Peer-review started: July 31, 2015
First decision: November 6, 2015
Revised: November 24, 2015
Accepted: December 13, 2015
Article in press: December 14, 2015
Published online: January 28, 2016
Processing time: 180 Days and 22.2 Hours
AIM: To investigating the relationship between thoracic and cardiac 18F-Natrium-Fluoride (18F-NaF) uptake, as a marker of ongoing calcification and cardiovascular risk factors.
METHODS: Seventy-eight patients (44 females, mean age 63, range 44-83) underwent whole body 18F-NaF positron emission tomography/computed tomography. Cardiovascular risk (CVR) was used to divide these patients in three categories: Low (LR), medium (MR) and high risk (HR). 18F-NaF uptake was measured by manually drawing volumes of interest on the ascending aorta, on the aortic arch, on the descending aorta and on the myocardium; average standardized uptake value was normalized for blood-pool, to obtain target-to-background ratio (TBR). Values from the three aortic segments were then averaged to obtain an index of the whole thoracic aorta.
RESULTS: A significant difference in whole thoracic aorta TBR was detected between HR and LR (1.84 ± 0.76 vs 1.07 ± 0.3, P < 0.001), but also between MR and HR-LR (1.4 ± 0.4, P < 0.02 and P < 0.01, respectively). Significance of this TBR stratification strongly varied among thoracic aorta subsegments and the lowest P values were reached in the descending aorta (P < 0.01). Myocardial uptake provided an effective CVR classes stratification (P < 0.001).Correlation between TBR and CVR was appreciable when the whole thoracic aorta was considered (R = 0.67), but it peaked when correlating the descending thoracic segment (R = 0.75), in comparison with the aortic arch and the ascending segment (R = 0.55 and 0.53, respectively).
CONCLUSION: Fluoride uptake within the thoracic aorta wall effectively depicts patients’ risk class and correlates with cardiovascular risk. Descending aorta is the most effective in CVR determination.
Core tip: We evaluated, in 78 patients who underwent whole body 18F-Natrium Fluoride (18F-NaF) positron emission tomography/computed tomography, the 18F-NaF uptake in different segments of thoracic aorta and within the myocardium, as a measure of ongoing molecular calcification. In particular, we tested the hypothesis of a correlation between thoracic aorta uptake and cardiovascular risk (CVR). We thus assessed 18F-NaF uptake (TBR) in different CVR groups (high, medium and low) and its correlation with absolute CVR value. TBR stratified the three CVR classes, mostly in the descending aortic segment and in the myocardium. Thoracic aorta uptake correlated with CVR and with myocardial uptake.