Podcast
Questions and Answers
Which artifact produces replications of moving anatomy across the image in the phase encoding axis?
Which artifact produces replications of moving anatomy across the image in the phase encoding axis?
- Phase mismapping (correct)
- Frequency encoding
- Ghosting
- Slice-select gradient
What is the main cause of phase mismapping in MRI?
What is the main cause of phase mismapping in MRI?
- Anatomy moving during the pulse sequence
- Anatomy moving along the slice-select gradient
- Anatomy moving along the phase-encoding gradient (correct)
- Anatomy moving along the frequency encoding gradient
Which of the following can cause phase mismapping in MRI?
Which of the following can cause phase mismapping in MRI?
- Respiration
- Pulsation of vessels and CSF
- Swallowing
- All of the above (correct)
What happens to ghosting with distance from the source of motion?
What happens to ghosting with distance from the source of motion?
What does the physical separation between each ghost depend on?
What does the physical separation between each ghost depend on?
What is the purpose of the phase-encoding gradient in MRI?
What is the purpose of the phase-encoding gradient in MRI?
What results in periodic perturbations of the data collected in k-space?
What results in periodic perturbations of the data collected in k-space?
Which axis does ghosting artifact typically occur along in the image?
Which axis does ghosting artifact typically occur along in the image?
What factors affect the separation between ghosts in an image?
What factors affect the separation between ghosts in an image?
What does swapping phase and frequency encoding directions accomplish?
What does swapping phase and frequency encoding directions accomplish?
What is the purpose of presaturation pulses in MRI?
What is the purpose of presaturation pulses in MRI?
What technique can be used to reduce or eliminate respiratory motion artifact in chest and abdominal imaging?
What technique can be used to reduce or eliminate respiratory motion artifact in chest and abdominal imaging?
What is the purpose of respiratory bellows in MRI?
What is the purpose of respiratory bellows in MRI?
What does a transducer do in the context of respiratory bellows?
What does a transducer do in the context of respiratory bellows?
Which technique utilizes signal collected by the transducer or navigator echoes to trigger an action?
Which technique utilizes signal collected by the transducer or navigator echoes to trigger an action?
What is the main drawback of respiratory triggering?
What is the main drawback of respiratory triggering?
What is the main trade-off of using respiratory gating?
What is the main trade-off of using respiratory gating?
What is the purpose of increasing the NSA (number of signal averages)?
What is the purpose of increasing the NSA (number of signal averages)?
What is the trade-off of increasing the NSA?
What is the trade-off of increasing the NSA?
What is the purpose of immobilizing the patient with pads and straps during an MRI scan?
What is the purpose of immobilizing the patient with pads and straps during an MRI scan?
What is the purpose of administering antispasmodic agents during an MRI scan?
What is the purpose of administering antispasmodic agents during an MRI scan?
Which of the following is the purpose of peripheral pulse triggering in medical imaging?
Which of the following is the purpose of peripheral pulse triggering in medical imaging?
What is the main limitation of peripheral pulse triggering compared to EKG triggering in medical imaging?
What is the main limitation of peripheral pulse triggering compared to EKG triggering in medical imaging?
What does peripheral pulse triggering use to detect the pulsation of blood through the capillaries?
What does peripheral pulse triggering use to detect the pulsation of blood through the capillaries?
When is peripheral pulse triggering most effective in reducing phase mismapping?
When is peripheral pulse triggering most effective in reducing phase mismapping?
What is the purpose of gradient moment rephasing in medical imaging?
What is the purpose of gradient moment rephasing in medical imaging?
Which of the following is NOT a limitation of peripheral pulse triggering in medical imaging?
Which of the following is NOT a limitation of peripheral pulse triggering in medical imaging?
What is the main advantage of EKG triggering compared to peripheral pulse triggering in medical imaging?
What is the main advantage of EKG triggering compared to peripheral pulse triggering in medical imaging?
What is used to trigger RF excitation pulses in peripheral pulse triggering?
What is used to trigger RF excitation pulses in peripheral pulse triggering?
When is peripheral pulse triggering not very useful in medical imaging?
When is peripheral pulse triggering not very useful in medical imaging?
