Magnetic resonance imaging techniques: fMRI, DWI, and PWI.

Magnetic resonance imaging (MRI) is a noninvasive technique which can acquire important quantitative and anatomical information from an individual in any plane or volume at comparatively high resolution. Over the past several years, developments in scanner hardware and software have enabled the acquisition of fast MRI imaging, proving extremely useful in various clinical and research applications such as in brain mapping or functional MRI (fMRI), perfusion-weighted imaging (PWI), and diffusion-weighted imaging (DWI). These techniques have revolutionized the use of MRI in the clinics, providing great insight into physiologic mechanisms and pathologic conditions. Since these relatively new areas of MRI have relied on fast scanning techniques, they have only recently been widely introduced to clinical sites. As such, this review article is devoted to the technological aspects of these techniques, as well as their roles and limitations in neuroimaging applications.