What question did this study set out to answer?

This research aims to investigate the role of perivascular inflammation in carotid webs using fat-attenuation index (FAI) analysis.

February 2, 2026

Abstract DP137: Evaluation of Pericarotid Fat Attenuation Index in Carotid Webs – A Preliminary Analysis

Key Result

The median Perivascular Adipose Tissue-Fat Attenuation Index (FAI) was significantly higher in patients with carotid webs and atherosclerosis (-51.77 HU) compared to those without (-59.32 HU, p=0.03).

Key Points

This research aims to investigate the role of perivascular inflammation in carotid webs using fat-attenuation index (FAI) analysis.
Conducted a retrospective cross-sectional analysis of a prospective carotid webs database from 2022-2025.
Measured fat-attenuation index (FAI) using CTA images and analyzed the relationship with symptomatic and asymptomatic carotid webs.
Utilized t-tests and generalized linear regression models to assess significance of findings.
40 patients were included, split evenly between symptomatic and asymptomatic carotid webs.
The overall median FAI was -57.95 HU, with significantly higher FAI in atherosclerotic patients compared to non-atherosclerotic ones.
No significant difference in FAI between symptomatic and asymptomatic webs (p=0.9), nor a significant relationship with stroke risk after adjusting for factors.

Structured PICO

Is Perivascular Adipose Tissue-Fat-Attenuation Index (PVAT-FAI) associated with symptomatic presentation or atherosclerosis in patients with carotid webs?

Population

40 patients with carotid webs (20 consecutive symptomatic and 20 asymptomatic/incidental carotid webs)

Intervention

Perivascular Adipose Tissue-Fat-Attenuation Index (PVAT-FAI) assessed via CTA

Comparator

Symptomatic vs asymptomatic carotid webs, and presence vs absence of atherosclerosis

Outcome

Perivascular Adipose Tissue-Fat-Attenuation Index (PVAT-FAI) in Hounsfield units (HU)surrogate

Perivascular inflammation assessed by FAI is associated with atherosclerosis but not symptomatic presentation in patients with carotid webs.

Main Result

Absolute Event Rate: 0% vs 0%

Abstract

Introduction: The risk of stroke from carotid webs (CaW) seems to be linked to their morphological characteristics. While metabolic factors may also influence the likelihood of symptomatic presentation, this aspect remains unexplored. Perivascular Adipose Tissue-Fat-Attenuation Index (PVAT-FAI) assessed via CTA has emerged as a biomarker of inflammation, predicting coronary atherosclerosis progression. We aim to evaluate the occurrence and implications of peri-vascular inflammation in CaW via FAI analysis. Methods: Retrospective cross-sectional analysis of a prospective CaW database between 2022-2025 at two CSCs. FAI were obtained in Hounsfield unit(HU) of fat from the region of interest(ROI) from CTAs. FAI values range from -190 to -30 HU (lipid rich–less inflammation; more aqueous–more inflammation). CTA-DICOM image (axial) in 3D-Slicer was used. A semi-automated method for contrasted carotid lumen ( Fig1A/1B) and vessel wall segmentation (10 slices /6.2mm) at the web level (Fig1C/1D) was used. The vessel’s average diameter was obtained (centerline extraction method - Fig1E) for the perivascular area to extend the ROI radially (Fig1F). The PVAT region is exported to obtain HU values using RStudio. T-test and generalized linear regression models were used. Results: 40 patients met the inclusion criteria, of which 20 are consecutive symptomatic and 20 asymptomatic/incidental carotid webs. The overall median FAI was -57.95 HU (IQR: -62 to -48.15). Of the 40 cases 16(40%) had co-existent atherosclerotic changes at level of web by CTA. The median FAI for patients with atherosclerosis was significantly higher than for patients with no atherosclerosis (-51.77 IQR: -58.39 to -45.94 vs -59.32 IQR: -64.88 to -50.82;p=0.03). The median FAI for asymptomatic webs was -57.49 (IQR: -62 to -48.15), comparable to symptomatic carotid webs (-58.35 IQR: -61.76 to -48.77;p=0.9). The median FAI for patients in symptomatic and asymptomatic webs without associated atherosclerosis were comparable (-59.32 IQR: -65.28 to -48.77 vs -59.56 IQR: -63.93 to -55.49;p=0.9). There is no significant relationship between FAI and symptomatic webs while adjusting for atherosclerosis and age (p=0.7). Conclusion: Perivascular inflammation was commonly observed in CaW patients. Since FAI constitutes a non-invasive biomarker for local inflammation, this study suggests a potential pathophysiological metabolic role in the development of ischemic events in CaW. Further studies are warranted.