[801] Cerebral Ischemia and Connectivity

Mapping the cerebral ischemic tissue at risk with diffusion and perfusion MR imaging

Stroke is now considered a treatable medical emergency. The role of neuroimaging is not only to demonstrate the presence or absence of a lesion, but to demonstrate the presence of cerebral tissue at risk of undergoing further infarction if nothing is done. This area at risk is the ischemic penumbra. Traditionally defined by nuclear medicine methods it can now be assessed in vivo by Magnetic resonance imaging methods such as diffusion and perfusion MR imaging. This has led to the development of the model of the so-called diffusion-perfusion mismatch. It is believed that one of the earliest changes that can be assessed in the brain parenchyma is the anisotropy index, reflected in both ADC maps and on anisotropy images. Our aim is to investigate the behaviour of the area within the mismatch both under normal conditions and after treatment.

MR imaging in first-onset schizophrenia

It has been shown that there is a strong relationship between smoking marijuana at an early age and the occurrence of schizophrenic symptoms. We study a collective of young patients having a first onset of schizophrenic symptoms. They will undergo an MR protocol consisting in 3D imaging as well as diffusion tensor imaging.

Diffusion tensor imaging of chronic ischemia

A subset of patients with cognitive deficits may have underlying vascular disease, mainly atherosclerosis affecting the carotids. Therefore these patients may benefit from treatment of vascular disease such as antihypertensive treatment and even carotid stenting.