title: In vivo monitoring of acute flavivirus (Modoc) encephalitis with regional and whole-brain quantitative diffusion magnetic resonance imaging.
abstract: In vivo imaging of structural changes in the brain of patients with encephalitis has become an important aid in diagnostic and therapeutic procedures. Diffusion-weighted magnetic resonance imaging (DWI) was employed to quantitate regional and whole-brain diffusion-weighted MRI changes in a hamster model for acute flavivirus encephalitis. The regional apparent diffusion coefficient (ADC) was determined in hyperintense regions seen on T2-weighted images (i.e., the thalamic area and the temporal lobe), but anatomical variation and structural heterogeneity of encephalitic lesions severely impeded the placement of regions of interest (ROI). Therefore, quantitative whole-brain diffusion-weighted imaging was carried out and revealed a significantly reduced ADC (P = .02) in the brain of hamsters with acute encephalitis (n = 7) as compared to that of healthy, uninfected controls (n = 3). Furthermore, the ADC histogram demonstrated a reduced peak height and center of gravity during the acute encephalitis. Our findings could further support the use of diffusion-weighted imaging for in vivo monitoring of acute flavivirus encephalitis and for the study of therapeutic approaches.
authors.affiliation: Department of Neurology, Ruprecht-Karls-University Heidelberg, Germany. jsellner@arcor.de
authors.forename: Johann
authors.initials: J
authors.lastname: Sellner
authors.forename: Pieter
authors.initials: P
authors.lastname: Leyssen
authors.forename: Sabine
authors.initials: S
authors.lastname: Heiland
authors.forename: Philipp
authors.initials: P
authors.lastname: Rau
authors.forename: Johan
authors.initials: J
authors.lastname: Neyts
authors.forename: Francisco
authors.initials: F
authors.lastname: Martinez-Torres
authors.forename: Peter
authors.initials: P
authors.lastname: Schramm
authors.forename: Werner
authors.initials: W
authors.lastname: Hacke
authors.forename: Uta
authors.initials: U
authors.lastname: Meyding-Lamadé
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology / Q000821:virology*; D001931:Brain Mapping; D006224:Cricetinae; D004195:Disease Models, Animal; D018792:Encephalitis, Viral / Q000473:pathology*; D018178:Flaviviridae Infections / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008991:Monitoring, Physiologic