文档介绍：10/17/99 Chapter 5 L. Bolinger
CHAPTER FIVE IC RESONANCE IMAGING
History:
1937 - First ic resonance experiment - . Rabi (Nobel Prize in Physics for this work
awarded in 1944)
1946 - First ic resonance experiment in bulk material - Felix Bloch and Edward Purcell
(Both were awarded the Nobel Prize in Physics for this work - 1952)
1950 - Spin Echo phenomena discovered and explained - Edwin Hahn
1954 - Diffusion measurements described - Edward Purcell
1965 - Cooley and Tukey describe a fast Fourier Transform algorithm
1966 - Richard Ernst and W. Anderson describe Fourier Transform Spectroscopy in MR
1971 - Jeener describes first two dimensional MR experiment
1972 - Richard Ernst does first two dimensional MR experiment
1973 - Paul Lauterbur reports first MR image (projection reconstruction)
1973 - Peter Mansfield and P. Grannell describe the relationship between FT of a signal
produced in a ic field gradient and the spatial spin density.
1975 - Richard Ernst describes phase encoding using changes in time gradient is applied
1980 - Edelstein describes "Spin Warp" imaging changing gradient amplitude
Early 1980's - mercial MR imagers
1991 - Richard Ernst wins the Nobel Prize in Chemistry for his many contributions to the
development of methodology in ic resonance
Quantum Mechanics
The Nature of Quantum Mechanics
Energy is quantized
There are specific energy levels that atoms and particles can obtain. To move between
these energy levels, packets (quanta) of energy must be absorbed. Thus, there is no
continuim of energy levels as usually encountered in classical mechanics.
For any single particle, we don't know what its energy is, only the probability of it to be in each
energy level available to it.
We cannot know for sure that a single particle is in any specific energy level. However, we
can know the probability of it being in a specific energy level. Thus, for large number of
particles we can at least determine th