Practice Test Geeks(ARRT) American Registry of Radiologic Technologists Computed Tomography Certification Practice Test
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Image Acquisition and Evaluation Flashcards

7 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 7 Image Acquisition and Evaluation flashcards as text

  1. A lateral knee radiograph shows the femoral condyles are not superimposed. Which positioning correction is needed?

    Answer: Rotate the patient's foot internally or externally to align the condyles

    Failure to superimpose the femoral condyles on a lateral knee indicates the leg is rotated; adjusting internal or external rotation corrects this.

  2. In digital radiography, what is the purpose of the exposure index (EI) deviation index (DI)?

    Answer: To indicate how far the actual exposure deviates from the target exposure

    The deviation index (DI) compares the actual EI to the target EI, indicating over- or underexposure so the technologist can adjust technique.

  3. Which technical factor change reduces patient dose while maintaining adequate image quality on a chest radiograph?

    Answer: Increase kVp and decrease mAs proportionally

    Increasing kVp and reducing mAs (high-kVp technique) maintains exposure to the detector while lowering patient dose due to increased beam penetration.

  4. A PA hand radiograph shows significant motion blur. Which receptor/technique change would most improve sharpness?

    Answer: Use a smaller focal spot and immobilize the hand

    A smaller focal spot reduces geometric unsharpness, and immobilization eliminates motion unsharpness, both improving recorded detail.

  5. Which term describes the minimum detectable difference in tissue density that can be distinguished on a radiograph?

    Answer: Contrast resolution

    Contrast resolution is the ability to distinguish between tissues of similar attenuation — the minimum density difference that can be detected.

  6. On an AP pelvis, which criterion confirms the patient is not rotated?

    Answer: The femoral necks are equal in length and the obturator foramina are symmetric

    Symmetrical obturator foramina and equal femoral neck lengths on both sides confirm the pelvis is not rotated on an AP projection.

  7. Which artifact in computed radiography (CR) is caused by previous exposure data remaining on the phosphor plate?

    Answer: Ghost image (latent image artifact)

    Ghost images occur when a CR plate is not fully erased before reuse, leaving residual signal from a previous exposure.