ASL (Arterial Spin Labeling) – historical and current perfusion MR methods

Abstract

Despite continuous scientific and technological advances in MR imaging, MR perfusion methods have not yet been widely deployed for routine clinical diagnostics. This is especially true for ASL (arterial spin labelling) methods used to evaluate cerebral perfusion. This method does not require a contrast agent, as new discoveries about gadolinium accumulation in the cerebellum and brain nucleus appear to be a valuable asset and provide the opportunity to be more widely deployed in clinical practice. The aim of this paper is to present the historical determinants of the development of MR perfusion techniques, the disadvantages and advantages and possible clinical applications and prospects of ASL development. Both historical articles published on MR in the 1990s and current research between 2006-2016 have been reviewed. The authors present in the work the MR perfusion method focusing on issues related to arterial spin labeling (ASL). Historically CASL (continuous ASL) and PCSL (pulsed ASL) techniques have been described and the pseudocontinuous ASL (pseudocontinuous ASL) 3D technique presents its technical and methodological considerations, advantages and disadvantages over previous methods. The methods of test protocol optimization and accompanying artifacts, as well as possible clinical applications and development perspectives, have been described.