title: Usefulness of diffusion-weighted MRI in human herpesvirus-6 encephalitis.
abstract: We report a patient with human herpesvirus-6 (HHV-6) encephalitis diagnosed by diffusion-weighted magnetic resonance imaging (DW-MRI). A previously healthy 10-month-old girl developed acute encephalopathy. HHV-6 DNA was detected in her cerebrospinal fluid during the acute phase of the disease by polymerase chain reaction. The patient demonstrated cortical diffusion abnormalities in affected brain parenchyma, partially as the initial or most sensitive sign of encephalitis that could be detected not by conventional MRI but by DW-MRI. Serial imaging showed that the diffusion abnormality DW-MRI returned to normal after 45 days.
  
  
  CONCLUSIONS
  DW-MRI may be a valuable tool for early detection and diagnosis of HHV-6 encephalitis and is more sensitive than conventional MRI to detect a subtle edematous change in the brain.
authors.affiliation: Department of Pediatrics, Kansai Medical University, Moriguchi-shi, Osaka 570-8506, Japan. takaya@takii.kmu.ac.jp
authors.forename: Junji
authors.initials: J
authors.lastname: Takaya
authors.forename: Atsushi
authors.initials: A
authors.lastname: Araki
authors.forename: Kizo
authors.initials: K
authors.lastname: Mori
authors.forename: Kazunari
authors.initials: K
authors.lastname: Kaneko
mesh_terms: D003951:Diagnostic Errors; D038524:Diffusion Magnetic Resonance Imaging; D018792:Encephalitis, Viral / Q000175:diagnosis*; D005074:Evoked Potentials, Visual; D005260:Female; D015654:Herpesvirus 6, Human; D006801:Humans; D007223:Infant; D019349:Roseolovirus Infections / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed