Quantitative evaluation of BBB permeability after embolic stroke in rat using MRI

Area of Science:

• Neuroimaging
• Stroke Research
• Biomedical Engineering

Background:

• The blood-brain barrier (BBB) integrity is crucial in stroke pathophysiology.
• Early detection of BBB disruption aids in timely therapeutic interventions.
• Current methods for assessing BBB compromise post-stroke have limitations.

Purpose of the Study:

• To identify and validate magnetic resonance imaging (MRI) parameters for predicting BBB disruption after embolic stroke.
• To evaluate the sensitivity of quantitative MRI parameters in detecting early signs of BBB breakdown.

Main Methods:

• Embolic stroke was induced in rats, with and without rt-PA treatment.
• Quantitative MRI parameters including K(i), V(p), k(inv), ADC(w), T2, and CBF were measured.
• Post-mortem histological analysis was performed to detect fibrin leakage, confirming BBB disruption.

Main Results:

• The transfer constant (K(i)), distribution volume (V(p)), and inverse of magnetization transfer rate (k(inv)) were sensitive early indicators (2-3 hours) of BBB disruption and subsequent fibrin leakage.
• Cerebral blood flow (CBF) did not show significant differences between ischemic tissue with compromised versus intact BBB.
• These MRI parameters effectively predicted BBB compromise.

Conclusions:

• Specific quantitative MRI parameters (K(i), V(p), k(inv)) can sensitively predict blood-brain barrier disruption following embolic stroke.
• These non-invasive MRI markers offer a promising approach for early assessment of BBB integrity in stroke models.
• The findings support the use of advanced MRI techniques for monitoring stroke progression and therapeutic response.