Physics 2 Quiz 2.1

1. To reduce truncation artifact, decrease phase encoding steps from 256 to 128.

True

False

2. To reduce phase mismapping, the direction of the phase encoding gradient can be changed to get rid of the artifact interfering with the area of interest. This is know as:

Out of phase artifact

Wrap around

Chemical shift artifact

Swapping phase and frequency

3.

What is the artifact seen in this image?

How is this corrected?

Submit

4. No phase wrap over-samples along the phase encoding axis by increasing number of phase encodings performed. This is achieved by enlarging the FOV in phase-direction so phase curve extends over a wider area of anatomy.

True

False

5. The 2 forms of gating are: (select all that apply)

ECG

Pulsation

Peripheral

ECH

Black box

Submit

6. Aliasing or wrap around produces images where anatomy that exists outside the FOV is folded onto the top of anatomy inside the FOV.

True

False

7.

What is the artifact seen in this image?

How is this corrected?

Submit

8. Cardiac gating uses a set of bellows around the patient's chest which expand and contracts when imaging the chest or abdomen.

True

False

9. Artifacts that can occur in images are caused by all of the following except:

Incorrect signal received (interference)

Computer errors

Spatial localization errors

System errors (image reconstruction errors)

10. Phase mismapping is caused by anatomy moving along the phase encoding gradient during the pulse sequence.

True

False

11. Frequency Wrap-Around is improved by using a larger FOV or oversampling

True

False

12. Phase mismapping or ghosting - produces replications of moving anatomy across the image in the frequency

True

False

13. Gradient moment nulling ______. (select all that apply)

Increases ghosting caused by flowing nuclei moving along gradients

Produces bright signal from flowing nuclei

Reduces ghosting caused by flowing nuclei moving along gradients

Produces dark signal from these flowing nuclei

Submit

14. Which of the following are ways to prevent phase wrap artifact? (select all that apply)

PreSat Band

Increase Bandwidth

Oversampling

Decrease Slice Thickness

Increase the Matrix

Use a Bigger Coil

Increase FOV

Submit

15. ROPE is a respiratory compensation method. What does ROPE stand for?

Respiratory ordered phase encoding

Respiratory open phase encoding

Rapid ordered phase encoding

Real ordered phase encoding

Physics 2 Quiz 2.1

1. To reduce truncation artifact, decrease phase encoding steps from 256 to 128.

2.

What first name or nickname would you like us to use?

2. To reduce phase mismapping, the direction of the phase encoding gradient can be changed to get rid of the artifact interfering with the area of interest. This is know as:

3.

4. No phase wrap over-samples along the phase encoding axis by increasing number of phase encodings performed. This is achieved by enlarging the FOV in phase-direction so phase curve extends over a wider area of anatomy.

5. The 2 forms of gating are: (select all that apply)

6. Aliasing or wrap around produces images where anatomy that exists outside the FOV is folded onto the top of anatomy inside the FOV.

7.

8. Cardiac gating uses a set of bellows around the patient's chest which expand and contracts when imaging the chest or abdomen.

9. Artifacts that can occur in images are caused by all of the following except:

10. Phase mismapping is caused by anatomy moving along the phase encoding gradient during the pulse sequence.

11. Frequency Wrap-Around is improved by using a larger FOV or oversampling

12. Phase mismapping or ghosting - produces replications of moving anatomy across the image in the frequency

13. Gradient moment nulling ______. (select all that apply)

14. Which of the following are ways to prevent phase wrap artifact? (select all that apply)

15. ROPE is a respiratory compensation method. What does ROPE stand for?