Technical Note: Development of a cranial phantom for assessing perfusion, diffusion, and biomechanics

Area of Science:

• Biomedical Engineering
• Medical Imaging Physics
• Neuroscience

Background:

• Accurate simulation of intracranial tissue properties is crucial for advancing neuroimaging.
• Existing phantoms often lack the integrated modeling of blood perfusion, water diffusion, and biomechanics.

Purpose of the Study:

• To develop and validate a novel cranial phantom.
• To simulate the complex interplay of blood perfusion, water diffusion, and biomechanics within intracranial tissues.

Main Methods:

• A cranial phantom was constructed mimicking brain parenchyma, cerebral vasculature, and cerebrospinal fluid spaces.
• Pulsatile and steady blood flow were applied, with synchronized MRI measurements of pressure, apparent diffusion coefficient (ADC), and total simulated cerebral blood flow (tSCBF).
• Compliance index (CI) was assessed under varying flow rates and phantom compliance levels; perfusion-related diffusion coefficients (D* and D) were determined under steady flow.

Main Results:

• Phantom measurements (pressure, ADC, tSCBF) dynamically responded to pulsatile flow rates.
• Increased input flow rates correlated with higher pressure changes (ΔP), ADC changes (ΔADC), and tSCBF.
• Reduced phantom compliance led to significantly higher ΔP and ΔADC, and a lower CI, indicating altered biomechanical properties.

Conclusions:

• The developed cranial phantom effectively models the integrated relationships between blood perfusion, water diffusion, and biomechanics.
• This novel phantom provides a valuable tool for validating new MRI techniques.
• It facilitates the optimization of imaging parameters for enhanced intracranial tissue analysis.