Dementia is a common and growing problem, with 20% of those over 80 years of age suffering from this disorder. The prospect of more effective treatments has caused an increasing demand for a more accurate and earlier diagnosis of different dementia syndromes. Neuroimaging techniques may have an important role in the clinical evaluation of dementia for early diagnosis, differential diagnosis and may help in the prediction of conversion to dementia in individuals at a higher risk of developing the disorder. Moreover, new MRI techniques might not only further broaden our understanding of the pathophysiology but also accelerate treatment discovery. This review will focus on the use of conventional and non-conventional MRI techniques to investigate dementias.