Computed Tomography (CT) Flashcards
7 cards from real Computed Tomography Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Computed Tomography (CT) flashcards as text
What is the primary purpose of a CT gantry tilt?
Answer: To align the scan plane with anatomical structures while avoiding radiation-sensitive organs
Gantry tilt allows the scan plane to be angled relative to the patient's body axis to align with anatomy or minimize dose to sensitive structures like the lens of the eye.
Which CT image reconstruction algorithm produces the sharpest edges but introduces the most noise?
Answer: Bone (sharp) kernel
Bone or high-frequency kernels enhance edge detail for structures like cortical bone but amplify image noise compared to smooth kernels.
In CT angiography, what timing method uses real-time monitoring of contrast arrival in a target vessel?
Answer: Bolus tracking (SmartPrep/Care Bolus)
Bolus tracking monitors a region of interest in real time and automatically triggers scanning when contrast attenuation reaches a preset threshold.
What does the term 'pitch' refer to in helical CT?
Answer: Table movement per rotation divided by total beam collimation
Pitch is defined as table feed per 360° gantry rotation divided by the total X-ray beam width (collimation), affecting coverage speed and dose.
Which parameter most directly controls CT image noise?
Answer: mAs
mAs (milliampere-seconds) determines the quantity of X-ray photons produced; higher mAs means more photons, less quantum noise, and better image quality.
A patient's kidneys appear hyperdense on a non-contrast CT. What is the most likely cause?
Answer: Recent IV contrast administration or nephrocalcinosis
Hyperdense kidneys on non-contrast CT are most commonly due to residual contrast from a recent scan or calcifications (nephrocalcinosis).
What is the advantage of using a smaller CT field of view (FOV)?
Answer: Improved spatial resolution for the targeted anatomy
A smaller FOV assigns more pixels per unit area, increasing spatial resolution and displaying finer anatomical detail in the region of interest.