Breast US board review for ARRT (all solved correctly)

Propagation speed is what in body correct answers 1.54mm/ms or 1540m/s Name acoustic variables correct answers pressure, density and particle motion What is the relationship between speed, stiffness, and density? correct answers speed and stiffness do the same thing speed and density do different things What is frequency? correct answers # of cycles per second How is frequency measured? correct answers Hz What does frequency affect? correct answers detail and contrast resolution What is the round trip travel time for sound for every cm of depth? correct answers 13ms Range equation correct answers distance to reflector(mm)=speed of sound(mm) x TT(ms) _____________________ 2 What transducers are used in breast US? correct answers linear array, 7.5- 18 mHz Equation for wavelength correct answers wavelength(mm)=prop speed(mm/ms) ______________ frequency(mHz) equation for intensity correct answers intensity= power= Amplitude squared ____ frequency What effect does increasing amplitude have on power and intensity? correct answers Amplitude is squared so everything goes up When does refraction occur? correct answers when sound strikes a boundary obliquely (based on prop speed differences) When does reflection occur? correct answers when sound strikes a perpendicular boundary between 2 tissues (based on impedance) Attenuation coefficient is... correct answers dB/cm= 1/2 x frequency (mHz)