Differentiation Between Ischemic and Hemorrhagic Strokes – A Pilot Study with Transtemporal Investigation of Brain Parenchyma Elasticity Using Ultrasound Shear Wave Elastography

Introduction Ultrasound shear wave elastography is well established in diagnostics of several parenchymatous organs and is recommended by respective guidelines. So far, research about applications in relevant neurological conditions is missing, especially in adults. Here we aimed to examine the method for the differentiation of ischemic (IS) and hemorrhagic strokes (HS) and cerebral mass effects. Materials & Methods 50 patients with a confirmed diagnosis of HS or IS were enrolled in this prospective study. 2D shear wave elastography was performed on the ipsilateral and the contralateral side with a modified acoustic radiation force impulse (ARFI) technique (ElastPQ mode, Philips). Lesion volumetry was conducted based on computed tomography data for correlation with elastography results. Results Elastography measurements (EM) revealed a highly significant difference between IS and HS with mean values of 1.94 and 5.50 kPa, respectively (p < 0.00 001). Mean values of brain tissue on the non-affected side were almost identical (IS 3.38 (SD = 0.63); HS 3.35 (SD = 0.66); p = 0.91). With a sensitivity of 0.98 and a specificity of 0.99, a cut-off value of 3.52 kPa for discrimination could be calculated. There was a significant correlation of mass effect represented by midline shift and EM values on the contralateral side (Pearson correlation coefficient = 0.68, p < 0.0003). Conclusion Ultrasound brain parenchyma elastography seems to be a reliable sonographic method for discriminating between large IS and HS and for detecting and tracking conditions of intracerebral mass effects.