CT Equipment and Technology 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 CT Equipment and Technology flashcards as text
What defines a 'dual-source' CT scanner?
Answer: A system with two X-ray tube and detector array pairs offset at approximately 90°
Dual-source CT uses two X-ray tube/detector systems mounted approximately 90° apart, enabling ultra-fast acquisition and simultaneous dual-energy imaging.
What is the primary function of the high-voltage generator in a CT system?
Answer: To supply stable high voltage (kVp) to the X-ray tube for X-ray production
The high-voltage generator converts standard AC power into the kilovoltage (80–140 kVp) required by the X-ray tube anode-cathode circuit to produce X-rays.
What does 'isotropic resolution' mean in CT imaging?
Answer: Equal spatial resolution in all three dimensions (x, y, and z)
Isotropic resolution means voxels are equal in all three dimensions, allowing high-quality multiplanar reformations in any plane without degradation.
What is the typical kilovoltage peak (kVp) range used in routine clinical CT scanning?
Answer: 80–140 kVp
Clinical CT scanners operate at 80–140 kVp, with lower values used for pediatric patients and iodinated contrast studies, and higher values for large patients.
What is the primary advantage of iterative reconstruction over filtered back projection (FBP) in CT?
Answer: Reduced image noise at a given radiation dose level
Iterative reconstruction models the CT system physics more accurately than FBP, enabling significant noise reduction and allowing dose reduction while maintaining diagnostic image quality.
In CT imaging, what does the term 'image noise' primarily refer to?
Answer: Random variation in CT numbers (HU) across a uniform object
CT image noise is the random fluctuation in Hounsfield units across a uniform region, primarily caused by quantum mottle from insufficient photon statistics.
In CT scanner design, what is the 'focal spot' of the X-ray tube?
Answer: The small area on the anode where electrons strike and X-rays are produced
The focal spot is the small area on the rotating anode target where the electron beam strikes, causing X-ray emission; its size directly affects spatial resolution.