SPI REVIEW QUESTIONS: Transducers, Exam Questions & Answers

SPI REVIEW QUESTIONS: Transducers, Exam Questions & Answers-Which of the following applies to therapeutic ultrasound transducers? A. backing material at least 2X thickness of that used in imaging transducers B. narrow bandwidth C. frequencies >15MHz used due to the increased potential for focused cavitation D. low Q factor - B: Narrow Bandwidth Which type of transducer has the smallest field of view in the near field? A. curvilinear B. vector C. sector D. linear - C: Sector Which of the following transducer frequencies can be used for imaging or therapeutic purposes? A. 15MHz B. 3MHz C. 1MHz D. 5MHz - B: 3MHz therapeutic transducers range between 0.7-3MHz A curved array transducer is preferred over a sector array transducer of the same frequency for fetal and abdominal imaging because: A. it offers increased penetration B. it produces a lower intensity beam C. it has a wider near field D. it offers less beam divergence - C: it has a wider near field Mirrors and lenses can be used to ________________. A. mechanically focus the US beam B. increase the PRF of the transducer C. improve sound transmission into the body D. electronically focus the US beam - A: mechanically focus the ultrasound beam Which of the following describes a purpose for applying acoustic gel to the face of the transducer? A. To increase the amount of reflection that occurs within the first 2cm of tissue B. To reduce the difference in impedance between the matching layer and the skin C. To increase the amount of refraction that occurs within the first 2cm of tissue D. To reduce the beam intensity just before the sound beam enters the patient - B: to reduce the difference in impedance between the matching layer and the skin 8. A ___________MHz transducer will have the thinnest element. A. 3 B. 5 C. 7 D. 12 - D: 12 higher frequencies will have the thinnest elements Which of the following transducers will produce the highest frequency sound waves? A. 6mm element thickness, 2mm/μs propagation speed of the element B. 2mm element thickness, 6mm/μs propagation speed of the element C. 6mm element thickness, 6mm/μs propagation speed of the element D. 2mm element thickness, 2mm/μs propagation speed of the element - B. 2mm element thickness, 6mm/ms propagation speed of the element