Quantifying sodium [18F]fluoride uptake in abdominal aortic aneurysms.
Debono S., Nash J., Fletcher AJ., Syed MBJ., Semple SI., van Beek EJR., Fletcher A., Cadet S., Williams MC., Dey D., Slomka PJ., Forsythe RO., Dweck MR., Newby DE.
BACKGROUND: Aortic microcalcification activity is a recently described method of measuring aortic sodium [18F]fluoride uptake in the thoracic aorta on positron emission tomography. In this study, we aimed to compare and to modify this method for use within the infrarenal aorta of patients with abdominal aortic aneurysms. METHODS: Twenty-five patients with abdominal aortic aneurysms underwent an sodium [18F]fluoride positron emission tomography and computed tomography scan. Maximum and mean tissue-to-background ratios (TBR) and abdominal aortic microcalcification activity were determined following application of a thresholding and variable radius method to correct for vertebral sodium [18F]fluoride signal spill-over and the nonlinear changes in aortic diameter, respectively. Agreement between the methods, and repeatability of these approaches were assessed. RESULTS: The aortic microcalcification activity method was much quicker to perform than the TBR method (14 versus 40 min, p