• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/7

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

7 Cards in this Set

  • Front
  • Back

Processes involved at the cathode

1. Tungsten filament is heated


2. Causes excitation in the tungsten particles


3. Electrons leave the tungsten atoms


4. Form a space around the cathode


5. Potential difference (voltage) applied


6. Electrons accelerated toward the anode


7. Slowed down of stopped within the anode target


8. Produces heat and x rays

Computed Radiography

CR uses an imaging plate to capture an image


The plate is made of a storage phosphor that captures xray energy


When scanned with a laser the plate emits light


This is captured by the plate reader in order to build up and image from measurements made on the released energy


Storage phosphors capture a wide range of exposures


They produce a signal directly proportional to the energy they have stored

Computed Radiography 2

Film systems are sensitive to only a narrow range of exposures


This means that a high-quality image can be produced regardless of the relative amount of exposure of the plate


Can produce a good quality image with poorer exposures than film


Uses cassettes but not film - provide a digital image


Cheaper than DR - usually the first alternative in converting from film to digital imaging


Can be used portably

Digital radiography

No screens


Charged coupling device (CCD) or amorphous selenium plate


Xray energy is converted directly into electrical energy


The image is shown almost immediately on the monitor - real time


Straight from image to capture to digital image on the monitor display


Faster so more patient throughput- but more expensive

Image display

When an image has been processed into a digital form it can be:


-displayed on a monitor


-printed on film


-sent to a distant location


-stored on a disc


Laser camera printing - computed images can be altered while viewing a monitor and then printed on to a film by a laser camera


Multiple images can be copied on to a single sheet and multiple copies can be printed of a single images

Contrast enhancement

Alteration of pixel values to display different brightness levels


Higher pixel - better detail


Aim is to improve diagnostic accuracy


Poor contrast = missed diagnosis

PACS

Picture archiving and communication system


Provides:


Capture


Storage


Display of medical images


Distribution