Diffusion-perfusion MR evaluation of perihematomal injury in hyperacute intracerebral hemorrhage

Background: It has been suggested that a zone of perihematomal ischemia ana logous to an ischemic penumbra exists in patients with primary intracerebra l hemorrhage (ICH). Diffusion-perfusion MRI provides a novel means of asses sing injury in perihematomal regions in patients with ICH. Objective: To ch aracterize diffusion-perfusion MRI changes in the perihematomal region in p atients with hyperacute intracerebral hemorrhage. Methods: Twelve patients presenting with hyperacute, primary ICH undergoing CT scanning and diffusio n-perfusion MRI within 6 hours of symptom onset were reviewed. An automated thresholding technique was used to identify decreased apparent diffusion c oefficient (ADC) values in the perihematomal regions. Perfusion maps were e xamined for regions of relative hypo- or hyperperfusion. Results: Median ba seline NIH Stroke Scale score was 17 (range, 6 to 28). Median hematoma volu me was 13.3 mL (range, 3.0 to 74.8 mL). MRI detected the hematoma in all pa tients on echo-planar susceptibility-weighted imaging and in all seven pati ents imaged with gradient echo sequences. In six patients who underwent per fusion imaging, no focal defects were visualized on perfusion maps in tissu es adjacent to the hematoma; however, five of six patients demonstrated dif fuse ipsilateral hemispheric hypoperfusion. On diffusion imaging, perihemat omal regions of decreased ADC values were identified in three of 12 patient s. All three subsequently showed clinical and radiologic deterioration. Con clusions: 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 hemisph eric hypoperfusion.