As MRI becomes ever easier to access, it is clear that there is a group of patients, scanned for a wide range of symptoms, where the imaging looks inflammatory, despite the discordance with the clinical presentation. This is the so-called radiologically isolated syndrome, which can be a source of anxiety and difficulty for both patient and clinician. The evidence for its relationship to the clinically isolated syndrome and therefore to multiple sclerosis is presented, and I will describe a pragmatic approach to managing the situation.