In the earliest ASL methods readout (imaging) was confined to a single slice obtained with an echo-planar gradient echo technique. Multi-slice methods soon followed, as well as image …

The choice of optimal imaging parameters is dependent upon the exact ASL method utilized (2D vs 3D, PICORE vs FAIR vs pCASL, etc.) Even small variations of each sequence (such as …

Since its original description pCASL has become very popular and is currently our ASL method of choice. Compared to PASL, pCASL offers higher SNR and is less sensitive to tag dispersion. …

ASL has several intrinsic limitations, and is not currently as widely used as many other MRA techniques. First, because ASL-MRA relies on the replacement of saturated blood by tagged …

The main problems with CASL were its high tissue energy deposition and transmitter duty-cycle requirements accompanying the use of continuous RF-pulses. Thus came PASL, a family of …

Abstract Arterial spin labeling (ASL) perfusion is a MRI technique to quantify tissue blood flow. ASL is a non-invasive technique that labels the protons in the arterial blood by radiofre-quency …

ASL suffers from the same artifacts as other MR techniques, including susceptibility, flow, and motion. However, some of these problems manifest differently on ASL than on conventional …

The acronym GRASE stands for “ G radient A nd S pin E cho”. It is a hybrid technique that generates and records a series of alternately acquired gradient echoes and spin echoes from …

The technique we now know of as CASL (Continuous Arterial Spin Labeling) was the first true ASL method, described by Williams, Detre, and colleagues in the early 1990s. CASL used a …

CEST signal, on the other hand, originates from the endogenous mobile proteins and metabolites in biological tissues, or from exogenously administered contrast agents. Because ASL, CEST, …