J Lipid Atheroscler.  2019 Sep;8(2):232-241. 10.12997/jla.2019.8.2.232.

Analysis of ¹⁸F-Fluorodeoxyglucose and ¹⁸F-Fluoride Positron Emission Tomography in Korean Stroke Patients with Carotid Atherosclerosis

• Kim JM
• Lee ES
• Park KY
• Seok JW
• Kwon OS

• KMID: 2458388
• DOI: http://doi.org/10.12997/jla.2019.8.2.232

Abstract

OBJECTIVE
The objective of this study was to analyze uptake patterns and intensity of ¹â¸F-fluorodeoxyglucose (FDG) and ¹â¸F-sodium fluoride (NaF) radioligands in carotid atheroma among stroke patients according to carotid atheroma characteristics.
METHODS
Between September 2015 and January 2017, consecutive acute stroke or transient ischemic attack patients with 50% or more proximal internal carotid artery stenosis on brain computed tomography angiography were prospectively enrolled. All patients received FDG and NaF positron emission tomography (PET) evaluation when their neurological status was stabilized. Uptake values of FDG and NaF were compared by target to blood ratio (TBR) according to the calcification burden, atheroma volume and the presence of a necrotic core of carotid atheroma.
RESULTS
A total of 18 patients with 36 carotid arteries were finally enrolled, with 10 patients diagnosed as acute cerebral infarction due to symptomatic carotid stenosis. FDG uptake at symptomatic carotid arteries was significantly more increased than that at asymptomatic arteries (TBR: 1.17±0.23 vs. 1.01±0.15, Mann-Whitney U-test, p=0.02), but NaF uptake was not different (TBR: 1.38±0.49 vs. 1.51±0.40, p=0.40). In terms of calcification degree, NaF uptake increased as calcification burden increased (none, 1.28±0.36; spotty, 1.29±0.29; linear, 1.74±0.44; analysis of variance, p=0.02).
CONCLUSION
Carotid evaluation by FDG is superior to NaF PET in the detection of symptomatic carotid atherosclerosis among stroke patients. NaF PET uptake reflects the overall calcification burden.

Keyword

Stroke; Aarotid artery; Atherosclerosis; Positron emission tomography; Glucose

MeSH Terms

Angiography
Arteries
Atherosclerosis
Brain
Carotid Arteries
Carotid Artery Diseases*
Carotid Stenosis
Cerebral Infarction
Electrons*
Fluorides
Glucose
Humans
Ischemic Attack, Transient
Plaque, Atherosclerotic
Positron-Emission Tomography*
Prospective Studies
Stroke*
Fluorides
Glucose

Figure

• 

  Fig. 1 Study flow chart. A total of 22 patients were initially included in the study and classified in the symptomatic or asymptomatic carotid atherosclerosis groups. A total of 18 patients were finally assessed after PET study (mean age: 75±12 years, including 9 female patients). Two patients in the symptomatic carotid atherosclerosis group were excluded due to stroke mimic: one patient with sudden onset facial palsy and motor aphasia was found to have low grade glioma involving the left frontal cortex 2 months after the index event. The other patient with recurrent mental deterioration and dysarthria was found to have nonconvulsive seizure instead of transient ischemic attack. Another 2 patients were excluded from the asymptomatic carotid atherosclerosis group because concealed neoplasm was detected from FDG PET (one patient with colon cancer, the other with adrenal adenoma). CAS, carotid atherosclerosis; FDG, fluorodeoxyglucose; PET, positron emission tomography.

• 

  Fig. 2 Representative radiotracer uptake patterns according to atheroma characteristics. (A) A 76-year-old female patient was diagnosed with left hemispheric border zone infarction from DWI MRI with a severe left carotid stenosis from CTA. Axial section of CTA revealed an atheroma with perivascular rim enhancement and minimal calcification (red arrows). PET images showed increased FDG uptake (arrowhead) and minimal NaF uptake (arrowhead). (B) A 55-year-old male patient had multiple infarctions involving the right middle cerebral artery territory from DWI and moderate stenosis at the left proximal carotid artery (asymptomatic atherosclerosis, yellow arrow). Axial CTA showed considerable atheroma burden with multiple spotty calcification and PET image revealed minimal FDG uptake and increased NaF uptake at atheroma (arrowhead). (C) An 85-year-old female patient was diagnosed with right corona radiata infarction due to proximal carotid atherosclerosis. Axial CTA showed large atheroma with heterogeneous signal intensity due to heavy calcification burden and necrotic core (red arrow). PET image showed increased uptake of both FDG and NaF radiotracers (arrowhead). CTA, computed tomography angiography; FDG, fluorodeoxyglucose; PET, positron emission tomography; NaF, sodium fluoride; DWI, diffusion-weighted imaging; MRI, magnetic resonance imaging.

• 

  Fig. 3 Comparison of FDG and NaF uptake in terms of atheroma characteristics. (A) Although FDG uptake was not significantly different according to calcification status of internal carotid arteries (none, 1.12±0.15; spotty, 1.00±0.14; linear, 1.08±0.23; ANOVA, p=0.38), uptake values of NaF showed the maximum intensity on the severe calcified atheroma group (none, 1.28±0.36; spotty, 1.29±0.29; linear, 1.74±0.44; ANOVA, p=0.02). (B) Uptake values of FDG radiotracers were not significantly different according to the presence of necrotic core (1.09±0.14 vs. 1.15±0.24, Mann Whitney U-test, p=0.67), although levels of NaF tended to be increased in atherosclerotic walls with necrotic core (1.34±0.55 vs. 1.51±0.38, Mann Whitney U-test, p=0.09). FDG, fluorodeoxyglucose; NaF, sodium fluoride; ANOVA, analysis of variance.

• 

  Fig. 4 Comparison of FDG and NaF uptake values in terms of atheroma volume. The uptake levels of FDG or NaF radiotracer were not significantly different according to atheroma volume status (FDG: mild, 1.13±0.11; moderate, 1.06±0.12; severe, 1.18±0.31; ANOVA, p=0.34; NaF: mild, 1.36±0.34; moderate, 1.32±0.38; severe, 1.63±0.65; ANOVA, p=0.25). ANOVA, analysis of variance; FDG, fluorodeoxyglucose; NaF, sodium fluoride.

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