Longitudinal imaging in dementia.

Dementia represents one of the major public health problems facing ageing populations, with 20% of those over 80 years of age suffering from this disorder. The advent of therapeutic agents has brought about an increasing demand for a more accurate and earlier diagnosis, and the value of neuroimaging in improving the diagnostic process is becoming widely accepted. Neuroimaging assessments may add weight to a diagnosis of neurodegeneration as opposed to healthy ageing, improve the differential diagnosis, aid in the prediction of conversion to dementia in individuals at a higher risk of developing the disorder, track disease progression and provide an outcome measure for assessment of drug efficacy.