Zheng J, Ehrhardt J C, Cizadlo T, Yuh W T
Department of Radiology, College of Medicine, University of Iowa, Iowa City 52242, USA.
J Magn Reson Imaging. 1997 Sep-Oct;7(5):843-7. doi: 10.1002/jmri.1880070511.
An inversion recovery asymmetric spin-echo (IR-ASE) echo-planar imaging (EPI) sequence has been developed for functional studies of the brain. This technique uses an 180 degrees inversion pulse with a long inversion time (TI) to suppress the pulsatile cerebrospinal fluid and an asymmetric spin-echo readout to obtain activation signals from brain capillaries. Because gradient-echo sequences are most sensitive to large vessels, motor cortex activation studies using a gradient-echo technique also were conducted for comparison with the IR-ASE method. The results suggest that the IR-ASE pulse sequence may be a useful complement to the gradient-echo technique for the study of neuronal activity of the human brain.
