Abstract: Aim The identification of the vulnerable atheroma plaque could allow a more
effective treatment of cerebrovascular accident (CVA). Active calcification and
inflammation of the carotid atheroma were assessed and compared in symptomatic
and asymptomatic plaques by 18F-NaF and 18F-FDG PET/CT.
Methods Nine patients investigated for recent CVA and no preventive treatment
with statins were enrolled. In each patient, at least one atheroma plaque was
detected by CT angiogram. In total, 18 plaques were available: 9 symptomatic
and 9 asymptomatic. 18F-NaF uptake and 18F-FDG uptake by each plaque were
assessed visually and semiquantitatively by calculating target/background ratios
(TBRs) and TBR indexes (TBR symptomatic/TBR asymptomatic and 18F-NaF
TBR/18F-FDG TBR within each of the 2 clinical groups of plaques).
Results All plaques showed 18F-NaF and 18F-FDG uptake, and semiquantitation
showed higher 18F-NaF uptake by 11 of the 18 plaques, 6 symptomatic and 5
asymptomatic. In the symptomatic group, the mean 18F-NaF TBR was
212 044, and in the asymptomatic group, it was 185 046. The 18FNaF/
18F-FDG showed that, overall, 18F-NaF uptake is higher than 18F-FDG. In
the symptomatic plaques, the 18F-NaF was higher for the low calcium content
and the lowest for the high.
Conclusion Active calcification and inflammation are simultaneous processes in the
symptomatic and asymptomatic carotid atheroma. However, active calcification
seems predominant over inflammation in both groups. In the symptomatic plaques,
the highest 18F-NaF uptake does not correspond with the largest calcium
content. These patterns open new insights on the role of 18F-NaF in the study of
calcification and in the identification of the vulnerable carotid atheroma.