Applications of diffusion tensor MR imaging in multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system that is the most common cause of nontraumatic disability in young adults in the United States. In recent years, magnetic resonance imaging (MRI) has been established as an important paraclinical tool in MS for the assessment of clinical diagnosis, natural history, and treatment effects. In MS studies, there are many advantages to having a sensitive and reliable in vivo method for investigating the specific pathological changes of white matter and its integrity during the disease process. As a consequence, in the past decade, the application of MRI to the study of MS has been explored from conventional MRI to new advanced quantitative techniques with greater pathological specificity and sensitivity. Diffusion tensor imaging (DTI) is one of the most promising techniques with regard to MS. It quantifies the amount of nonrandom water diffusion within tissues and provides unique in vivo information about the pathological processes that affect water diffusion as a result of brain microstructural damage. This review outlines the current state of the art and future direction of DTI and fiber tractography in the study of MS disease.