Principles of Radiographic Imaging Final

An effective method for reducing scatter radiation production is the

15% rule of kVp change.

For most additive pathologies, an increase of _______ in kVp, is generally enough to compensate for the added attenuation.

5-15%

Which statement about radiographic grids is incorrect? *The radiopaque strips are typically made of thin lead. *A grid is a series of lead strips that alternate with radiopaque interspace strips. The interspace strips are usually made of aluminum. *Grids may have grid strips running in perpendicular directions.

A grid is a series of lead strips that alternate with radiopaque interspace strips.

Which type of specialized photoreceptor cells are found in the retina?

Cones

X-rays are attenuated *exponentially. *linearly. *based upon the direction of the central ray. as a function of mAs.

Exponentially

When kilovoltage is increased with no other changes in technical factors, fewer scattered photons will result. Correct! False True

False

All of the following are true of Compton scatter EXCEPT: *It contributes no meaningful information the final image. * Its production increases as tissue density increases. *It is a significant contributor to occupational radiation exposure. *It is not a factor of exposure technique selection.

Its production increases as tissue density increases.

The greatest factor in the production of scatter radiation is kVp. mAs. Patient thickness. patient position.

Patient thickness

Select the TRUE statement from the choices given. *Visual acuity is improved in low-light conditions. * Pattern recognition is very intensely studied as part of a radiologist's education. *An AP projection of the knee demonstrates the patella posterior to the femur. *Because of the boundary effect, a 10-12 percent density change is visually perceptible.

Pattern recognition is very intensely studied as part of a radiologist's education.

Shape distortion can be the result of a patient's body habitus. (T/F)

True

When performing a KUB on a patient with ascites, using AEC and the proper detector combination, the responsible radiographer would: *immediately increase the AEC sensitivity to +2 *decrease the kVp to reduce the amount of Compton *take a scout image using manual techniques, to establish a back-up time for the AEC *allow the AEC system to adjust the exposure for the patient condition

allow the AEC system to adjust the exposure for the patient condition

The principal controlling factor of radiographic contrast using film-screen technology is kVp. mAs. focal spot size. anode angle.

kVp

With digital imaging technologies, the final brightness and contrast appearance of an image is due to kVp. window and level controls. look-up table (LUT) application. image rescaling.

look-up table (LUT) application.

As you analyze your image, you come to the conclusion that it must have more exposure. As a general rule, you should increase *kVp. *mAs by 2X. *the SID. *mAs by a 0.5 multiplier.

mAs by 2X.

When collimating down from a 14"x17" field size to a 8"x10" field size,

mAs must be increased to maintain image receptor exposure.

When using a radiographic grid with computed radiography (CR), *radiographic grids are unnecessary. *none of the above. *the Moire effect is a consideration. *higher frequency grids are undesirable.

the Moire effect is a consideration.