title: Unusual acute encephalitis involving the thalamus: imaging features.
abstract: OBJECTIVE
  To describe the brain CT and MR imaging findings of unusual acute encephalitis involving the thalamus.
  
  
  METHODS
  We retrospectively reviewed the medical records and CT and/or MR imaging findings of six patients with acute encephalitis involving the thalamus. CT (n=6) and MR imaging (n=6) were performed during the acute and/or convalescent stage of the illness.
  
  
  RESULTS
  Brain CT showed brain swelling (n=2), low attenuation of both thalami (n=1) or normal findings (n=3). Initial MR imaging indicated that in all patients the thalamus was involved either bilaterally (n=5) or unilaterally (n=1). Lesions were also present in the midbrain (n=5), medial temporal lobe (n=4), pons (n=3), both hippocampi (n=3) the insular cortex (n=2), medulla (n=2), lateral temporal lobe cortex (n=1), both cingulate gyri (n=1), both basal ganglia (n=1), and the left hemispheric cortex (n=1).
  
  
  CONCLUSIONS
  These CT or MR imaging findings of acute encephalitis of unknown etiology were similar to a combination of those of Japanese encephalitis and herpes simplex encephalitis. In order to document the specific causative agents which lead to the appearance of these imaging features, further investigation is required.
authors.affiliation: Department of Radiology, Kangwon National University Hospital, Korea.
authors.forename: S S
authors.initials: SS
authors.lastname: Kim
authors.forename: K H
authors.initials: KH
authors.lastname: Chang
authors.forename: K W
authors.initials: KW
authors.lastname: Kim
authors.forename: M H
authors.initials: MH
authors.lastname: Han
authors.forename: S H
authors.initials: SH
authors.lastname: Park
authors.forename: H W
authors.initials: HW
authors.lastname: Nam
authors.forename: K H
authors.initials: KH
authors.lastname: Choi
authors.forename: W H
authors.initials: WH
authors.lastname: Cho
mesh_terms: D000208:Acute Disease; D000328:Adult; D004660:Encephalitis / Q000134:cerebrospinal fluid / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D013788:Thalamus / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed