MRI Artefacts_261

 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