title: Clinico-radiological features of subarachnoid hyperintensity on diffusion-weighted images in patients with meningitis.
abstract: OBJECTIVE
  To investigate the clinical and radiological features of meningitis with subarachnoid diffusion-weighted imaging (DWI) hyperintensity.
  
  
  METHODS
  The clinical features, laboratory data, and radiological findings, including the number and distribution of subarachnoid DWI hyperintense lesions and other radiological abnormalities, of 18 patients seen at five institutions were evaluated.
  
  
  RESULTS
  The patients consisted of eight males and 10 females, whose ages ranged from 4 months to 82 years (median 65 years). Causative organisms were bacteria in 15 patients, including Haemophilus influenzae, Streptococcus pneumoniae, Streptococcus agalactiae, Staphylococcus aureus, Klebsiella pneumoniae, and Listeria monocytogenes. The remaining three were fungal meningitis caused by Cryptococcus neoformans. Subarachnoid DWI hyperintense lesions were multiple in 16 of the 18 cases (89%) and predominantly distributed around the frontal lobe in 16 of the 18 cases (89%). In addition to subarachnoid abnormality, subdural empyema, cerebral infarction, and intraventricular empyema were found in 50, 39, and 39%, respectively. Compared with paediatric patients, adult patients with bacterial meningitis tended to have poor prognoses (7/10 versus 1/5; p = 0.1).
  
  
  CONCLUSIONS
  Both bacterial and fungal meningitis could cause subarachnoid hyperintensity on DWI, predominantly around the frontal lobe. This finding is often associated with poor prognosis in adult bacterial meningitis.
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. madarafuebuki@yahoo.co.jp
authors.forename: T
authors.initials: T
authors.lastname: Kawaguchi
authors.forename: K
authors.initials: K
authors.lastname: Sakurai
authors.forename: M
authors.initials: M
authors.lastname: Hara
authors.forename: M
authors.initials: M
authors.lastname: Muto
authors.forename: M
authors.initials: M
authors.lastname: Nakagawa
authors.forename: J
authors.initials: J
authors.lastname: Tohyama
authors.forename: T
authors.initials: T
authors.lastname: Oguri
authors.forename: S
authors.initials: S
authors.lastname: Mitake
authors.forename: M
authors.initials: M
authors.lastname: Maeda
authors.forename: N
authors.initials: N
authors.lastname: Matsukawa
authors.forename: K
authors.initials: K
authors.lastname: Ojika
authors.forename: Y
authors.initials: Y
authors.lastname: Shibamoto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008581:Meningitis / Q000175:diagnosis* / Q000382:microbiology; D016920:Meningitis, Bacterial / Q000175:diagnosis; D016921:Meningitis, Fungal / Q000175:diagnosis; D008875:Middle Aged; D011379:Prognosis; D013346:Subarachnoid Space