title: Quantification of Cerebral Edema After Subarachnoid Hemorrhage.
abstract: Global cerebral edema (GCE) is a manifestation of early brain injury (EBI) after subarachnoid hemorrhage (SAH) and is an independent risk factor for poor outcome. The lack of a quantitative method to measure GCE limits the study of its pathophysiology. The goal of this study is to develop a quantitative surrogate marker that represents GCE after SAH.
  
  
  
  Patients with spontaneous SAH were enrolled into a prospective observational database. Initial CT scans were graded for GCE using established qualitative criteria. Selective sulcal volume (SSV) was defined as total mL of sulcal volumes on axial CT slices above the most cranial section of the lateral ventricles to the last visible section. Using a semiautomatic threshold approach, sulcal regions were traced out with manual adjustments when necessary. The volume of sulci in each slice was calculated and multiplied by the slice thickness and number of slices to calculate the SSV. All volumetric analysis was performed using Medical Image Processing, Analysis and Visualization Version 7.0.1 (MIPAV).
  
  
  
  A total of 109 subjects were included in our analysis. Mean selective sulcal volumes (SSV) differed between subjects with and without GCE 4.5 and 21.2 mL (P < 0.001). When separated into quartiles, the odds of qualitative GCE increases as SSV decreases. Compared to the highest SSV quartile, smaller SSV was associated with worse clinical outcomes.
  
  
  
  GCE can be quantified using volumetric analysis of SSV measurements on routine CT scans. Smaller SSV on admission is predictive of worse clinical outcomes. SSV may be an important marker of EBI after SAH.
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA. huimahn.a.choi@uth.tmc.edu.|Department of Neurology, University of Texas, Houston Health Science Center, Houston, TX, USA. huimahn.a.choi@uth.tmc.edu.
authors.forename: H Alex
authors.initials: HA
authors.lastname: Choi
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.|Department of Neurology, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: Suhas S
authors.initials: SS
authors.lastname: Bajgur
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: Wesley H
authors.initials: WH
authors.lastname: Jones
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: Jude P J
authors.initials: JP
authors.lastname: Savarraj
authors.affiliation: Department of Neurology, Seoul National University, Seoul, South Korea.
authors.forename: Sang-Bae
authors.initials: SB
authors.lastname: Ko
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.|Department of Neurology, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Edwards
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.|Department of Neurology, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: Tiffany R
authors.initials: TR
authors.lastname: Chang
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: Georgene W
authors.initials: GW
authors.lastname: Hergenroeder
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Dannenbaum
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: P Roc
authors.initials: PR
authors.lastname: Chen
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Day
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: Dong H
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, University of Texas, Houston Health Science Center, Houston, TX, USA.
authors.forename: Kiwon
authors.initials: K
authors.lastname: Lee
authors.affiliation: Memorial Hermann Hospital-Texas Medical Center, Houston, TX, USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Grotta
mesh_terms: D000328:Adult; D000368:Aged; D001929:Brain Edema / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012042:Registries; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Global cerebral edema; SAH; Sulcal volume