Ultrasonographic superb microvascular imaging for emergency surgery of intracerebral hemorrhage

Abstract

Ultrasonography (US) has been used as a reliable imaging modality, providing real-time information during neurosurgical operations. One recent innovative US technique, superb microvascular imaging (SMI), visualizes small vessels and flow, which are not detected with standard US with doppler. We apply SMI to intraoperative US monitoring in emergency surgery for intracerebral hemorrhage (ICH). Eleven consecutive patients with ICH underwent endoscopic emergency surgery under US monitoring with SMI. After performing a small craniotomy, US images were obtained using SMI, a fusion technique, and a contrast agent technique, with the probe on the brain surface during surgery. Fusion images were obtained with the probe on the head before craniotomy in some patients. Animated US images with SMI could differentiate hematoma containing no vessels from brain tissue, and flow images using SMI and contrast agent techniques clarified the borderlines. Animated fusion images of intraoperative US and preoperative CT provided information on the extent of hematoma and residual hematoma during emergency surgery. We made various fusion CT images showing intracranial hematoma with US probes and decided on the skin incision line before beginning surgery, as if we were using a neuronavigation system. US with SMI, contrast agent, and fusion techniques provide information on the extent of intracranial hematoma and residual hematoma with no vessels and no flow. Monitoring by US and fusion CT images is useful for ICH surgery as a next-generation neuronavigator.

Keywords: Intracerebral hemorrhage; Intraoperative monitoring; Microvascular imaging; Ultrasonography.