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Diffusion-perfusion MR evaluation of perihematomal injury in hyperacute intracerebral hemorrhage
C S Kidwell1, J L Saver, J Mattiello
1Stroke Center, Department of Neurology, UCLA Medical Center, Los Angeles, CA 90095, USA. ckidwell@ucla.edu
Background:
It has been suggested that a zone of perihematomal ischemia analogous to an ischemic penumbra exists in patients with primary intracerebral hemorrhage (ICH). Diffusion-perfusion MRI provides a novel means of assessing injury in perihematomal regions in patients with ICH.
Objective:
To characterize diffusion-perfusion MRI changes in the perihematomal region in patients with hyperacute intracerebral hemorrhage.
Method:
Twelve patients presenting with hyperacute, primary ICH undergoing CT scanning and diffusion-perfusion MRI within 6 hours of symptom onset were reviewed. An automated thresholding technique was used to identify decreased apparent diffusion coefficient (ADC) values in the perihematomal regions. Perfusion maps were examined for regions of relative hypo- or hyperperfusion.
Results:
Median baseline NIH Stroke Scale score was 17 (range, 6 to 28). Median hematoma volume was 13.3 mL (range, 3.0 to 74.8 mL). MRI detected the hematoma in all patients on echo-planar susceptibility-weighted imaging and in all seven patients imaged with gradient echo sequences. In six patients who underwent perfusion imaging, no focal defects were visualized on perfusion maps in tissues adjacent to the hematoma; however, five of six patients demonstrated diffuse ipsilateral hemispheric hypoperfusion. On diffusion imaging, perihematomal regions of decreased ADC values were identified in three of 12 patients. All three subsequently showed clinical and radiologic deterioration.
Conclusions:
A rim of perihematomal decreased ADC values was visualized in the hyperacute period in a subset of patients with ICH. The presence of a rim of decreased ADC outside the hematoma correlated with poor clinical outcome. Although perfusion maps did not demonstrate a focal zone of perihematomal decreased blood flow in any patient, most patients had ipsilateral hemispheric hypoperfusion.
Insights
A rim of decreased diffusion in the area surrounding brain bleeds (intracerebral hemorrhage) was seen in some patients. This finding on diffusion-perfusion MRI correlated with worse outcomes, suggesting a potential imaging biomarker for stroke.
Area of Science:
- Neurology
- Radiology
- Neuroimaging
Background:
- A perihematomal ischemic penumbra may exist in intracerebral hemorrhage (ICH).
- Diffusion-perfusion MRI offers a novel method to assess perihematomal injury in ICH patients.
Purpose of the Study:
- To characterize diffusion-perfusion MRI changes in the perihematomal region in hyperacute ICH patients.
Main Methods:
- Reviewed 12 hyperacute ICH patients within 6 hours of symptom onset undergoing CT and diffusion-perfusion MRI.
- Used automated thresholding to identify decreased apparent diffusion coefficient (ADC) values in perihematomal regions.
- Examined perfusion maps for hypo- or hyperperfusion.
Main Results:
- MRI detected hematomas in all patients.
- No focal perfusion defects were seen adjacent to the hematoma, but five of six patients showed diffuse ipsilateral hypoperfusion.
- Decreased ADC values in perihematomal regions were found in 3 of 12 patients, all of whom deteriorated.
Conclusions:
- A rim of decreased ADC values in the hyperacute period was visualized in a subset of ICH patients.
- The presence of this rim correlated with poor clinical outcome.
- Most patients exhibited ipsilateral hemispheric hypoperfusion, though focal perihematomal hypoperfusion was not observed.