Ch 6. end of chapter questions

b) radiolucent

____ 1. The portion of a dental image that appears dark or black is termed:

a. dense

b. radiolucent

c. radiopaque

d. transparent

b) radiopaque

____ 2. The portion of a dental image that appears light or white is termed:

a. radiolucent

b. radiopaque

c. dense

d. high density

d) air space

____ 3. Which appears most radiolucent on a dental image?

a. bone

b. enamel

c. dentin

d. air space

b) enamel

____ 4. Which appears most radiopaque on a dental image?

a. bone

b. enamel

c. dentin

d. all of the above

a) density

____ 5. The overall blackness or darkness of a dental image is termed:

a. density

b. contrast

c. subject thickness

d. diagnostic quality

a) an increase in density; the image appears darker

____ 6. Increasing the milliamperage (mA) will cause:

a. an increase in density; the image appears darker

b. an increase in density; the image appears lighter

c. a decrease in density; the image appears darker

d. a decrease in density; the image appears lighter

a) an increase in density; the image appears darker

____ 7. Increasing the operating kilovoltage (kV) will cause:

a. an increase in density; the image appears darker

b. an increase in density; the image appears lighter

c. a decrease in density; the image appears darker

d. a decrease in density; the image appears lighter

a) an increase in density; the image appears darker

____ 8. Increasing the exposure time will cause:

a. an increase in density; the image appears darker

b. an increase in density; the image appears lighter

c. a decrease in density; the image appears darker

d. a decrease in density; the image appears lighter

d) any of the above

____ 9. A dental patient has thick soft tissues and dense bones. To compensate for this increase in subject thickness and to provide an image of diagnostic density, the dental radiographer may:

a. increase the exposure time

b. increase the milliamperage

c. increase the kilovoltage

d. any of the above

b) contrast

____ 10. The difference in the degrees of densities between adjacent areas on a dental image is termed:

a. film contrast

b. contrast

c. subject thickness

d. diagnostic quality

b) low contrast

____ 11. A dental image that demonstrates many shades of gray is said to have:

a. high contrast

b. low contrast

c. high density

d. low density

a) high contrast

____ 12. A dental image that demonstrates very dark areas and very light areas is said to have:

a. high contrast

b. low contrast

c. high density

d. low density

b

____ 13. In Figure 6-18, which exhibits high contrast?

a. A

b. B

c. C

a

____ 14. In Figure 6-18, which exhibits low contrast?

a. A

b. B

c. C

a

____ 15. In Figure 6-18, which exhibits long-scale contrast?

a. A

b. B

c. C

b

____ 16. In Figure 6-18, which exhibits short-scale contrast?

a. A

b. B

c. C

c

____ 17. In Figure 6-18, which exhibits no contrast?

a. A

b. B

c. C

a) kilovoltage

____ 18. The one exposure factor that has a direct influence on the contrast of a dental image is:

a. kilovoltage

b. milliamperage

c. exposure time

d. subject thickness

d) a compromise between short-scale contrast and long-scale contrast

____ 19. The type of contrast preferred in dental imaging is:

a. low contrast

b. long-scale contrast only

c. short-scale contrast only

d. a compromise between short-scale contrast and long-scale contrast

c) to increase the penetrating quality of the x-ray beam

____ 20. The stepwedge is used for all of the following except:

a. to demonstrate short-scale and long-scale contrast

b. to monitor quality control of film processing

c. to increase the penetrating quality of the x-ray beam

d. to demonstrate densities

a) sharpness

____ 21. The capability of the receptor to reproduce distinct outlines of an object is termed:

a. sharpness

b. magnification

c. distortion

d. diagnostic quality

c) penumbra

____ 22. The unsharp or blurred edges seen on an image are termed:

a. distortion

b. umbra

c. penumbra

d. contrast

d) magnification

____ 23. The geometric characteristic that refers to an image that appears larger than its actual size is termed:

a. distortion

b. detail

c. definition

d. magnification

b) distortion

____ 24. A variation in the true size and shape of the object being imaged is termed:

a. magnification

b. distortion

c. sharpness

d. resolution

increase, decrease, increase, increase, decrease

For questions 25 to 35, fill in the blank with the words increase or decrease.

____ 25. Decrease focal spot size = __________ sharpness.

____ 26. Increase crystal size = __________ sharpness.

____ 27. Decrease crystal size = __________ sharpness.

____ 28. Decrease movement = __________ sharpness.

____ 29. Increase movement = __________ sharpness.

decrease, increase, decrease, decrease, decrease, increase

For questions 25 to 35, fill in the blank with the words increase or decrease.

____ 30. Increase target-receptor distance = _________________ magnification.

____ 31. Increase object-receptor distance = _________________ magnification.

____ 32. Decrease object-receptor distance = _________________ magnification.

____ 33. Object and receptor are parallel = _________________ distortion.

____ 34. Beam perpendicular to object and receptor = __________ distortion.

____ 35. Beam not perpendicular to object and receptor = __________ distortion.

Proper density, contrast, sharp outlines, and entire anatomy

What 4 things does a radiograph need to be diagnostic?

kVp

What is the most important thing the overall contrast is determined by?

increased

When you increase the kVp, the energy of the xrays are (increased/decreased)

increases, decreases

Increasing kVp (increases/decreases) density but (increases/decreases) contrast

decreases, increases

Decreasing kVp (increases/decreases) density but (increases/decreases) contrast

Only has 2 densities (black and white) and functions at a lower kVp

Describe how a short-scale contrast (high contrast) image looks

Has many densities (lots of grey) and functions at a higher kVp

Describe how a long-scale (low contrast) image looks

both

Does an aluminum stepwedge demonstrate short-scale contrast or high-scale contrast

penumbra

A certain lack of image sharpness is present in every radiograph; it is called the...

focal spot size, composition, and movement

What 3 things influence sharpness?