Echo-volume imaging.
Two single-shot volume imaging techniques are described. The first, single-echo echo-volume imaging, is essentially the echo-volume imaging (EVI) sequence suggested by Mansfield (J. Phys. C. 10, L55 (1977)). The second is a multi-spin-echo approach in which one plane of k-space is collected during each spin echo. In both techniques, phase encoding gradients are applied in the z direction, and three-dimensional k-space is filled by a raster pattern in Cartesian coordinates. Spatial saturation is used to avoid aliasing in the y direction, and a selctive pulse is applied to excite the desired slab of tissue and eliminate aliasing in z. The average echo-times, measured from the center of the 90 degrees pulse to the center of the acquisition k-space (kx = ky = kz = 0), were 45 and 104 ms for single echo and multi-echo methods, respectively. Images of the human brain using both sequences are shown.
Song
A W
AW
Biophysics Research Institute, Medical College of Wisconsin, Milwaukee 53226.
Wong
E C
EC
Hyde
J S
JS
D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology; D003199:Computer Systems; D003287:Contrast Media; D017352:Echo-Planar Imaging / Q000295:instrumentation / Q000379:methods*; D006321:Heart / Q000033:anatomy & histology; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods*; D007596:Joints / Q000502:physiology; D009068:Movement; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation
D003287:Contrast Media