Diffusion magnetic resonance imaging has emerged as a sensitive, noninvasive tool for assessing the abnormalities in the central nervous system. Applications have been reported in many neurological disorders. However, because of the motion-sensitizing diffusion gradient and the prolonged diffusion encoding time, clinical practice could be difficult especially in patients with motor disorders such as Huntington Disease. Currently there existed no useful biomarker which could reflect either the disease progression or severity of Huntington disease. There is a growing interest in imaging Huntington disease using diffusion magnetic resonance imaging because of its capability to depict the micro-environmental changes.