title: Nipah virus encephalitis: serial MR study of an emerging disease.
abstract: OBJECTIVE
  To report the serial magnetic resonance (MR) imaging findings of the Nipah virus.
  
  
  METHODS
  Twelve patients underwent serial MR imaging. Eight patients were examined at the outbreak; 11, at 1 month; and seven, at 6 months. Contrast material-enhanced MR images, diffusion-weighted images, and single-voxel proton MR spectroscopic images were reviewed. Clinical and neurologic assessment, as well as analysis of the size, location, and appearance of brain lesions on MR images, were performed.
  
  
  RESULTS
  During the outbreak, all eight patients had multiple small foci of high signal intensity within the white matter on T2-weighted images. In six patients, cortical and brain stem lesions were also detected, and five patients had diffusion-weighted MR imaging-depicted hyperintensities. One month after the outbreak, five patients had widespread tiny foci of high signal intensity on T1-weighted images, particularly in the cerebral cortex. Diffusion-weighted images showed decreased prominence or disappearance of lesions over time. There was no evidence of progression or relapse of the lesions at 6-month follow-up. MR spectroscopy depicted reduction in N-acetylaspartate-to-creatine ratio and elevation of choline-to-creatine ratios.
  
  
  CONCLUSIONS
  The Nipah virus has findings unlike other viral encephalitides: small lesions that are primarily within the white matter, with transient punctate cortical hyperintensities on T1-weighted images.
authors.affiliation: Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore. tchoyoson_lim@notes.ttsh.gov.sg
authors.forename: C C Tchoyoson
authors.initials: CC
authors.lastname: Lim
authors.forename: Kim En
authors.initials: KE
authors.lastname: Lee
authors.forename: Wei Ling
authors.initials: WL
authors.lastname: Lee
authors.forename: Paul A
authors.initials: PA
authors.lastname: Tambyah
authors.forename: Cheng Chuan
authors.initials: CC
authors.lastname: Lee
authors.forename: Yih Yian
authors.initials: YY
authors.lastname: Sitoh
authors.forename: Alexandra P
authors.initials: AP
authors.lastname: Auchus
authors.forename: B K Michael
authors.initials: BK
authors.lastname: Lin
authors.forename: Francis
authors.initials: F
authors.lastname: Hui
mesh_terms: D000328:Adult; D000368:Aged; D000382:Agricultural Workers' Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D021821:Communicable Diseases, Emerging / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D004196:Disease Outbreaks; D018792:Encephalitis, Viral / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D018184:Paramyxoviridae Infections / Q000175:diagnosis* / Q000453:epidemiology; D018098:Paramyxovirinae