title: A Novel Imaging Technique (X-Map) to Identify Acute Ischemic Lesions Using Noncontrast Dual-Energy Computed Tomography.
abstract: BACKGROUND
  We evaluated whether X-map, a novel imaging technique, can visualize ischemic lesions within 20 hours after the onset in patients with acute ischemic stroke, using noncontrast dual-energy computed tomography (DECT).
  
  
  METHODS
  Six patients with acute ischemic stroke were included in this study. Noncontrast head DECT scans were acquired with 2 X-ray tubes operated at 80 kV and Sn150 kV between 32 minutes and 20 hours after the onset. Using these DECT scans, the X-map was reconstructed based on 3-material decomposition and compared with a simulated standard (120 kV) computed tomography (CT) and diffusion-weighted imaging (DWI).
  
  
  RESULTS
  The X-map showed more sensitivity to identify the lesions as an area of lower attenuation value than a simulated standard CT in all 6 patients. The lesions on the X-map correlated well with those on DWI. In 3 of 6 patients, the X-map detected a transient decrease in the attenuation value in the peri-infarct area within 1 day after the onset.
  
  
  CONCLUSIONS
  The X-map is a powerful tool to supplement a simulated standard CT and characterize acute ischemic lesions. However, the X-map cannot replace a simulated standard CT to diagnose acute cerebral infarction.
authors.affiliation: Departments of Radiology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Japan. Electronic address: kyo@med.u-toyama.ac.jp.
authors.forename: Kyo
authors.initials: K
authors.lastname: Noguchi
authors.affiliation: Department of Research & Collaboration, Siemens Healthcare, Tokyo, Japan.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Itoh
authors.affiliation: Departments of Radiology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Japan.
authors.forename: Norihito
authors.initials: N
authors.lastname: Naruto
authors.affiliation: Department of Neurology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Japan.
authors.forename: Shutaro
authors.initials: S
authors.lastname: Takashima
authors.affiliation: Department of Neurology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Japan.
authors.forename: Kortaro
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kuroda
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging*; D002545:Brain Ischemia / Q000150:complications / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D020521:Stroke / Q000000981:diagnostic imaging* / Q000209:etiology; D013997:Time Factors; D014057:Tomography, X-Ray Computed
keywords: Acute ischemic stroke; CT; X-map; diagnosis; noncontrast dual-energy computed tomography