Related Experiment Videos
Assessment of diffusion and perfusion deficits in patients with small subcortical ischemia
Claudia A Doege1, Christian M Kerskens, Berenice I Romero
1Department of Neurology, Humboldt University, Charité, Berlin, Germany.
Background And Purpose:
Using perfusion- and diffusion-weighted MR imaging in acute ischemic stroke of the middle cerebral artery (MCA), previous studies have shown a typical pathophysiologic pattern that is characterized by a perfusion deficit larger than the diffusion lesion (mismatch), with the final lesion usually comprising the initial diffusion lesion (core) plus parts of the initial mismatch area. Little is known about underlying pathophysiology in small ischemic stroke. In this study, we used perfusion- and diffusion-weighted MR imaging to investigate the underlying pathophysiology of small subcortical ischemia.
Methods:
Six consecutive patients (age range, 42-76 years) with small subcortical ischemia were examined by using a 1.5-T MR system 2-5, 22-55, and 144-392 hours after the onset of symptoms. T2-weighted, diffusion-weighted imaging at b=0 s/mm2 and b=1000 s/mm2, and bolus-track perfusion-weighted imaging were performed. Lesion sizes were determined on the basis of T2-weighted findings as well as those of apparent diffusion coefficient (ADC) maps and CBF.
Results:
In every patient, the initial CBF lesion was smaller than the initial ADC lesion. Both the CBF lesion and the ADC lesion increased in size from first to second examination. In all instances, however, the CBF lesion remained smaller than the ADC lesion. The CBF lesion observed during the acute phase and the one seen on the following days were both smaller than the final T2 lesion.
Conclusion:
Our data suggest that in contrast to previous findings in MCA ischemia in small subcortical infarcts tissue damage may spread beyond the area of the initial perfusion disturbance. In light of the small number of patients, further studies will have to address the relevance of this observation.
Insights
In small subcortical ischemic strokes, tissue damage may extend beyond the initial perfusion deficit, unlike in middle cerebral artery strokes. Further research is needed to confirm this finding in small infarcts.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Previous studies on middle cerebral artery (MCA) ischemia show a perfusion deficit larger than the diffusion lesion (mismatch).
- The final lesion typically includes the initial diffusion lesion (core) and parts of the mismatch area.
- Pathophysiology of small subcortical ischemic stroke is not well understood.
Purpose of the Study:
- Investigate the underlying pathophysiology of small subcortical ischemic stroke.
- Utilize perfusion- and diffusion-weighted MR imaging to examine lesion evolution.
- Compare perfusion and diffusion lesion dynamics in small subcortical infarcts.
Main Methods:
- Six patients with small subcortical ischemia underwent 1.5-T MRI at multiple time points (2-5, 22-55, 144-392 hours post-symptom onset).
- Imaging included T2-weighted, diffusion-weighted (b=0 and b=1000 s/mm2), and bolus-track perfusion-weighted imaging.
- Lesion sizes were assessed using T2-weighted images, apparent diffusion coefficient (ADC) maps, and cerebral blood flow (CBF) maps.
Main Results:
- The initial cerebral blood flow (CBF) lesion was consistently smaller than the initial apparent diffusion coefficient (ADC) lesion in all patients.
- Both CBF and ADC lesions increased in size between the first and second examinations.
- Throughout the study, the CBF lesion remained smaller than the ADC lesion, and both were smaller than the final T2 lesion.
Conclusions:
- Findings suggest that in small subcortical infarcts, tissue damage may spread beyond the initial perfusion disturbance.
- This contrasts with established patterns observed in middle cerebral artery (MCA) ischemia.
- Further studies are required to determine the clinical relevance of these observations due to the small sample size.