Radioation Detection Systems

What are the components of Film Screen Xrays?

1. film

2. intesnsifying screen

3. cassette

4. film processing area

5. Trained personnel

What chemical in film screens causes the chemical reaction to occur for the processing?

Silver Bromide Crystals

Computed Radiography Components

1. Imaging plate

2. Cassette

3. CR reader

4. Display monitor

True or False: CR does not utilize a reusable plate.

FALSE

Pros of CR

• improved contrast resolution

• improved efficiency

• post-processing manipulation

• mobile plate for special views

Cons of CR

• expensive plates

• artifacts common

• less efficient than DR

Where are CR mainly used?

Equine Radiographs

WHat causes the reaction in CR? How are they read?

PSPs that are read by a laser

Indirect Digital Radiography

• Cesium iodide scintillator converts xrays to visible light

  • xrays → light → electrical signal

• CCD = dental rads

• TFT = preferred but expensive

Direct Digital Radiography

• Amorphous selenium photoconductor converts xrays to electrons

  • xrays → electrical signal

• AVOIDS LIGHT DISPERSION (better spatial resolution)

Dose Creep

slowly increasing the exposure parameters over time which results in higher scatter radiation

DICOM

standard digital image format to maintain quality though transfer of image data that allows for post-processing manipulation

What is the purpose of a grid?

removes scatter radiation and improves image contrast (placed between patient and detector)

What happens when grids are misaligned?

Lead strips will absorb the primary radiation affecting image quality