week 2 Flashcards
word magnetism is derived from the Greek work
Magnes
what present name Magnes
Manisa
- any material or object that produces a magnetic field, which is a force field that can attract or repel other materials
magnet
Magnets can be either
natural - magnetite
manmade - electronics, motors, and compasses
- made first experiment in 1820
- first clear link between electricity and magnetism, laying the foundation for the field of electromagnetism.
Hans Oersted
- developed a method to measure the magnetic properties of atomic nuclei, laying the groundwork for Nuclear Magnetic Resonance (NMR).
▪ coined the term Nuclear Magnetic Resonance
▪ Rewarded with Nobel Physics Prize in 1944
Isidor Isaac Rabi
- simple relation between resonance, magnetic field strength and frequency of radio waves
- His work led to the development of NMR spectroscopy
- continued extensive studies with the NMR of water, thereby laying the groundwork for later developments that led to MRI
- rewarded with Nobel Physics Prize in 1952
Felix Bloch & Edward Purcell
▪ showed that malignant tissue has a different NMR spectrum from normal tissue while working with NMR spectroscopy
▪ produced a crude NMR image of a rat tumor in 1974 and the first body image in 1977. That image took almost 4 hours to produce.
Raymond Damadian
- Raymond Damadian and his collegues at FONAR built the first whole-body MRI system, “___”, had a field strength of only ~0.05 T.
- did produce the worlds first MR images of the human. By collecting data from 106 voxels, one voxel at a time (a four hour scan), the image was crude, but clearly showed the heart, lungs, and the walls of the chest cavity.
Indomitable
“The Father of Magnetic Resonance Imaging”
Raymond Damadian
1960s to 1970s
- Proposed the concept of using magnetic field gradients to create two-dimensional images.
- Gradient System (Gx, Gy, Gz) to pick up and excite a particular section of human body in three dimension then broadcast a first visual of 2 tube in Nature Magazine. - He also called this imaging
by the name of Zeugmatography - His pioneering work in MRI earned him a Nobel Prize in Physiology or Medicine in 2003
Paul C. Lauterbur - 1973
built the base of Magnetic Resonance by offering the method of frequency and phase coding. He thought of using Fourier Transform instead of Radon Transform and applied successfully.
Richard Ernst -1975
- developed Echo Planar Imaging (EPI) provided imaging very fast, Same year that Damadian accomplished imaging of entire human body.
▪ MRI method is used for functional MR neuroimaging today.
Peter Mansfield 1977
Types of Magnets
Permanent Magnets
Temporary Magnets
Electromagnets
These magnets maintain their magnetism over time without needing any external power.
Permanent Magnets
become magnetic only when exposed to a magnetic field. Once the external field is removed, they lose their magnetism.
Temporary Magnets
created by running an electric current through a coil of wire, usually wrapped around a core made of ferromagnetic material like iron.
Electromagnets
Magnets have two poles:
where the magnetic force is the strongest
north and south
area around a magnet where its magnetic force is felt is called
magnetic field
strength of the B0 magnetic field is expressed in units called
tesla (T)
Who was the assistant of Raymond Damadian during his experiment in MRI?
Larry Minkoff
Ørsted’s discovery was the first clear link between electricity and magnetism, laying the foundation for the field of electromagnetism. This experiment was done in the year___
1820
His work led to the development of NMR spectroscopy
Edward Purcell
continued extensive studies with the NMR of water, thereby laying the groundwork for later developments that led to MRI.
Felix Bloch
When was the date of experiments of Edward Purcell and Felix Bloch? How about the date when they received their Nobel Prize?
1946, 1952
Showed that malignant tissue has a different NMR spectrum from normal tissue while working with NMR spectroscopy
Raymond Damadian 1960-1970
Damadian produced a crude NMR image of a rat tumor in ___ and the first body image in __. That image took almost 4 hours to produce.
- 1974
- 1977 (3 years apart)
Raymond Damadian and his collegues at FONAR built the first whole-body MRI system, “Indomitable”, had a field strength of only ~___
- 0.05 T
indomitable did produce the worlds first MR images of the human. By collecting data from ___ voxels, one voxel at a time (a four hour scan), the image was crude, but clearly showed the heart, lungs, and the walls of the chest cavity
106
Proposed the concept of using magnetic field gradients to create two-dimensional images. He is____ and he had his experiment in the year___
Paul C. Lauterbur, 1973
Gradient System (Gx, Gy, Gz) to pick up and excite a particular section of human body in three dimension then broadcast a first visual of 2 tube in Nature Magazine. Paul C. Lauterbur also called this imaging by the name of ____
Zeugmatography
In 1980, ____and his friends began obtaining visuals by using Ernst Technique. - Initial MR works based on weight of protons and T1 technique began in clinically
Peter H. Hawkins
Contrast agent got attraction and started being used in 1980s and for the first time, Schering Company applied for patent for _____. It was the first contrast agent to be used in MRI
- Gd-DTPA.
in 1987, 1987, ____was used to imaging of heart’s phase in real-time. While ___accomplished imaging of veins without constant agents by developing Magnetic Resonance Angiography (MRA)
- EPI technique
- Charles Dumoulin
year when functional Magnetic Resonance Imaging (fMRI) was discovered. Then by that time, it was possible to explore deep parts of human brain by using fMRI
1993
year when FDA (Food and Drug Ac.) allowed marketing up to 4 Tesla devices
1998
year when New York State and Princeton University achieved imaging of lungs
1994
The area around a magnet where its magnetic force is felt is called the magnetic field. It’s invisible, but you can visualize it using iron filings or compasses
magnetic field
magnetic field/magnet field is represented by a symbol ____
Bo
