Role of MRI Diffusion Tensor Imaging in Assessment of Normal Appearing White Matter in Cases of Multiple Sclerosis

Emad Hamid Abdel Dayem, Tarek Hamed Gomaa, Hanaa Abdel Kader Abdel Hameed, Samer Malak Botros,

Role of MRI Diffusion Tensor Imaging in Assessment of Normal Appearing White Matter in Cases of Multiple Sclerosis

Document Type : Original Article

Author

Hanaa Abdel Kader Abdel Hameed, Samer Malak Botros, Emad Hamid Abdel Dayem, Tarek Hamed Gomaa

Department of Radiodiagnosis, Ain Shams University, Cairo, Egypt

Abstract

Background: Multiple sclerosis (MS) is an inflammatory demyelinating condition of the central nervous system (CNS) that is generally considered to be autoimmune in nature. White matter tracts are affected, including those of the cerebral hemispheres, infratentorium, and spinal cord. Several methods have been proposed, mainly using conventional MR modalities like T1, FLAIR or T2 images and enhanced MRI to delineate lesions. Conventional MR techniques cannot give detailed information about the integrity and location of WM tracts. Diffusion MRI is one of the non-conventional MRI techniques used for assessment of multiple sclerosis. The emergence of diffusion tensor imaging (DTI) is of great interest in MS. DTI probe the details of water diffusion within tissues, and could therefore reveal alterations in normal appearing white matter fibers before being visible in conventional MRI. Fractional anisotropy (FA), is the measure of the portion of the diffusion tensor that results from anisotropy (i.e, a measure of the directionality of the molecular motion of water).
Purpose: to evaluate the role of diffusion tensor imaging (DTI) in the examination of the brain white matter that shows normal appearance on conventional MRI sequences in patients with MS, thus assessing its ability to detect early abnormalities at diffusion level. Methods: the study included 50 patients; 38 females and 12 males having MS (between 20 and 40 years of age) referred from Neurologists to Radiodiagnosis Department with 10 ages’ matched healthy control volunteers. Each patient included in the study was subjected to full history taking, reviewing medical sheet and MR examination including: Conventional MR examination and Diffusion Tensor imaging. Technique was performed using a standard 3 Tesla unit (Acheiva, Philips).
Results: the study showed that DTI can reveal normal appearing white matter affection in MS cases before visible sizable plaques can be detected by conventional MRI.
Conclusion: the current application of diffusion MRI to patients with MS shows that it has enhanced our understanding of the disease pathophysiology. The study reviewed here provides evidence that DTI-derived measures are more specific to the disease pathological processes and sensitive to the diffuse microscopic injury in the NAWM.

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