18F-Sodium fluoride positron emission tomography and computed tomography in acute aortic syndrome Link to paper on JACC: Cardiovascular Imaging Authors Maaz B. J. Syed, Alexander J. Fletcher, Samuel Debono, Rachel O. Forsythe, Michelle C. Williams, Marc R. Dweck, Anoop S. V. Shah, Mark G. Macaskill, Adriana Tavares, Martin A. Denvir, Kelvin Lim, William A. Wallace, Jakub Kaczynski, Tim Clark, Stephanie L. Sellers, Neil Masson, Orwa Falah, Roderick T. A. Chalmers, Andrew L. Tambyraja, Edwin J. R. van Beek, David E.Newby Abstract Background: Acute aortic syndrome is associated with aortic medial degeneration. 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) detects microscopic tissue calcification as a marker of disease activity. Objectives: In a proof-of-concept study, this investigation aimed to establish whether 18F-NaF PET combined with computed tomography (CT) angiography could identify aortic medial disease activity in patients with acute aortic syndrome. Methods: Patients with aortic dissection or intramural hematomas and control subjects underwent 18F-NaF PET/CT angiography of the aorta. Aortic 18F-NaF uptake was measured at the most diseased segment, and the maximum value was corrected for background blood pool activity (maximum tissue-to-background ratio [TBRmax]). Radiotracer uptake was compared with change in aortic size and major adverse aortic events (aortic rupture, aorta-related death, or aortic repair) over 45 ± 13 months. Results: Aortic 18F-NaF uptake co-localized with histologically defined regions of microcalcification and elastin disruption. Compared with control subjects, patients with acute aortic syndrome had increased 18F-NaF uptake (TBRmax: 1.36 ± 0.39 [n = 20] vs 2.02 ± 0.42 [n = 47] respectively; P < 0.001) with enhanced uptake at the site of intimal disruption (+27.5%; P < 0.001). 18F-NaF uptake in the false lumen was associated with aortic growth (+7.1 mm/year; P = 0.011), and uptake in the outer aortic wall was associated with major adverse aortic events (HR: 8.5 [95% CI: 1.4-50.4]; P = 0.019). Conclusions: In patients with acute aortic syndrome, 18F-NaF uptake was enhanced at sites of disease activity and was associated with aortic growth and clinical events. 18F-NaF PET/CT holds promise as a noninvasive marker of disease severity and future risk in patients with acute aortic syndrome. (18F Sodium Fluoride PET/CT in Acute Aortic Syndrome [FAASt]; NCT03647566) Keywords Aortic dissection Aortic growth Intramural hematoma Major adverse aortic events Microcalcification Vascular injury Related links Link to paper on JACC: Cardiovascular Imaging Professor David Newby Professor Edwin van Beek Dr Adriana Tavares Professor Marc Dweck Dr Michelle Williams Heart / cardiovascular What is a PET scan? What is a CT scan? What is a PET-CT scan? Social media tags and titles Featured paper: 18F-Sodium fluoride positron emission tomography and computed tomography in acute aortic syndrome @EdinUniCVS @imagingmedsci @MarcDweck Publication date 26 Jul, 2022