Unit 8 Quiz

Question 1

_____________appears as a dense line on the image at a specific point which is caused by extraneous RF entering the room interfering with the signal coming from the patient.

Answer 1

Zipper artifact

Question 2

Anti-aliasing along the phase axis is also known as:

Answer 2

Anti-foldover

Question 3

An artifact that produces a banding artifact at the interfaces of high / low signal is known as?

Answer 3

Truncation

Question 4

In gradient-echo pulse sequences a Moiré pattern, a black & white banding that encompasses the edge of the FOV, is cause by a combination of:

Answer 4

Wrap & field inhomogenity

Question 5

The use of foam pads or water bags between the coil & the patient will usually take care of what artifact?

Answer 5

Shading

Question 6

The 180 rephasing pulse used in spin echo sequences is very effective at compensating for phase differences between fat & water in magnetic susceptibility, while _____ is/are very poor at this.

Answer 6

Gradient echo sequences

Question 7

When fat & water signals are out of phase their signals cancel each other out.

Answer 7

True

Question 8

The number one problem to look for when you see zipper artifact on your images & before you call for service is burned out light bulbs.

Answer 8

True

Question 9

Chemical shift can be limited by scanning at lower field strengths & by keeping the FOV to a minimum.

Answer 9

True