Ch 12/15

Question 1

Lead strips are angled to match the angle of photons in the primary beam as they diverge

Answer 1

Focused grid

Question 2

Number of lead strips per inch or centimeter

Answer 2

Grid frequency

Question 3

Expression of the ability of image intensifier tube to convert x ray energy into light energy and increase the brightness of image in process

Answer 3

Brightness gain

Question 4

Primarily due to Compton interaction between x ray and photons and matter

Answer 4

Scatter radiation

Question 5

Grid Bucky moves slightly from side to side during x ray exposure

Answer 5

Reciprocates

Question 6

Constructed to allow a cassette to slide into place behind the grid

Answer 6

Grid cap

Question 7

Flat panel detector fluoroscopy units operate at

Answer 7

50-1200 mA

Question 8

Absorbs x rays and emits light

Answer 8

Input

Question 9

Provide radiation exposure data and need to be recorded in the patient medical record

Answer 9

DAP/KAP and cumulative air kerma

Question 10

Introduced in 1950

Answer 10

Image intensifier

Question 11

Located inside the fluoroscopic tower

Answer 11

Image intensifier

Question 12

Fluoroscopic image is viewed by looking at a

Answer 12

Television monitor

Question 13

Absorption of transmitted photons by grid cause by a misalignment issue

Answer 13

Grid cutoff

Question 14

Refers to a LARGE area of pixel being sensitive to x rays. This is important to flat panel fluoroscopy

Answer 14

Large fill factor

Question 15

Ratio of number of light photons at the output phosphor as compared with the input phosphor

Answer 15

Flux gain

Question 16

Absorbs light and produce electrons

Answer 16

Photocathode

Question 17

Occurs when Sid is outside of the grid focal range

Answer 17

Off focus grid cutoff

Question 18

Television Monitor can resolve approximately

Answer 18

1-2Lp/mm

Question 19

When fluoroscopic image has noise or is noisy

Answer 19

The quantity of radiation (ma ) must be increase

because tissue has few photon being used to create the image

Question 20

Base on creating GAP by increasing OID

Answer 20

Air gap technique

Question 21

Distortion of the fluoroscopic image that appears as unequal magnification

Answer 21

Pinchusion appearance

Question 22

Increasing collimation results in

Answer 22

Decreasing scatter production and high contrast

Question 23

Plasma monitor contains thin layer of

Answer 23

Pixels and each pixel contains neon and xenon gas filled cells

Question 24

MAgnification of the fluoroscopic image occurs when

Answer 24

Electrostatic lenses have more voltage applied creating more negative charge

Question 25

Significant collimation reduces

Answer 25

Radiation and scatter

Question 26

Reason for having the grid move slightly during exposure is to

Answer 26

Blur out the grid lines

Question 27

Two forms of flat panel detectors may be for fluoroscopic applications

Answer 27

1. Cesium iodide amorphous silicon indirect capture detector 2. Amorphous selenium direct - capture detector

Question 28

The material between grid’s lead strips must be

Answer 28

Radiolucent

Question 29

The higher the grid ratio….

Answer 29

The BETTER the scatter clean up and HIGHER the contrast Spatial resolution is not affected when using a grid

Question 30

Two major factors that affects the a,out of scarred radiation

Answer 30

Volume of tissue irradiated and Kvp

Question 31

Using magnification mode

Answer 31

Improves spatial resolution of fluoroscopic imaging

Question 32

Electronic vacuum tube that converts the remnant beam -> light -> electrons -> light

Answer 32

Image intensifier

Question 33

Electrostatic focusing lenses have…

Answer 33

Negative charge

Question 34

Major problem with fluoroscopy

Answer 34

Images are very dim and hard to see

Question 35

Has rectangular field of view and wider dynamic range

Answer 35

Flat panel detector

Question 36

Input Is made of

Answer 36

cesium iodide

Question 37

Refers to length of each PULSE

Answer 37

Pulse width

Question 38

Simply a design of the unit that rapidly turns the x ray beam on and off during operation

Answer 38

Pulse fluoroscopy

Question 39

Typical fluoroscopic system have spatial resolution capabilities in the ranges of

Answer 39

4-6lp/mm

Question 40

Caused by using a grid with frequency similar to the cr laser scanning frequency as well as using a grid cassette in the Bucky

Answer 40

Moire effect

Question 41

Least amount of of spatial resolution of all components of the fluoro system

Answer 41

Television monitor

Question 42

Converting light image to an electronic image greatly improve digital imaging

Answer 42

CCD

Question 43

Loss of brightness around the periphery of the fluoroscopic image

Answer 43

Vignetting

Question 44

Attached directly to the input phosphor

Answer 44

Photocathode

Question 45

Flat piece of lead with a hole in it

Answer 45

Aperture diaphragm

Question 46

Unrestricted beam is

Answer 46

Round

Question 47

Produces the greatest amount of scatter exiting the patient

Answer 47

Large field size and high kvp

Question 48

When electrons are EMITTED in response to the presence of light, occurs at the PHOTOcathode

Answer 48

Photoemission

Question 49

Range of Sid that will work with specific grids

Answer 49

Focal Range

Question 50

Absorbs electrons and emits light

Answer 50

Output phosphor

Question 51

Invented by Thomas Edison 1896

Answer 51

Commercial fluoroscope

Question 52

Maintain brightness and contrast during fluoro

Answer 52

Automatic brightness control ABC

Question 53

Located very close to the output phosphor

Answer 53

Anode

Question 54

To produce quality fluoro images with digital decos

Answer 54

1. Respond quickly 2. Maintain large fill factor 3. ASIC in place to reduce noise

Question 55

Used to make adjustments in MAs when guide changes are made

Answer 55

Grid3 conversion factor

Question 56

When grid is added or change is made to a higher ratio grid

Answer 56

MAs increased to compensate for reduction in radiation reaching ir

Question 57

Fluoro allows imaging ion anatomy in motion

Answer 57

Dynamic imaging