Multislice perfusion of the kidneys using parallel imaging: image acquisition and analysis strategies.

Flow-sensitive alternating inversion recovery arterial spin labeling with parallel imaging acquisition is used to acquire single-shot, multislice perfusion maps of the kidney. A considerable problem for arterial spin labeling methods, which are based on sequential subtraction, is the movement of the kidneys due to respiratory motion between acquisitions. The effects of breathing strategy (free, respiratory-triggered and breath hold) are studied and the use of background suppression is investigated. The application of movement correction by image registration is assessed and perfusion rates are measured. Postacquisition image realignment is shown to improve visual quality and subsequent perfusion quantification. Using such correction, data can be collected from free breathing alone, without the need for a good respiratory trace and in the shortest overall acquisition time, advantageous for patient comfort. The addition of background suppression to arterial spin labeling data is shown to reduce the perfusion signal-to-noise ratio and underestimate perfusion.