Imaging in the dementias

Abstract

There are over 50 causes of dementia. Some of these may have clear clinical features, but others may be difficult to diagnose. A diagnosis and a prognosis is important to both patients and families so that appropriate care and drug therapies can be employed. Neuroimaging techniques are considered in two categories: structural and functional. The former include computed tomography and magnetic resonance imaging, and the latter singlephoton emission tomography and positron emission tomography. A more recent synthesis of both methods is image registration whereby the functional image is superimposed on the structural one, which can then demonstrate the anatomical region in which the functional defect has occurred.