Sonography Canada - Core Exam 114 Questions and Answers A+ Score.

Sonography Canada - Core Exam 114 Questions and Answers A+ Score. what is the I SPPA for mechanical bioeffects? - ANSWER 190W/cm^2 what is the I SPTA for thermal bioeffects? - ANSWER 720mW/cm^2 recommended MI for fetal scanning - ANSWER MI 1.9 recommended TI for fetal scanning - ANSWER TI 0.7 after what fetal age is safe to use PW doppler? - ANSWER 14 weeks what does ALARA stand for - ANSWER as low as reasonably achievable frequency - ANSWER # of cycles/second f = 1/p period - ANSWER time it takes for 1 cycle to occur (usec) P = 1/f wavelength - ANSWER length of 1 cycle (mm) wavelength = c/f inversely proportionate to frequency assumed speed of sound in soft tissue - ANSWER 1540 m/s 1.54mm/usec intensity - ANSWER I = power/area measured in Watts proportionate to amplitude squared range equation - ANSWER distance to reflector = 1/2 speed of sound x GRT go return time (GRT) - ANSWER 13usec for 1cm of depth acoustic impedance (z) - ANSWER difference between media determining % reflection and % transmission of sound (Rayls) z= density x speed of sound Sonography Canada - Core Exam Questions and Answers A+ Score. z = p x c % reflection equation - ANSWER larger AI difference results in ___ reflection - ANSWER greater pulse duration (PD) - ANSWER time for one pulse tx is ringing PD = period x n; n = # of cycles in pulse pulse repetition period (PRP) - ANSWER the time from the beginning of one pulse to the beginning of the next time tx is ringing and listening for 1 scan line PRP = 13usec/cm x imaging depth pulse repetition frequency (PRF) - ANSWER # of pulses in 1 second (kHz) PRF = 1/PRP duty factor - ANSWER % tx is ringing over tx ringing and listening DF = (PD/PRP) x 100% frame time - ANSWER time it takes to create a single frame (msec) FT = PRP x lines/frame frame rate - ANSWER # of frames per second (Hz) FR = 1/FT spatial pulse length (SPL) - ANSWER length of space of one pulse (mm) SPL = wavelength x n; n = # of cycles in pulse Is sound a transverse or longitudinal wave? - ANSWER longitudinal what kind of pressure wave is sound? - ANSWER mechanical infrasound range - ANSWER 20Hz audible sound range - ANSWER 20Hz - 20kHz ultrasound range - ANSWER 20kHz .