Investigating Leptomeningeal Anastomoses' Role in Collateral Blood Flow using SPECT and 4D Flow MRI

Area of Science:

• Neuroscience
• Medical Imaging
• Computational Biology

Background:

• Leptomeningeal anastomoses (LMAs) are essential for cerebral collateral circulation.
• Their small size and variability make quantitative assessment challenging.
• Understanding LMA function is critical for diagnosing and treating cerebrovascular diseases.

Purpose of the Study:

• To investigate the functional role of LMAs in cerebral collateral circulation.
• To model patient-specific LMA configurations and their interactions with the cerebral vasculature.
• To account for uncertainty in peripheral vessel anatomy for improved accuracy.

Main Methods:

• Generated synthetic vascular trees using a stochastic, anatomically informed sampling process.
• Optimized LMA configurations using an island genetic algorithm (IGA).
• Minimized discrepancies between 4D Flow MRI and SPECT data to simulate LMA-mediated flow redistribution.

Main Results:

• Successfully recreated physiologically plausible collateral patterns across four clinical scenarios.
• Demonstrated the ability to model LMA configurations in cases of mild to severe, asymmetric, and symptomatic unilateral stenosis.
• Provided a novel method for quantitative assessment of LMAs in patient-specific cases.

Conclusions:

• The developed computational approach effectively models LMA function and its impact on cerebral blood flow.
• This method offers a promising tool for understanding cerebrovascular diseases and personalizing treatment strategies.
• Further research can refine these models for broader clinical application in neurovascular imaging.