X-ray Tube Quiz

A dual focus tube has two ______.

• anodes

• rotors

• stators

• filaments

A circular effective focal spot is preferred. Usually, however, it has a double banana shape.

• True

• False

Differences in x-ray intensity across the focal spot are due to:

• the design of the filament and

• the design of the focusing cup

• the voltage on the focusing cup

• All of the above

The x-ray intensity is lower on the anode side of the tube because of the ______.

• focusing cup

• filament length

• heel effect

• line focus principle

The cathode side of the tube should be directed toward the ____ part of the patient.

• upper

• lower

• thicker

• thinner

X-ray tubes are designed so that electrons from the cathode do not interact with the target at the actual focal spot.

• True

• False

What do electrons that bounce off the focal spot produce?

• On-focus radiation

• Off-focus radiation

• Direct radiation

• Scattered radiation

Why is off-focus radiation considered undesirable?

• It reduces the size of the focal spot

• It increases the patient's exposure to radiation unnecessarily

• It enhances image contrast

• It ensures patient tissue is accurately imaged

Which of the following is used for reducing off-focus radiation?

• A fixed diaphragm in the tube housing near the window of the x-ray tube

• Metal x-ray tube enclosures

• A triode like grid

• Extra tube enclosures

Which method is NOT a way that heat is dissipated from the anode of the x-ray tube?

• Radiation

• Conduction

• Charge attraction

• Convection