30 Questions
What is the primary reason why MRI does not require labelled probe molecules?
Most elements have at least one NMR sensitive isotope
What is the property of atomic nuclei that NMR and MRI take advantage of?
Magnetic properties
What is the fundamental reason behind the unique sources of contrast in an MRI?
Different spin alignment of atomic nuclei
Why does MRI not require high energy radiation?
Because it uses magnetic fields instead of radiation
What is the significance of spin in NMR and MRI?
It is an intrinsic property of atomic nuclei
What is the main advantage of NMR and MRI over other imaging techniques?
They provide information otherwise unobtainable
Which type of contrast does MRI excel at?
Soft tissue contrast
What is the primary limitation of performing MRI with isotopes other than 1H?
Insufficient signal strength
What happens to the spin alignment when a magnetic field is applied?
The spins align with the magnetic field
Which of the following is NOT a factor affecting the overall sensitivity of a nucleus in MRI?
Patient's body temperature
Why is 1H the isotope of choice for clinical MRI?
It has the highest natural abundance
What is necessary to perform MRI with isotopes of low abundance, such as 13C?
Isotopically labelled samples
What is the typical resolution of high-resolution MRI, also known as 'NMR Microscopy'?
10 μm
What is the main reason to combine MRI with NMR sources of contrast?
To discriminate between different regions of tissue
What is the effect of motion during an MRI imaging sequence?
It causes artifacts in the image
What is the purpose of a Diffusion-MRI pulse sequence?
To measure the diffusion of nuclei
What is the source of contrast in an MRI image?
Any NMR observable with a spatial dependence
What is the effect of chemical shift on the NMR signal?
It causes a small change in resonance frequency
Why are superconducting magnets used in MRI machines?
Because they can be kept at extremely low temperatures
What is the purpose of an oxygen sensor in an MRI facility?
To prevent asphyxiation in case of a magnet quench
What is the effect of increasing B0 on the acquired signal?
The signal becomes stronger
What is the advantage of using an RF coil that is just big enough?
It increases the signal-to-noise ratio
Why are strong magnets required in MRI machines?
To increase the signal-to-noise ratio
What happens to an MRI magnet when it is not in use?
It remains on, even when the machine is turned off
What is the effect of a local distortion of the magnetic field on the MRI image?
It causes some parts of the sample to appear in the wrong place.
What is the purpose of introducing a contrast agent in MRI?
To change the relaxation properties of a specific tissue.
What type of image is obtained when the relaxation properties of the tissue are weighted?
T1-weighted image.
What is the term for the movement of nuclei in a magnetic field?
Precession.
What is the cause of the artifact in the MRI image if the acquisition parameters are improperly set?
Incorrect setting of the imaging pulse sequence.
What is the term for the probability of finding a nucleus in a particular position?
Q-space probability.
Test your knowledge of Nuclear Magnetic Resonance Spectroscopy, a medical imaging technique that utilizes molecular motion. Learn about its advantages, natural abundance, and sensitivity of nuclei.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
