Forbes contributors publish independent expert analyses and insights. Jesse Pines is an expert in healthcare innovation and wellness. A patient enters the MRI scanner for a full-body imaging session — ...

MRI is a diagnostic test that doctors use to diagnose and track the progress of amyotrophic lateral sclerosis (ALS). ALS is a progressive disease that damages nerve cells in the brain and spinal cord.

President Trump's doctor revealed Monday the justification for the president's October MRI scan, saying the results were "perfectly normal." The big picture: Magnetic resonance imaging (MRI) scans are ...