TECHNIQUES AND APPROACHES TO PROTON NMR IMAGING OF THE HEAD

NMR imaging appears to offer several advantages over X-ray computerized tomography (CT) techniques: it uses no ionizing radiation and, indeed, appears to be essentially without any biological hazard; it provides inherently superior soft tissue contrast; and it is intrinsically a whole-volume imaging technique. The principles of nuclear magnetic resonance (NMR) imaging are presented and their application to NMR head scanning is discussed. Examples are given of images obtained using a variety of pulse sequences and spatial encoding techniques, and these serve to highlight the essentially multiplex nature of the NMR signal. The significance of the image appearance in terms of its anatomical and physico-chemical correlates is outlined, and the potential future role of this new diagnostic technique in neurology and radiology is considered.