Free Sonography Principles & Instrumentation Questions and Answers — Questions and Answers
Question 1: Which phantom from the list below does sonographic quality assurance?
- Tissue equivalent phantom (Correct answer)
- Constancy test phantom
- Sensitometry wedge phantom
- Axis alignment phantom
Correct answer: Tissue equivalent phantom
Tissue equivalent phantoms are specifically designed to mimic the acoustic properties of human tissue, such such as speed of sound, attenuation, and scattering. This allows for comprehensive evaluation of an ultrasound system's performance, including axial and lateral resolution, penetration, and image uniformity. Therefore, they are essential tools for sonographic quality assurance programs.
Question 2: The speed of sound for tissue comparable phantoms should be equal to:
- 4.28 mm/us
- 1,540 m/s (Correct answer)
- 1.84 mm/us
- 1,960 m/s
Correct answer: 1,540 m/s
The average speed of sound in soft human tissue is approximately 1,540 meters per second (or 1.54 mm/µs). For phantoms to accurately simulate human tissue and allow for proper calibration and quality assurance of ultrasound equipment, their speed of sound must match this value. This ensures that the ultrasound system's distance measurements and image reconstruction are accurate.
Question 3: Which of the following is an ergonomic device built into sonographic equipment for the sonographer's musculoskeletal safety?
- Wrist support brace
- Long transducer cable
- Monitor articulation (Correct answer)
- Fixed control panel
Correct answer: Monitor articulation
Monitor articulation allows sonographers to adjust the display screen's height, tilt, and swivel to their individual needs and scanning position. This ergonomic feature helps reduce neck, back, and eye strain by promoting a neutral posture during examinations. By minimizing physical discomfort and awkward positions, it directly contributes to musculoskeletal safety and helps prevent work-related injuries.
Question 4: A pulsed sound wave is best described by the following acoustic parameter:
- Duty factor (Correct answer)
- Period
- Propagation speed
- Frequency
Correct answer: Duty factor
The duty factor is the fraction of time that the pulsed ultrasound system is actively transmitting sound. It is a dimensionless number representing the ratio of pulse duration to the pulse repetition period. Since a pulsed wave involves intermittent periods of transmission and listening, the duty factor is a key acoustic parameter that specifically characterizes its intermittent nature.
Question 5: The maximum sound speed is found in:
- Liver
- Bone (Correct answer)
- Blood
- Fat
Correct answer: Bone
The speed of sound is highest in denser and stiffer media. Among the options provided, bone is the densest and stiffest tissue in the human body. This allows sound waves to propagate through it much faster than through softer tissues like liver, blood, or fat, where the speed of sound is significantly lower.
Question 6: Which of the subsequent PRF values has the longest PRP?
- 1,000 Hz
- 12 kHz
- 7 Hz (Correct answer)
- 3 kHz
Correct answer: 7 Hz
Pulse Repetition Period (PRP) and Pulse Repetition Frequency (PRF) are inversely related, meaning PRP = 1/PRF. To achieve the longest PRP, you need the lowest PRF. Among the given options, 7 Hz is the lowest frequency, which will result in the longest time between consecutive ultrasound pulses.
Question 7: As frame rate goes up, _________ resolution goes up.
- Spatial
- Elevational
- Lateral
- Temporal (Correct answer)
Correct answer: Temporal
Temporal resolution refers to the ability of an ultrasound system to accurately display structures in motion over time. It is directly related to the frame rate, which is the number of images acquired per second. As the frame rate increases, more images are captured in a given time, leading to a smoother and more accurate representation of moving structures, thus improving temporal resolution.
Free Sonography Principles & Instrumentation Questions and Answers
Which phantom from the list below does sonographic quality assurance?