Cerebral perfusion imaging provides information about the blood supply of tissue. It reveals functional changes of the brain before and after structural changes, which can be used to improve the sensitivity and accuracy of stroke and tumor diagnosis. There has been an increasing interest in developing methods for non-contrast perfusion imaging, because of the risk of nephrogenic systemic fibrosis (NSF) in patients with kidney dysfunction and the need for repeated blood flow measurements in a short period of time for functional studies.Magnetic resonance imaging (MRI) provides a safer option for perfusion imaging without a contrast agent: arterial spin labeling (ASL). In this work, we propose several new techniques to improve the quality and quantification of ASL MRI.Using the water spins of blood as a tracer makes ASL safer than other perfusion imaging methods, but also results in a low signal-noise-ratio (SNR). Conventionally, ASL uses lengthy scan times to improve image quality and compensate for motion. However, this strategy is typically used to measure the perfusion bolus at a single time point, which can limit the accuracy of perfusion quantification, particularly in the setting of disease. Measuring multiple time points, which is called dynamic ASL, can improve quantification of cerebral ii iii blood flow (CBF) and yield additional information, but long scan times may be needed. In this work, we describe the following advances that can be used to improve dynamic ASL:(1) accurate reference T 2 mapping; (2) robust and rapid single-shot data acquisition; (3) dynamic model-based image reconstruction; and (4) optimal experiment design.As a parameter estimation problem, CBF is quantified based on other reference parameters, such as T 1 and T 2 . Here, I introduce a novel T 2 mapping paradigm, which combines the conventional image reconstruction and parameter regression steps into one state tracking step. Using the unscented Kalman filter (UKF), the proposed method uses a T 2 decay model to estimate T 2 information from k-space data directly and efficiently. It achieves accurate estimation up to an undersampling factor of 8, which is comparable to a compressed sensing method with model-based sparsity. This new paradigm can be adapted to Cartesian and non-Cartesian trajectories, and other parameter mapping models.In order to improve ASL image quality, a rapid and robust ASL sequence was developed with a combined parallel and compressed sensing image reconstruction. Pseudo continuous radio frequency (RF) pulses are used to tag the proximal blood. A 3D turbo spin echo sequence with stack-of-spiral readouts [1] is used to acquire k-space data. Additionally, pulsatile motion artifacts are corrected by exploiting the redundancy among multiple receiver coils. A dual-density spiral trajectory is used to achieve single-shot imaging, which improves the SNR and freezes motion. ASL image quality and SNR are further improved by parallel reconstruction with spatial sparsity constraints.Accurate CBF mapping requires dy...