebral ischemic symptoms within 30 days prior to inclusion. Plaques were assessed histologically following endarterectomy. The level of agreement between (18)F-FDG uptake (mean SUVmax and SUVmax ), and target-to-background ratio, symptoms, plaque echolucency, and histological evidence of inflammation was assessed.

Results: The amount of (18)F-FDG uptake in plaques and the amount of inflammation on histological assessment were significantly correlated (r = 0·521, P = 0·003). (18)F-FDG uptake was significantly higher in symptomatic plaques with median SUVmax 1·75 (1·26-2·04) in symptomatic, and 1·43 (1·15-2·28) in asymptomatic patients (P = 0·03). (18)F-FDG uptake was also positively correlated with echolucency on Doppler ultrasound (P = 0·03).

Conclusion: (18)F-FDG uptake on PET/CT correlated with histological assessments of inflammation and was higher in patients with symptomatic compared with asymptomatic carotid artery plaques. These results support the use of (18)F-FDG PET/CT in the detection inflammation in carotid atherosclerosis, which may be of help in the detection of vulnerable plaques.

Keywords: carotid plaque; carotid plaque echogenicity; carotid stenosis; carotid ultrasound; ischemic stroke; positron emission tomography.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Carotid Stenosis* / diagnostic imaging
Endarterectomy, Carotid
Female
Fluorodeoxyglucose F18*
Humans
Inflammation / complications
Inflammation / diagnostic imaging*
Male
Middle Aged
Neurologic Examination
Positron-Emission Tomography*
Retrospective Studies
Severity of Illness Index
Statistics, Nonparametric
Tomography, X-Ray Computed
Ultrasonography, Doppler, Color

Substances

Fluorodeoxyglucose F18