Ultrasound perfusion imaging in acute middle cerebral artery infarction predicts outcome

Background and Purpose - Initial reports indicate that transcranial harmonic imaging after ultrasound contrast agent bolus injection (BHI) can detect cerebral perfusion deficits in acute ischemic stroke. We evaluated parametric images of the bolus washout kinetics. Methods - Twenty-three patients with acute internal carotid artery infarction were investigated with perfusion harmonic imaging after SonoVue bolus injection ≤40 hour after the onset of symptoms. The findings were compared with those of cranial computed tomography (CCT) and clinical course 4 months after stroke. Results - Images of pixel-wise peak intensity (PPI) and time to peak intensity could be calculated for all patients. Spearman rank correlations of r=0.772 (P<0.001) and r=0.572 (P=0.008) between area of PPI signal decrease and area of infarction in the follow-up CCT as well as outcome after 4 months were obtained, respectively. Conclusions - In the early phase of acute ischemic stroke, BHI after SonoVue bolus injection is a useful ultrasound tool for analyzing cerebral perfusion deficits at the patient's bedside. BHI data correlate with the definite area of infarction and outcome after 4 months.