Nonmedical Applications of MRI

A resonance unique to brain and nerve tissue and believed to be a specific marker for neurons (nerve cells) is V-acetylaspar-tate (NAA), structure 16-6, appearing at 2.0 ppm. NAA often decreases in the damaged brain tissue, suggesting that neurons have died. The damaged brain tissue also contains elevated lactate, structure 16-7, which is an indication that anaerobic metabolism, a pathway forced by oxygen deficit, is taking place. Only the methyl doublet of lactate (1.3 ppm) appears in the spectrum the methine quartet overlaps the water resonance and is normally never observed in vivo. 

Although MRI grew out of a technique—NMR spectroscopy—that was at the time, and still remains, primarily a tool of chemical analysis, its development and applications have largely been driven by the needs of medicine. Yet there are numerous instances in fields such as chemistry, physics, biology, geology, and many engineering disciplines where MRI could be a useful tool for scientific investigations. It is only 

Flow is an important parameter in industrial processes. Magnetic resonance imaging has been used to determine the velocity profile in flowing fluids. In the case of laminar flow 

As a final example, we mention the combination of solid-state spectroscopy (Chapter 15) with imaging. The imaging of solids is difficult because the 7Ys are often too short compared with the time it takes to switch and apply field gradients for slice selection and phase and frequency encoding, while in addition extremely large gradient amplitudes are required to overcome the broad line widths. The time to ramp 

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