ARDMS Ultrasound Physics & Instrumentation Practice Exam

What is defined as the time from the start of one pulse to the start of the next pulse?

1. Pulse width

2. Pulse repetition frequency

3. Pulse repetition period

4. Duty cycle

The correct answer is: Pulse repetition period

The time from the start of one pulse to the start of the next pulse is defined as the pulse repetition period. This term encompasses the entire cycle of the ultrasound pulse, including both the pulse duration and the time interval between pulses. Understanding the pulse repetition period is crucial in ultrasound physics as it directly affects the depth of penetration and the temporal resolution of ultrasound imaging. A longer pulse repetition period indicates that the system is optimized for deeper structures, while a shorter period is used for imaging superficial structures. In contrast, pulse width refers specifically to the duration of the pulse itself, not the interval between pulses. Pulse repetition frequency is the number of pulses transmitted per second, which is inversely related to the pulse repetition period. The duty cycle, on the other hand, is the ratio of the pulse duration to the pulse repetition period, reflecting the amount of time the system is actively transmitting versus receiving.