Introduction to Digital Radiography & PACS

What is Digital Imaging?

An imaging acquisition process that produces an electronic image that can be viewed and manipulated on a computer 

• images are available almost immediately 

• can be viewed simultaneously from multiple locations 

• changed the way imaging department do business 

Analog

• Continuously varying electrical currents — continuous signal

• Can be converted to digital format by analog to digital converter (ADC)

Digital

• Definite qualities of current

• Digital to analog converters sometimes used to send data faster (DAC)

• After transmission ADC converts data back to digital format

kVp 

Quality/ Penetration 

mAs

Quantity/ Patient dose

Distance

Resolution/ Exposure

Grids

Scatter / Contrast

Focal Spot Size

Resolution

Collimation 

Scatter / Contrast / and Patient Dose

Computer Algorithms

Contrast

Computer controls contrast therefore:

higher kVp with lower mAs can be used to reduce patient dose without adversely affecting contrast 

Computer

machine that performs mathematical computations 

Algorithms 

preprogrammed instruction 

Computer Program

collection of thousands of interrelated algorithms

Operating Console of x-ray machine: 

essentially a microcomputer