Quiz 3 C14 (Bush) 23 (C&A)

Question 1

The two principal characteristics of a medical image are _______________________.

Answer 1

spatial resolution and contrast resolution

Question 2

Spatial frequency is used to describe the quality of spatial resolution in terms of _____________.

Answer 2

line pairs

Question 3

In digital imaging, spatial resolution is ultimately limited by ___________________.

Answer 3

pixel size

Question 4

As spatial frequency increases, the object size _____ and the spatial resolution _____.

Answer 4

decreases; increases

Question 5

If there were such thing as a perfect imaging system, the MTF would be equal to ________.

Answer 5

one

Question 6

A _______________ test tool is used to acquire data for an MTF curve.

Answer 6

bar pattern

Question 7

The human visual system can distinguish ________ shades of gray.

Answer 7

30

Question 8

The number of gray shades that an imaging system can reproduce is called its ________________.

Answer 8

dynamic range

Question 9

Screen-film radiography has a dynamic range of __________. Digital Imaging has a dynamic range > ______________.

Answer 9

1000____65,00

Question 10

The bit capacity of each pixel identifies the ___________ of a digital imaging system.

Answer 10

dynamic range

Question 11

The ________________ digital imaging system uses the highest dynamic range.

Answer 11

mammography

Question 12

The portion of useful image-forming x-rays is referred to as the ___________.

Answer 12

signal

Question 13

Recent studies have shown that denser breast tissue is best imaged with _____________________.

Answer 13

digital mammography

Question 14

As mAs is increased the signal-to-noise ratio is ____________.

Answer 14

increased

Question 15

Image detail is also called _______________________.

Answer 15

spatial resolution

Question 16

Of all radiographic imaging systems, _____________ has the best contrast resolution.

Answer 16

computed tomography

Question 17

It is __________of the scope of practice of a radiologic technologist to use post-exposure shuttering, cropping, electronic collimation or electronic masking to eliminate any anatomical information.

Answer 17

outside

Question 18

T or F: Electronic masking to improve image viewing conditions should be applied in a manner that demonstrates the actual exposure field edge to document appropriate collimation.

Answer 18

true

Question 19

T or F: Masking should be applied over anatomy that was contained in the exposure field at the time of image acquisition.

Answer 19

false

Question 20

Any part of the radiographic image that is not part of the signal is known as what?

Answer 20

noise