Practice Test Geeks(ARRT) American Registry of Radiologic Technologists Computed Tomography Certification Practice Test
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CT Physics Flashcards

6 cards from real ARRT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 CT Physics flashcards as text

  1. What does CT stand for in medical imaging?

    Answer: Computed Tomography

    CT (Computed Tomography) uses X-ray technology and computer processing to create detailed cross-sectional images of the body.

  2. What is the primary advantage of CT over conventional X-ray?

    Answer: CT provides cross-sectional images with superior soft tissue contrast

    CT provides detailed cross-sectional images with much better soft tissue contrast resolution than conventional X-rays, allowing visualization of subtle differences between tissues.

  3. What is the purpose of contrast media in CT scans?

    Answer: To enhance the visibility of specific structures and pathology

    Contrast media (dye) enhances the visibility of blood vessels, organs, and abnormalities by changing how X-rays interact with specific tissues.

  4. What is the ALARA principle in radiation safety?

    Answer: As Low As Reasonably Achievable — minimize radiation exposure

    ALARA means keeping radiation doses as low as reasonably achievable while still obtaining diagnostic-quality images, balancing benefit against risk.

  5. What is a Hounsfield unit?

    Answer: A quantitative measurement of tissue density on CT images

    Hounsfield units (HU) measure tissue density on CT, with water at 0 HU, air at -1000 HU, and dense bone at +1000 HU or higher.

  6. What is the window level and window width on CT images?

    Answer: Settings that control the brightness and contrast of displayed images

    Window level sets the center brightness (what HU appears as middle gray) and window width controls contrast range (how many HUs span from black to white).