Chapter 13

“acceptance of a range of exposure factors to produce an acceptable image

Patient factors

Image-quality factors

Exposure-technique factors

Harder to penetrate then normal

Easier to penetrate then normal

low density =________ Brightness

High density =________ Brightness

Tissue density

Radiographic density

MAs is the controlling factor for_____

Change from 200 mA to 300 mA =______% increace

MAs/Quantity of exposure is directly proportional to ________

Tissue density  Increased tissue density—as in bone, for example—causes a lighter area on the radiograph because it absorbs more of the primary radiation, leaving less exposure on the IR.

Radiographic density  Increased radiographic density means that the image is darker … In other words, radiographic density and tissue density are inversely related to each other.

Image with excessive brightness

Image with insufficient brightness

When film images (made with manual technique settings) are underexposed or overexposed, a general rule states that a minimum change in mAs of 25% to 30% is required to make a visible difference in radiographic density on the repeat radiograph.”