Terminology

Question 1

Indirect capture

Answer 1

Uses amorphous silicone xrays to visible light to electrical signal

Question 2

Direct capture

Answer 2

Uses amorphous selenium xrays directly to electrical signal

Question 3

Contrast resolution

Answer 3

Ability to distinguish anatomic structures with similar contrast

Question 4

CCD

Answer 4

Computer chip. Analog to digital converter

Question 5

Micron

Answer 5

Unit of length

Question 6

Pixel

Answer 6

Unit of an image. 8 bits = 1 byte

Question 7

Pixel pitch

Answer 7

Center of 1 pixel to center of another

Question 8

Exposure Latitude

Answer 8

1000:1 range of under/overesposures that can create a still acceptable image. wide in digital

Question 9

Window width

Answer 9

Contrast of an image. High/widening width will increase contrast (more grays) Lower/narrow will decrease contrast (black/white) kvp

Question 10

Window level/centering

Answer 10

Brightness of an image. Increase center results = darker image. Decrease center results = whiter image. Mas

Question 11

DQE

Answer 11

Efficiency of machine from input/output of signal & noise. Expressed as %

Question 12

MTF

Answer 12

Measures resolution/spatial frequency. Ability to produce an image similar to the object

Question 13

Spatial resolution

Answer 13

The ability to distinguish between two adjacent structures in an image

Question 14

Pixel size affects:

Answer 14

Archival quality, storage & transmission time

Question 15

Flat field uniformity

Answer 15

Analysis of homogenity of detector field

Question 16

Dynamic range

Answer 16

Gray scale range

Question 17

Thickness equalization

Answer 17

A process where detector looks at variations in pixel density and estimates thickness of breast in each pixel