Learn More
BACKGROUND AND PURPOSE We sought to evaluate the application of T2-weighted and diffusion-weighted magnetic resonance imaging techniques in the study of a focal ischemic lesion in the rat brain. METHODS Unilateral cortical infarcts were induced using the photosensitive dye rose bengal and 560 nm light irradiation. Magnetic resonance images were recorded(More)
The use of MR imaging to image anisotropically restricted diffusion (ARD) of water in the nervous system is described. The theoretical basis for the use of the pulsed gradient spin echo sequences is outlined, including an estimate of the range of cell dimensions that can be studied with this technique. The importance of restricted diffusion across(More)
A pulsed magnetic field gradient spin echo technique was used to study the brain of two volunteers and eight patients. The pulsed gradients were applied both perpendicular and parallel to the image slice. Striking changes in signal intensity were demonstrated in white matter depending on the direction in which pulsed gradients were applied. These effects(More)
We present T2-weighted and diffusion-weighted images of kainic acid lesions in the rat brain. Our observations show improved image contrast between edematous lesions and unaffected tissue using diffusion-weighted imaging. Furthermore, we show that the anisotropic intensity changes associated with this sequence can be used to highlight white matter tracts(More)
Phase difference images, obtained by comparing data from motion-sensitized and -unsensitized spin-echo sequences, can be used to study intravoxel coherent motions. The resulting images, which have been routinely used to study fast flowing blood, may potentially yield information about perfused flows and bulk tissue motion. The likely limitations and(More)
Convertible exchangeable preferred stock includes an option for the issuer to exchange the preferred for convertible bonds with identical pre-tax cash flows and conversion terms. In other respects this innovative corporate security is identical to traditional convertible preferred stock. The exchange feature provides the issuer with a potentially valuable(More)
The perceptual lag phenomenonly was investigated by varying motor speed and time of exposure to a noisy field. Ss were 90 male cadets used in a 3 X 3 factorial design. Three motor speeds of 1, 10, and 20 r.p.m. were used in conjunction with noisy field viewing times of 5, 10, and 30 minutes, respectively. Ss' speed estimations of a moving contour before and(More)
  • 1