Digital imaging review

Question 1

When talking about the imaging plate we think of mA as____ and kVp as ___

Answer 1

Data and penetration

Question 2

what is a bit?

Answer 2

single digit-smallest

Question 3

What is a byte?

Answer 3

group of 8 digits

Question 4

What is bit depth?

Answer 4

the number of bits used for gray scale –dynamic range

Question 5

The human eye can approximately see how many shades of gray?

Answer 5

32

Question 6

What is voxel?

Answer 6

individual pixel w/ associated volume of tissue based on slice thickness

Question 7

What is spatial resolution?

Answer 7

Detail of image and how it’s displayed/ Display monitor and receptor

Question 8

What is nyquist frequency?

Answer 8

The frequency determines the level of spatial resolution for an image receptor

Question 9

DELS collect the _____that represent individual components of a digital image?

Answer 9

electrons

Question 10

A charge-coupled device needs a ____ to produce light photons.

Answer 10

scintillator

Question 11

What is the primary cause of rejected images ?

Answer 11

Positioning errors

Question 12

What removes unwanted data by mathematical equations?

Answer 12

filtering

Question 13

What is DICOM?

Answer 13

digital imaging communication

Question 14

What does PAC stand for ?

Answer 14

Picture archiving and communications system

Question 15

What is DSA?

Answer 15

digital subtraction angiography, uses digitally recorded x-ray images to subtract images of vessels

Question 16

What are the two type of flat-panel image receptors

Answer 16

scintillator and non-scintillator

Question 17

A charged couple device or CCD does what?

Answer 17

Converts x-ray beam to light mostly used with flouroscopy

Question 18

What does a non-scintillator do?

Answer 18

it’s a think film transistor

Question 19

What does a scintillator do?

Answer 19

converts to light

Question 20

The extraction of PSP is either with

Answer 20

flying spot or a line scan

Question 21

A flying spot is___

Answer 21

cassette based

Question 22

A line scan is ____

Answer 22

cassette-less

Question 23

An analog digital converter is used for _____ and ____

Answer 23

A flying spot and a line scan

Question 24

The steps of extraction are on a cassette

Answer 24

1. ENERGY in phosphor
2. info EXTRACTED
3. info SENT to cpu.
4. Cassette becomes ERASED

Question 25

DEL size determines spatial resolution for a

Answer 25

flat panel device

Question 26

Algorythms , histrograms and look-up tables do what?

Answer 26

Software in the computer that help determine (grayscale) WL, WW , it's what processing needs

Question 27

What does post processing do?

Answer 27

Limits radiologist ability to read x-ray

Question 28

What controls WL and WW

Answer 28

algorithyms, histograms and look-up tables

Question 29

What are algorithyms?

Answer 29

mathematical formulas require for image resolution

Question 30

What are histograms?

Answer 30

graph of the number of pixels in an image , can change an alter brightness / contrast

Question 31

What are look-up tables?

Answer 31

Determines the number ASSIGNED to input pixels

Question 32

What is quantization?

Answer 32

more sampling , how much information

Question 33

What is image orientation?

Answer 33

Image displayed exactly as read

Question 34

Each vendor provides a set of numbers known as _____ that confirm that a correct exposure is used in producing a digital image

Answer 34

exposure indicators

Question 35

Intensifying screens convert the x-ray beam into____

Answer 35

light

Question 36

T or F When an intensifying screens crystal gives off more light, less radiation is required to make image

Answer 36

true

Question 37

Random access memory RAM can be___

Answer 37

erased, you can change in the computer

Question 38

Read only memory ROM ___

Answer 38

can't be erased, supplied by manufacturer

Question 39

What are the digital image components?

Answer 39

1. Data acquisition ( x-raying pt. method of collecting info) 2. Image processing (converting signals to image) 3. Image display, storage archiving ( how its stored) 4. Image communication

Question 40

Digital detectos give an electrical signal that is in ___ form

Answer 40

analog

Question 41

Steps in analog digitizing

Answer 41

analog digital converter, processing algorithyms, convert back to analog signal before displayed Pt. --analog digital converter, After computer processes digital analog converter.

Question 42

A change in either the matrix size or the FOV will _____

Answer 42

Change the size of the pixels

Question 43

contrast resolution in digital imaging is directly related to the ________

Answer 43

bit depth of the pixels in the image

Question 44

Spatial resolution is controlled by

Answer 44

pixel size and sample frequency

Question 45

RIS stand for

Answer 45

radiology information system

Question 46

HIS stand for

Answer 46

Hospital information system

Question 47

EMR stand for

Answer 47

Electronic medical records