The introduction of neuroimaging techniques has revolutionized the study of the biology of psychiatric disorders with implications for psychiatric practice. These comprise structural (computerized axial tomography, magnetic resonance imaging (mri)) and functional (including neurochemical/ neuropharmacological techniques such as singlephoton emission computerized tomography (spect), positron emission tomography (pet), functional magnetic resonance imaging (fmri), and magnetic resonance spectroscopy) techniques.

The aim of this symposium is to show why structural mri can help us to develop a better understanding of the morbid anatomy and pathophysiology of psychiatric disorders. We will do so by first giving a short overview of the role of radiology in psychiatry from a clinical perspective. Then we will pay attention to the fact that over the last decade, several new structural imaging approaches have developed. Here, we will show how diffusion tensor imaging (dti) can reveal the course and structural integrity of white matter projections in autism.

Another important trend includes integration of genetic information into mri research. Therefore we will also report results from a database of over 1500 healthy subjects with both structural brain data (mri) and genetic data (saliva samples) where whole-brain analyses of local gray and white matter density were performed using voxel-based morphometry in conjunction with genotyping. Finally, it is also important to value the role of classical volumetry in psychiatric research since this allows a neat analyses of specific brain regions that may be affected as a cause or consequence of the disease. We will do so by presenting a study investigating volumetric changes in patients suffering from an acute stage of a first depressive episode and being in remission from a first episode in comparison to matched controls. This will also highlight how structural mri can elucidate the plasticity that underlies acute and remitted forms of psychiatric diseases.