Part I Flashcards
[person/s] made Fourier transformer that allows us to convert signals to digital, provide numerical values
Jean Baptiste and Joseph Fourier
Introduce principles in electricity and magnetism
Hans Christian Oersted
law of magnets induction and electromagnetism
Michael Faraday
Created EM wave theory - categorize ionizing and non-ionizing radiation
James Clerk Maxwell
Contributed to EM waves - radiofrequency
Heinrich Hertz
Created rotating field in 1882
Nikola Tesla
1956 SI unit for magnetic flux density
TESLA
Strength of magnetism of MF in a specific area
Magnetic flux density
coined the phrase NMR ( Nuclear Magnetic Resonance)
Wolfgang Pauli
[year, person] first NMR experiment, observe that nucleon follow direction with magnetism
1937, Isidor Isaac Rabi
[year, person] NMR Experiment on hydrogen atoms in solid and liquid state, observed a signal in the nucleus, NMR
1946
Felix Bloch - liquid state
Edward Purcell -solid state
Used to measure signal from solid to liquid
Spectroscopy
[year, person] invented MRI scanner INDOMITABLE, father of MRI
1977, Dr. Raymond Damadian
[year, person] national inventors hall of fame - contributed by experimenting an animals
1989 Dr. Raymond Damadian
[date] Damadian performed first whole body TRANSAXIAL PROTON DENSITY
July 3, 1977
time for scanning in first MRI Scanner
4 hrs and 5 min
Designed the implementing use of Gx, Gy and Gz. G (gradient)
Paul Lauterber
[year, person] developed ECHOPLANAR IMAGING TECHNIQUE
1933 Peter Mansfield
Vector quantity made up of a north and south pole
MF
Atoms are composed of:
electrons, nucleus ( protons and neutrons)
Most commonly used particle on MRI, nucleus is only made of 1 proton, also known as hydrogen
protium
[proton spin] 3 Atomic movements
- Electron rotate an orbit of particles
- Electron rotate on own axis
- Nucleus moving/spinning around own place
Concentration of hydrogen atoms in tissue
Spin density
high density (high hydrogen atom) = higher signal
Wobbling
Pathway for rotation
Precession
Spin of the nuclues
Angular momentum
provides direction
Applied MF
The frequency at which the nucleus precess is a function of both the strength of the MF and particular nuclear
Larmour Relationship
Larmour Relationship
The frequency at which the nucleus precess is a function of both the strength of the MF and particular nuclear
Frequency used to stimulate H atoms, absorbs then release signal
1-100 MHz
Energy applied to pt, lower part of EM Spectrum, absorbed by nucleus
RF
Summation of all the magnetic moments of the individual nuclei
Net magnetization
Explain phase coherent (one direction)
Happens only introduction of magnetism
Photons precess at the same Larmour frequency in MHz and synchronized at the same point of phase
Photons precess at the same Larmour frequency in MHz and synchronized at the same point of phase
Phase coherent
Explain Free Precession (incoherent)
H is in any direction, natural state
Each proton precess at their own phase and is unsynchronized
Each proton precess at their own phase and is unsynchronized
Free Precession
Other name for Relaxation time: T1
Spin Lattice RT/ Longitudinal RT
Energy is transferred from the excited proton (spin) to the molecular surrounding (lattice)
Spin lattice
Time for the transverse component of net magnetism to decay at 37% of its original value
Relaxation time/T2
Other name for relaxation time/T2
Spin spin relaxation time
Signals becomes week and net magnetization goes to free phase
Decay/dephase
