פוטוגרפיה מצגת 17

Front 1

What does CR stand for?

Back 1

computed radiography

Front 2

What is the difference between analog and computed images?

Back 2

Analog images are recorded and viewed on the same material (film), computed are recorded on one material (cassette) and viewed on another (computer screen)

Front 3

What types of imaging were in the analog era?

Back 3

film, cassettes with folia

Front 4

What is a dark room?

Back 4

a room from which normal light is excluded to allow for the processing of photosensitive material

Front 5

What is a safelight?

Back 5

a lamp that provides light which is safe for photosensitive materials like film

Front 6

What is radiation effects on living cells called?

Back 6

biological effects

Front 7

What are the two types of biological effects?

Back 7

determinist--immediate and serious

stockist--delayed, genetic

Front 8

What factors help determine biological effects?

Back 8

rate: low radiation over long period of time safer than high radiation at once

volume: small area of body exposed to high radiation (like radiotherapy) safer than whole-body exposure

type of tissue exposed: some tissue more sensitive (kids, embryo; reprod. organs, bone marrow, lymph nodes, cornea)

Front 9

In what units are biological effects measured?

Back 9

Exposed dose

Absorbed dose

Equivalent dose

Effective dose

Front 10

What is the exposed dose?

Back 10

Amount of radiation (ions of xrays per kg of air), measured in rem or sev

Front 11

What is the absorbed dose?

Back 11

Amount of radiation absorbed by patient, measured in rad or gray

Front 12

What is the equivalent dose?

Back 12

Amount of radiation damage (absorbed dose X factor depending on type of radiation), measured in rem or sev

Front 13

What is the effective dose?

Back 13

Severity of radiation damage (equivalent dose + factor depending on type of tissue), measured in rem or sev

Front 14

What are the disadvantages of an analog system?

Back 14

• space
  
• manual labor
• low availability
• one copy

Front 15

What do the following stand for?

CR

DR

DICOM

RIS

HIS

IP

PACS

Mini-PACS

Back 15

CR computerized radiography

DR direct radiography

DICOM digital imaging and communications in medicine

RIS radiography information system

HIShospital information system

IP image plate

PACS picture archiving and communication system

Mini-PACS PACS limited to burning dvds

Front 16

What is the RIS?

Back 16

a system that gives patient a code and shows which images were ordered plus details

Front 17

What is the HIS?

Back 17

includes dr report and notes

Front 18

Cassettes started with ___ and moved to ___.

Back 18

intensifying screens, folia

Front 19

A digital cassette without film is called ___.

Back 19

an image plate

Front 20

The folia in an IP uses a receiver that includes ___ crystals.

Back 20

phosphorus

Front 21

What is the job of the crystals in a folia in an IP?

Back 21

to receive the radiation and store it as PSP

Front 22

What is PSP?

Back 22

photostimulable storage phosphor

Front 23

The PSP (ionized crystals) emit visual light when interact with __ and again with ___.

Back 23

x-ray, laser

Front 24

What is PSL?

Back 24

photostimulated luminescence

Front 25

What are the properties of a digital cassette?

Back 25

• cassette with an IP inside made of phosphor (radiation causes changes according to amount)
• have barcode with id
• 4 sizes (18, 24, 43, and scoliosis)
• expensive to buy and fix
• needs special (soft) storage

Front 26

The job of the receiving screen is to ___ the image and ____ for ____.

Back 26

receive, preserve, a few hours

Front 27

The IP is a ___ screen made from ___.

Back 27

fluorescent, phosphor

Front 28

What is the תא and what does the reader do?

Back 28

Slot

removes the IP from the cassette, reads it, erases it, and puts it back in the cassette, converts the analog info to digital and sends it to archive and display

Front 29

What is the פענוח station?

Back 29

• work station for drs to read and interpret images
  
• connected to PACS
• communicates with DICOM (shrinks, preserves info)
• includes tools for processing (multi-modality support)
• high-quality display allows for magnification dep on type of check

Front 30

What is the receiving/recording process for film?

Back 30

Received, recorded, and viewed on same film then stored in archive

Front 31

What is the receiving/recording process for CR?

Back 31

received on IP (stored in PACS, CD, computer),

recorded on different system onto CD or film

*latent picture needs to be revealed and converted from analog to digital (2 systems: PMT--photomultiplier tube, ADC--analog digital converter)

Front 32

Describe the exposure process for an image in CR

Back 32

1. x photons from tube hit crystals in folia, cause ionization and turn photons into light
2. fleuroscence creates a latent picture on the folia
3. electrons stay trapped in the folia (more particles make the picture darker)
4. reader removes folia and scans it with a laser light to reveal hidden picture--wherever it hits trapped electron, light escapes again
5. light is translated to signal to computer

Front 33

What is PSP?

Back 33

photostimulable phosphor --xrays react with this type of crystals and trigger PSL

Front 34

What is PSL?

Back 34

• x-photons hit PSP are are absorbed into the phosphor layer in a photoelectric process
  
• the crystals ionize and e- (with absorbed energy) go up one level
• energized electrons stat trapped in the crystals--where the tissue let them pass, the picture is darker

Front 35

An IP contains information in the form of a ____.

Back 35

latent picture

Front 36

What are the steps involved in creating an image in CR (in the reader)?

Back 36

1. open cassette and removes folia
2. laser passes over folia and radiates crystals
3. the crystals that were exposed to more energy (earlier) emit more light
4. light is transferred as an electric signal "written" onto the screen of the computer

Front 37

How is light converted into a digital picture?

Back 37

The PMT (photomultiplier) collects light and translates it into an electric signal. The ADC (analog digital converter) converts the electric signal to a digital picture AND improves the resolution.

Front 38

How does the reader erase the folia?

Back 38

it scans the crystals with a strong light

Front 39

What is a photomontage?

Back 39

When folia was not erased and two images are superimposed