Ultrasound Physics Questions & Answers

Ultrasound Physics Questions & Answers 10 dB change - CORRECT ANSWER- means that the final intensity will be 10 times bigger than the original 13 microsecond rule - CORRECT ANSWER- in soft tissue, every 13 microseconds of go-return time, we know the reflector is 1cm deep in the body 3 components of Attenuation - CORRECT ANSWER- Absorption, reflection, scattering 3 dB chance is what? - CORRECT ANSWER- double so a 9 dB chance is 2x2 so 4 6 dB change - CORRECT ANSWER- 3 dB & 3dB; 2x2=4....so 6 dB is four times the original intensity 6 ways to measure Intensity - CORRECT ANSWER- SPTP, SATP, SPTA, SATA, SPPA, SAPA 9dB change - CORRECT ANSWER- 3db & 3dB & 3dB; 2x2x2. means a 9dB change will be 8 times bigger than the original. Absorption - CORRECT ANSWER- The conversion of sound energy into heat. Soft tissue absorption accounts for 80% of total attenuation. Bone is a great absorber. Acute Angles - CORRECT ANSWER- Are oblique Angles, and are less than 90degree angles Angle of incidence - CORRECT ANSWER- A sound pulse strikes many tissue interfaces as it courses through soft tissue Attenuation and intensity and power and amplitude - CORRECT ANSWER- They decrease as a sound wave travels Attenuation is greater when? - CORRECT ANSWER- frequency increases and path length increases Attenuation Units - CORRECT ANSWER- -dB, not always reported as a negative