Aortic Uptake of F-NaF and F-FDG and Calcification Predict the Development of Abdominal Aortic Aneurysms and Is Attenuated by Drug Therapy.

BACKGROUND

Abdominal aortic aneurysms expand over time and increase the risk of fatal ruptures. To predict expansion, the isolated assessment of F-fluorodeoxyglucose (FDG) and sodium fluoride (NaF) uptake or calcification volume in aneurysms has been investigated with variability in results. We systematically evaluated whether F-FDG and F-NaF uptake was predictive of abdominal aortic aneurysm expansion.

METHODS

Seventy-four male Sprague-Dawley rat abdominal aortic aneurysm models were imaged using positron emission tomography-computed tomography with F-FDG and F-NaF at 1, 2, 4, 6, and 8 weeks after CaCl or saline stimulation. In the 1-week cohort (n=25), the correlation between F-FDG or F-NaF uptake and pathological markers was investigated. In the time course cohort (n=49), animals received either atorvastatin, losartan, aldactone, or risedronate to assess the effect of these drugs, and the relationship between aortic size and sequential F-FDG and F-NaF uptake or calcification volume was examined.

RESULTS

In the 1-week cohort, the maximum standard unit value of F-FDG and F-NaF uptake correlated with CD68- (r=0.82; =0.001) and von Kossa staining-positive areas (r=0.89; <0.001), respectively. In the time course cohort, F-FDG and F-NaF uptake changed in a time-dependent manner and drugs attenuated this uptake. Specifically, F-FDG showed high uptake at weeks 1 and 2, whereas a high F-NaF uptake was noted throughout the study period. Atorvastatin and risedronate showed a decreased and increased aortic size, respectively. The final aortic area correlated well with F-FDG and F-NaF uptake and calcification volume, especially at 1 and 2 weeks (F-NaF [1 week]: r=0.61, F-FDG [2 weeks]: r=0.51, calcification volume [1 week]: r=0.59; <0.001). Multiple linear regression analysis showed that the combination of these factors predicted the final aortic size, with F-NaF uptake at 1 week being the strongest predictor.

CONCLUSIONS

The uptake of F-NaF and F-FDG and the calcification volume at appropriate times correlated with the development of abdominal aortic aneurysms, with F-NaF uptake being the strongest predictor.