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Updated: May 19, 2026
MRI-guided Disruption of the Blood-brain Barrier using Transcranial Focused Ultrasound in a Rat Model
Published on: March 13, 2012
MRI study on reversible and irreversible electroporation induced blood brain barrier disruption
Mohammad Hjouj1, David Last, David Guez
1Center for Bioengineering in the Service of Humanity and Society, School of Computer Science and Engineering, Hebrew University, Jerusalem, Israel.
Abstract:
Electroporation, is known to induce cell membrane permeabilization in the reversible (RE) mode and cell death in the irreversible (IRE) mode. Using an experimental system designed to produce a continuum of IRE followed by RE around a single electrode we used MRI to study the effects of electroporation on the brain. Fifty-four rats were injected with Gd-DOTA and treated with a G25 electrode implanted 5.5 mm deep into the striata. MRI was acquired immediately after treatment, 10 min, 20 min, 30 min, and up to three weeks following the treatment using: T1W, T2W, Gradient echo (GE), serial SPGR (DCE-MRI) with flip angles ranging over 5-25°, and diffusion-weighted MRI (DWMRI). Blood brain barrier (BBB) disruption was depicted as clear enhancement on T1W images. The average signal intensity in the regions of T1-enhancement, representing BBB disruption, increased from 1887±83 (arbitrary units) immediately post treatment to 2246±94 20 min post treatment, then reached a plateau towards the 30 min scan where it reached 2289±87. DWMRI at 30 min showed no significant effects. Early treatment effects and late irreversible damage were clearly depicted on T2W. The enhancing volume on T2W has increased by an average of 2.27±0.27 in the first 24-48 hours post treatment, suggesting an inflammatory tissue response. The permanent tissue damage, depicted as an enhancing region on T2W, 3 weeks post treatment, decreased to an average of 50±10% of the T2W enhancing volumes on the day of the treatment which was 33±5% of the BBB disruption volume. Permanent tissue damage was significantly smaller than the volume of BBB disruption, suggesting, that BBB disruption is associated with RE while tissue damage with IRE. These results demonstrate the feasibility of applying reversible and irreversible electroporation for transient BBB disruption or permanent damage, respectively, and applying MRI for planning/monitoring disruption volume/shape by optimizing electrode positions and treatment parameters.
Insights
This study shows magnetic resonance imaging (MRI) can monitor electroporation effects in the brain. MRI effectively distinguishes between temporary blood-brain barrier (BBB) disruption and permanent tissue damage from reversible (RE) and irreversible (IRE) electroporation.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Medical Imaging
Background:
- Electroporation induces reversible (RE) or irreversible (IRE) cell membrane changes.
- RE can transiently open the blood-brain barrier (BBB), while IRE causes cell death.
- MRI offers potential for visualizing and quantifying these electroporation effects in brain tissue.
Purpose of the Study:
- To investigate the use of MRI to study the effects of electroporation on the brain.
- To differentiate between BBB disruption (RE) and permanent tissue damage (IRE) using MRI.
- To assess MRI's feasibility for planning and monitoring electroporation treatments.
Main Methods:
- Fifty-four rats were treated with electroporation using a G25 electrode in the striata after Gd-DOTA injection.
- Multi-sequence MRI (T1W, T2W, GE, DCE-MRI, DWMRI) was acquired at various time points up to three weeks post-treatment.
- Image analysis focused on quantifying BBB disruption via T1-enhancement and tissue damage via T2W enhancement.
Main Results:
- BBB disruption, visualized by T1-enhancement, peaked around 20-30 minutes post-treatment.
- T2W imaging revealed an initial inflammatory response followed by permanent tissue damage.
- Permanent tissue damage (IRE) was significantly smaller than the BBB disruption volume (RE), indicating MRI can differentiate these effects.
Conclusions:
- MRI is feasible for monitoring and differentiating reversible (BBB disruption) and irreversible (tissue damage) electroporation effects in the brain.
- MRI can guide electrode placement and treatment parameters for targeted electroporation therapies.
- The study demonstrates MRI's utility in planning and evaluating electroporation-based interventions.
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