12 March 2008 Correlations between DTI and FLAIR images reveal the relationships of microscopic and macroscopic white matter degeneration in elderly subjects
Author Affiliations +
Abstract
Fluid attenuated inversion recovery (FLAIR) detects the T2 prolongation in whiter matter lesions (WML) measured on a macroscopic scale, whereas diffusion tensor imaging (DTI) more specifically detects the white matter (WM) integrity alterations as measured by water diffusion on a microscopic scale. Both techniques have been widely used to evaluate WM changes associated with aging, dementia and cerebral vascular disease, however, the relationship between white matter lesions (FLAIR) and changes of DTI remains largely unknown. We addressed this issue using a voxel based correlation analysis between DTI and FLAIR images acquired from 33 elderly subjects at 4T. The WML volume and intensity were correlated the fraction anisotropy (FA) or mean diffusivity (MD) across all the subjects on a voxelwise basis. Our results revealed that significant DTI-WML correlations occur at regions overlapping the major WML distributions with moderate intensity, and that no significant correlations were detected in periventricular regions where the FLAIR intensities are particularly high. We investigated WM degeneration as a continuum from normal WM to cerebrospinal fluid (CSF) using a two-compartment WM model. The simulation results indicated that the FLAIR intensity of WML reaches a maximum when the lesion severity is around 0.7, which is the same point where correlations between DTI and WML disappear. Based on these findings, WM degeneration in elderly subjects may be better characterized by using regional DTI-WML correlations in different stages of WM degeneration. DTI and FLAIR, taken together improve specificity for characterization of WM degeneration than each measure alone.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
W. Zhan, Y. Zhang, P. Lorenzen, S. G. Mueller, N. Schuff, M. W. Weiner, "Correlations between DTI and FLAIR images reveal the relationships of microscopic and macroscopic white matter degeneration in elderly subjects", Proc. SPIE 6916, Medical Imaging 2008: Physiology, Function, and Structure from Medical Images, 691609 (12 March 2008); doi: 10.1117/12.773040; https://doi.org/10.1117/12.773040
PROCEEDINGS
9 PAGES


SHARE
Back to Top