title: Simple and reproducible linear measurements to determine ventricular enlargement in adults.
abstract: BACKGROUND
  Recent studies have suggested that Evan's Index (EI) is not accurate and instead endorse volumetric measurements. Our aim was to evaluate the reproducibility of linear measurements and their correlation to ventricular volume.
  
  
  METHODS
  Using magnetic resonance (MR) images of 30 patients referred for normal pressure hydrocephalus (NPH), EI, frontal-occipital horn ratio (FOR), third ventricular width and height, frontal horn width (FHW), and callosal angle (CA) at the foramen of Monro and the posterior commissure (PC) were independently measured by residents in neurosurgery and radiology, a neurosurgeon and radiologist, and a medical student. Intraclass correlation coefficients (ICC) were calculated to establish inter-rater agreement among the reviewers. Pearson's correlation coefficients were done to assess the relationship of the linear measurements with total ventricular volume. Kappa analyses were performed to assess the degree of agreement between cutpoints determined by the ROC analysis for the linear measurements and reviewers' gestalt impression about ventricular size with volumetric abnormality.
  
  
  RESULTS
  The overall inter-rater agreement among reviewers was almost perfect for EI (ICC = 0.913), FOR (ICC = 0.830), third ventricular width, FHW (ICC = 0.88), and CA at PC (ICC = 0.865), substantial for temporal horn width (ICC = 0.729) and CA at foramen of Monro (ICC = 0.779), and moderate for third ventricular height (ICC = 0.496). EI, FOR, third ventricular width, temporal horn width, and CA at PC measures correlated with total ventricular volume. There was fair-to-almost-perfect agreement of the individual reviewer's gestalt responses of abnormatility with volumetric abnormality. Gestalt responses were better for more senior raters.
  
  
  CONCLUSIONS
  Linear measurements are reliable and reproducible methods for determining ventricular enlargement.
authors.affiliation: Department of Neurosurgery, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Reinard
authors.affiliation: Department of Neurosurgery, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Azam
authors.initials: A
authors.lastname: Basheer
authors.affiliation: Department of Neurosurgery, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Phillips
authors.affiliation: University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
authors.forename: Allison
authors.initials: A
authors.lastname: Snyder
authors.affiliation: Department of Diagnostic Radiology, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Ajay
authors.initials: A
authors.lastname: Agarwal
authors.affiliation: Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Kourosh
authors.initials: K
authors.lastname: Jafari-Khouzani
authors.affiliation: Department of Radiology, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Hamid
authors.initials: H
authors.lastname: Soltanian-Zadeh
authors.affiliation: Department of Neurosurgery, Henry Ford Hospital, Detroit, MI, USA ; Department of Public Health Sciences, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Lonni
authors.initials: L
authors.lastname: Schultz
authors.affiliation: Department of Diagnostic Radiology, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Aho
authors.affiliation: Department of Neurosurgery, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Schwalb
keywords: Evan's Index; normal pressure hydrocephalus; ventriculomegaly