Rapid and continuous monitoring of cerebral perfusion by magnetic resonance line scan assessment with arterial spin tagging

A new approach is presented for rapid and continuous monitoring of cerebral perfusion which is based upon line-scan MR column imaging with arterial sp in tagging (AST) of endogenous water. Spin tagging of arterial water proton s is accomplished using adiabatic fast passage inversion, followed by acqui sition of the perfusion sensitive MR signal from a column placed at the des ired level through the brain using line scan localization techniques. A per fusion sensitive line scan is followed by a non-perfusion sensitive line sc an, and perfusion is calculated pixel-by-pixel from the intensity differenc e of the two lines. Continuous perfusion measurements are reported with tem poral resolution of 10 s in pixels of volume 0.027 cm(3) or less. Examples of the methodology are given during hypercapnic challenge induced with carb on dioxide, and during an ischemic event induced by reversible middle cereb ral artery occlusion. The method is also used to characterize the signal re sponse as a function of arterial inversion time and post inversion acquisit ion delay. These methods permit rapid and continuous monitoring of cerebral perfusion with high spatial resolution, and can be interleaved with MR mea surements of diffusion and T-1 to follow the progression of cerebral events during physiological or pharmacological intervention. Copyright (C) 1999 J ohn Wiley & Sons, Ltd.