Magnetic Resonance Spectroscopy and Imaging

FIGURE 5.15 A beam of electrons, protons, or other spin-1 /2 particles only deflects into two directions, not the continuous distribution predicted classically. 

Spin behavior is not just a bizarre curiosity of quantum mechanics. The difference in energy between electron spin states or nuclear spin states in a magnetic field has proven invaluable for chemistry. The largest commercially available superconducting magnets can give fields of about 20 Tesla (400,000 times stronger than the Earth s field) which are uniform to better than one part per billion. In such fields, the two states 

FIGURE 5.16 It is impossible to specify more than one component of the spin angular momentum vector. Measurement of any one component scrambles all of the others. 

FIGURE 5.17 NMR spectra oftwo different molecules 1,1-dichloroethane (top and 1,2-dichloroethane (bottom). The horizontal scale is in parts per million (PPM) away from a reference peak (at the far right), which by convention is dimethyl sulfoxide (DMSO). The different structure of the two spectra arises from chemical shifts and scalar couplings, and permits determination of structural features. 

Physicists pioneered NMR spectroscopy in the 1940s, and used it to understand the bizarre properties of nuclear spin angular momentum. The discovery of chemical shifts and scalar coupling made it universally applicable to chemistry, and every major chemistry department in the country has NMR spectrometers which use this effect. Many 

---

Figure 24, presented originally by Belton (1995), illustrates the enormous range in distance scales that can be probed using various magnetic resonance spectroscopy and imaging techniques. Approximate distance ranges for molecular, microscopic, and macroscopic regions are provided for perspective on the left side of Figure 24. The criterion used for the demarcation between macroscopic and microscopic regions was based on the size of objects that are no longer visible with the naked or unaided eye, i.e., less than 40 xm (Hills, 1998).

L. H. Sutcliffe, The design of spin probes for electron magnetic resonance spectroscopy and imaging, Phys. Med. Biol., 43 (1998) 1987-1993. 

Bachelard H (ed.) (1997) Magnetic Resonance Spectroscopy and Imaging in Neurochemistry, Advances in Neurochemistry, vol. 8. New York Plenum Press. 

R517 A. Webb, Increasing the Sensitivity of Magnetic Resonance Spectroscopy and Imaging , Anal. Chem. (Washington, DC, U. S.), [online computer file],... 

Thelwall, P. E. and K. M. Brindle 1999. Analysis of CHO-Kl cell growth in a fixed bed bioreactor using magnetic resonance spectroscopy and imaging. Cytotechnology 30(1-3) 121-132. 

Kaspar A, Bilecen D, Scheffler K and Seelig J (1996) Aluminium-27 nuclear magnetic resonance spectroscopy and imaging of the human gastric lumen. Magnetic Resonance in Medicine 36 177-192. 

Alam TM, Celina M, Collier IP, Currier BH, Currier JH, Jackson SK, Kuethe DO, Timmins GS. -irradiation of ultrahigh-molecular-weight polythylene Electron paramagnetic resonance and nuclear magnetic resonance spectroscopy and imaging studies of the mechanism of subsurface oxidation. J Polym Sci Part A Polym Chem 2004 42 5929-59. 

T. Sassa, T. Suhara, H. Ikehira, T. Obata, F. Girard, S. Tanada, Y. Okubo, 19F-magnetic resonance spectroscopy and chemical shift imaging for schizophrenic patients using haloperidol decanoate. Psychiatry Clin. Neurosci. 56 (2002) 637-642. 

Oppenheimer SM, Bryan RN, Conturo TE, Soher BJ, Preziosi TJ, Barker PB (1995) Proton magnetic resonance spectroscopy and gadolinium-DTPA perfusion imaging of asymptomatic MRI white matter lesions. Magn Reson Med 33 61-68... 

Zarifi, M. K., A. A. Tzdka, L. G. Astrakas, T. Y. Poussaint, D. C. Anthony, and B. T. Darras. 2001. Magnetic resonance spectroscopy and magnetic resonance imaging findings in Krabbe s disease. J Child Neurol 16 522-526. 

R607 J.-C. Beloeil, Magnetic Resonance Imaging, Magnetic Resonance Spectroscopy and Chemistry , Actualite Chimique, 2011, 348-349, 102. 

Skibsted, J., C. Hall and H. J. Jakobsen. 2002. Nuclear magnetic resonance spectroscopy and magnetic resonance imaging of cements and cement-based materials. In Struoture and Performanoe of Cements, Second ed., Bensted, J., and P. Barnes (eds.), 457—476. London Spon Press. 

Other optical and spectroscopic techniques are also important, particularly with regard to segmental orientation. Some examples are fluorescence polarization, deuterium nuclear magnetic resonance (NMR), and polarized IR spectroscopy [4,246,251]. Also relevant here is some work indicating that microwave techniques can be used to image elastomeric materials, for example, with regard to internal damage [252,253]. 

Morris PG (1999). Magnetic resonance imaging and magnetic resonance spectroscopy assessment of brain function in experimental animals and man. Journal of Psychopharmacology, 13, 330-336. 

---