[Diagnosis of amyotrophic lateral sclerosis: advances in magnetic resonance imaging]

Amyotrophic lateral sclerosis is a chronic progressive neurodegenerative disease of unknown etiology. It selectively affects both upper and lower motor neurons. Nowadays, amyotrophic lateral sclerosis is diagnosed on the basis of clinical and electromyographic findings and by ruling out other diseases with similar symptoms. To date, there are no specific tests or biologic markers to confirm the diagnosis. This article discusses new MRI techniques like magnetization transfer imaging, MR spectroscopy, functional MRI, diffusion tensor imaging, and volumetric techniques that can contribute to early confirmation of the diagnosis and to the follow-up of this disease. We review the usefulness of each of these techniques and discuss their possible applications in clinical practice.