MRI Registry Review Questions and
Answers Latest Update Already Passed
What is the effect of using a stronger gradient field in MRI?
✔✔ It improves spatial encoding but may increase heating and noise
How does temperature affect superconducting MRI magnets?
✔✔ They must be kept at extremely low temperatures using liquid helium to remain functional
What is the purpose of fat saturation in post-contrast imaging?
✔✔ To improve the visibility of enhancing lesions
How does a shorter TR affect signal intensity in T1-weighted imaging?
✔✔ It increases T1 contrast and reduces overall signal
What causes the zipper artifact in MRI?
✔✔ External RF interference entering the scanner environment
1
,How does MR spectroscopy differ from standard MRI?
✔✔ It analyzes tissue metabolism rather than producing anatomical images
Why is gradient shimming performed in MRI?
✔✔ To improve magnetic field homogeneity and reduce distortions
How does slice selection work in MRI?
✔✔ A gradient field is applied to select a specific imaging plane
What is the main challenge of imaging the abdomen in MRI?
✔✔ Motion artifacts caused by breathing and peristalsis
How does functional MRI (fMRI) detect brain activity?
✔✔ By measuring blood oxygen level-dependent (BOLD) changes
What is the role of the RF shield in an MRI suite?
✔✔ To prevent external radiofrequency interference from affecting image quality
2
,What is the primary purpose of the radiofrequency (RF) pulse in MRI?
✔✔ To excite hydrogen protons and generate a signal
What factor primarily determines the strength of the MRI signal?
✔✔ Proton density and relaxation times of tissues
Why is a superconducting magnet preferred in most MRI scanners?
✔✔ It provides a strong and stable magnetic field with minimal energy consumption
What does T2 relaxation time measure in MRI?
✔✔ The time it takes for transverse magnetization to decay
How does increasing the number of signal averages (NEX) affect an MRI scan?
✔✔ It improves signal-to-noise ratio but increases scan time
Why is fat suppression used in MRI imaging?
✔✔ To enhance visualization of pathology by reducing fat signal
3
, What is the purpose of gradient coils in an MRI system?
✔✔ To spatially encode signals and create image slices
How does echo time (TE) influence image contrast?
✔✔ Longer TE enhances T2 contrast, while shorter TE enhances T1 contrast
Why is gadolinium used as a contrast agent in MRI?
✔✔ It shortens T1 relaxation time, improving contrast between tissues
What causes susceptibility artifacts in MRI?
✔✔ Differences in magnetic properties between tissues, such as near metal implants
How does slice thickness affect spatial resolution in MRI?
✔✔ Thinner slices improve resolution but decrease signal-to-noise ratio
What is the main advantage of fast spin-echo (FSE) sequences?
✔✔ Faster imaging with reduced motion artifacts
4
Answers Latest Update Already Passed
What is the effect of using a stronger gradient field in MRI?
✔✔ It improves spatial encoding but may increase heating and noise
How does temperature affect superconducting MRI magnets?
✔✔ They must be kept at extremely low temperatures using liquid helium to remain functional
What is the purpose of fat saturation in post-contrast imaging?
✔✔ To improve the visibility of enhancing lesions
How does a shorter TR affect signal intensity in T1-weighted imaging?
✔✔ It increases T1 contrast and reduces overall signal
What causes the zipper artifact in MRI?
✔✔ External RF interference entering the scanner environment
1
,How does MR spectroscopy differ from standard MRI?
✔✔ It analyzes tissue metabolism rather than producing anatomical images
Why is gradient shimming performed in MRI?
✔✔ To improve magnetic field homogeneity and reduce distortions
How does slice selection work in MRI?
✔✔ A gradient field is applied to select a specific imaging plane
What is the main challenge of imaging the abdomen in MRI?
✔✔ Motion artifacts caused by breathing and peristalsis
How does functional MRI (fMRI) detect brain activity?
✔✔ By measuring blood oxygen level-dependent (BOLD) changes
What is the role of the RF shield in an MRI suite?
✔✔ To prevent external radiofrequency interference from affecting image quality
2
,What is the primary purpose of the radiofrequency (RF) pulse in MRI?
✔✔ To excite hydrogen protons and generate a signal
What factor primarily determines the strength of the MRI signal?
✔✔ Proton density and relaxation times of tissues
Why is a superconducting magnet preferred in most MRI scanners?
✔✔ It provides a strong and stable magnetic field with minimal energy consumption
What does T2 relaxation time measure in MRI?
✔✔ The time it takes for transverse magnetization to decay
How does increasing the number of signal averages (NEX) affect an MRI scan?
✔✔ It improves signal-to-noise ratio but increases scan time
Why is fat suppression used in MRI imaging?
✔✔ To enhance visualization of pathology by reducing fat signal
3
, What is the purpose of gradient coils in an MRI system?
✔✔ To spatially encode signals and create image slices
How does echo time (TE) influence image contrast?
✔✔ Longer TE enhances T2 contrast, while shorter TE enhances T1 contrast
Why is gadolinium used as a contrast agent in MRI?
✔✔ It shortens T1 relaxation time, improving contrast between tissues
What causes susceptibility artifacts in MRI?
✔✔ Differences in magnetic properties between tissues, such as near metal implants
How does slice thickness affect spatial resolution in MRI?
✔✔ Thinner slices improve resolution but decrease signal-to-noise ratio
What is the main advantage of fast spin-echo (FSE) sequences?
✔✔ Faster imaging with reduced motion artifacts
4
