Improved cardiac arterial spin labelling in the mouse heart by optimisation of acquisition and analysis

Methods Perfusion maps are generated by pixel-wise comparison of T1 maps from slice-selective and global inversion recoveries. T1 was quantified using ECG-gated LookLocker approach [3], with 4 lines of k-space acquired every heartbeat to speed up acquisition by approximately four times compared with previous approaches (eg. [2],[3]). A data logger (CED) was used to record ECG, RF and respiration events and was programmed to gate on each ECG peak detected as well as to interpolate peaks missed by physiological monitoring software. Using the information recorded, lines of k-space were binned as ‘acquired during respiration’ or not. Images with many lines or centre lines of k-space acquired during respiration were rejected. ASL data were acquired on a 9.4T Varian system with 35mm-long volume RF coil (Rapid) (TE=1.18ms, flip=5°, resolution=200μm, slice thickness=1.5mm) and image analysis was performed in Matlab.