Advanced

AJNR - American Journal of Neuroradiology

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Castriota-Scanderbeg, A. Articles by Caltagirone, C. Search for Related Content PubMed PubMed Citation Articles by Castriota-Scanderbeg, A. Articles by Caltagirone, C.

American Journal of Neuroradiology 24:663-670, April 2003
© 2003 American Society of Neuroradiology

BRAIN

Coefficient D_av Is More Sensitive Than Fractional Anisotropy in Monitoring Progression of Irreversible Tissue Damage in Focal Nonactive Multiple Sclerosis Lesions

Alessandro Castriota-Scanderbeg^a, Fabrizio Fasano^b, Gisela Hagberg^b, Ugo Nocentini^c, Massimo Filippi^d and Carlo Caltagirone^c

^a Department of Radiology, Scientific Institute Fondazione S. Lucia, Rome
^b the Laboratory of Neuroimaging, Scientific Institute Fondazione S. Lucia, Rome
^c the Neurological Rehabilitation Unit, Scientific Institute Fondazione S. Lucia and Università "Tor Vergata," Rome
^d the Neuroimaging Research Unit, Department of Neuroscience, Scientific Institute Ospedale San Raffaele, Milan, Italy

Address reprint requests to Alessandro Castriota-Scanderbeg, MD, Department of Radiology, Scientific Institute Fondazione S. Lucia, via Ardeatina 306, 00179 Rome, Italy

BACKGROUND AND PURPOSE: Persistently hypointense lesions on T1-weighted MR images have been shown to correlate with the amount of axonal damage and clinical disability in multiple sclerosis (MS) patients. The purpose of this study was to investigate whether diffusion coefficient D_av and fractional anisotropy (FA) are able to detect quantifiable differences among three groups of focal nonactive multiple sclerosis (MS) lesions that appear qualitatively different on T1-weighted images.

METHODS: Conventional and diffusion tensor MR images of the brain were obtained in 18 patients with relapsing remitting (n = 10) or secondary progressive (n=8) MS and in 18 healthy volunteers. Focal nonactive MS lesions were classified as T1 isointense, T1 mildly hypointense, and T1 severely hypointense on unenhanced T1-weighted images. Differences among groups were assessed with one-way analysis of variance using the T1 lesion appearance as the grouping factor and either FA or coefficient D_av as the dependent measure.

RESULTS: FA was lowest and coefficient D_av was highest in T1 severely hypointense lesions, and then, in ascending and descending order, respectively, T1 mildly hypointense lesions and T1 isointense lesions. A significant difference in the values of FA was detected only between T1 isointense lesions and T1 severely hypointense lesions (P < .01), whereas no difference was found between T1 mildly hypointense lesions and either one of these two groups. A significant difference was found in the values of coefficient D_av among all investigated lesion groups. Coefficient D_av was found to correlate inversely with the T1-weighted contrast ratio (r=-0.58, P < .0001), whereas FA and FA (percentage of FA variation in the lesion, a relative FA measure that minimizes the effect of FA spatial dependence) were not.

CONCLUSION: Coefficient D_av is more sensitive than FA to variations in the degree of T1 hypointensity and, thus, in the amount of the permanent brain tissue damage in patients with MS.

This article has been cited by other articles:

				P. G. P. Nucifora, R. Verma, S.-K. Lee, and E. R. Melhem Diffusion-Tensor MR Imaging and Tractography: Exploring Brain Microstructure and Connectivity Radiology, November 1, 2007; 245(2): 367 - 384. [Abstract] [Full Text] [PDF]

				F.G. Garaci, V. Colangelo, A. Ludovici, F. Gaudiello, S. Marziali, D. Centonze, L. Boffa, G. Simonetti, and R. Floris A Diffusion Longitudinal MR Imaging Study in Normal-Appearing White Matter in Untreated Relapsing-Remitting Multiple Sclerosis AJNR Am. J. Neuroradiol., March 1, 2007; 28(3): 475 - 478. [Abstract] [Full Text] [PDF]

				T. D. Warner, M. Behnke, F. D. Eyler, K. Padgett, C. Leonard, W. Hou, C. W. Garvan, I. M. Schmalfuss, and S. J. Blackband Diffusion Tensor Imaging of Frontal White Matter and Executive Functioning in Cocaine-Exposed Children Pediatrics, November 1, 2006; 118(5): 2014 - 2024. [Abstract] [Full Text] [PDF]

				Y. Ge Multiple Sclerosis: The Role of MR Imaging AJNR Am. J. Neuroradiol., June 1, 2006; 27(6): 1165 - 1176. [Abstract] [Full Text] [PDF]

				M. Rovaris, A. Gass, R. Bammer, S. J. Hickman, O. Ciccarelli, D. H. Miller, and M. Filippi Diffusion MRI in multiple sclerosis Neurology, November 22, 2005; 65(10): 1526 - 1532. [Abstract] [Full Text] [PDF]

				M Symms, H R Jager, K Schmierer, and T A Yousry A review of structural magnetic resonance neuroimaging J. Neurol. Neurosurg. Psychiatry, September 1, 2004; 75(9): 1235 - 1244. [Abstract] [Full Text] [PDF]