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WorksheetsMRI Artefacts_261
Total questions: 15
Worksheet time: 8mins
How can we reduce the chemical shift artifact?
Reduce Bandwidth
Increase Bandwidth
Reduce SNR
Increase FOV
What type of image is affected by phase cancellation artifact?
Spin-Echo
Gradient-Echo
Echo Planar Imaging
Turbo Spin Echo
Which protons are excited in “Fat-Sat” sequence?
Fat protons only
Fat and water protons
Water protons only
Soft tissue
What is the most common cause of zipper artifacts?
Patient monitoring devices
Open doors
Substances with radiofrequency susceptibility
The cold head
What is the cause of Herring-bone artifacts?
A spike of noise in the raw data
Multiple data errors in a single image
Electric discharges when components interact with the magnet
A malfunction in the RF coil
How does the gradient non-linearity distort the image
A pattern of stripes appear in the imafe
Image information is compressed in the borders of the FOV.
Image information is compressed in the center of the FOV
Pixels are stretched, causing curved image borders.
What phases are used to sample in a respiratory and cardiac gating method?
Inspiration and systole
Expiration and diastole
Inspiration and diastole
Systole and Expiration
How are blood flow artifacts avoided?
With the TOF scanning technique
With the Regional Saturation Technique (REST)
Using SE sequences
Using EPI sequences
What is a HASTE or SS-TSE?
A piece of hardware
An ultra fast pulse sequence
A software
An artifact
WHICH OF THE FOLLOWING OCCUR ONLY IN METAL ARTIFACTS AND NOTIN SUSCEPTIBILITY ARTIFACTS?
Alterations in the intensity of the image
Geometry distortion in nearby tissue.
Signal spikes in the raw data
Signal loss
Susceptibility artifacts are worse than metal artifacts
True
False
Which elements have a higher susceptibility
Bones and air
Molecules with iron (hemoglobin)
Soft tissue
water
What kind of artifact is it?
Gibb's Artifact
Phase wrap
Partial volume artifact
Parallel imaging artifact
What types of digital artifacts exist?
Hering-Bone Artefact and Phase Cancellation Artefact
Gibbs’ Artefact, Phase Wrap-Around Artefact, Parallel Imaging Artefacts, Partial Volume
Artefact and Cross-talk
Phase Envelope Artefact, Zipper Artefact, Peristaltic Movement Artefact
Parallel Image Artefact and Peristaltic Movement Artefact
It is the type of digital artefact that is characterized by representing a lot of information in a
single voxel, that is to say that different types of tissue are found in a single voxel
Gibbs’ Artefact
Phase Wrap-Around Artefact
Partial volume Artefact
Parallel image Artefacts
