title: Magnetic resonance diffusion-weighted imaging: quantitative evaluation of age-related changes in healthy liver parenchyma.
abstract: The purpose of this study was to verify in healthy liver parenchyma the possible influence of age on DwI-related parameters: apparent diffusion coefficient (ADC), perfusion fraction (PF), diffusion and pseudodiffusion coefficient (D and D*). Forty healthy adult volunteers (age range 26-86 years), divided into four age groups, were prospectively submitted to a breath-hold magnetic resonance diffusion imaging (MR-DwI) (two b values, 0-300 and 0-1000 s/mm²). A smaller cohort of 16 subjects underwent a free-breath multi-b acquisition (16 b values, 0-750 s/mm²). Quantitative analysis was performed by two observers with manually defined regions of interest, on the most homogeneous portion of the right liver lobe. Individual and group statistical analysis of data was performed: ANOVA to establish differences between groups and Pearson correlation coefficient to investigate the association between DwI parameters and age. The mean, S.D. and 95% limits of agreement of ADC values for each age-defined group are reported. ANOVA showed no significant differences between group means (P always >.05). No significant correlation between subjects' age and DwI parameters was established, both in breath-hold and free-breath acquisitions, on the whole range of adopted b values. Our study conducted on healthy liver parenchyma shows that there are no significant differences in ADC, PF, D and D* of younger or older subjects.
authors.affiliation: Section of Radiodiagnostics, Department of Clinical Physiopathology, University of Florence, Azienda Ospedaliero-Universitaria, Florence, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Pasquinelli
authors.forename: Giacomo
authors.initials: G
authors.lastname: Belli
authors.forename: Lorenzo Nicola
authors.initials: LN
authors.lastname: Mazzoni
authors.forename: Luigi
authors.initials: L
authors.lastname: Grazioli
authors.forename: Stefano
authors.initials: S
authors.lastname: Colagrande
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D000704:Analysis of Variance; D016880:Anisotropy; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016014:Linear Models; D008099:Liver / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies