Diffusion tensor trace mapping in normal adult brain using single-shot epitechnique - A methodological study of the aging brain

Citation
Zg. Chen et al., Diffusion tensor trace mapping in normal adult brain using single-shot epitechnique - A methodological study of the aging brain, ACT RADIOL, 42(5), 2001, pp. 447-458
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging
Journal title
ACTA RADIOLOGICA
ISSN journal
0284-1851 → ACNP
Volume
42
Issue
5
Year of publication
2001
Pages
447 - 458
Database
ISI
SICI code
0284-1851(200109)42:5<447:DTTMIN>2.0.ZU;2-Q
Abstract
Purpose: To quantify age-related changes of the average diffusion coefficie nt value in normal adult brain using orientation-independent diffusion tens or trace mapping and to address the methodological influences on diffusion quantification. Material and Methods: Fifty-four normal subjects (aged 20-79 years) were st udied on a 1.5-T whole-body MR medical unit using a diffusion-weighted sing le-shot echo-planar imaging technique. Orientation-independent diffusion te nsor trace maps were constructed for each subject using diffusion-weighted MR measurements in four different directions using a tetrahedral gradient c ombination pattern. The global average (including cerebral spinal fluid) an d the tissue average of diffusion coefficients in adult brains were determi ned by analyzing the diffusion coefficient distribution histogram for the e ntire brain. Methodological influences on the measured diffusion coefficien t were also investigated by comparing the results obtained using different experimental settings. Results: Both global and tissue averages of the diffusion coefficient are s ignificantly correlated with age (p<0.03). The global average of the diffus ion coefficient increases 3% per decade after the age of 40, whereas the in crease in the tissue average of diffusion coefficient is about 1% per decad e. Experimental settings for self-diffusion measurements, such as data acqu isition methods and number of b-values, can slightly influence the statisti cal distribution histogram of the diffusion tensor trace and its average va lue. Conclusion: Increased average diffusion coefficient in adult brains with ag ing are consistent with findings regarding structural changes in the brain that have been associated with aging. The study also demonstrates that it i s desirable to use the same experimental parameters for diffusion coefficie nt quantification when comparing between different subjects and groups of i nterest.