Abstract 015: Pioneering NaF‐PET/CT Imaging for Early Detection of Atherosclerosis: Potential Implications for Neurointerventional Surgery
Authors: Teichner Eric M , Subtirelu Robert C , Ashok Arjun B , Su Yvonne , Anderson Victoria A , Writer Milo , Al‐Daoud Omar , Ismoilov Miraziz , Parikh Chitra , Raynor William Y , Talasila Sahithi , Høilund‐Carlsen Poul F , Alavi Abass , Revheim Mona‐Elisabeth 
Published: March 2024

Introduction
Cerebrovascular disease (CVD), particularly carotid artery atherosclerosis, contributes substantially to global morbidity and mortality. The ability to precisely detect atherosclerosis is crucial, as it directly influences patient management, including decisions regarding surgical interventions. Given the high prevalence and severe outcomes of CVD, there is an urgent need for improved early detection methods. Utilizing a novel approach, this study pioneers the use of 18F‐sodium fluoride (NaF) PET/CT imaging for the early identification of microcalcification, a key marker of atherosclerosis. A nuanced understanding of vascular calcification's temporal progression may aid in optimally timing surgical interventions, such as carotid endarterectomy or carotid artery stenting, thereby reducing stroke risk.

Methods
Our study participant is a 31‐year‐old male with atrial fibrillation, multiple cardiovascular risk factors, and class 2 obesity, enrolled in the Cardiovascular Molecular Calcification Assessed by 18F‐NaF PET/CT (CAMONA) study. The patient underwent both FDG‐PET/CT and NaF‐PET/CT imaging. We utilized OsiriX MD software v.13.0.1 (Pixmeo SARL, Bernex, Switzerland), to compute the standardized uptake value (SUVmean), serving as a measure of disease progression in both the global brain and the bilateral carotid arteries. Subsequently, we employed MIMneuro version 7.1.5 (MIM Software, Inc., Cleveland, OH, USA) to conduct a comprehensive regional brain metabolism analysis, harnessing the power of an integrated anatomical atlas.

Results
NaF‐PET/CT imaging revealed elevated NaF uptake in the bilateral carotid arteries (z‐score = 0.012), suggesting notable microcalcification. Conversely, FDG‐PET/CT imaging revealed low FDG uptake in the carotid arteries, with an average SUVmean of 0.66 for both right and left carotids and a z‐score of −2.32. Analysis of global brain metabolism demonstrated decreased FDG uptake detected by FDG‐PET/CT (z‐score = ‐2.32). Concurrently, we identified a decline in regional brain metabolism, with prominent decreases observed in regions including the brainstem (z score = −1.95), medial temporal lobe (z‐score = −1.81), cerebellum (z–score = −2.13), hippocampus (z‐score = −2.13), inferior frontal gyrus (z‐score = −3.53), lateral orbital gyrus (z‐score = −3.24), and putamen (z‐score = −2.47) (Figure 1).

Conclusion
Our findings highlight the potential of NaF‐PET/CT imaging to enhance early detection of carotid artery atherosclerosis and cerebral hypometabolism. These results highlight the subtle, yet potent, potential of NaF‐PET/CT scans to detect active, asymptomatic cases where FDG‐PET/CT scans may not indicate high activity. The findings suggest that NaF‐PET could play a pivotal role in diagnosing and managing CVD where traditional tracers encounter limitations. Early recognition of these alterations facilitates clinical decision‐making, including determining the necessity and timing of surgical intervention. This advanced diagnostic tool presents an opportunity to improve pre‐operative assessments by providing insights into disease progression prior to macrocalcification development, a clear advantage over existing imaging modalities. The correlation between vascular calcification and decreased cerebral metabolism enhances our understanding of CVD pathophysiology, thereby paving the way for transformative therapeutic interventions. While these findings provide preliminary insight, further research is crucial to corroborate our results and delineate their potentially transformative implications on patient care, particularly in the context of surgical interventions.