Cerebrovascular diseases.

Conventional neuroradiological techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), make a fundamental contribution in both the acute and chronic phases of stroke. Recent years have witnessed the development of new imaging modalities, which include diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI), CT-angiography (CTA), MR-angiography (MRA), magnetic resonance spectroscopy (MRS), diffusion tensor imaging (DTI) and functional MRI (fMRI). While CTA, MRA, DWI and PWI are commonly used for clinical purposes, DTI, MRS and fMRI are becoming increasingly important in the field of experimental research of cerebrovascular diseases, but are still far from becoming of primary usefulness in the everyday clinical setting.