ARDMS SPI STUDY GUIDE With Guaranteed Accurate Answers

In soft tissue, if the frequency of a wave is increased the Propagation Speed (PS) will... - correct answer Remain the Same because stiffness and density affect Propagation Speed. What is the audible range? - correct answer 20-20,000Hz >20,000Hz=Ultrasound Frequency is measured in - correct answer Hertz (Hz) is Cycles per Second Not affected by sonographer Increase Frequency; Decrease Depth A period is the length of time it takes for - correct answer one complete wavelength to pass a fixed point PRP is determined by - correct answer Transmit time and receive time. Period is measured in - correct answer Time (μs) When the sonographer changes the imaging depth what parameters are changed? - correct answer PRP, PRF, Duty Factor What is duty factor? - correct answer The percentage or fraction of time that the system is transmitting a pulse (Time Sound is ON or ON-Time). Propagation Speed in SOFT TISSUE - correct answer 1.54 mm/μs (1540 m/sec) Unit of measurement for Pulse Duration, Duty Factor, PRP, and Period - correct answer Time, (μs) Pulse duration is determined by - correct answer Sound Source Only Pulse Duration is controlled by - correct answer the ultrasound system and transducer Pulse Duration Formula - correct answer pulse duration (μs) = # cycles in pulse/frequency(MHz) PD= Nu