Evaluation of non-stenotic carotid atherosclerotic plaques with combined FDG-PET imaging and CT angiography in patients with ischemic stroke of unknown origin

J Nucl Cardiol. 2022 Jun;29(3):1329-1336. doi: 10.1007/s12350-020-02511-8. Epub 2021 Jan 18.

Abstract

Objectives: Non-stenotic plaques are an underestimated cause of ischemic stroke. Imaging aspects of high-risk carotid plaques can be identified on CT angiography (CTA) and 18F-fluoro-deoxyglucose positron emission tomography (FDG-PET) imaging. We evaluated in patients with cryptogenic ischemic stroke the usefulness of FDG-PET-CTA.

Methods: 44 patients imaged with CTA and FDG-PET were identified retrospectively. Morphological features were identified on CTA. Intensity of FDG uptake in carotid arteries was quantified on PET.

Results: Patients were imaged 7 ± 8 days after stroke. 44 non-stenotic plaques with increased 18F-FDG uptake were identified in the carotid artery ipsilateral to stroke and 7 contralateral. Most-diseased-segment TBR on FDG-PET was higher in artery ipsilateral vs. contralateral to stroke (2.24 ± 0.80 vs. 1.84 ± 0.50; p < .05). In the carotid region with high FDG uptake, prevalence of hypodense plaques and extent of hypodensity on CTA were higher in artery ipsilateral vs. contralateral to stroke (41% vs. 11%; 0.72 ± 1.2 mm2 vs. 0.13 ± 0.43 mm2; p < .05).

Conclusions: In patients with ischemic stroke of unknown origin and non-stenotic plaques, we found an increased prevalence of high-risk plaques features ipsilateral vs. contralateral to stroke on FDG-PET-CTA imaging suggesting a causal role for these plaques.

Keywords: FDG-PET; cryptogenic stroke; non-stenotic plaque; vulnerable plaque.

MeSH terms

  • Carotid Arteries
  • Computed Tomography Angiography
  • Fluorodeoxyglucose F18
  • Humans
  • Ischemic Stroke*
  • Plaque, Atherosclerotic* / complications
  • Plaque, Atherosclerotic* / diagnostic imaging
  • Positron-Emission Tomography / methods
  • Retrospective Studies
  • Stroke* / diagnostic imaging

Substances

  • Fluorodeoxyglucose F18