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OBJECTIVE Methods for automatically registering and reslicing MR images using an interpolation function that matches the structure of the image data are described. MATERIALS AND METHODS Phantom and human brain images were matched by rigid body rotations and translations in two and three dimensions using a least-squares optimization procedure. Subvoxel(More)
Increased acquisition efficiency has been achieved by exciting several slices simultaneously. The mixed data were unfolded to produce separate slices using the spatial encoding information inherent in a multicoil receiver system. Each coil yields a linear combination of signals from all excited slices weighted by the sensitivity of each coil. A matrix(More)
To assess the effect of stimulus correlated motion on the appearance of functional magnetic resonance images, conventional visual and motor protocols were each performed by four normal volunteers and an image co-registration technique was used to retrospectively monitor subject motion. In three studies synthetic data sets were constructed from single(More)
Inversion recovery (IR) sequences with an inversion time (TI) designed to markedly reduce or null the signal from CSF (TI of approximately 2,100 ms at 1.0 T) and a very long echo time (TE) of 240 ms were used to image the brain of two normal adult volunteers, one 34-year-old man with an intrinsic tumor, and one 3-month-old infant with an infarct. Using(More)
OBJECTIVE The aim of this study was to examine the potential of accurate image registration for detecting subtle changes in the brain. MATERIALS AND METHODS Isotropic T1-weighted volume images were obtained in 10 normal subjects and five patients on two or more occasions (including pre- and postcontrast studies). The images were segmented and a 3D rigid(More)
Studies of climate change typically consider measurements or predictions of temperature over extended periods of time. Climate, however, is much more than temperature. Over the oceans, changes in wind speed and the surface gravity waves generated by such winds play an important role. We used a 23-year database of calibrated and validated satellite altimeter(More)
Brain MR examinations were performed on one normal and 30 abnormal neonates and infants with a variety of clinical problems using pulsed gradient spin echo (PGSE) sequences sensitized in different directions to detect changes due to anisotropically restricted diffusion of water within the brain. Anisotropically restricted diffusion was demonstrated within(More)
Ten patients with multiple sclerosis (MS) were scanned by means of cranial X-ray computed tomography (CT) with and without intravenous contrast enhancement, and by nuclear magnetic resonance (NMR) using an inversion-recovery sequence. Altogether 19 lesions varying in size between about 7 mm X 5 mm and 13 mm X 8 mm were demonstrated by CT. They were all(More)
A fiducial marker is described in which a small cell containing a short T1 solution is surrounded by single- or quadrature-tuned windings. It is shown how these can be used to enhance small externally applied RF pulses, which do not significantly perturb the magnetization of the tissue, to excite the fiducial sample, and get substantial signals from it. The(More)