ARDMS Ultrasound Physics & Instrumentation Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Study for the ARDMS Ultrasound Physics and Instrumentation Exam. Practice with flashcards and multiple choice questions, each question includes hints and explanations. Prepare for success!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What is the effect of increasing pulse repetition frequency on duty factor?

Duty factor will remain unchanged
Duty factor will decrease
Duty factor will increase
Duty factor will vary sporadically

The correct answer is: Duty factor will increase

The duty factor is defined as the ratio of the time the ultrasound system is actively transmitting sound waves to the total time of the pulse cycle (the sum of the time both transmitting and receiving). It is expressed as a percentage. When the pulse repetition frequency (PRF) increases, the system emits more pulses in a given time period. As a consequence, the time spent in the "on" state (transmitting) also increases relative to the "off" time (receiving), leading to a greater proportion of the total cycle time being spent transmitting. This results in an increase in the duty factor. In summary, with an increased pulse repetition frequency, the time spent transmitting rises, thus increasing the duty factor as well. This relationship illustrates how modulation of PRF directly influences the duty factor, enhancing the transmission portion of the cycle in ultrasound imaging.