This study aims to measure in vivo the spinal cord gray and white matter in patients with Amyotrophic Lateral Sclerosis and healthy persons that match the patients' age and sex using rAMIRA imaging, a novel Magnetic Resonance Imaging (MRI) method. Patients and healthy control persons prospectively undergo MRI examinations, clinical examinations including assessments of disability, and tests of muscle force using hand held dynamometry. Serum markers of neuro-axonal injury are also assessed. Examinations for patients and healthy control persons are scheduled every six months over a time span of two years.