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 is the function of the analog-to-digital converter (ADC) in a CT system?
Answer: To convert the electrical detector signal into digital data for processing
The ADC converts the analog electrical signal from the detector into a digital format that can be processed by the reconstruction computer.
In multi-detector CT, pitch is defined as:
Answer: Table feed per rotation divided by total beam collimation
Pitch = table feed per rotation ÷ total beam collimation (detector rows × single detector width), directly affecting dose and image overlap.
What is the role of the post-patient anti-scatter grid in CT?
Answer: To block scattered radiation from reaching the detectors
The anti-scatter grid blocks off-axis scattered radiation produced within the patient from reaching the detectors, improving image contrast.
What type of anode is used in modern CT X-ray tubes to manage heat load?
Answer: Rotating tungsten-rhenium alloy anode
Modern CT tubes use rotating anodes made of tungsten-rhenium alloy to distribute heat over a larger focal track area, allowing sustained high-output scanning.
What does 'z-axis coverage' refer to in multi-detector CT?
Answer: The total anatomical length imaged per gantry rotation
Z-axis coverage is the total length along the patient's long axis covered per rotation, determined by the number of detector rows multiplied by individual detector width.
What is the purpose of using a 'sharp' (bone) reconstruction kernel in CT?
Answer: To enhance edge detail and spatial resolution at the cost of increased noise
Sharp kernels apply high-pass filtering that enhances edge detail and spatial resolution, making them ideal for bone and lung imaging despite increased noise.
What is the primary goal of automatic tube current modulation (ATCM) in CT?
Answer: To maintain consistent image noise while minimizing radiation dose
ATCM automatically adjusts tube current based on real-time patient attenuation, delivering consistent noise levels while reducing dose in less-attenuating regions.