title: Ultrasonography Monitoring with Superb Microvascular Imaging Technique in Brain Tumor Surgery.
abstract: BACKGROUND
  Neuronavigation based on preoperative magnetic resonance imaging has been developed as a useful tool to improve visibility of the surgical site in the operative field. Ultrasonography (US) monitoring has also been used as a reliable imaging technique, providing real-time information during neurosurgical operations. We combined the latest innovative imaging technique for detecting very low-flow components, Superb Microvascular Imaging (SMI), with US monitoring during brain tumor surgery.
  
  
  METHODS
  Fifteen patients diagnosed with brain tumor (8 malignant and 7 benign) underwent neurosurgery with US monitoring using an Aplio 400/500 US system with the new SMI technique (imaging frequency, 10-12 MHz; frame rate, 28-31 Hz). Features of the SMI images in the gray scale mode include 1) visualization of low-velocity flow with minimal motion artifact, 2) high resolution of images, and 3) high frame rates. The tumors, tumor vessels, compressed and shifted healthy vessels, and cistern were clearly visualized on the SMI images in the gray scale mode, detailing the characteristics of healthy brain tissue (vertically penetrating, fine, straight vessels), glioblastoma (rounding, dilating, and bending vessels), low-grade glioma (fine and straight vessels), meningioma (many large and branching vessels), and lymphoma (less vascular, low echoic tumor) and demonstrating the tumor-defined border. We also performed biopsies under US monitoring with SMI.
  
  
  CONCLUSIONS
  We combined SMI technique with US monitoring during brain tumor surgery and observed healthy and tumor vessels. Further research is important for the development of a more precise and reliable neurosurgery.
authors.affiliation: Department of Neurosurgery, Edogawa Hospital, Tokyo, Japan; Department of Neurosurgery, Saitama Medical Center, Jichi Medical University, Saitama, Japan. Electronic address: m.ishikawa@edogawa.or.jp.
authors.forename: Mami
authors.initials: M
authors.lastname: Ishikawa
authors.affiliation: Department of ENT Surgery, Sakura Hospital, Toho Medical Center, Chiba, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ota
authors.affiliation: Department of Neurosurgery, Sano Kosei Hospital, Tochigi, Japan.
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Nagai
authors.affiliation: Department of Neurosurgery, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Kusaka
authors.affiliation: Department of Neurosurgery, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Neurosurgery, Edogawa Hospital, Tokyo, Japan.
authors.forename: Heiji
authors.initials: H
authors.lastname: Naritaka
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D055806:Microvessels / Q000000981:diagnostic imaging* / Q000601:surgery*; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D038361:Neuronavigation / Q000379:methods; D019635:Neurosurgical Procedures / Q000379:methods; D018084:Ultrasonography, Interventional / Q000379:methods*
keywords: Intraoperative monitoring; Microvascular imaging; Tumor vessels; Ultrasonography