Related Experiment Video
Updated: Jul 3, 2026
A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
Temporal MRI assessment of intracerebral hemorrhage in rats
Robert A Knight1, Yuxia Han, Tavarekere N Nagaraja
1Henry Ford Hospital, Department of Neurology-NMR Research, 2799 West Grand Blvd, Detroit, MI 48202, USA. knight@neurnis.neuro.hfh.edu
Background And Purpose:
MRI was used to evaluate the effects of experimental intracerebral hemorrhage (ICH) on brain tissue injury and recovery.
Methods:
Primary ICH was induced in rats (n=6) by direct infusion of autologous blood into the striatum. The evolution of ICH damage was assessed by MRI estimates of T(2) and T(1sat) relaxation times, cerebral blood flow, vascular permeability, and susceptibility-weighted imaging before surgery (baseline) and at 2 hours and 1, 7, and 14 days post-ICH. Behavioral testing was done before and at 1, 7, and 14 days post-ICH. Animals were euthanized for histology at 14 days.
Results:
The MRI appearance of the hemorrhage and surrounding regions changed in a consistent manner over time. Two primary regions of interest were identified based on T(2) values. These included a core, corresponding to the bulk of the hemorrhage, and an adjacent rim; both varied with time. The core was associated with significantly lower cerebral blood flow values at all post-ICH time points, whereas cerebral blood flow varied in the rim. Increases in vascular permeability were noted at 1, 7, and 14 days. Changes in T(1sat) were similar to those of T(2). MRI and histological estimates of tissue loss were well correlated and showed approximately 9% hemispheric tissue loss.
Conclusions:
Although the cerebral blood flow changes observed with this ICH model may not exactly mimic the clinical situation, our results suggest that the evolution of ICH injury can be accurately characterized with MRI. These methods may be useful to evaluate therapeutic interventions after experimental ICH and eventually in humans.
Insights
Magnetic Resonance Imaging (MRI) effectively tracked brain tissue injury and recovery after experimental intracerebral hemorrhage (ICH) in rats. This imaging technique shows promise for evaluating new treatments for brain bleeds.
Area of Science:
- Neuroimaging
- Experimental Neurology
- Biomedical Engineering
Background:
- Intracerebral hemorrhage (ICH) is a severe neurological condition with significant morbidity and mortality.
- Understanding the dynamic evolution of brain tissue injury and recovery post-ICH is crucial for developing effective treatments.
Purpose of the Study:
- To evaluate the utility of Magnetic Resonance Imaging (MRI) in characterizing brain tissue injury and recovery following experimental intracerebral hemorrhage (ICH).
- To assess the temporal changes in various MRI parameters and their correlation with histological outcomes and behavioral deficits.
Main Methods:
- Experimental ICH was induced in rats by autologous blood infusion into the striatum.
- Serial MRI scans were performed to measure T(2) and T(1sat) relaxation times, cerebral blood flow, vascular permeability, and susceptibility-weighted imaging.
- Behavioral testing and histological analysis were conducted to complement MRI findings.
Main Results:
- MRI revealed consistent temporal changes in the hemorrhage core and surrounding rim, correlating with tissue loss.
- Reduced cerebral blood flow was observed in the hemorrhage core, while vascular permeability increased in the rim over time.
- MRI-estimated tissue loss (approximately 9%) correlated well with histological findings.
Conclusions:
- MRI can accurately characterize the evolution of ICH injury and associated tissue damage in an experimental model.
- The described MRI techniques offer a valuable tool for assessing therapeutic interventions in experimental ICH and potentially in human clinical trials.
