Non-gadolinium perfusion technique (arterial spin labeling)

Abstract

Arterial spin labeling (ASL) is a magnetic resonance imaging (MRI) technique that allows a noninvasive quantitative measurement of cerebral blood flow (CBF). In clinical applications, ASL has been demonstrated to provide reproducible and reliable CBF measurements of several neurological diseases. In comparison with conventional approaches that use radioactive tracers or paramagnetic contrast agents, ASL is completely noninvasive and, therefore, more cost efficient for the hospital and patients. Furthermore, the noninvasive nature of ASL makes it highly repeatable, suitable for routine clinical practice. The repeatability and high temporal resolution also make ASL an excellent candidate technique for functional studies in neuroscience. Although somewhat constrained by its inherent low signal-to-noise ratio (SNR) and limited spatial resolution, recent technical developments have made exceptional advancements in perfusion sensitivity and image resolution. The usage of ASL is expected to grow significantly in both clinical and research environments. In this chapter, the general principles of ASL and specific implementations, with advantages and pitfalls, are discussed.