MRI Physics I Final Exam Question And
Answers 100% Correct
Which names contributed to development of NMR/MRI? - Correct Answer-Felix Bloch, Edward
Purcell, Peter Mansfield, Paul Lauterbur, Damadian
Which individual discovered that tumors and normal tissue can be distinguished by NMR
because of their relaxation times? - Correct Answer-Damadian
Which individual discovered that a charged particle such as a proton spinning around its own
axis has a magnetic field known as a magnetic moment? - Correct Answer-Felix Bloch
Which individual developed the equation that shows precession of nuclear spins being
proportional to magnetic field strength? - Correct Answer-Larmor
Which individuals won the 2003 Nobel prize in medicine for their work in the 1970s
development MR imaging techniques and capabilities? - Correct Answer-Lauterbur and
Mansfield
What is the principle advantage of MRI over other modalities? - Correct Answer-Soft tissue
contrast
What makes permanent magnets unique? - Correct Answer-B0 is vertical
Which of the following components of an MRI magnet functions to create a large magnetic
field? - Correct Answer-B0
,Resistive magnets can be turned off at the end of the work day. (T/F) - Correct Answer-True
Resistive magnet typical field strength of _____. - Correct Answer-0.2T
Passive shielding can be achieved lining the room with _______. - Correct Answer-steel
Active shielding can be described as: - Correct Answer-Additional superconducting coils build
into the MR scanner
What is active shimming? - Correct Answer-Prescanning before running each sequence
What is passive shimming? - Correct Answer-Steel bars placed inside the bore of the MRI
scanner
_________________ refers to the uniformity of the main magnetic field and is measured in
_________________ - Correct Answer-Homogeneity, parts per million (ppm)
What provides localization in MRI? - Correct Answer-Gradient magnetic fields
How is the MRI system cooled to produce a high B0 field? - Correct Answer-with cryogens
Which of the following is not contained within the gantry? - Correct Answer-MR computer
console
Why are MRI scans so loud? - Correct Answer-Switching of the gradient coils
, What do shim coils do? - Correct Answer-Make B0 more homogenous
Which type of MRI magnet is most common in practice? - Correct Answer-Superconducting
magnet
The gradient rise time is defined as the - Correct Answer-time it takes for the gradient to reach
its maximum strength
The gradient slew rate is - Correct Answer-The rate of ascent or descent of a gradient from zero
to its maximum amplitude
What is the percentage of time that the gradient will be working at ta maximum strength during
a pulse sequence? - Correct Answer-Duty cycle
Which term is the measure of maximum strength the gradient coil can achieve? - Correct
Answer-Gradient amplitude
What uses a set of coils that allows current to pass through and decreases the inhomogeneity of
the main magnetic field? - Correct Answer-Active shimming
Which of the following are the two main techniques to help reduce the inhomogeneities of the
main magnetic field? - Correct Answer-Active shimming and passive shimming
What is made out of ferromagnetic material (usually steel) that is placed inside the walls of the
MRI scan room? - Correct Answer-Passive shielding
What techniques are used to contain the fringe field? - Correct Answer-Active shielding and
passive shielding
Answers 100% Correct
Which names contributed to development of NMR/MRI? - Correct Answer-Felix Bloch, Edward
Purcell, Peter Mansfield, Paul Lauterbur, Damadian
Which individual discovered that tumors and normal tissue can be distinguished by NMR
because of their relaxation times? - Correct Answer-Damadian
Which individual discovered that a charged particle such as a proton spinning around its own
axis has a magnetic field known as a magnetic moment? - Correct Answer-Felix Bloch
Which individual developed the equation that shows precession of nuclear spins being
proportional to magnetic field strength? - Correct Answer-Larmor
Which individuals won the 2003 Nobel prize in medicine for their work in the 1970s
development MR imaging techniques and capabilities? - Correct Answer-Lauterbur and
Mansfield
What is the principle advantage of MRI over other modalities? - Correct Answer-Soft tissue
contrast
What makes permanent magnets unique? - Correct Answer-B0 is vertical
Which of the following components of an MRI magnet functions to create a large magnetic
field? - Correct Answer-B0
,Resistive magnets can be turned off at the end of the work day. (T/F) - Correct Answer-True
Resistive magnet typical field strength of _____. - Correct Answer-0.2T
Passive shielding can be achieved lining the room with _______. - Correct Answer-steel
Active shielding can be described as: - Correct Answer-Additional superconducting coils build
into the MR scanner
What is active shimming? - Correct Answer-Prescanning before running each sequence
What is passive shimming? - Correct Answer-Steel bars placed inside the bore of the MRI
scanner
_________________ refers to the uniformity of the main magnetic field and is measured in
_________________ - Correct Answer-Homogeneity, parts per million (ppm)
What provides localization in MRI? - Correct Answer-Gradient magnetic fields
How is the MRI system cooled to produce a high B0 field? - Correct Answer-with cryogens
Which of the following is not contained within the gantry? - Correct Answer-MR computer
console
Why are MRI scans so loud? - Correct Answer-Switching of the gradient coils
, What do shim coils do? - Correct Answer-Make B0 more homogenous
Which type of MRI magnet is most common in practice? - Correct Answer-Superconducting
magnet
The gradient rise time is defined as the - Correct Answer-time it takes for the gradient to reach
its maximum strength
The gradient slew rate is - Correct Answer-The rate of ascent or descent of a gradient from zero
to its maximum amplitude
What is the percentage of time that the gradient will be working at ta maximum strength during
a pulse sequence? - Correct Answer-Duty cycle
Which term is the measure of maximum strength the gradient coil can achieve? - Correct
Answer-Gradient amplitude
What uses a set of coils that allows current to pass through and decreases the inhomogeneity of
the main magnetic field? - Correct Answer-Active shimming
Which of the following are the two main techniques to help reduce the inhomogeneities of the
main magnetic field? - Correct Answer-Active shimming and passive shimming
What is made out of ferromagnetic material (usually steel) that is placed inside the walls of the
MRI scan room? - Correct Answer-Passive shielding
What techniques are used to contain the fringe field? - Correct Answer-Active shielding and
passive shielding
