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Summary and Discussion

  • M. M. Kaila
  • Rakhi Kaila
Chapter
Part of the Series in BioEngineering book series (SERBIOENG)

Abstract

Animal and plant life to some extent is replica of the life inside earth itself. Earth lives and so do we. Inside earth’s crust there are elements like iron, copper, silicon, sodium, magnesium, uranium, etc., etc. in the form of stable and not so stable compounds. We mine them, process them and use them, in various technologies, including nuclear energy for peaceful, and sometimes not so peaceful purposes. There are circulating molten solid currents, due to high pressures and temperatures, inside earth’s crust, which give rise to the magnetism inside and outside earth. We are quite familiar with the N–S poles of the giant magnet, in the core of the earth. It provided the source of navigation and discovery of unknown places on the surface of earth, for centuries, to some clever people. The N–S magnetic axis of the earth is not along the geographic N–S poles of the earth. The N–S magnetic axis of the earth is not fixed in time either. It reorients itself on daily, monthly and yearly basis. Why it does so? One scientific reason we know of is that the earth is bombarded by heavy mass of charged particles, on regular basis, from Sun. The mother nature’s magnetic field on the surface of earth which is of the order of only milli to micro Tesla, protects our body from harmful effects of the radiation, we receive on earth on daily basis from the surrounding universe. The radiation e.g., the solar radiation, provides us life on earth, as well, on daily basis. The magnetic field on the surface of earth, changes in a systematic manner, with distance. One can see magnetic field gradient present on the earth and it varies slowly, and is stronger in one direction than the other. Our body is exposed to it all the time. Is it shear coincidence that we use magnetic field gradients of the order mT/meter, close to present on earth, to produce MRI pictures in human body? May be. May be not. Some researchers have used earth’s field as the source of magnetic field to perform MRI experiments. This curiosity has produced some interesting results. That is how the development of the MRI technology we use today was stated half a century ago and is still evolving. This applies to every science-based technology we use.

Keywords

Static Magnetic Field Electric Field Gradient Transverse Magnetization Magnetic Field Gradient Double Quantum 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. 1.
    Lawrence, G.W. Jr.: The NMR of Spin-3/2 Nuclei: the effect of second-order dynamic frequency shifts. Magn. Reson. 43, 443–448 (1981)Google Scholar
  2. 2.
    Ra, J.B., HILAL, s.K., Cho, zH.: A method for in vivo MR imaging of the short T2 component of sodium-23. Magn. Reson. Med. 3, 296–302 (1986)Google Scholar
  3. 3.
    Tanase, C., Boada, F.E.: Algebraic description of spin 3/2 dynamics in NMR experiments. J. Magn. Reson. 173, 236–253 (2005)Google Scholar
  4. 4.
    Choy, J., Ling, W., Jerschow, A.: Selective detection of ordered sodium signals via the central transition. J. Magn. Reson. 180, 105–109 (2006)Google Scholar
  5. 5.
    Stobbe, R., Beaulieu, C.: In vivo sodium magnetic resonance imaging of the human brain using soft inversion recovery fluid attenuation. Magn. Reson. Med. 54, 1305–1310 (2005)Google Scholar
  6. 6.
    Pear, J., Legion J.S.: Detection of biexponential relaxation in sodium-23 facilitated by double-quantum filtering. J. Magn. Reson. 69, 582–584 (1986)Google Scholar
  7. 7.
    Hancu, I., Boada F.E., Shen, G.X.: Three-dimensional triple-quantum–filtered 23 Na imaging of in vivo human brain. Magn. Reson. Med. 42, 1146–1154 (1999)Google Scholar
  8. 8.
    Fleysher, R., Fleysher, L., Gonen, O.: The optimal MR acquisition strategy for exponential decay constants estimation. Magn. Reson. Imag. 26, 433–435 (2008)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • M. M. Kaila
    • 1
  • Rakhi Kaila
    • 2
  1. 1.School of PhysicsUniversity of New South WalesSydneyAustralia
  2. 2.School of MedicineUniversity of New South WalesSydneyAustralia

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