Ch. 4 PPT

Question 1

Which is the old technology, computed radiography or direct radiography?

Answer 1

computed radiography

Question 2

Picture elements are called:

Answer 2

pixels

Question 3

Combination of rows and columns of small, square pixels:

Answer 3

matrix

Question 4

Increasing the number of pixels improves ____.

Answer 4

spatial resolution

Question 5

Pixel size is ___ related to FOV.

Answer 5

directly

Question 6

Pixel size is ___ related to matrix size

Answer 6

inversely

Question 7

Increasing the Field of View for the same matrix will ___ the size of the pixel. This will ___ spatial resolution.

Answer 7

increase , decrease

Question 8

Increasing the matrix size for the same Field of View will ___ the size of the pixel. This will ___ spatial resolution.

Answer 8

decrease, increase

Question 9

Increasing pixel density and decreasing pixel pitch ____ spatial resolution.

Answer 9

increases

Question 10

___ is the pixel spacing or distance measured from the center of a pixel to an adjacent pixel

Answer 10

Pixel pitch

Question 11

Decreasing pixel density and increasing pixel pitch ___ spatial resolution

Answer 11

decreases

Question 12

A digital composite of the varying x-ray intensities exiting the patient.

Answer 12

Image matrix

Question 13

The ability of a detector to accurately capture the range of photon intensities that exit the patient is called:

Answer 13

Dynamic range

Question 14

___ have a wider dynamic range than ___.

Answer 14

Digital IRs (image receptors), film-screen detectors

Question 15

___ represents the number of digital pixel values versus the relative prevalence of those values in the latent image.

• Amount of exposure is on the __-axis
• Incidence of pixels is on the __-axis

Answer 15

Histogram

• X
• Y

Question 16

An image-processing technique commonly used to assess the raw data prior to image display.

Answer 16

Histogram Analysis

Question 17

During histogram analysis, if you select a part other than the imaged one, a ____ may occur.

Answer 17

histogram-analysis error

Question 18

___ is computer software operations available to you that allow manual manipulation of the displayed image

Answer 18

Postprocessing

Question 19

___ sets the midpoint of the range of brightness visible in the image

Answer 19

Window level

Question 20

Increasing the window level ___ the image brightness; decreasing the window level ___ the image brightness

Answer 20

increases, decreases

Question 21

a control that adjusts the radiographic contrast

Answer 21

window width

Question 22

Decreasing the window width (narrow) ___ the image contrast; increasing the window width (wide) ___ the image contrast

Answer 22

increases, decreases

Question 23

Does windowing alter the original stored pixel values of an image?

Answer 23

No, it only alters how they are stored

Question 24

CR or DR?

Answer 24

DR

Question 25

CR or DR?

Answer 25

CR