Background
18
F-NaF positron emission tomography (PET) targets microcalcifications. We compared in vitro microPET assessed
18
F-NaF uptake between culprit and non-culprit human carotid plaques. Furthermore, we compared
18
F-NaF uptake with calcification visualized on microcomputed tomography (microCT).
Methods
Carotid plaques from stroke patients undergoing surgery were incubated in
18
F-NaF and scanned using a microPET and a microCT scan. The average PET assessed
18
F-NaF uptake was expressed as percentage of the incubation dose per gram (%Inc/g).
18
F-NaF PET volume of interest (VOI) was compared with CT calcification VOI.
Results
23 carotid plaques (17 culprit, 6 non-culprit) were included. The average
18
F-NaF uptake in culprit carotid plaques was comparable with the uptake in non-culprit carotid plaques (median 2.32 %Inc/g [IQR 1.98 to 2.81] vs. median 2.35 %Inc/g [IQR 1.77 to 3.00],
P
= 0.916). Only a median of 10% (IQR 4 to 25) of CT calcification VOI showed increased
18
F-NaF uptake, while merely a median of 35% (IQR 6 to 42) of
18
F-NaF PET VOI showed calcification on CT.
Conclusions
18
F-NaF PET represents a different stage in the calcification process than CT. We observed a similar PET assessed
18
F-NaF uptake and pattern in culprit and non-culprit plaques of high-risk patients, indicating that this method may be of more value in early atherosclerotic stenosis development.
Electronic supplementary material
The online version of this article (10.1007/s12350-018-1325-5) contains supplementary material, which is available to authorized users.
Background
While [18F]-fluordeoxyglucose ([18F]FDG) uptake is associated with arterial inflammation, [18F]-sodium fluoride ([18F]NaF) is a marker for arterial micro-calcification. We aimed to investigate the prospective correlation between both PET markers over time and whether they are prospectively ([18F]FDG) and retrospectively ([18F]NaF) related to progression of systemic arterial disease in a longitudinal study in patients with type 2 diabetes mellitus (T2DM).
Methods
Baseline [18F]FDG PET/Low Dose (LD) Computed Tomography (CT) scans of ten patients with early T2DM without cardiovascular history (70% men, median age 63 years) were compared with five-year follow-up [18F]NaF/LDCT scans. Systemic activity was expressed as mean target-to-background ratio (meanTBR) by dividing the maximal standardized uptake value (SUVmax) of ten arteries by SUVmean of the caval vein. CT-assessed macro-calcifications were scored visually and expressed as calcified plaque (CP) score. Arterial stiffness was assessed with carotid-femoral pulse wave velocity (PWV). Five-year changes were expressed absolutely with delta (Δ) and relatively with %change.
Results
Baseline meanTBR[18F]FDG was strongly correlated with five-year follow-up meanTBR[18F]NaF (r = 0.709, P = .022). meanTBR[18F]NaF correlated positively with ΔCPscore, CPscore at baseline, and follow-up (r = 0.845, P = .002 and r = 0.855, P = .002, respectively), but not with %change in CPscore and PWV.
Conclusion
This proof-of-concept study demonstrated that systemic arterial inflammation is an important pathogenetic factor in systemic arterial micro-calcification development.
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