200/500 Davies Review SPI questions with verified answers

The half intensity depth for a 2MHz transducer in soft tissue is CORRECT ANSWERS: 3cm Attenuation is lowest in which of the following mediums CORRECT ANSWERS: water Increasing frequency will result in all the following except CORRECT ANSWERS: a. range resolution improvement b. transverse resolution improvement c. increase depth of penetration d. decrease in beam diameter Ultrasound transducers utilize which effect upon transmission CORRECT ANSWERS: reverse piezoelectric Ultrasound transducers utilize which effect upon reception CORRECT ANSWERS: piezoelectric All of the following possess the piezoelectric property naturally except CORRECT ANSWERS: a. quartz b. Rochelle Salts c. Tourmaline d. Lead Zirconate Titonate Man-made materials receive the piezoelectric property through the process called CORRECT ANSWERS: Polarization The most common man made ceramic used in ultrasound transducers today is CORRECT ANSWERS: lead zirconate titanate The point at which an ultrasound transducer gives up it's piezoelectric property is CORRECT ANSWERS: curie The Temperature at which lead zirconate titanate loses it's piezoelectic property is CORRECT ANSWERS: 600ºF The "center"/"natural" frequency for pulsed wave transducers is determined primarily by the elements CORRECT ANSWERS: thickness The material that reduces the impedance difference between the active element and soft tissue is the CORRECT ANSWERS: matching layer The optimal thickness for the matching layer is CORRECT ANSWERS: 1/4 wavelength The optimal impedance value for the matching layer is CORRECT ANSWERS: Mean between the active element and soft tissue