SPI PRACTICE QUESTIONS WITH VERIFIED CORRECT ANSWERS. 2024 EDITION. ALREADY GRADED A+, Exams of Physics

Download SPI PRACTICE QUESTIONS WITH VERIFIED CORRECT ANSWERS. 2024 EDITION. ALREADY GRADED A+ and more Exams Physics in PDF only on Docsity! SPI PRACTICE QUESTIONS WITH VERIFIED CORRECT ANSWERS. 2024 EDITION. ALREADY GRADED A+ _________ is a redirection of US in many directions as a result of a *rough* boundary between two media - ANSscattering ___________ resolution is determined by SPL - ANSradial or axial ______________ is the distance covered by one cycle - ANSwavelength ______________ is the time to complete one cycle - ANSperiod A circular hyperechoic structure is located at a depth of 5 cm. The structure has abnormally low attenuation and the speed in the mass is 1,400 m/s. Which of the following is most likely to appear beneath the structure? - ANSreflectors beneath the structure appear abnormally deep in the image A Doppler exam is performed with a 5 MHz probe and a PRF of 15 kHz. Which of these Doppler shifts will create aliasing? - ANS14 kHz A hydrophone is used to measure: - ANSintensity (or frequency) A pulse is emitted by a transducer and is traveling in soft tissue. The go-return-time, or time-of-flight, of a sound pulse is 130 microseconds. What is the reflector depth? - ANS10 cm A quality assurance program: - ANSis needed by all labs A shadow appears on an ultrasound scan. Which of the following statements is true about the shadow artifact? - ANSit appears as hypoechoic A shadow appears on an ultrasound scan. Which of the following statements is true about the structure immediately above the shadowing artifact? - ANSattenuation properties are too high A single element transducer is focused: - ANSby the manufacturer A sound beam is created by a single, disc-shaped crystal. Which of these beams has the shallowest focus? - ANS2 MHz, 9 mm diameter A sound wave is traveling in the body and propagating from one form of soft tissue to another. For example, sound is moving from muscle to blood. What percentage of the sound wave is most likely to be reflected at the muscle-blood boundary? - ANS.5% A sound wave with a frequency of 5 MHz is travelling in soft tissue. What is the wavelength? - ANS.3 mm A sound wave's frequency is 10 MHz. The wave is traveling in soft tissue. What is its wavelength? - ANS.15 mm A system which is not working well now does not display clear images in the far field. This may be a problem with: - ANStransducer, receiver, monitor, or scan converter A transducer converts __________ from one form to another - ANSenergy A transducer with more than one active element is called: - ANSarray According to AIUM, there have been no confirmed bioeffects below intensities of ______ watts per square centimeter SPTA - ANS.01 Aliasing is an artifact observed when performing Doppler ultrasonography. Which of the following signals is most likely to alias? - ANS7 MHz with a PRF of 3 kHz All of the following are limitations of analog scan converts EXCEPT: - ANSlow spatial resolution All of the following are primarily used to change the overall brightness of an entire image EXCEPT: - ANScompensation All of the following are true EXCEPT: - ANStwo waves with identical frequencies must interfere constructively All of the following are true EXCEPT: - ANStwo waves with identical frequencies must interfere constructively All of the following are true of normal cavitation EXCEPT: - ANSharmful bioeffects are commonly observed All of the following are true regarding temporal resolution EXCEPT: - ANSdecreased temporal resolution is associated with shorter pulse duration All of the following artifacts place the erroneous reflection below the true reflector EXCEPT: - ANSside lobe All of the following describe dynamic range EXCEPT: logarithmic, comparison, relative, absolute, ratio - ANSabsolute All of the following regarding the hemodynamics of a stenosis are true EXCEPT: - ANSpressure is lowest downstream How much time is required for a sound pulse to travel round trip to and from a reflector that is 2 cm deep in soft tissue? - ANS26 microseconds Identify two advantages of coded excitation: - ANSimproved contrast resolution and penetration If 300,000 cycles occur in a second, what is the wave's frequency? - ANS.3 MHz If a 5 MHz sound wave is traveling in the tissues listed below, which will have the longest wavelength? - ANSbone If a 5 MHz sound wave is traveling in the tissues listed below, which will have the shortest wavelength? - ANSair If a manufacturer changed the lines per frame and kept the imaging depth the same, what else would change? - ANSframe rate If a reflector is moved twice as far away from the transducer, how will this affect the time-of-flight of a sound pulse? - ANSdouble it If a wave's amplitude is doubled, what happens to the power? - ANSquadrupled If the frame rate increases and the lines per frame is unchanged, what else must happen? - ANSdepth decreases If the frequency is decreased, the numerical value of the radial resolution is: - ANSincreased If the frequency of an US wave is doubled, what happens to the period? - ANShalved If the frequency of US is increased from 0.77 MHz to 1.54 MHz, what happens to the wavelength? - ANShalved If the frequency of US is increased from 0.77MHz to 1.54MHz, what happens to the propagation speed? - ANSremains the same If the intensity is increased by 3 dB, it: - ANSdoubles If the intensity of a sound beam remains unchanged while the beam area is reduced in half, what has happened to the power? - ANShalved If the lines per frame is increased while the imaging depth is unchanged then: - ANSthe frame rate decreases If the SPL is 10 mm, what is the axial resolution? - ANS.5 cm If the transducer diameter increases, the lateral resolution at its smallest dimension is: - ANSincreased If we increase frequency, the near zone length is: - ANSincreased If we increase the transducer diameter, the beam diameter in the far zone is: - ANSdecreased If wires in an AIUM test object do not appear in the same place as on the display, what is amiss? - ANSregistration accuracy Images on videotapes are stored using: - ANSmagnetism Impedance is the _________ of _________ and _________ - ANSproduct, propagation speed, density Impedance is the product of __________ and __________ - ANSdensity and propagation speed Improving the ability to measure the maximum velocity with Doppler is accomplished with all of the following EXCEPT: - ANSincreasing the transducer's frequency In a B-mode display, which of the following axis are used for the amplitude of the reflection? - ANSz-axis In a real-time scanner, which of these choices determines the maximum frame rate? - ANSdepth of view In an air-tissue interface, what percentage of the US is reflected? - ANSnear 100% In B-mode, which input is used with the amplitude of reflection? - ANSz-axis In soft tissue: Distance traveled = __________ x round trip time - ANSpropagation speed In which of these biologic tissues will sound waves propagate most quickly? - ANStendon In which of these media will sound travel the slowest? - ANShigh density, low stiffness In which way is an annular phase array transducer different than a linear phased array transducer? - ANSthe annular is steered mechanically Lateral resolution can be improved by: - ANSfocusing List the following in increasing order: deci, kilo, micro, mega, milli - ANSmicro, milli, deci, kilo, mega Multiple reflections that are equally spaced are called: - ANSreverberations Post processing occurs when the image: - ANSentered the A/D converter but before display Power of sound has units of: - ANSwatts Pre-processing occurs: - ANSwhen the patient is scanned Propagation speed = ______________ x wavelength - ANSfrequency Put in decreasing order of propagation speed: gas, liquid, solid - ANSsolid, liquid, gas Put in decreasing order: deci, deca, micro, centi - ANSdeca, deci, centi micro Put in increasing order of propagation speed: bone, water, air - ANSair, water, bone Quality assurance studies should be performed: - ANSroutinely Rayl is the unit of: - ANSimpedance Rectification and smoothing are components of: - ANSdemondulation Refraction only occurs if there are: - ANSoblique incidence and different propagation speeds Reject is used to: - ANSadjust the appearance of lowly reflective objects Snell's law describes the physics of: - ANSrefraction Sound intensity is decreased by 75%. How many decibels of attenuation is that? - ANS6 dB Sound is traveling from medium 1 to medium 2. Propagation speeds of M1 is 1,600 m/s and M2 is 1,500 m/s. There is oblique incidence - ANSangle of incidence = angle of reflection Sound waves are: - ANSlongitudinal, mechanical T/F: A sonographer's education ends when they become registered - ANSfalse T/F: A sound wave is made of compressions and rarefactions - ANStrue The range equation relates distance from the reflector to: - ANStime-of-flight and propagation speed The region from the transducer to the minimum beam cross-sectional area is the: - ANSfresnel zone The relative output of an US instrument is calibrated in dB and the operator increases the output by 60 dB. The beam intensity is increased by which of the following? - ANS1,000,000 The speed of sound in soft tissue is closest to: - ANS1,500 m/s The time from the beginning of a pulse until its end is ______________? - ANSpulsed duration The units of attenuation are ______; this is a ______________ scale - ANSdB, logarithmic The units of PRF are: - ANSper minute To measure the US beam intensity, use a: - ANScalibrated hydrophone Traveling through the same medium, if the frequency is doubled, the propagation speed is: - ANSunchanged Traveling through the same medium, if the frequency is doubled, the wavelength is: - ANShalved Two objects start at the same point. One object moves towards the west at 5 miles per hour. The other object moves towards the west at 15 miles per hour. A sound wave is sent from the first object to the second to measure a Doppler frequency. Which of the following statements is true? - ANSthe doppler frequency will be negative Under which circumstance is cavitation most likely to occur? - ANSlow frequency and high signal amplitude Under which condition is axial resolution improved? - ANSdecreased pulse duration Under which of the following conditions is axial resolution improved? - ANSdecreased SPL Under which of the following conditions is lateral resolution improved? - ANSdecreased beam diameter Volume has which of the following units? - ANScm^3 What are attenuation's three components? - ANSscattering, reflection, absorption What are the units of intensity? - ANSwatts/cm2 What are the units of longitudinal resolution? - ANSfeet What are typical clinical Doppler frequencies? - ANS1-10,000 Hz What artifact has a grainy appearance and is caused by the interference effects of scattered sound? - ANSspeckle What best describes the features of a sound wave and medium that determine the speed of sound? - ANSdensity and stiffness What can pulsed Doppler measure that continuous wave cannot? - ANSlocation What component of a transducer changes electrical to mechanical and mechanical back to electrical energy? - ANSPZT What component of the US unit contains the memory bank? - ANSscan converter What determines the center frequency of a transducer? - ANSthickness What determines the frequency of a sound beam from a pulsed transducer? - ANSPZT thickness What determines the spatial resolution of a monitor? - ANSthe number of lines per frame What determines whether reflection will occur when a sound beam strikes a boundary at normal incidence? - ANSimpedance differences What does a hydrophone measure? - ANSacoustic output of an ultrasound imaging system What Doppler angle is most inaccurate? - ANS60-75 degrees What happens to the speed of sound in a medium when the bulk modulus of the medium decreases? - ANSslower What happens to the speed of sound in a medium when the bulk modulus of the medium increases? - ANSfaster What happens to venous blood flow to the heart during expiration? - ANSdecreased What has the greatest influence upon color jet size? - ANScolor doppler gain settings What increases patient exposure? - ANSexam time What information does Doppler shift provide? - ANSvelocity What is another name for longitudinal resolution? - ANSaxial or depth What is displayed on the x-axis of an M-mode image? - ANStime What is displayed on the y-axis of an M-mode image? - ANStime-of-flight What is NOT associated with PACS? - ANSanalog replay What is NOT related to CW wave transducers? - ANSwide bandwidth What is not the responsibility of the sonographer? - ANSadjust converter matrix What is NOT true regarding normal cavitation? - ANSharmful bioeffects are commonly observed What is related to frequency to the 4th power? - ANSrayleigh scattering What is the *fraction* of time that a transducer is transmitting? - ANSduty factor What is the accuracy of reflector depth called? - ANSdepth calibration What is the accuracy of reflector depth position on an A, B, or M-mode display called? - ANSdepth calibration What is the actual time that an US machine is creating a pulse? - ANSpulse duration What is the approximate attenuation coefficient of 1 MHz US in soft tissue? - ANS.5 dB/cm What is the elimination of voltages that do NOT exceed a certain level? - ANSreject What is the first thing you should do when entering a hospital room? - ANScheck the patient's wristband for identification What is the Fraunhofer zone? - ANSfar zone What is the frequency of a wave with a 1 msec period? - ANS1 KHz What is the greatest advantage of one and one-half dimensional array transducers? - ANSimproved slice thickness resolution Which of the following best describes a vector array transducer? - ANSelectronic steering and focusing, trapezoidal shape Which of the following best describes demodulation of electronic signals? - ANSchanging the shape or form of the signal Which of the following best describes the *empirical* approach to the study of bioeffects? - ANSexposure-response Which of the following best describes the *mechanistic* approach to the study of bioeffects? - ANScause-effect Which of the following best describes the features of a sound wave and medium that determine the speed of sound in the medium? - ANSdensity and stiffness of the medium Which of the following choices best describes an ideal epidemiological bioeffects study? - ANSrandomized and prospective Which of the following choices best describes axial resolution artifact? - ANStwo reflectors positioned in front of the other appears as one reflection Which of the following choices determines the signal amplitude in the transducer of an ultrasound system? - ANSreflected intensity of the sound beam Which of the following choices determines the signal amplitude in the transducer of an ultrasound? - ANSreflected intensity Which of the following clinical modalities has the lowest output intensity? - ANSgray scale imaging Which of the following describes the situation where the minimum amount of attenuation will occur? - ANS4 cm depth and 6 MHz frequency Which of the following forms of cavitation are most likely to produce micro-streaming in the intracellular fluid and shear stresses? - ANSstable cavitation Which of the following forms of focusing is achieved during reception? - ANSdynamic aperture Which of the following functions of a receiver is used to create similar brightness reflections from identical reflectors positioned at different depths in the body? - ANScompensation Which of the following has a propagation speed closes to soft tissue? - ANSmuscle Which of the following has the greatest influence on temporal resolution? - ANSpropagation speed and image depth Which of the following has the greatest output intensity? - ANSpulsed doppler Which of the following improves signal-to-noise ratio? - ANSframe averaging Which of the following is a benefit of using a contrast agent? - ANSincreased amplitude of the returning doppler signals Which of the following is associated with cavitation? - ANSmechanical index Which of the following is associated with power Doppler? - ANSpoor temporal resolution and flash artifact Which of the following is determined by the source and the medium? - ANSrange resolution Which of the following is most directly related to temporal resolution? - ANSframe rate Which of the following is not a beam steering technique for a mechanical scanhead? - ANSphased beam Which of the following is NOT used to measure the output of ultrasound systems? - ANScalibrated absorpterometer Which of the following is proportional to the square of the amplitude? - ANSpower Which of the following is the best lateral resolution? - ANS.06 cm Which of the following is the cause of slice thickness artifact? - ANSbeam dimension greater in size than the reflector Which of the following is the correct order of receiver operation? - ANSamplification, demodulation, reject Which of the following is the spectral analysis technique of choice for PW and CW Doppler? - ANSFFT Which of the following lists is in decreasing order? kilo, deci, micro, hecto, milli, nano - ANSkilo, hecto, deci, milli, micro, nano Which of the following situations should result in a cessation of the use of diagnostic ultrasound? - ANSthe benefits are out-weighted by the risks Which of the following sound waves is ultrasonic and least useful? - ANS30 KHz Which of the following statements about Doppler is most correct? - ANSnon-directional Doppler uses non-coherent processing, while bi-directional Doppler uses phase- quadrature processing Which of the following statements related to venous flow is most correct? - ANSduring inspiration, venous flow in the arms increases & during expiration, venous flow in the legs increases Which of the following steps is performed just prior to storage of image data in a digital scan converter? - ANSA-to-D conversion Which of the following tissues will most likely create Rayleigh scattering? - ANSred blood cells Which of the following transducers will create a sound beam with the least amount of divergence? - ANShigh frequency, large diameter Which of the following transducers will create sound with the lowest frequency? - ANSthick crystal, PZT in which sound travels slowly Which of the following will have the lowest SPTA intensity at a depth of one near zone? - ANS4 MHz, 12 mm diameter Which of the following will reduce ghosting artifact? - ANSwall filter Which of the following will result in the greatest number of shades of gray in a digital image display? - ANSlarge pixels with many bits/pixel Which of the following will result in the highest mechanical index? - ANSlow frequency and high signal amplitude Which of these biologic tissues will sound waves propagate most quickly? - ANStendon Which of these boundaries will create the strongest reflection? - ANSair-soft tissue Which of these boundaries will create the weakest reflection? - ANSsoft tissue-blood Which of these cannot be performed by the sonographer? - ANSclean pixels Which of these factors has the greatest influence on PRP? - ANSdisplay depth Which of these intensities is the smallest? SATP, SPTP, SATA - ANSSATA Which of these statements is true of a 25 MHz sound pulse? - ANShighly attenuating, short SPL