Davies Physics SPI questions with complete solutions

While performing a Doppler ultrasound examination you adjust the pulse repetition frequency to 12 kilohertz this can also be expressed as CORRECT ANSWERS: 12,000 Hz When you change the transmit frequency which of the following is altered CORRECT ANSWERS: Number of cycles per second Relative measurement of intensity based on a logarithmic scale is expressed in CORRECT ANSWERS: Decibels The mass you are imaging has a diameter of 35 mm. This value can also be expressed as CORRECT ANSWERS: 3.5 cm In sound wave propagation a region of elevated pressure is termed CORRECT ANSWERS: Compression When you switch from a 2.5 mhz to a 5 mhz transducer the sound wavelength CORRECT ANSWERS: The sound wavelength is halved Wavelength depends on what two factors? CORRECT ANSWERS: Frequency and propagation speed Which of the following human tissues has the highest rate of attenuation of an ultrasound wave? CORRECT ANSWERS: Lung The propagation speed for sound is lowest in which of the following biological tissues CORRECT ANSWERS: Fat Which of the following factors does not affect impedance CORRECT ANSWERS: Frequency You are Imaging a structure containing two media having the same acoustic impedance. What will occur at the boundary of the two structures? CORRECT ANSWERS: All of the sound will be transmitted What is the purpose of the gel coupling between the transducer and the skin? CORRECT ANSWERS: To provide a medium for sound transmission since ultrasound does not propagate through air The unit of impedance is CORRECT ANSWERS: Rayl With absorption acoustic energy is converted to CORRECT ANSWERS: Heat The intensity transmission coefficient at the interface between two structures equals 1 /100. What is the intensity reflection coefficient? CORRECT ANSWERS: 99/100 Which of the following is an example of Rayleigh scattering CO