Venous Vessel Size Imaging Derived From A Breath-Hold Task.

Area of Science:

• Neuroimaging
• Biophysics
• Medical Physics

Background:

• Vessel size imaging (VSI) measures brain vessel radius, traditionally requiring contrast agents.
• Existing methods for venous VSI often rely on hypercapnia/hyperoxia, necessitating external equipment.
• A non-invasive, practical alternative for venous VSI is needed.

Purpose of the Study:

• To demonstrate the feasibility of venous VSI using a simple breath-hold task.
• To develop a method for measuring venous vessel radii in the brain without contrast agents or specialized gas delivery.
• To validate the breath-hold approach against established VSI techniques.

Main Methods:

• 14 subjects underwent brain scans on a 3-T scanner during a breath-hold task.
• Simultaneous gradient-echo and spin-echo signals were acquired using SAGE-EPI.
• Parametric maps of mean venous vessel radius were calculated from ΔR2* and ΔR2 changes.
• Numerical simulations were used to establish a relationship between vessel size index (q) and vessel radius.

Main Results:

• Venous vessel radii were determined to be 7.18 ± 0.49 μm in gray matter and 6.06 ± 0.22 μm in white matter.
• The breath-hold method provided results consistent with previous contrast-based and hypercapnia studies.
• The study established an empirical relation between vessel size index q and average vessel radii.

Conclusions:

• A simple breath-hold task can be effectively used for non-invasive venous vessel size imaging (VSI).
• This method avoids contrast agents and specialized equipment, offering a practical alternative for vascular property assessment.
• The findings support the validity and feasibility of this novel noninvasive neuroimaging technique.