Figure 7.

Example of the potential of multiband (also known as simultaneous multi-slice (SMS) acquisition) for ASL (scans acquired on a 3 T MRI scanner (Ingenia, Philips, The Netherlands; scanner software was locally adapted to allow multiband ASL) on a 43-year-old, male volunteer who provided informed consent under an approved IRB-protocol for protocol development). Left: traditional readout with single-shot EPI (half Fourier of 0.8; readout time per slice 60 ms; 24 slices; 1800 ms labelling duration; 1800 ms PLD; two background suppression inversion pulses; 30 averages; total scan time 5m08s). Right: same settings except for multiband factor of 4; 38 averages; total scan time 5m11s. Upper row: coronal reconstruction of mean control scans showing a gradual decrease in background suppression efficiency for the traditional readout (Left) and four bands of decreasing background suppression efficiency for the multiband-4 readout (Right). Middle row: ASL-images. Lower row: SNR images calculated as ASL-signal divided by standard deviation over the acquired averages multiplied by the square root of the number of averages to achieve the effective SNR corrected for the shorter achievable TR for multiband readout as compared to the traditional readout.