NMR imager

Edelstein W A, Hutchison J M S, Johnson G and Redpath T W 1980 Spin warp NMR imaging and appiications to human whoie-body imaging B 25 751-6... 

Johnson G, Hutchison J M S, Redpath T W and Eastwood L M 1983 improvements in performance time for simuitaneous three-dimensionai NMR imaging J. Magn. Reson. 54 374-84... 

Mansfieid P and Morris P G 1982 NMR imaging in biomedicine (New York Academic)... 

Hafner S, Demco D E and Kimmich R 1996 Magic echoes and NMR imaging of solids Solid State Nucl. Magn. Reson. 6 275-93... 

Wehrli F W, MacFall J R, Shutts D, Breyer R and Flerfkens R J 1984 Mechanisms of contrast in NMR imaging J. Comput. Assist. Tomogr. 8 369-80... 

Flaase A and Frahm J 1985 Multiple chemical-shift-selective NMR imaging using stimulated echoes J. Magn. Reson. 64 94-102... 

Moran P R 1982 A flow velooity zeugmatographio interlaoe for NMR imaging in humans Magn. Reson. Imaging 1 197-203... 

Bryant D J, Payne J A, Firmin D N and Longmore D B 1984 Measurement of flow with NMR imaging using a gradient pulse and phase differenoe teohnique J. Comput. Assist. Tomogr. 8 588-93... 

Taylor D G and Bushell M C 1985 The spatial-mapping of translational diffusion-ooeffioients by the NMR imaging teohnique B 30 345-9... 

Jeong E K, Aitobeiii S A and Fukushima E 1994 NMR imaging studies of stratified flows in a horizontai rotating oyiinder Rhys. Fluids 6 2901-6... 

Simple and Complex Organic Molecules. Using modem direct fluorination technology, the synthesis of even the most complex perfluorocarbon stmctures from hydrocarbon precursors is now possible. For example, syntheses of the first perfluoro crown ethers, perfluoro 18-crown-6, perfluoro 15-crown-5, and perfluoro 12-crown-4 (54) have been reported. Perfluoro crown ethers (54,55) are becoming important as the molecules of choice for many F-nmr imaging appHcations (56) in humans and are particularly effective in brain and spinal diagnostics when... 

Hyde, PD Ediger, MD, NMR Imaging of Diffusion of Small Organic Molecules in Silk Fibroin Gel, Macromolecules 24, 620, 1991. 

Manz, B Stilbs, P Jonsson, B Soderman, O Callaghan, PT, NMR Imaging of the Time Evolution of Electroosmotic Flow in a Capillary, Journal of Physical Chemistry 99, 11297, 1995. Matthew, JB Hanania, GIH Gurd, FRN, Electrostatic Effects in Hemoglobin Bohr Effect and Ionic Strength Dependence of Individual Groups, Biochemistry 18, 1928, 1979. 

Figure 7.21 One-dimensional NMR imaging. When a magnetic field gradient is applied across a sample, it gives a spectrum that is a profile of the sample in the direction of the gradient.

Figure 7.22 The principle of creating a two-dimensional NMR image. A number of profiles of the sample are obtained in different orientations in the presence of magnetic field gradients pointing in different directions (designated by arrows). The x -gradient yields an x -profile, and a /gradient generates a y -profile. A combination of these profiles produces a two-dimensional image.

We attempt to describe NMR Imaging in a simplified manner using only three essential equations that explain why we see a signal and what it looks like. The first equation describes the nuclear spin magnetization, thus the strength of the NMR signal (and indeed much more) ... 

In this section, we will describe three building blocks of NMR imaging phase encoding, frequency encoding and slice selection. All three are related to the signal by the fourth equation ... 

The recipe for the first building block of NMR imaging, the phase encoding, thus goes like this apply a phase gradient of effective area k acquire the signal S(k) repeat for a number of different equidistant values of k perform the inverse... 

Fig.1.6 Left the field of view has been chosen sufficiently large to coverthe whole object a correct image is obtained. Right the field of view is only half as wide the top and bottom portions of the object are folded back into the opposite side of the image. In a real NMR image, the assignment of position becomes ambiguous.

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