¹⁸F-Sodium Fluoride Uptake in Abdominal Aortic Aneurysms: The SoFIA³ Study

Area of Science:

• Vascular biology and imaging
• Cardiovascular research
• Nuclear medicine

Background:

• Fluorine-18-sodium fluoride (18F-NaF) uptake indicates active vascular calcification, a hallmark of high-risk atherosclerotic plaque.
• Abdominal aortic aneurysm (AAA) is a serious condition where the aorta in the abdomen widens, increasing rupture risk.

Purpose of the Study:

• To evaluate if 18F-NaF positron emission tomography (PET) and computed tomography (CT) can predict AAA growth and clinical outcomes.
• To assess the utility of 18F-NaF PET-CT in identifying active disease within aneurysms.

Main Methods:

• Prospective case-control and longitudinal cohort studies involving patients with AAA and control subjects.
• Abdominal ultrasound, 18F-NaF PET-CT, CT angiography, and calcium scoring were performed.
• Clinical endpoints included aneurysm expansion and the composite of AAA repair or rupture.

Main Results:

• 18F-NaF uptake was significantly higher in AAA compared to control subjects and non-aneurysmal regions.
• Histology confirmed 18F-NaF uptake localized to areas of aneurysm disease and active calcification.
• In the longitudinal cohort, aneurysms in the highest tertile of 18F-NaF uptake showed 2.5x faster expansion and were nearly 3x more likely to experience AAA repair or rupture.

Conclusions:

• 18F-NaF PET-CT is a promising imaging technique for identifying active disease in AAA patients.
• This method serves as an additive predictor for aneurysm growth and future clinical events, improving risk assessment.