06) Image Artifacts

What is the artifact?

A) ghosting

B) EPI aliasing

C) GRE aliasing

D) spin echo aliasing

E) 3D aliasing

C) GRE aliasing

What is depicted in the image?

A) metastasis

B) hemorrhage

C) artifact caused by flow

D) artifact caused by T2 blurring

E) cyst

B) hemorrhage

I probably would have put C) artifact from flow.

This is a picture showing:

A) artifact

B) pathology

C) artifact and pathology

D) normal anatomy

E) none of the above

C) artifact and pathology

If you could choose a different scanning sequence, which of the following sequences would be most susceptible to the effect shown in this figure?

A) GRE

B) FSE

C) EPI

D) STIR

E) FLAIR

C) EPI

How can this artifact be reduced?

A) use of shorter scan time

B) use of respiratory gating

C) switching of frequency- and phase-encode direction

D) increasing the field of view

E) changing from FSE to GRE

D) increasing the field of view

In which locations would chemical shift most likely be found?

A) In the lung as with respiratory motion.

B) Near adjacent tissues with dramatically different fat content.

C) Post surgical prothesis

D) Between Ascites and the aorta

E) Between the liver and the diaphragm

B) Near adjacent tissues with dramatically different fat content.

Which of the following is true of chemical shift?

A) seen in the phase encoding direction

B) caused by T1 effects.

C) caused by T2 effects.

D) increased by large receiver bandwidths

E) caused by different resonant frequencies

Which of the following is true regarding truncation?

A) occurs at borders having different intensity changes

B) can be discerned on most clinical mri images

C) can be reduced by increasing the matrix size

D) all of the above

E) A and C

Spikes in k space:

A) always occur along the frequency-encode direction

B) always occur along in phase-encode direction

C) can be caused by loose electrical connections

D) can be caused because of difference in resonant frequencies

E) can be caused by patient motion.

C) can be caused by loose electrical connections

10.

Which of the following is seen in the clinical image (pick as many as can be discerned)?

A) ghosting

B) susceptibility

C) aliasing

D) zippers

E) dielectric effects

A) ghosting

C) aliasing

11.

Which of the following strategies can minimize the artifact in the image below?

A) increasing the FOV or adjusting image slice positioning.

B) increasing the resolution.

C) shimming.

D) decreasing the matrix size

E) none of the above

B) increasing the resolution.

12.

This artifact can be caused by:

A) RF interference

B) T1 effects

C) T2 effects

D) Different resonant frequencies

E) Poor encoding of a single line of k space data

A) RF interference

13.

One can reduce the amount of artifact in this image by changing the scanning protocol in what manner?

A) use of breath holding

B) decreasing NEX

C) changing from GRE to FSE

D) all the above

E) A and C

A) use of breath holding

14.

Which of the following strategies can minimize the artifact in the image below?

A) increasing the FOV or adjusting image slice positioning.

B) increasing the resolution.

C) shimming.

D) decreasing the matrix size

E) none of the above

A) increasing the FOV or adjusting image slice positioning.

15.

Which of the following statement about a feature(s) in this image is true?

A) represents truncation artifact

B) is associated with trauma

C) is frequently seen at the borders of CSF and the spinal cord

D) none of the above

E) A and C

B) is associated with trauma

16.

Which of the following is true in this figure?

A) represents artifact

B) represents pathology

C) this type of artifact can be caused by eddy currents

D) none of the above

E) A and C

A) represents artifact

17.

Which of the following strategies can minimize the artifact in the image below?

A) increasing the FOV or adjusting image slice positioning.

B) increasing the resolution.

C) using a different pulse sequence

D) decreasing the matrix size

E) increasing the bandwidth

C) using a different pulse sequence

18.

Which of the following is true in this figure?

A) artifact occurs in the frequency-encode direction

B) artifact occurs in the phase-encode direction

C) artifact caused by T1 effects.

D) artifact caused by T2 effects

E) this type of artifact becomes less complex as sequence is changed from 2D to 3D

B) artifact occurs in the phase-encode direction

19.

Which of the following strategies can minimize the artifact in the image below?

A) increasing the FOV or adjusting image slice positioning.

B) increasing the resolution.

C) shimming

D) decreasing the matrix size

E) increasing the bandwidth

20.

Which of the following materials will cause the greatest susceptibility artifact?

A) clinically-relevant concentrations of gadolinium-based contrast agent within muscle, assuming a 15-minute delay after bolus injection.

B) a cyst, within fatty tissues

C) iron shavings from a machine shop, embedded in the eye

D) a wooden splinter, embedded in the skin

E) a renal artery

C) iron shavings from a machine shop, embedded in the eye