Human Brain Perfusion MRI at 7T Using a Segmented True FISP ASL Method

Introduction: Ultra-high field (7T) MR imaging, in principle, should benefit arterial spin labelling (ASL) methods due to increased signal to noise ratio (SNR) and longer T1 relaxation times of blood and tissue. However, most ASL methods are based on echo planar imaging (EPI), which is prone to image distortion caused by B1 and B0 magnetic field inhomogeneity, an effect that increases at higher field strengths (1). It has previously been shown that through the use of a true FISP based ASL sequence (2-4) it is possible to measure local tissue perfusion with high spatial resolution and without the distortion artefacts commonly associated with EPI in high-field (3T) imaging (5). Here we presen