Circle of Willis Variants in Nepali Population Evaluated in TOF MR Angiography

NCT06751420 | Completed

• 2 other identifiers: 11/2024GIH
• Study Type: observational
• Target: 383
• Locations: 1 country
• Sites: 1

Brief Summary

The brain, though it constitutes only 2% of total body weight, receives 20% of the cardiac output. Blood supply to the brain comes from two major pairs of arteries: the anterior carotid arteries and the posterior vertebral arteries, which form an important collateral network. This network ensures that blood flow is maintained even if one of the arteries is obstructed. In 1664, Sir Thomas Willis first described this system, which was later named the "Circle of Willis" (COW) after him. Normally, there is little blood mixing between the branches of the circle, but during blockages in the main arteries, these collaterals can activate to maintain cerebral perfusion. The COW consists of an anterior and posterior portion. The anterior portion, supplied by the carotid arteries and their branches, and the posterior portion, formed by the vertebrobasilar system, provide critical blood flow to the brain. The key arteries involved in the COW include the internal carotid arteries (ICAs), anterior cerebral arteries (ACAs), anterior communicating artery (ACom), posterior cerebral arteries (PCAs), basilar artery (BA), and posterior communicating arteries (PComs). Anatomical variations in the COW are common, with a complete arterial circle being rare. Studies have documented a range of normal variants of the COW, which are likely to arise during vasculogenesis. Magnetic resonance imaging (MRI), using the non-invasive time of flight (TOF) technique, is a cost-effective and contrast-free method for visualizing the COW in three dimensions, making it preferable to conventional angiography. The variants of COW and diameters of arteries of COW are of clinical importance given its critical role in brain blood supply. Understanding CoW variants can reveal predispositions to conditions like stroke and aneurysms. This research will provide prevalence data on CoW configurations, aiding diagnostic and treatment strategies for cerebrovascular diseases, and may offer insights into vascular development influences.

Conditions

Circle of Willis; Aneurysm, Congenital, Ruptured

Keywords

Circle of Willis; Time Of Flight Magnetic Resonance Angiogram; Brain

Outcome Measures

Primary Outcomes (1)

• Prevalence of different type of anterior and posterior circulation

  Prevalence of different type of anterior and posterior circulation in Nepali population

  6 months

Interventions

Magnetic Resonance Imaging DIAGNOSTIC_TEST

Magnetic Resonance Imaging Time Of Flight Angiography

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients of all gender and age 18 and above

You may qualify if:

• adult patients (18+ years) with high-quality, three-dimensional time-of-flight MR angiography (TOF-MRA) imaging that clearly visualizes the Circle of Willis (CoW) and is performed for neurological assessments, such as headache or transient ischemic attacks.

You may not qualify if:

• patients with incomplete or poor-quality imaging, prior neurosurgical interventions, or significant vascular pathologies (e.g., aneurysms, arteriovenous malformations, severe atherosclerosis) that could distort natural CoW anatomy. Additionally, images with motion artifacts and cases with missing essential demographic or clinical information are excluded.

Sponsors & Collaborators

• Grande International Hospital, Nepal: lead

Study Sites (1)

Tokha Road, Dhapasi

Kathmandu, Bagmati, 44600, Nepal

Location

MeSH Terms

Conditions

Aneurysm; Rupture

Interventions

Magnetic Resonance Imaging

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases; Wounds and Injuries

Intervention Hierarchy (Ancestors)

Tomography; Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis

Study Officials

• PRAJWAL DAHAL, MD

  Grande International Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: December 20, 2024
• First Posted: December 27, 2024
• Study Start: July 1, 2024
• Primary Completion: December 20, 2024
• Study Completion: December 20, 2024
• Last Updated: December 27, 2024

Record last verified: 2024-12

Data Sharing

• IPD Sharing: Will not share

Locations

NE (1)