title: Assessment of white matter damage in subacute sclerosing panencephalitis using quantitative diffusion tensor MR imaging.
abstract: OBJECTIVE
  Subacute sclerosing panencephalitis (SSPE), a rare progressive degenerative disease, is caused by persistent infection with a defective measles virus. The correlation between the clinical staging and MR imaging is usually poor. The aim of the study was to investigate the role of diffusion tensor imaging (DTI) in the early detection of white matter damage in SSPE in the presence of normal findings on conventional imaging.
  
  
  METHODS
  DTI was performed in 21 patients in stage II SSPE and 10 age/sex-matched healthy controls. Fractional anisotropy (FA) and mean diffusivity (MD) values were calculated in the periventricular white matter, corpus callosum, and posterior limb of the internal capsule in patients with normal and abnormal findings on conventional imaging as well as healthy controls.
  
  
  RESULTS
  The patients were grouped into those with normal (n = 11) and abnormal (n = 10) findings on conventional imaging for the purpose of quantitative DTI analysis. Abnormal- and normal-appearing white matter on T2-weighted images showed significantly decreased FA values in all the regions compared with those in healthy controls. MD values were significantly increased in the periventricular white matter region of the frontal and parietooccipital lobe in patients with normal as well as abnormal findings on conventional imaging compared with those in healthy controls.
  
  
  CONCLUSIONS
  DTI detects early white matter abnormalities that may have significant therapeutic implication, even in the presence of normal findings on conventional imaging, in patients with SSPE.
authors.affiliation: Department of Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, UP, India.
authors.forename: R
authors.initials: R
authors.lastname: Trivedi
authors.forename: R K
authors.initials: RK
authors.lastname: Gupta
authors.forename: A
authors.initials: A
authors.lastname: Agarawal
authors.forename: K M
authors.initials: KM
authors.lastname: Hasan
authors.forename: A
authors.initials: A
authors.lastname: Gupta
authors.forename: K N
authors.initials: KN
authors.lastname: Prasad
authors.forename: G
authors.initials: G
authors.lastname: Bayu
authors.forename: D
authors.initials: D
authors.lastname: Rathore
authors.forename: R K S
authors.initials: RK
authors.lastname: Rathore
authors.forename: P A
authors.initials: PA
authors.lastname: Narayana
mesh_terms: D000293:Adolescent; D001284:Atrophy; D001925:Brain Damage, Chronic / Q000175:diagnosis*; D002540:Cerebral Cortex / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D020772:Internal Capsule / Q000473:pathology*; D008297:Male; D009460:Neurologic Examination; D012016:Reference Values; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D013344:Subacute Sclerosing Panencephalitis / Q000175:diagnosis*; D013788:Thalamus / Q000473:pathology