CBET Diagnostic Imaging Equipment

Question 1

What type of radiation does a conventional X-ray machine produce?

Accepted Answer

Ionizing electromagnetic radiation (X-rays)

Answer

X-ray tubes produce ionizing electromagnetic radiation by accelerating electrons into a tungsten anode, emitting photons in the X-ray spectrum.

Question 2

Which unit measures absorbed radiation dose in tissue?

Accepted Answer

Gray (Gy)

Answer

The Gray is the SI unit of absorbed dose, defined as one joule of energy deposited per kilogram of tissue.

Question 3

What is the primary safety concern for BMETs working on MRI equipment?

Accepted Answer

Extremely strong static magnetic field attracting ferromagnetic objects

Answer

MRI scanners operate with static fields up to 3 T or higher; ferromagnetic tools or implants can become dangerous projectiles near the bore.

Question 4

In ultrasound imaging, what physical principle allows tissue boundaries to be visualized?

Accepted Answer

Reflection of sound waves at acoustic impedance mismatches

Answer

Sound waves reflect at interfaces between tissues of different acoustic impedance; the transducer detects these echoes to reconstruct an image.

Question 5

A CT scanner's X-ray tube requires replacement. Which parameter most directly indicates tube wear?

Accepted Answer

Total accumulated milliampere-seconds (mAs) / heat units

Answer

Accumulated heat units or mAs track the thermal stress on the anode; manufacturers define tube replacement thresholds based on this metric.

CBET - Certified Biomedical Equipment Technician Practice Test