Mammography Equipment Ch. 5

Question 1

describes the angle between the surface of the target and the vertical line, perpendicular to the image plate

Answer 1

anode angle

Question 2

refers to the current in which electrons oscillate back and forth through a conductor in alternating positive and negative directions

Answer 2

alternating current

Question 3

the rate of changing direction

Answer 3

frequency (Alternating Current)

Question 4

measured in Hertz

Answer 4

frequency

Question 5

the number of forward-backward cycles per second

Answer 5

hertz

Question 6

are produced when an outer projectile electron is slowed by the electric field of the target atom nucleus

Answer 6

bremsstrahlung x-rays

Question 7

refers to how dark the image is

Answer 7

brightness

Question 8

term used to replace ‘density’-which is used to describe analog images

Answer 8

brightness

Question 9

what is the brightness of a digital image controlled by

Answer 9

the processing software

Question 10

is produced when an outer shell electron fills an inner shell void in the atom of an element

Answer 10

characteristic radiation

Question 11

if the outer shell electron fills the void in the K shell, the x-ray emission is termed ______.

Answer 11

K Characteristic X-rays

Question 12

describes the interaction between low-energy electrons and atoms. the x-ray loses no energy but changes direction slightly

Answer 12

coherent/classical scattering

Question 13

occurs when moderate energy x-rays interact with an outer shell electron and eject the electron from the atom. the x-ray loses energy and changes direction.

Answer 13

compton scattering

Question 14

during compton scattering, the ejected electron is called __________.

Answer 14

compton electron

Question 15

the ability to image two separate objects and visibly detect them as seperate entities

Answer 15

resolultion

Question 16

refers to the minimum difference between two adjacent structures that can be detected in the image as separate entities

Answer 16

contrast

Question 17

in digital imaging, what is contrast dependent on?

Answer 17

pixel size

Question 18

refers to a set of computer software standards that permit wide range of digital imaging programs to understand each other

Answer 18

DICOM

Question 19

a storage option in digital imaging

Answer 19

DLT (Digital linear tape)

Question 20

is electron flow in one direction along a conductor. the currect is either always positive or always negative

Answer 20

Direct Current

Question 21

the area projected onto the patient and the image plate, and it is the value given when describing the focal spot of the mammography units

Answer 21

effective focal spot

Question 22

convert a conventional radiograph to a digital version via a scanning device

Answer 22

film digitizers

Question 23

describes the number of lead strips per centimeter in a grid

Answer 23

grid frequency

Question 24

what is a common range of grid frequencies for mammography?

Answer 24

30-50 lines/cm

Question 25

the height of the lead strips divided by the distance between the strips

Answer 25

grid ratio

Question 26

what are some common grid ratios in mammography

Answer 26

4:1 or 5:1

Question 27

describes the process by which light is reflected back toward the emulsion after it passes through the emulsion and base

Answer 27

halation

Question 28

the thickness of absorbing material necessary to reduce the x-ray intensity by half of its original value

Answer 28

half-value layer (HVL)

Question 29

describes the intensity of light incident on a surface

Answer 29

illuminance

Question 30

replaces the cassette used in analog imaging

Answer 30

image plate (IP)

Question 31

what kind of technology is used in the imaging plate?

Answer 31

photostimulable phosphor (PSP)

Question 32

the device that receives the energy of the x-ray beam

Answer 32

image receptor

Question 33

replaces the screen/film system in analog imaging

Answer 33

image receptor

Question 34

describes the brightness of a light source

Answer 34

luminance

Question 35

is calculated by dividing the source-to-image receptor distance (SID) by the source-to-object distance (SOD)

Answer 35

magnification factor

Question 36

an array of pixels in which each pixel is a sample of the image represented by a numerical value

Answer 36

matrix

Question 37

the unsharp shadow or "blur" surrounding the image

Answer 37

pneumbra

Question 38

the smallest component of the digital image

Answer 38

pixel (picture element)

Question 39

is a storage option in digital imaging

Answer 39

RAID

Question 40

the conversion of alternating current (AC) to direct current (DC)

Answer 40

rectification

Question 41

may refer to any diode produced using thin film technology

Answer 41

thin-film transitor (TFT) or thin-film diode (TFD)

Question 42

are photoconductors used to collect electrons

Answer 42

amorphous silicon or amorphous selenium

Question 43

have amorphous silicon or amorphous selenium deposited on thin films

Answer 43

thin-film transitor (TFT) or thin-film diode (TFD)

Question 44

states that the optical density produced on the radiograph will be equal when any combination of mA and exposure time is used as long as the product is equal

Answer 44

Reciprocity law

Question 45

the ability to detect small objects with high subject contrast

Answer 45

spatial resolution

Question 46

the ability to distinguish anatomic structures with similar contrast

Answer 46

contrast resolution

Question 47

the emission of electrons from a hot cathode into a vacuum

Answer 47

thermionic emission

Question 48

the ability to make medical images accessbile across multiple modalities and between different organizations

Answer 48

vendor neutral archives (VNAs)