PRELIM Flashcards
the medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body.
MAGNETIC RESONANCE IMAGING
It is a medical technique that uses a magnetic field and computer-generated radio waves to create detailed images of the organs and tissues in your body.
MAGNETIC RESONANCE IMAGING
what year did Damadian discovered that MRI could be used for medical diagnosis. Cancer tumours emitted different signals compared to healthy tissue.
1971
in what year did Damadian built the first whole-body MRI in which he called the ‘Indomitable’ (impossible). Over 60 million MRI examinations are now carried out annually.
1977
Damadian built the first whole-body MRI in 1977, which he called the ‘Indomitable’, what does mean?
impossible
Damadian built the first whole-body MRI in 1977, which he called the ‘__________’ (impossible). Over 60 million MRI examinations are now carried out annually. called what?
Indomitable
how many millions? MRI examinations are now carried out annually.
over 60 millions
who was able to image a student’s finger in 15-23 minutes in 1974.
Mansfield
when was Mansfield able to image a student’s finger in 15-23 minutes in what year
in 1974.
what Mansfield was able to image in 15-23 minutes in 1974.
a student’s finger
how many minutes Mansfield was able to image a student’s finger in 1974.
in 15-23 minutes
who was the person/s race to create the first whole-body MRI scanner began shortly thereafter
Damadian and Mansfield
how many years later when Damadian created the first whole-body human scanner in May of 1977.
Three years later
Three years later, Damadian created what? in May of 1977.
the first whole-body human scanner
Three years later, Damadian created the first whole-body human scanner in what month and year
May of 1977.
the inventor of the first magnetic resonance scanning machine celebrates his 85th birthday on March 16. Damadian, a physician, performed the first full-body scan of a human being in 1977.
Dr. Raymond Damadian
Dr. Raymond Damadian, the inventor of the first magnetic resonance scanning machine celebrates his 85th birthday on what month and date?
March 16
Dr. Raymond Damadian, the inventor of the first magnetic resonance scanning machine celebrates on how old he is his on March 16?
85th birthday
a physician, performed the first full-body scan of a human being in 1977.
Dr. Raymond Damadian
Damadian, a physician, performed the first full-body scan of a human being in what year?
1977.
Damadian, a physician, performed what? in 1977.
the first full-body scan of a human being
MR imaging was invented by who developed a mechanism to encode spatial information into an NMR signal using magnetic field gradients in September 1971;
Paul C. Lauterbur
what did Paul C. Lauterbur invented who developed a mechanism to encode spatial information into an NMR signal using magnetic field gradients in September 1971
MR imaging
MR imaging was invented by Paul C. Lauterbur who developed a mechanism to encode spatial information into an NMR signal using magnetic field gradients in what month and year?
September 1971
MR imaging was invented by Paul C. Lauterbur what he is dveloped?
developed a mechanism to encode spatial information into an NMR signal using magnetic field gradients
MR imaging was invented by Paul C. Lauterbur who developed a mechanism to encode spatial information into an?
an NMR signal using magnetic field gradients
he published the theory behind it in March 1973.
Paul C. Lauterbur
Paul C. Lauterbur published the theory behind it in what month and year?
March 1973.
what is a material or object that produces a magnetic field
A magnet
is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel cobalt, etc. and attracts or repels other magnets.
magnetic field
A magnet is a material or object that produces what?
magnetic field
is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials.
A magnetic field
surround magnetized materials, and are created by electric currents such as those used in electromagnets, and by electric fields varying in time.
Magnetic fields
is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger-Marsden gold foil experiment.
The atomic nucleus
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in what year by Ernest Rutherford based on the 1909 Geiger-Marsden gold foil experiment.
1911
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by who?
Ernest Rutherford
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on what year?
1909
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 what experiment?
Geiger-Marsden gold foil experiment.
is a quantum-mechanical property, akin to the angular momentum of a classical sphere rotating on is axis, except it comes in discrete units of integer or half-integer multiples of . The proton, like the electron and neutron, has a spin of ℏ/2
PROTON SPIN
is a quantum-mechanical property, akin to the angular momentum of a classical sphere rotating on is axis, except it comes in discrete units of integer or half-integer multiples of . The proton, like the electron and neutron, has a spin of ℏ/2
Spin
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
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
Radiofrequency ablation, also called what?
fulguration
TYPES OF MAGNET USED IN MRI
- PERMANENT MAGNET
- RESISTIVE MAGNET
- SUPERCONDUCTIVE MAGNET
employ powerful magnets which produce a strong magnetic field that forces protons in the body to align with the field. When a radiofrequency current is then pulsed through the patient, the protons are simulated, and spin out of equilibrium, straining against the pull of the magnetic field.
MRIs
MRI contains with
Magnet
RF coils
Gradient coils
scanner
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
The uniform magnetic field is found inside the coil, especially in the center. These magnets are relatively inexpensive to make but require a large contact flow of current while magneitzed and imaging. The coil has an electrical resistance that requires cooling of the magnet.
resistive magnet
is an electromagnet made from coils of superconducting wires in is superconducting state the wire has no electrical resistance and therefore can conduct much larger electric currents than ordinary wire, creating intense magnetic field.
A Superconducting magnet
uses in MRI, because wrapped up in coil, generating magnets all around
A Superconductive magnet
Most MRI systems use what type of magnet
superconducting magnets
The primary advantage is that a superconducting magnet is capable of what? than the other two types (resistive and permanent) considered below.
producing much stronger and stable magnetic field
The primary advantage is that a superconducting magnet is capable of producing much stronger and stable magnetic field than the other two types of magnet
resistive and permanent
the one who receive a primary radiation
patient
what receive primary radiaion radtech
scattered
what to patient to film, comes from primary radiation
SECONDARY RADIATION
is the the construct which determines teh ate at which excited protons reach equilibrium or go out of phase with each other
T2 (transverse relaxation time)
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)
is the concentration of signal bearing spins. The instrumental variables are the: Repetition Time TR, and Echo Time TE.
spin density
two types of spin density: The instrumental variables are the:
- Repetition Time TR, and
- Echo Time TE.
what type of spin density that - maintain detailed and well persecute anatomical.
*LONG TR, SHORT TE
is the ratio of the magnetic momentum in a particle to its angular momentum.
The gyromagnetic ratio
The gyromagnetic ratio, often denoted by the symbol of?
gamma
The gyromagnetic ratio the SI unit is what
the radian per second per tesla (rads-1T-1)
What is The gyromagnetic ratio of the proton
2.675 221 900 (18) 108s-1T-1
a vector quantity that is a measure of the torque exerted on a magnetic system (such as bar magnet or dipole) when placed in a magnetic field is the product of the distance between its poles and the strength of either pole.
MAGNETIC MOMENTUM
also known as spin, is the velocity of rotation of something around an axis. Gyroscopes are simple decrease that exploit the conservation of angular momentum to stabilize, guide or measure rotational movement in many type of systems
ANGULAR MOMENTUM
are simple decrease that exploit the conservation of angular momentum to stabilize, guide or measure rotational movement in many type of systems
Gyroscopes are simple decrease that exploit the conservation of angular momentum to stabilize, guide or measure rotational movement in many type of systems
it plays in Nuclear Magnetic Resonance (NMR) and MRI
The gyromagnetic ratio of a nucleus
is particulate important because of the role it plays in Nuclear Magnetic Resonance (NMR) and MRI
The gyromagnetic ratio of a nucleus
The gyromagnetic ratio of a nucleus is particulate important because of the role it plays in what?
Nuclear Magnetic Resonance (NMR) and MRI
is a special case of forced vibrations. When the frequency of an externally applied periodic force on a body is equal to its natural frequency, the body rapidly begins to vibrate with an increased amplitude
RESONANCE
are critical to nuclear excitation and signal reception in MRI. The interactions between these fields and human tissues in anatomical geometrics result in a variety of effects regarding image of humans integrity and safety.
RADIOFREQUENCY FIELD
are critical to nuclear excitation and signal reception in MRI. The interactions between these fields and human tissues in anatomical geometrics result in a variety of effects regarding image of humans integrity and safety.
RF magnetic fields
MRI uses magnetic fields and radiowaves to measure how much water is in different tissues of the body, maps the location of the water and then uses. This information to generate a detailed image. The images are so detailed because over bodies are made up of around 65% water, so to have a lots of resource to measure.
IMPORTANT OF RF IN AN MRI
IMPORTANT OF RF IN AN MRI?
MRI uses magnetic fields and radiowaves to measure what? This information to generate a detailed image.
how much water is in different tissues of the body, maps the location of the water and then uses.
MRI uses magnetic fields and radiowaves to measure how much water is in different tissues of the body, maps the location of the water and then uses. This information to generate a detailed image. The images are so detailed because over bodies are made up of around how many percent of water? so to have a lots of resource to measure.
65% water
magnetic fields used in MRI are typicals in the range 1 to 4. The corresponding Larmour frequencies are about 43 to 170 MHz. These frequencies are in the RF range, which are much lower than x-rays capitalized and do not disrupt tissue.
LARMOUR FREQUENCY
LARMOUR FREQUENCY, magnetic fields used in MRI are typicals inwhat range?
range 1 to 4
The corresponding Larmour frequencies are about how many MHz? These frequencies are in the RF range, which are much lower than x-rays capitalized and do not disrupt tissue.
43 to 170 MHz
These frequencies are in the RF range, which are much lower than x-rays capitalized and do not disrupt tissue.
LARMOUR FREQUENCY
vector in MRI is the summation of the magnetic moment of the individual hydrogen nuclei. In the absence of an external magnetic field, the individual magnetic moment are randomly oriented and share they are in opposition
net magnetization
in what year,Felix Bloch and Edward Purcell first discovered the properties of magnetic resonance.
1940s