title: Intraoperative Navigated Angiosonography for Skull Base Tumor Surgery.
abstract: BACKGROUND
  One of the main challenges during skull base tumor surgery is identifying the relationships between the lesion and the principal intracranial vessels. To this end, neuronavigation systems based on preoperative imaging lack accuracy because of brain shift and brain deformation. Intraoperative navigated B-mode ultrasonography is useful in defining the extent of brain tumor. Doppler imaging adds information regarding flow entity in neighboring vessels. Second-generation ultrasound contrast agents improve the signal-to-noise ratio of B-mode imaging and permit the study of the vessel's course, blood flow, and perfusion characteristics of focal lesions. We report our experience using intraoperative navigated contrast-enhanced ultrasound to perform a navigated angiosonography (N-ASG) for the visualization of vessels in a series of 18 skull base tumors.
  
  
  METHODS
  We performed N-ASG in a series of 18 skull base tumors (10 meningiomas, 3 craniopharyngiomas, 2 giant pituitary adenomas, 1 posterior fossa epidermoid, 2 dermoid cysts). N-ASG was obtained after craniotomy before resecting each lesion and during tumor removal, after intravenous injection of ultrasound contrast agent.
  
  
  RESULTS
  In all 18 cases, major vessels and their branches were simultaneously identified (both high and low flow) using N-ASG, which allowed to visualize the whole length of each vessels. N-ASG was also useful in highlighting the lesion, compared with standard B-mode imaging, and showing its perfusion patterns.
  
  
  CONCLUSIONS
  N-ASG can be applied to skull base tumor surgery, providing helpful information about the relationship between principal intracranial vessels and tumors. This technique could be of assistance in approaching the tumor and avoiding vascular damages.
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy. Electronic address: francesco.prada@istituto-besta.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Prada
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Del Bene
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Casali
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Saladino
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Federico Giuseppe
authors.initials: FG
authors.lastname: Legnani
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Perin
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Moiraghi
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Richetta
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Rampini
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Mattei
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Ignazio Gaspare
authors.initials: IG
authors.lastname: Vetrano
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Fornaro
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Saini
authors.affiliation: Department of Radiology, Ospedale Valduce, Como, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Martegani
authors.affiliation: Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy; Department of Neurological Surgery, Johns Hopkins Medical School, Baltimore, Maryland, USA.
authors.forename: Francesco
authors.initials: F
authors.lastname: DiMeco
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging / Q000601:surgery; D000328:Adult; D000368:Aged; D002533:Cerebral Angiography / Q000379:methods*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging*; D003397:Craniopharyngioma / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery; D008579:Meningioma / Q000000981:diagnostic imaging / Q000601:surgery; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D038361:Neuronavigation / Q000379:methods*; D019635:Neurosurgical Procedures / Q000379:methods*; D010911:Pituitary Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery; D019292:Skull Base Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D018608:Ultrasonography, Doppler
keywords: Angiosonography; Brain tumor; Contrast-enhanced ultrasound; Intraoperative imaging; Intraoperative ultrasound; Skull base surgery; Vascular surgery