title: Apparent diffusion coefficient in the aging mouse brain: a magnetic resonance imaging study.
abstract: Novel magnetic resonance imaging sequences have and still continue to play an increasing role in neuroimaging and neuroscience. Among these techniques, diffusion-weighted imaging (DWI) has revolutionized the diagnosis and management of diseases such as stroke, neoplastic disease and inflammation. However, the effects of aging on diffusion are yet to be determined. To establish reference values for future experimental mouse studies we tested the hypothesis that absolute apparent diffusion coefficients (ADC) of the normal brain change with age. A total of 41 healthy mice were examined by T2-weighted imaging and DWI. For each animal ADC frequency histograms (i) of the whole brain were calculated on a voxel-by-voxel basis and region-of-interest (ROI) measurements (ii) performed and related to the animals' age. The mean entire brain ADC of mice <3 months was 0.715(+/-0.016) x 10(-3) mm2/s, no significant difference to mice aged 4 to 5 months (0.736(+/-0.040) x 10(-3) mm2/s) or animals older than 9 months 0.736(+/-0.020) x 10(-3) mm2/s. Mean whole brain ADCs showed a trend towards lower values with aging but both methods (i + ii) did not reveal a significant correlation with age. ROI measurements in predefined areas: 0.723(+/-0.057) x 10(-3) mm2/s in the parietal lobe, 0.659(+/-0.037) x 10(-3) mm2/s in the striatum and 0.679(+/-0.056) x 10(-3) mm2/s in the temporal lobe. With advancing age, we observed minimal diffusion changes in the whole mouse brain as well as in three ROIs by determination of ADCs. According to our data ADCs remain nearly constant during the aging process of the brain with a small but statistically non-significant trend towards a decreased diffusion in older animals.
authors.affiliation: University of Heidelberg, Department of Neurology, INF 400-Kopfklinik, D-69120 Heidelberg, Germany. philipp.rau@gmail.com
authors.forename: Philipp R
authors.initials: PR
authors.lastname: Rau
authors.forename: Johann
authors.initials: J
authors.lastname: Sellner
authors.forename: Sabine
authors.initials: S
authors.lastname: Heiland
authors.forename: Konstanze
authors.initials: K
authors.lastname: Plaschke
authors.forename: Peter D
authors.initials: PD
authors.lastname: Schellinger
authors.forename: Uta K
authors.initials: UK
authors.lastname: Meyding-Lamadé
authors.forename: Wolfram R
authors.initials: WR
authors.lastname: Lamadé
mesh_terms: D000375:Aging / Q000473:pathology / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000473:pathology / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D051379:Mice; D008815:Mice, Inbred Strains