Radiology

Identify the milliamperage range used for current dental x-ray machines

• 1 - 5 mA

• 6 - 8 mA

• 9 - 15 mA

• greater than 15 mA

Answer explanation

The recommended mA setting for dental imaging is 6-8 mA. A setting above 15 mA may cause excessive heat in the x-ray tube.

If kilovoltage is decreased with no other variations in exposure factors, the resultant image will:

• appear lighter

• appear darker

• remain the same

• either a or b

An image that has many light and dark areas and few shades of gray, would be produced with:

• low kilovoltage

• high kilovoltage

• low milliamperage

• high milliamperage

Tags

NGSS.HS-PS4-5

Increasing milliamperage alone results in an image with:

• high contrast

• low contrast

• increased density

• decreased density

Answer explanation

Milliamperage regulates the temperature of the cathode filament, and it does affect the quantity of x-rays produced. Increasing milliamperage alone has little to no effect on the contrast of the film, but it does cause an increase in density.

The total energy contained in the x-ray beam in a specific area at a given time is termed:

• kilovoltage

• beam quality

• intensity

• milliampere-second

Answer explanation

Intensity is defined as the total energy contained in the x-ray beam in a specific area at a given time; it is the product of the quality and quantity.

Tags

NGSS.HS-PS4-3

NGSS.HS-PS4-5

The half value layer (HVL) is the amount of:

• lead that restricts the diameter of the beam by half

• copper needed to cool the anode

• aluminum needed to reduce scatter radiation by half

• aluminum needed to reduce the x-ray beam intensity by half

Answer explanation

The half-value layer is defined as the amount of lead needed to restrict the diameter of the x-ray beam by half.

Tags

NGSS.HS-PS4-5

If the half value layer is 3 mm, what thickness of aluminum is necessary to decrease the intensity by half?

• 1.5 mm

• 3 mm

• 6 mm

• 9 mm

Tags

NGSS.HS-PS4-4

Identify the term that describes how dark and light areas are differentiated on an image

• contrast

• density

• intensity

• polychromatic

ALARA stands for _____

• As Low As Reasonably Achievable

• As Long As Radiation Allows

• All Levels Are Radically Acceptable

• Any Level of Radiation Allowed

Tags

NGSS.HS-PS4-3

Which of the following can reduce the radiation exposure in radiology department?

• increase exposure time

• reduce distance from the source

• use lead shielding

• wear surgical apron

Tags

NGSS.HS-ETS1-3