AbstractIntroductionExcluding post traumatic injury, Multiple Sclerosis (MS) is the most common disabling neurological disorder of young adults. Although the effect on mortality is limited, the association of a young demographic and significant morbidity combine to make MS a devastating disease. Since MS was given its first detailed description in 1868, diagnostic criteria continue to evolve. Recently, there has been an international commitment to combine both clinical and paraclinical tests to arrive at an earlier diagnosis. Widespread acceptance of the use of MRI in diagnosis, monitoring and research has made the role of the radiologist more critical than ever in this disease. The primary diagnostic criteria for MS are the International Panel criteria, commonly referred to as the McDonald criteria and it is essential that the radiology community is aware of the work preceding these criteria, so that they are understood in the correct context and the importance acknowledged.MethodsLiterature review utilising key word search to obtain the historical and current context of magnetic resonance imaging in the diagnosis of MS.ResultsA succinct description of the evolution of criteria for the diagnosis of MS.ConclusionsRadiologists must recognise that there are specific diagnostic criteria for MS that continue to evolve as a result of new research, improved technology and clinical experience and it is crucial that these criteria be applied in daily practice. It should be evident that diagnostic imaging criteria for MS will be most effective when combined with standardised MRI protocols such as those published by the international Consortium of Multiple Sclerosis Centres.