Multi-parametric Perfusion MRI by Arterial Spin Labeling

Magnetic resonance imaging (MRI) with perfusion-weighted imaging (PWI) provides information about lesion-related changes in cerebral blood flow (CBF) in the brain, including dynamic susceptibility contrast (DCS) and arterial spin labeling (ASL) sequences. DSC-PWI is most commonly used in the clinic to assess cerebral perfusion, but it has several disadvantages, including the need for administration of a contrast agent and the risk of high-pressure bolus injection. In contrast to DSC-PWI, ASL is a MR imaging technique used to noninvasively assess CBF by magnetic labeling of incoming arterial blood water. Depending on the labeling methods, ASL techniques are divided into different types, such as continuous ASL (CASL), pulsed ASL (PASL), and pseudo-continuous ASL (pCASL), with pCASL being the most commonly used method. Based on multi-delay ASL, various perfusion parameters such as arterial transit time (ATT) and cerebral blood volume (CBV) can be determined. ASL has been extended beyond traditional perfusion measurements to include water exchange across the blood-brain barrier (BBB) and oxygen extraction, etc. In addition, a number of new ASL techniques have emerged in recent years, such as velocity-selective ASL (VS ASL), 4D-ASL-MRA, and territorial ASL (t-ASL). ASL can be used to assess CBF both at rest and during hemodynamic challenges, such as CO2 breathing or task activation.
In a wide range of psychiatric and neurological disorders, changes in CBF patterns may be potential indicators of altered brain metabolism and function that may contribute to understanding the underlying mechanisms of disease. ASL can also be applied to body organs such as kidney, liver and heart muscle.

This Research Topic aims to present recent methodological developments in ASL technology and its applications in the study of brain and body organ hemodynamic function in health and disease, and how ASL could facilitate pathophysiological interpretation and clinical intervention in these diseases. We welcome, but are not limited to, contributions in the following areas:
- New and emerging ASL technologies for image/data acquisition and reconstruction that enable rapid and robust investigation of brain and body organ hemodynamic function;
- New and emerging quantitative models that improve the quantification accuracy and reliability of perfusion measurement and/or enable multiparametric perfusion imaging with ASL;
- Translation and application of ASL in neurological and psychiatric disorders, particularly those that have not been extensively studied in the literature (e.g., sensory and motor disorders, neurodevelopmental disorders, small vessel disorders);
- Population studies using large databases of ASL data to derive characteristic perfusion patterns associated with genetic factors, disease development, and other imaging and fluid biomarkers;
- New applications of ASL in imaging perfusion and flow of body organs (e.g., placenta, skeletal muscle, prostate, and breast);
- Development and application of ASL at ultra-high magnetic field (7T and above) and low magnetic field (< 1T)