Dayu Gai on

Dayu Gai

  • Nothing to disclose
11 results found

Question 623

If an aluminum filter 5 mm thick transmits 25% of a monoenergetic x-ray beam, then 10 mm will transmit:


Question 632

Electrons striking the tungsten anode of an x-ray tube with 80 keV energy can produce...


Question 634

The finite size of the x-ray tube focal spot gives rise to...


Question 643

To reduce perceived image noise by a factor of 10, the number of information carriers (x-ray photons) must ideally be increased by a factor of...


Question 648

The x-ray tube current (mA) influences which one of the following parameters?


Question 649

The proportion of the energy of an electron beam incident on the x-ray tube anode that is converted into x-rays is approximately...


Question 742

A narrow beam of monoenergetic x-ray photons is directed from an x-ray tube located 50cm above the surface of a water-filled container 20cm thick. The half value layer for the beam of x-ray photons is 10cm of water. The exposure at the bottom of the container relative to that incident on the surface is about...


Question 743

The annual effective dose limit for members of the public is...


Question 744

An apron with a 0.5 mm lead equivalent thickness typically attenuates scattered 100 kVp x-rays by what amount?


Question 759

A hypothetical patient receives an entrance skin dose of 20 Gy after a cardiac pacemaker insertion. The most likely effect is which of the following?


Question 761

Which of the following dose reduction techniques will improve image quality?