title: Ventricular Temperatures in Idiopathic Normal Pressure Hydrocephalus (iNPH) Measured with DWI-based MR Thermometry.
abstract: OBJECTIVE
  The brain produces intense heat as a result of cerebral metabolism and cerebral blood flow, and the generated heat is removed mainly through circulation of the intracranial blood vessels and cerebrospinal fluid (CSF). Because magnetic resonance (MR) images are constructed from analysis of the spin of various molecules, the diffusion coefficient can be used as a parameter that reflects the temperature of water molecules. We used diffusion-weighted imaging (DWI)-based MR imaging to measure the temperature of the CSF around the lateral ventricles in patients with idiopathic normal pressure hydrocephalus (iNPH).
  
  
  METHODS
  Our study included 33 cases of iNPH (Group N, mean age, 75.1 years) and 40 age-matched controls (Group C, mean age, 74.5 years). We calculated CSF temperature in the ventricular domain using the conversion formula to evaluate the feasibility of iNPH study.
  
  
  RESULTS
  The mean temperatures were significantly higher in Group N (37.6°C ± 0.4°C) than Group C (36.7°C ± 0.5°C; P < 0.01). The cut-off value of 37.2°C (more than the mean + 2 standard deviations [SD] of the values in Group C) showed sensitivity of 72.4% and specificity of 77.5% for distinguishing the 2 groups. We confirmed improved CSF temperature in the lateral ventricles in all patients examined both before and after shunting.
  
  
  CONCLUSIONS
  Elevated ventricular temperatures in patients with iNPH (Group N) may represent a disturbance in heat balance. Our results showed that thermometry using DWI-based MR imaging can help in the noninvasive and consistent evaluation of CSF temperature and may thus provide a useful supplementary brain biomarker for iNPH.
authors.affiliation: Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine.
authors.forename: Nagato
authors.initials: N
authors.lastname: Kuriyama
authors.forename: Kei
authors.initials: K
authors.lastname: Yamada
authors.forename: Koji
authors.initials: K
authors.lastname: Sakai
authors.forename: Takahiko
authors.initials: T
authors.lastname: Tokuda
authors.forename: Kentaro
authors.initials: K
authors.lastname: Akazawa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tomii
authors.forename: Aiko
authors.initials: A
authors.lastname: Tamura
authors.forename: Masaki
authors.initials: M
authors.lastname: Kondo
authors.forename: Isao
authors.initials: I
authors.lastname: Watanabe
authors.forename: Etsuko
authors.initials: E
authors.lastname: Ozaki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Matsui
authors.forename: Masanori
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Toshiki
authors.initials: T
authors.lastname: Mizuno
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D000368:Aged; D000465:Algorithms; D001831:Body Temperature / Q000502:physiology*; D016022:Case-Control Studies; D002552:Cerebral Ventricles / Q000503:physiopathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000134:cerebrospinal fluid / Q000503:physiopathology* / Q000601:surgery; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data; D008297:Male; D059906:Neuroimaging / Q000706:statistics & numerical data; D012372:ROC Curve; D012680:Sensitivity and Specificity; D062125:Thermometry / Q000706:statistics & numerical data; D017287:Ventriculoperitoneal Shunt / Q000379:methods