# Morphological Variations of the Extracranial Internal Carotid Artery: Prevalence, Age and Sex-Related Associations, and Imaging Insights From Magnetic Resonance Angiography

## TL;DR

This study finds that variations in the extracranial internal carotid artery are common, especially in older adults, and can be effectively detected using magnetic resonance angiography.

## Contribution

The study provides new prevalence data and age-related insights into ICA morphological variations using non-invasive MRA.

## Key findings

- 70.05% of extracranial ICAs showed dolichoarteriopathy, with tortuosity being the most common type.
- Prevalence of ICA variations was significantly higher in individuals over 40 years old.
- MRA is a reliable non-invasive method for detecting and characterizing ICA morphological anomalies.

## Abstract

Introduction

Dolichoarteriopathies of the extracranial internal carotid artery (ICA), such as tortuosity, kinking, and coiling, are frequently encountered vascular variations that may influence cerebral hemodynamics and clinical outcomes.

Purpose

This study aims to determine the prevalence and types of extracranial internal carotid artery variations and assess their relationship with age and sex using non-invasive magnetic resonance angiography (MRA).

Methods

This cross-sectional observational study was conducted at a tertiary care centre from June 2024 to July 2025 and included 100 consecutive patients (18-90 years, both sexes) referred for head and neck magnetic resonance angiography. Patients with prior cerebrovascular disease, central nervous system neoplasms, recent major head trauma, or suboptimal imaging were excluded. Three-dimensional time-of-flight MRA was performed, and extracranial ICAs were independently evaluated by two radiologists for dolichoarteriopathy type and severity. Statistical analysis included frequency distribution and Chi-squared testing to assess associations with age and sex.

Results

A total of 197 extracranial ICAs were analyzed, of which 70.05% demonstrated dolichoarteriopathy. Tortuosity was the most common variant (69.56%), followed by kinking (23.18%) and coiling (7.24%). The prevalence was significantly higher in patients older than 40 years compared to those aged 40 years or younger (89.25% vs. 39.47%, p=0.001). Although dolichoarteriopathies were more frequent in females than males (74.62% vs. 67.69%), the difference was not statistically significant. Morphological patterns varied significantly with age but showed no significant association with sex or laterality.

Conclusion

ICA dolichoarteriopathies are common, predominantly age-related anomalies with potential clinical relevance. Non-invasive MRA provides a reliable means for their detection and characterization. Systematic assessment of ICA morphology is recommended, especially in older populations or individuals with vascular comorbidities. Prospective studies integrating clinical outcomes and hemodynamic analysis are warranted to further define their prognostic significance