Exposure III Exam 1

With increasing kVp levels, it is important to remember that with digital receptors and DR technologies

• less differential absorption occurs and a narrower histogram results.

• the difference between minimum and maximum incoming photon energies is reduced.

• more anatomical data can be recorded with a lower patient dose.

• all of the above.

A frontal projection chest radiograph that demonstrates a faint outline of the thoracic spine and many shades of gray to show the pulmonary markings of the lungs illustrates

• short-scale contrast and adequate penetration.

• underpenetration.

• overpenetration.

• long-scale contrast and adequate penetration.

Immediately after exposure and before a digitally acquired image is post-processed, the initial image shown demonstrates

• very low contrast

• focal spot blur

• extremely high contrast

• the heel effect

Which of the choices below does not increase contrast?

• decreasing kVp

• increasing grid ratio

• decreasing filtration

• increasing the amount of irradiated tissue

A fluoroscopic examination that uses barium as a contrast material would typically produce images with

• short scale contrast.

• low contrast.

• both a and c.

• long scale contrast.

When the tissue structure of the ankle joint is considered, the dramatic tissue differences between the muscles and bones of the ankle produce

• low subject contrast.

• high receptor contrast.

• low receptor contrast.

• high subject contrast.

An increase in x-ray beam filtration

• increases the number of Compton interactions.

• reduces contrast.

• increases the average photon energy.

• all of the above.

What should you expect to occur with a decrease in kVp, using digital receptors?

• a narrower histogram

• more Compton interactions

• an increase in Bremsstrahlung tissue interactions

• More photoelectric interactions

With digital imaging systems, the primary factors affecting final image contrast are the

• kVp and mAs.

• histogram and look-up table (LUT).

• EI numbers and S numbers.

• window level and brightness.

As kVp increases, the percentage of Compton interactions _______ and contrast_______

• decreases; decreases

• decreases; increases

• increases; increases

• increases; decreases