Members of
MRI
Since
its inception in 1946, MRI techniques have been dramatically
improved. What started out as largely an analytical tool,
improvements to: static magnetic fields; gradient magnetic
fields; and radio frequency (RF) transmitter and receiver
capabilities, have contributed to our ability to perform
biological imaging with the technique.
The four major processes that are needed for the creation of
in-vivo biological imaging are: (1) familiarity of elements of
interest to possess spin and abundance (2) a very strong
magnetic field (typically to the order of 0.5 Tesla to 3.0
Tesla in field strength), which is used to align spinning
element orientation with that of the magnetic field direction
(3) the ability to deliver a radio frequency pulse (RF) at the
frequency appropriate for the element that it's designed to
disturb from equilibrium (4) appropriate receiving devices in
order to collect the signal as the elements return to their
positions of equilibrium.
Most of the clinical imaging is done with the hydrogen proton
(which has the ability to spin) largely because of its
abundance. To the left is an example of a cross section (transaxial
slice) of a human liver. Below the liver image is a
longitudinal cross section (sagitlal slice) of a human knee.
Some things that can change the dynamic range of pixel
intensities in MRI are determined by: population density of
protons, biological environment conditions, pulse sequence
selection and settings, and utilization of MRI contrast
agents.
The greatest successes have come from environments where the
complementary nature of different imaging approaches has been
realized. The Magnetic Resonance Imaging & Spectroscopy
Center (MRISC) at the University of Kentucky represents a
multidisciplinary team of clinicians, physicists, engineers,
computer scientists, and technologists to advance in technical
aspects of diagnostic imaging, applications to patient care,
and applications for fundamental medical science. For an
introduction to them, visit them in research
and faculty/staff sections of this
home page.
