Carotid inflammation on ¹⁸F-fluorodeoxyglucose positron emission tomography associates with recurrent ischemic lesions.

Background: Inflammation plays an important role in the development of ischemic stroke. We hypothesized that inflammation of carotid atherosclerosis, as measured by (18)F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET), associates with the early recurrent ischemic lesions (ERILs).

Methods: This prospective study included patients with symptomatic carotid atherosclerosis. ERILs were defined as newly developed ischemic lesions in the territory of symptomatic internal carotid artery stenosis, as detected by follow-up diffusion-weighted imaging (DWI). The patients with and without ERILs were compared in terms of risk factors, inflammatory markers, and FDG uptake on PET.

Results: Of the 21 patients, 8 had ERILs (38.1%). Compared to the patients without ERILs, those with ERILs had higher FDG uptake (maximum standardized uptake value, 3.07 ± 0.79 vs. 2.17 ± 0.68, p=0.013) and were more likely to have irregular carotid plaques (100% vs. 38.5%, p=0.007). Inflammatory markers were not different between the two groups, and also did not correlate with FDG uptake.

Conclusions: Increased carotid plaque inflammation, as measured by FDG uptake on PET, may be a useful marker for identifying patients with symptomatic carotid atherosclerosis who are at risk of recurrence.