d i s t r i b u t i o n in Swiss cheese a n d curd size a n d d i s t r i b u t i o n in cottage cheese. Voids, liquids, a n d regions of liquid like disorder in soft p o l y m e r s (above t h e glass t r a n s i t i o n t e m p e r a t u r e ) , foams, solid fuel e l e m e n t s , gels, etc., should be a m e n a b l e t o s t u d y . C o m p o sition a n d d i s t r i b u t i o n of gels, greases, l u b r i c a n t s , a n d t h e like in or a r o u n d solid objects should also be a d d r e s s able. T h e reverse e x p e r i m e n t should n o t be discounted. T h e size a n d distri b u t i o n of solid objects (which t h e m selves d o n o t give a signal) in a soft m a t r i x (which does give a signal) can be observed as t h e presence of "black holes." Because T\ a n d Ti are sensitive t o t h e presence of p a r a m a g n e t i c species (such as O2, free radicals, a n d m a n y m e t a l species), t h e presence, distribu tion, a n d c o n c e n t r a t i o n of such m a t e rials is " r e p o r t e d " by observed T\ (or T 2 ) variations of signals from Ή or 19 F intrinsically p r e s e n t in t h e s a m p l e of i n t e r e s t or a d d e d as r e p o r t e r mole cules. 1 9 F tags offer t h e p o t e n t i a l t o follow d y n a m i c chemical a n d bio chemical processes in a m a n n e r a n a l o gous to t h a t presently d o n e b y posi t r o n emission t o m o g r a p h y ( P E T ) scanning. T h e size a n d d i s t r i b u t i o n of particles a n d also t h e d i s t r i b u t i o n a n d flow of fluids as a function of o p e r a t ing conditions in s e p a r a t i o n columns,
reactor b e d s , a n d t h e like could be ex a m i n e d . M u l t i n u c l e a r studies with N M R microscopes will p e r m i t analysis of seeds, t a b l e t s , pellets, etc. P r o b l e m s associated with t h e mixing, storage, application, a n d curing of coatings such as p a i n t s , varnishes, a n d a d h e sives a r e a n o t h e r a r e a of p o t e n t i a l in t e r e s t . All of t h e s e a r e a s a n d m a n y m o r e can be a d d r e s s e d with existing commercially available e q u i p m e n t . T h e future is even m o r e speculative. M u l t i n u c l e a r applications will u n d o u b t e d l y be forthcoming with im p r o v e m e n t s in field s t r e n g t h a n d sen sitivity. E x t e n s i o n of imaging tech niques t o h a r d solids will occur. T h r e e - a n d four-dimensional exten sions to chemical shift imaging a n d e x a m i n a t i o n of d y n a m i c processes will occur. A n d , c o m b i n a t i o n of N M R imaging with o t h e r t e c h n i q u e s will o p e n entirely new a p p r o a c h e s t o a wide variety of p r o b l e m s .
Ed.; Academic Press: New York, N.Y., 1982. Partain, C. L.; James, A. E., Jr.; Rollo, F. D.; Price, R. R. "Nuclear Magnetic Resonance (NMR) Imaging"; W. B. Saunders: Philadelphia, Pa., 1983. Witcofski, R. L.; Karstaedt, N.; Partain, C. L., Eds. "NMR Imaging: Proceedings of an International Symposium on Nu clear Magnetic Resonance Imaging"; Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, N.C., 1982.
Additional reading Hinshaw, W. S.; Lent, A. H. "An Introduc tion to NMR Imaging: From the Block Equation to the Imaging Equation," Proc. IEEE 1983, 71, 338. Ljunggern, S. "A Simple Graphical Repre sentation of Fourier-Based Imaging Methods," J. Magn. Res. 1983,54, 338. Mansfield, P.; Morris, P. G. "NMR Imag ing in Biomedicine"; Suppl. 2, Advances in Magnetic Resonance; Waugh, J. S.,
Stanford L. Smith is professor of chemistry and radiology at the Uni versity of Kentucky. He received his PhD from Iowa State University and his AB degree from Albion College. His research interests cover all as pects of NMR with particular empha sis on applications of 2D spectroscop ic techniques and imaging methods.
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