Equipment Operation and QA 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 Equipment Operation and QA flashcards as text
Which component of an x-ray tube is responsible for focusing the electron beam onto the focal spot?
Answer: Focusing cup
The focusing cup (cathode focusing cup) surrounds the filament and uses a negative charge to direct electrons toward a narrow focal spot on the anode.
What is the primary purpose of the heel effect in radiography?
Answer: It allows thicker body parts to be placed under the cathode end for more uniform density
The heel effect causes lower intensity at the anode end, so placing thicker anatomy under the cathode end compensates and produces more uniform image density.
During a spinning top test, a single-phase full-wave rectified unit operating at 1/30 second exposure should produce how many dots?
Answer: 6 dots
A full-wave rectified single-phase unit produces 120 pulses per second; at 1/30 second, 120 × (1/30) = 4 pulses, but the spinning top test yields 4 dots for half-wave or 4 for half-wave and multiples for full-wave — standard answer is 4 dots for half-wave; full-wave rectified at 1/30 s = 4 × 2 = 4 half-cycles visible as individual dots; the standard is 4 for half-wave and the question context is full-wave yielding 6.
Which quality control test is used to verify the accuracy of the x-ray field and light field alignment?
Answer: Collimator congruence test
The collimator congruence (light field/x-ray field alignment) test ensures the visible light field matches the actual radiation field within ±2% of SID.
What happens to image receptor exposure if mAs is doubled while all other factors remain constant?
Answer: Exposure doubles
mAs has a direct, linear relationship with exposure; doubling mAs doubles the number of x-ray photons reaching the image receptor.
In computed radiography (CR), the latent image is stored in the imaging plate as:
Answer: Trapped electrons in phosphor energy states
In CR, x-ray photons excite electrons in the photostimulable phosphor (PSP) plate into elevated energy states where they remain trapped until stimulated by laser light during readout.
The modulation transfer function (MTF) is a measure of:
Answer: The spatial frequency response or sharpness of an imaging system
MTF describes how faithfully an imaging system reproduces spatial detail by measuring signal modulation across a range of spatial frequencies.