Ch. 8 Digital Imaging

A conventional x-ray machine must allow for what exposure time?

1/100th of a second

What is an example of a wireless sensor?

phosphor plates

What are examples of wired sensors?

CCD and CMOS/APS

When an x-ray is converted into a computer, what is the range each pixel is represented by?

0 (black) to 255 (white)

The human eye can only perceive how many shades of gray?

32

obtaining a digital image from a sensor by using a scanner to convert to digital form

indirect

info transferred directly to computer with imaging software

direct

What is an example of indirect imaging?

scanning traditional films or phosphor plates

What is an example of direct imaging?

CMOS/APS or CCD

Digital radiography has how many shades of gray?

256

Film only has how many shades of gray?

16-25

An advantage of digital radiography is that it has what percentage less radiation exposure?

50%-90%

What are some advantages of digital radiography?

• more efficient

• ability to do remote consultation

• able to adjust density and contrast without more exposure

• environment friendly

• takes up less office space

What are some disadvanatges of digital radiography?

• high initial cost

• debatable image quality

• thicker sensor size may cause patient discomfort

• must be more vigilant with infection control as sensor can’t be heat sterilized

• images may not be used in court of law as they can be manipulated