Efficiency of background suppression for arterial spin labeling

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2005.Includes bibliographical references (leaves 49-51).Arterial spin labeling (ASL), a technique developed for the measurement of local tissue perfusion with MRI, is heavily dependent on distinguishing irrelevant static tissue signal from the labeled blood. Background suppression can greatly reduce motion and other sources of noise in Arterial Spin Labeling MRI. More sophisticated background suppression strategies with many inversion pulses may decrease the ASL signal causing reduced signal-to-noise ratios and quantitative accuracy. Numerical simulations and in-vivo measurements were used to measure the inefficiency of different adiabatic inversion pulses and to optimize pulse selection. The results emphasize the high potential efficiency of adiabatic inversion pulses but also the limited optimal range of pulse parameters.by Dairon Garcia.M.Eng