Ch 20, 21 & 22 (CR & DR)

Question 1

In what order was X-rays produced (CR, DR, film screen)

Answer 1

Film screen - CR - DR

Question 2

PSP stand for

Answer 2

Photostimulable Phosphor Plate

Question 3

What is CR processed by

Answer 3

A reader

Question 4

What is the heart of CR

Answer 4

PSP

Question 5

Direct conversion detectors do what

Answer 5

Convert photons straight to electronic signals

Question 6

Indirect conversion detectors do what

Answer 6

Take photons & convert them to light by way of a scintillator before a photodetector converts the light to an electronic signal.

Question 7

Which type of digital imagining is instantaneous

Answer 7

DR

Question 8

The image that has been captured has been stored by the IP but not processed

Answer 8

Latent Image

Question 9

An image that has been converted into numerical values for transmission or processing

Answer 9

A digital image

Question 10

Analog signals are converted to a binary language called what

Answer 10

Analog to Digital Converter

Question 11

Each binary digit/number is called a what

Answer 11

Bit

Question 12

A number of pixels laid out in rows or columns

Answer 12

Matrix

Question 13

Pixels represent what

Answer 13

Varying shades of grey

Question 14

Grey scale bit depth range

Answer 14

8 - 32 bits

Question 15

Depth in the matrix is called what

Answer 15

Voxel

Question 16

The size of the detector determines what

Answer 16

Field of View size

Question 17

Another word for spatial resolution

Answer 17

Detail

Question 18

The larger the matrix, spatial resolution is better or worse

Answer 18

Better

Question 19

The smaller the matrix, spatial resolution is better or worse

Answer 19

Worse

Question 20

The larger the matrix the smaller the what

Answer 20

Pixels

Question 21

Spatial resolution is measured in what

Answer 21

Line pairs per millimeter (lp/mm)

Question 22

LUT stands for

Answer 22

Look Up Table

Question 23

Grey scale processing is done by what 3 things

Answer 23

Histogram
LUT
Windowing

Question 24

Which processing feature is post processed

Answer 24

Windowing

Question 25

How is a a histogram formed

Answer 25

Digital system finds the min/max signal within the anatomical region of interest in the image & if it’s out of range it rescales it to be within range

Question 26

Without LUTs what would the image show

Answer 26

Low contrast images

Question 27

Window Width is what

Answer 27

Contrast

Question 28

Window level is what

Answer 28

Brightness

Question 29

What are the 3 types of noise

Answer 29

System noise - comes from the system (usually doesn’t effect image) Ambient noise - scatter (effects image) Quantum mottle - not using the correct KVP/mAs (effects image - grainy)

Question 30

How accurate the IR is at converting the incoming signal to the outgoing viewing device

Answer 30

Detective Quantum Efficiency (DQE)

Question 31

What do you want the DQE to be & what is it realistically

Answer 31

1 but it is typically 30%-70%

Question 32

The number that the system gives that tells you if your image is within an acceptable range - based on exposure factors and image quality

Answer 32

EI

Question 33

How many bits are required to form a byte

Answer 33

8

Question 34

How do you figure out how many pixels are in a matrix

Answer 34

Length x width

Question 35

What is the relationship between the bit depth and the density resolution of a digital image

Answer 35

The higher the bit depth the more shades of grey that are visible

Question 36

Low window level =

Answer 36

Light image

Question 37

High window level

Answer 37

Dark image

Question 38

What is a del/array

Answer 38

3 or more pixels in a row

Question 39

What is pixel pitch

Answer 39

Center of one pixel to center of next

Question 40

Signal to noise ratio - what is ideal

Answer 40

High signal, low noise

Question 41

Deviation Index

Answer 41

Comparison between actual exposure and the proper exposure received by the IR

Question 42

Where is the latent image held

Answer 42

In the PSP

Question 43

What is read on DR vs CR

Answer 43

CR - the entire IP is read DR - only reads the part that was exposed by radiation

Question 44

Selecting what projections your doing based on which parts are being imaged

Answer 44

APR - Anatomically Programmed Radiography

Question 45

Parts of the CR

Answer 45

Cassette PSP Plate Reader Computer Workstation

Question 46

What is the purpose of the felt in the cassette

Answer 46

To collect dust and particles & keeps static electricity down

Question 47

What is the cassette backed with

Answer 47

Aluminum

Question 48

What is the purpose of the aluminum backing of the cassette

Answer 48

Assists with eliminating back scatter

Question 49

Layers of PSP

Answer 49

Protective Phosphor Reflective Conductive Supportive

Question 50

Purpose of reflective layer in PSP

Answer 50

Reflects light when IP is being scanned

Question 51

Purpose of conductive layer of PSP

Answer 51

Conducts electricity away

Question 52

Supportive layer purpose of PSP

Answer 52

Gives it rigidity so it’s not floppy

Question 53

What is the red light in the reader

Answer 53

Laser light - caused the trapped photons to be released

Question 54

What is the blue light in the reader

Answer 54

The luminescence - emitted by the IP during processing

Question 55

Why do CR plates need to be read immediately

Answer 55

The image starts deteriorating immediately

Question 56

What is used to guide the controlled laser in the CR reader

Answer 56

Optical subsystem

Question 57

What is in the PSP that causes the PSP to fluoresce

Answer 57

Barium fluorohalide

Question 58

Spatial resolution for CR vs DR

Answer 58

DR has better spatial resolution than CR

Question 59

What is a TFT

Answer 59

Thin Film Transistor

Question 60

What does a TFT do

Answer 60

Discharges dels/array (pixels grouped together) to the computer workstation

Question 61

What absorbs light & converts to the electrical charges in the indirect conversion using a TFT array

Answer 61

The photodiode / Amorphous Silicone

Question 62

What does del stand for

Answer 62

Detector Elements

Question 63

What is a DEL

Answer 63

3 or more pixels grouped together that are discharged out by row

Question 64

What absorbs light & converts it to an electric charge in indirect conversion (NON TFT)

Answer 64

CCD converts it to electrical charges & also sends it to the computer

Question 65

What is the difference between TFT & CCD

Answer 65

TFT uses photodiodes in the form of a matrix. CCD uses fiberoptic wires

Question 66

What does CCD stand for

Answer 66

Charge Coupled Device

Question 67

What is a scintillator made of

Answer 67

Cesium iodine (CsI) OR gadolinium oxisulfide (Gd2O2S)

Question 68

What is the photoconductor made of that is used in direct conversion

Answer 68

Amorphous Selenium

Question 69

What is the 3rd indirect option that isn’t normally used

Answer 69

CMOS - complimentary metal oxide semiconductors