Calculated T1 images derived from a partial saturation-inversion recovery pulse sequence with adiabatic fast passage.

Calculated T1 images of the head and abdomen have been obtained using an alternating partial saturation-inversion recovery pulse sequence. Timing parameters were adjusted to yield optimum T1 contrast-to-noise ratio for this sequence for the range of T1 studied. Adiabatic fast passage (AFP) was implemented for the nonselective inverting pulse, to reduce the sensitivity of the measurement to RF and static field inhomogeneity. A nonlinear frequency sweep was used to improve the efficiency of the AFP pulse. The effect on the T1 calculation of slice selection during the pi/2 pulses was also determined and corrected for in the image reconstruction algorithm. The T1's determined by this method show a standard deviation of less than 10%, and good agreement with the literature.