QUIPSS II with window-sliding saturation sequence (Q2WISE).

A series of periodic saturation pulses used to minimize the error caused by varying transit delays in assessing perfusion using quantitative imaging of perfusion using a single subtraction II with thin-slice TI(1) periodic saturation (Q2TIPS) increases the specific absorption rate. Quantitative imaging of perfusion using a single subtraction II with window-sliding saturation sequence (Q2WISE) has been developed, in which numerous thin saturation pulses are replaced by two thin pulses and one thick saturation pulse arranged in a window-sliding manner within the labeling region to maintain a sharp slice profile while reducing specific absorption rate. Q2WISE essentially is a hybrid between Q2TIPS and quantitative imaging of perfusion using a single subtraction II for use in specific absorption rate intensive applications. Q2WISE was implemented on a 3 T MRI scanner to measure perfusion rates in the brain and kidneys of eight healthy volunteers and results were compared with those from Q2TIPS. Mean perfusion values of both methods for the brain (75 ± 17 [Q2WISE] and 74 ± 13 mL/100 g/min [Q2TIPS]) and kidney (308 ± 48 [Q2WISE] and 299 ± 43 mL/100 g/min [Q2TIPS]) were in very good agreement.