Radiation Physics and Protection — Flashcards

Flashcard 31: Milliampere second determines the amount of _____

Answer: radiation exposure

Flashcard 32: In the modern X-Ray tube, the outer tube is made of _____

Answer: stainless steel

Flashcard 33: MRI rooms are shielded completely by a continuous sheet or wire mesh of copper called _____, which provides RF shielding.

Answer: Faraday cage

Flashcard 34: _____ rays have the maximum tissue penetrating ability.

Answer: Gamma

Flashcard 35: _____ is arbitrarily assigned a value of +1000 HU

Answer: Cortical bone

Flashcard 36: Re-186 is a beta emitter that also emits _____ radiation.

Answer: Gamma radiation (in addition to beta)

Extra: Re-186 is used for bone pain palliation and radiosynovectomy. Unlike "pure" beta emitters like Strontium-89 or Phosphorus-32, Re-186 emits gamma rays (137 keV) which allow for scintigraphic imaging of the tracer distribution.

Flashcard 37: What is the most common cause of motion artifacts in X-ray imaging?

Answer: Patient movement

Flashcard 38: _____ rays have the maximum ionising potential but least penetrating ability

Answer: Alpha

Flashcard 39: When the voltage (kVP) increases, penetration of X-rays _____

Answer: increases

Flashcard 40: The magnetic field strength of MRI machines is measured in _____

Answer: Tesla