CBET Diagnostic Imaging Equipment 4

Question 1

In a CT scanner, what is the primary purpose of the anti-scatter grid?

Accepted Answer

Improve image contrast by blocking scattered X-rays

Answer

Reduce patient radiation dose

Answer

Increase detector sensitivity

Answer

Collimate the primary X-ray beam

Question 2

A fluoroscopy unit displays an 'image intensifier dose rate' alarm. Which parameter should the BMET check first?

Accepted Answer

Automatic brightness control (ABC) circuit operation

Answer

kVp calibration

Answer

Collimator alignment

Answer

Film processor chemistry

Question 3

What does 'spatial resolution' measure in diagnostic imaging?

Accepted Answer

The ability to distinguish two adjacent high-contrast objects as separate

Answer

The range of densities visible in a single image

Answer

The speed of image acquisition

Answer

The amount of noise present in the image

Question 4

During MRI QA, the BMET measures a phantom image and finds the signal-to-noise ratio (SNR) has dropped 20% from baseline. The most likely cause is:

Accepted Answer

RF coil damage or poor coupling

Answer

Incorrect slice thickness setting

Answer

Gradient amplifier overheating

Answer

Incorrect TR parameter

Question 5

Which unit describes the absorbed radiation dose in diagnostic imaging?

Accepted Answer

Gray (Gy)

Answer

Roentgen (R)

Answer

Sievert (Sv)

Answer

Becquerel (Bq)

Question 6

In ultrasound imaging, the term 'acoustic shadowing' occurs when:

Accepted Answer

Sound waves are reflected entirely by a highly attenuating structure

Answer

Gain is set too high causing saturation

Answer

The transducer frequency is below the tissue resonant frequency

Answer

Time-gain compensation is disabled

Question 7

A portable X-ray unit fails to produce an exposure when triggered. The BMET confirms the battery is fully charged. What should be checked next?

Accepted Answer

Handswitch and exposure control circuitry

Answer

High-voltage transformer primary winding

Answer

Focal spot size

Answer

Collimator lamp