Ch 08 Digital Radiography

Benefits and Challenges of Digital Radiography

• Benefits: Quick image display, less radiation, easier storage.

• Challenges: Equipment cost, need for computer storage, sensor fragility.

Equipment for Digital Radiography

Needs: x-ray machine with short exposure time, sensor or plate, computer with monitor and storage capacity.

Characteristics of a Digital Image

• Digital images are made of pixels, with more pixels meaning clearer images.

• Gray scale (shades of gray) helps show subtle details in x-rays.

Types of Digital Image Receptors

• Direct (sensor sends image directly to the computer)

• Indirect (plate must be scanned to create an image).

Direct Digital Imaging

Uses sensors (CCD or CMOS) to instantly send the image to a computer screen.

Sensor Types and Range

• CCD sensors have a narrow range and capture more detail.

• CMOS sensors are often wireless but with a narrower range.

• PSP sensors have the widest range

Wireless Sensor Limitations

Convenient but can be affected by other signals and are more expensive than wired options.

Sensor Sizes

Sensors come in sizes (0,1,2) similar to film and may have contoured edges for comfort.

Indirect Digital Imaging (PSP)

PSP plates capture images that must be scanned to display on a computer, without a direct connection.

PSP Image Storage

PSP plates store x-ray energy as a hidden image, which a scanner reads to create a digital image.

PSP Scanning Process

Plates are placed in a scanner, which uses a laser to read and display the image on a monitor.

PSP Limitations

PSP images take longer to produce, have lower resolution, and plates need clearing before reuse.

Radiation Exposure

CMOS sensors need less radiation than CCD and PSP sensors.