ARRT Practice Questions and Answers
Latest Update with Complete Solutions
What is the primary role of T1 relaxation in MRI?
✔✔ It represents the time taken for protons to realign with the magnetic field after excitation
How does increasing slice thickness affect MRI image quality?
✔✔ It increases signal-to-noise ratio but reduces spatial resolution
Why is a high signal-to-noise ratio (SNR) important in MRI?
✔✔ It improves image clarity and reduces graininess
What is the function of gradient coils in an MRI scanner?
✔✔ They create variations in the magnetic field to encode spatial information
Why is fat suppression used in MRI sequences?
✔✔ To reduce fat signal and enhance contrast between tissues
1
,How does motion affect MRI images?
✔✔ It causes blurring and artifacts, reducing image quality
What is the main advantage of spin-echo sequences?
✔✔ They provide high-quality images with minimal artifacts
Why is gadolinium commonly used as a contrast agent?
✔✔ It shortens T1 relaxation time, making structures more visible
What happens if the field of view (FOV) is too small?
✔✔ It increases resolution but may cause aliasing artifacts
Why is echo-planar imaging (EPI) used for functional MRI (fMRI)?
✔✔ It allows rapid image acquisition to track brain activity
How does increasing the number of excitations (NEX) impact MRI scans?
✔✔ It improves signal-to-noise ratio but increases scan time
2
,What is the purpose of an inversion recovery sequence?
✔✔ To suppress specific tissue signals for enhanced contrast
How does parallel imaging benefit MRI scans?
✔✔ It reduces scan time while maintaining image resolution
Why is k-space important in MRI?
✔✔ It stores raw data used for image reconstruction
What is the effect of a longer echo time (TE) in T2-weighted imaging?
✔✔ It increases T2 contrast, making fluid appear brighter
Why are phased array coils used in MRI?
✔✔ They improve signal reception and enhance image resolution
How does susceptibility-weighted imaging (SWI) help in neuroimaging?
✔✔ It highlights small hemorrhages and iron deposits in the brain
3
, What is the purpose of respiratory gating in MRI?
✔✔ To minimize motion artifacts from breathing
Why is a superconducting magnet preferred in MRI scanners?
✔✔ It provides a strong and stable magnetic field with minimal energy consumption
What does the Larmor equation determine in MRI?
✔✔ The resonance frequency of hydrogen protons
How does aliasing occur in MRI images?
✔✔ When undersampling causes overlapping of image structures
Why is time-of-flight (TOF) imaging used in MR angiography?
✔✔ It enhances blood flow signal without contrast agents
What effect does increasing bandwidth have on MRI images?
✔✔ It reduces chemical shift artifacts but decreases signal-to-noise ratio
4
Latest Update with Complete Solutions
What is the primary role of T1 relaxation in MRI?
✔✔ It represents the time taken for protons to realign with the magnetic field after excitation
How does increasing slice thickness affect MRI image quality?
✔✔ It increases signal-to-noise ratio but reduces spatial resolution
Why is a high signal-to-noise ratio (SNR) important in MRI?
✔✔ It improves image clarity and reduces graininess
What is the function of gradient coils in an MRI scanner?
✔✔ They create variations in the magnetic field to encode spatial information
Why is fat suppression used in MRI sequences?
✔✔ To reduce fat signal and enhance contrast between tissues
1
,How does motion affect MRI images?
✔✔ It causes blurring and artifacts, reducing image quality
What is the main advantage of spin-echo sequences?
✔✔ They provide high-quality images with minimal artifacts
Why is gadolinium commonly used as a contrast agent?
✔✔ It shortens T1 relaxation time, making structures more visible
What happens if the field of view (FOV) is too small?
✔✔ It increases resolution but may cause aliasing artifacts
Why is echo-planar imaging (EPI) used for functional MRI (fMRI)?
✔✔ It allows rapid image acquisition to track brain activity
How does increasing the number of excitations (NEX) impact MRI scans?
✔✔ It improves signal-to-noise ratio but increases scan time
2
,What is the purpose of an inversion recovery sequence?
✔✔ To suppress specific tissue signals for enhanced contrast
How does parallel imaging benefit MRI scans?
✔✔ It reduces scan time while maintaining image resolution
Why is k-space important in MRI?
✔✔ It stores raw data used for image reconstruction
What is the effect of a longer echo time (TE) in T2-weighted imaging?
✔✔ It increases T2 contrast, making fluid appear brighter
Why are phased array coils used in MRI?
✔✔ They improve signal reception and enhance image resolution
How does susceptibility-weighted imaging (SWI) help in neuroimaging?
✔✔ It highlights small hemorrhages and iron deposits in the brain
3
, What is the purpose of respiratory gating in MRI?
✔✔ To minimize motion artifacts from breathing
Why is a superconducting magnet preferred in MRI scanners?
✔✔ It provides a strong and stable magnetic field with minimal energy consumption
What does the Larmor equation determine in MRI?
✔✔ The resonance frequency of hydrogen protons
How does aliasing occur in MRI images?
✔✔ When undersampling causes overlapping of image structures
Why is time-of-flight (TOF) imaging used in MR angiography?
✔✔ It enhances blood flow signal without contrast agents
What effect does increasing bandwidth have on MRI images?
✔✔ It reduces chemical shift artifacts but decreases signal-to-noise ratio
4
