title: Changes of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in the model of experimental acute hydrocephalus in rabbits.
abstract: BACKGROUND
  To study the integrity of white matter, we investigated the correlation between the changes in neuroradiological and morphological parameters in an animal model of acute obstructive hydrocephalus.
  
  
  METHODS
  Hydrocephalus was induced in New Zealand rabbits (n = 10) by stereotactic injection of kaolin into the lateral ventricles. Control animals received saline in place of kaolin (n = 10). The progression of hydrocephalus was assessed using magnetic resonance imaging. Regional fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) were measured in several white matter regions before and after the infusion of kaolin. Morphology of myelinated nerve fibers as well as of the blood-brain barrier were studied with the help of transmission electron microscopy (TEM) and light microscopy.
  
  
  RESULTS
  Compared with control animals, kaolin injection into the ventricles resulted in a dramatic increase in ventricular volume with compression of basal cisterns, brain shift and periventricular edema (as observed on magnetic resonance imaging [MRI]). The values of ADC in the periventricular and periaqueductal areas significantly increased in the experimental group (P < 0.05). FA decreased by a factor of 2 in the zones of periventricular, periaqueductal white matter and corpus collosum. Histological analysis demonstrated the impairment of the white matter and necrobiotic changes in the cortex. Microsctructural alterations of the myelin fibers were further proved with the help of TEM. Blood-brain barrier ultrastructure assessment showed the loss of its integrity.
  
  
  CONCLUSIONS
  The study demonstrated the correlation of the neuroradiological parameters with morphological changes. The abnormality of the FA and ADC parameters in the obstructive hydrocephalus represents a significant implication for the diagnostics and management of hydrocephalus in patients.
authors.affiliation: A.L. Polenov Russian Scientific Research Institute of Neurosurgery, 191014, Mayakovsky str. 12, St. Petersburg, Russia, shevtsov-max@mail.ru.
authors.forename: Maxim A
authors.initials: MA
authors.lastname: Shevtsov
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Senkevich
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Kim
authors.forename: Kseniia A
authors.initials: KA
authors.lastname: Gerasimova
authors.forename: Tatyana N
authors.initials: TN
authors.lastname: Trofimova
authors.forename: Galina V
authors.initials: GV
authors.lastname: Kataeva
authors.forename: Sviatoslav V
authors.initials: SV
authors.lastname: Medvedev
authors.forename: Olga I
authors.initials: OI
authors.lastname: Smirnova
authors.forename: Zhanna I
authors.initials: ZI
authors.lastname: Savintseva
authors.forename: Marina G
authors.initials: MG
authors.lastname: Martynova
authors.forename: Olga A
authors.initials: OA
authors.lastname: Bystrova
authors.forename: Emil
authors.initials: E
authors.lastname: Pitkin
authors.forename: Galina Y
authors.initials: GY
authors.lastname: Yukina
authors.forename: William A
authors.initials: WA
authors.lastname: Khachatryan
mesh_terms: D000818:Animals; D016880:Anisotropy; D056324:Diffusion Tensor Imaging / Q000379:methods; D004195:Disease Models, Animal; D006849:Hydrocephalus / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D011817:Rabbits; D066127:White Matter / Q000473:pathology*