PRELIM Flashcards
The race to create the first whole-body MRI scanner began shortly thereafter, with both BLANK and BLANK participating.
Damadian, Mans feld
It is a measure of the time taken for spinning protons to lose phase coherence among the nuclei spinning perpendicular to the main field.
T2 (transverse relaxation time)
MR imaging was invented by
Paul C. Lauterbur
is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in
atomic nucleus, in 1911 by Ernest Rutherford based on the 1909 Geiger-Marsden gold foil experiment.
The uniform magnetic field is found inside the coil, epecially in the center. These magnets are relatively inexpensive to make but require a large constant flow of current while magnetized and imaging. The coil
has an electrical resistance that requires cooling of the magnet.
RESISTIVE MAGNET:
is a vector field that describes the magnetic
influence on moving electric charges, electric currents, and magnetic materials.
magnetic field
It is the rate of precession of the magnetic moment of the proton around the external magnetic field. The frequency of precession is related to the strength of the magnetic field
ARMOR RELATIONSHIP:
Three years later, Damadian created the first whole-body human scanner in BLANK
May of 1977.
Most MRI systems use
superconducting magnets.
built the first whole-body MRI scanner in
Damadian, 1977
the inventor of the first magnetic resonance scanning machine celebrates his 85th birthday on
March 16.
The primary advantage is that a superconducting magnet
is capable of producing a much stronger and stable magnetic field than the other two types
(resistive and permanent) considered below.
These are materials where the magnetic field is generated by the internal structure of the material itself. But in certain materials, called ferromagnets, all the spins and the orbits of the electrons will line up, causing the materials to become magnetic. This would be your normal iron, cobalt, nickel.
PERMANENT MAGNET:
( Paul C. Lauterbur ) he published the theory behind it in
March 1973.
A superconducting magnet is
an electromagnet made from coils of
superconducting wire. In its superconducting state the wire has no electrical resistance and therefore can conduct much larger electric currents than ordinary wire, creating intense magnetic fields.
SUPERCONDUCTIVE MAGNETS:
also called fulguration, is a medical procedure in which part of the electrical conduction system of the heart, tumor or other dysfunctional tissue is ablated using the heat generated from medium frequency alternating current.
Radiofrequency ablation
A term describing the degree, to which processing nuclear spins are synchronous.
PHASE COHERENT:
Over BLANK MRI examinations are now carried out annually.
60 million
a physician, performed the first full-body scan of a human being in 1977.
Damadian,
BLANK was able to image a student’s finger in BLANK in BLANK
Mansfield, 15-23 minutes in 1974.
the inventor of the first magnetic resonance scanning machine celebrates his 85th birthday on March 16.
Dr. Raymond Damadian
is the time constant which determines the rate at which excited protons reach equilibrium or go out of phase with each other.
T2 (transverse relaxation time)
built the first whole-body MRI scanner in 1977, which he called the
‘Indomitable’ (impossible).
who developed a mechanism to encode spatial information into an NMR signal using magnetic field gradients in
Paul C. Lauterbur, September 1971
In BLANK he discovered that MRI could be used for medical diagnosis
1971, Damadian
is a quantum-mechanical property, akin to the angular momentum of a classical sphere rotating on its axis, except it comes in discrete units of integer or half-integer multiples of h.
PROTON SPIN
