Ardms Spi Exam Latest Update Comprehensive Questions And Correct Answers| Already Graded A+/Passed 100%

ARDMS SPI EXAM LATEST UPDATE COMPREHENSIVE QUESTIONS AND CORRECT ANSWERS| ALREADY GRADED A+/PASSED 100% 3 - RIGHT ANSWER -What number is period? A 10 dB difference in signal intensity is equivalent to a _______ difference. - RIGHT ANSWER -tenfold A 2D image of internal body structures displayed as dots; the brightness of the dots is proportional to the amplitude of the echo; the image is applicable to both real-time and static scanners - RIGHT ANSWER -B-mode A 5 MHz transducer used in a pulse-echo system will generally produce - RIGHT ANSWER -a wide band of frequencies centered at 5 MHz A beam-intensity profile is often mapped with - RIGHT ANSWER -a hydrophone A decreased pulse duration leads to - RIGHT ANSWER -better axial resolution A device used to focus sound beams - RIGHT ANSWER -acoustic lens A digital scan converter is essentially a - RIGHT ANSWER -computer memory A disadvantage of pulsed-wave Doppler (PW) relative to continuous-wave Doppler (CW) is that - RIGHT ANSWER -it is subject to aliasing A Doppler instrument that can distinguish between positive and negative shifts is called - RIGHT ANSWER -bidirectional A Fourier transform of a returning echo will result in a presentation of the ____ contained within the echo - RIGHT ANSWER -frequencies A graphic presentation of moving structures in a waveform; the display is presented as a group of lines representing the motion of moving interfaces versus time - RIGHT ANSWER -M-mode A graphic presentation with vertical spikes arising from a horizontal baseline; the height of the vertical spikes represents the amplitude of the deflected echo - RIGHT ANSWER -A-mode A large amplitude pulse from the pulser results in - RIGHT ANSWER -a large amplitude pulse from the transducer A liquid placed between the transducer and the skin - RIGHT ANSWER -coupling medium A long near zone can be obtained by - RIGHT ANSWER -using a higher frequency transducer A material that changes its dimensions when an electric field is applied is called ____ material. - RIGHT ANSWER -piezoelectric A method of analyzing a waveform - RIGHT ANSWER -spectral analysis A method of reducing pulse duration by electrical or mechanical means - RIGHT ANSWER -damping a process of acoustic energy absorption - RIGHT ANSWER -relaxation A region that is anechoic is displayed as - RIGHT ANSWER -echo-free A region that is hyperechoic is - RIGHT ANSWER -echogenic A scan converter will accept echo signals from the receiver and store them in the "memory" of the instrument. Identify the types of memory used in scan converters. - RIGHT ANSWER -analog and digital A shortened spatial pulse length results in - RIGHT ANSWER -better axial resolution a simulated cyst - RIGHT ANSWER -What does the solid black arrow point to? a simulated solid lesion - RIGHT ANSWER -What does the curved open arrow point to? A sonographic image can be transferred from one computer to another by way of - RIGHT ANSWER -modem A structure that possesses echoes - RIGHT ANSWER -echogenic A tissue or structure that does not have internal echoes (echo-free) - RIGHT ANSWER -sonolucent a transducer with a large bandwidth is likely to have - RIGHT ANSWER -good axial resolution A wave vibrating at 1 million cycles per second has a frequency of - RIGHT ANSWER -1 MHz A wave vibration at 20 cycles per second has frequency of - RIGHT ANSWER -20 Hz A waveform transfers _____ from one point in space to another point in space. - RIGHT ANSWER -energy A-mode - RIGHT ANSWER -What mode is displayed in this diagram? Abbreviation for time gain compensation - RIGHT ANSWER -TGC According to Snell's law, the transmission angle is greater than the incidence angle if the propagation speed A. OF MEDIUM 2 MEDIUM 1 B. OF MEDIUM 1 MEDIUM 2 C. OF TWO MEDIA ARE EQUAL D. IS CALCULATED 3 dB DOWN - RIGHT ANSWER -of medium 2 medium 1 According to the AIUM, no significant biologic effects have been proven in mammals exposed to - RIGHT ANSWER -SPTA intensities below 100 mW/cm² According to the range equation, what two things are necessary to calculate the distance to the reflector? - RIGHT ANSWER -propagation speed and pulse round-trip time Acoustic enhancement can be observed when scanning - RIGHT ANSWER -weakly attenuating structures Acoustic impedance formula - RIGHT ANSWER -density × propagation speed Acoustic impedance is defined by which of the following? A. RAYONS B. METERS/dB C. mW/cm² D. RAYLS - RIGHT ANSWER -rayls Acoustic impedance is not dependent on which of the following? A. FREQUENCY B. DENSITY C. STIFFNESS D. NONE OF ABOVE - RIGHT ANSWER -frequency acoustic mirror - RIGHT ANSWER -# 461 Acoustic power output is determined primarily by - RIGHT ANSWER -the pulser voltage spike acousto-optical converter - RIGHT ANSWER -device that changes sound waves into visible light patterns All of the following are also known as lateral resolution except? A. AZIMUTHAL B. TRANSVERSE C. RANGE D. ANGULAR - RIGHT ANSWER -range Amplitude is measured in - RIGHT ANSWER -dB An 8-bit binary number is referred to as - RIGHT ANSWER -byte An 8-bit word microcomputer with 128K words of memory can store how many bits of data? - RIGHT ANSWER -128 × 1024 × 8 = 1,048,576 An annular array real-time scanner is steered - RIGHT ANSWER -mechanically An artifact that is produced from interaction of the incident beam with a curved surface and results in an acoustic shadow is referred to as - RIGHT ANSWER -edge artifact An artifact that results from a pulse that has traveled two or more round-trip distances between the transducer and the interface is called - RIGHT ANSWER -reverberation An artifact that results from refraction of the ultrasound beam at a muscle-fat interface and give rise to double images is called - RIGHT ANSWER -split image artifact An artifact that would least likely produce a pseudo-mass is - RIGHT ANSWER -comet tail artifact An echo that does not correspond to the real echo information - RIGHT ANSWER -artifact An echo that has undergone an attenuation of 3 dB will have an intensity that is ___ its initial intensity. - RIGHT ANSWER -½ An electronic device that translates signals from digital into analog and analog into digital - RIGHT ANSWER -modem An example of an acoustic window is - RIGHT ANSWER -liver interface or cystic structure an in vivo phenomenon characterized by erythrocytes within small vessels stopping the flow and collecting in the low pressure regions of the standing wavefield - RIGHT ANSWER -real cell stasis An increase in echoes from a region distal to a weakly attenuating structure or tissue - RIGHT ANSWER -enhancement An increase in reflection amplitude from reflectors that lie behind a weakly attenuating structure is called - RIGHT ANSWER -enhancement An ultrasound beam that is normally incident on an interface will experience no - RIGHT ANSWER -refraction An ultrasound instrument that could represent 64 shades of gray would require a ____ bit memory - RIGHT ANSWER -6 An ultrasound transducer converts - RIGHT ANSWER -electrical energy into mechanical energy and vice versa Annular phased arrays unlike linear phased arrays - RIGHT ANSWER -electronically focus in two dimensions rather than one Approximately what percentage of the ultrasound beam will be transmitted between fat and muscle? - RIGHT ANSWER -99% Arrange in the correct order of increasing propagation speed. GAS, BONE MUSCLE - RIGHT ANSWER -gas, muscle, bone Arrange the following media in terms of propagation speed from lowest to highest. BONE, FAT, AIR, MUSCLE - RIGHT ANSWER -air fat muscle bone Artifacts appearing as parallel, equally spaced lines are characteristic of - RIGHT ANSWER -reverberation As frequency increases, backscatter - RIGHT ANSWER -increases As frequency increases, the beam width will - RIGHT ANSWER -decrease As frequency increases, the penetration will - RIGHT ANSWER -decrease As frequency increases, the resolution will - RIGHT ANSWER -increase At the present time, most ultrasound contrast agents are based upon - RIGHT ANSWER -gas-filled bubbles Attenuation coefficient of sound can be defined by which of the following? A. dB/cm/MHz B. dB/cm²/Hz C. cm/Hz/dB D. m/dB/cm³ - RIGHT ANSWER -dB/cm/MHz Attenuation of an ultrasound beam can occur by which of the following? A. DIVERGENCE OF A BEAM B. SCATTERING C. REFLECTION - RIGHT ANSWER -all the above axial resolution - RIGHT ANSWER -The row of wires in the middle are used to check axial resolution - RIGHT ANSWER -Which AIUM test object function utilizes the A group of wires in the AIUM 100 mm test object? Axial resolution can be improved by - RIGHT ANSWER -reducing the spatial pulse length Axial resolution can be improved by using - RIGHT ANSWER -higher frequency transducers Axial resolution is also known as all of the following except? A. DEPTH B. RANGE C. AZIMUTHAL D. LONGITUDINAL - RIGHT ANSWER -azimuthal Axial resolution is dependent on? - RIGHT ANSWER -wavelength Axial resolution is primarily affected by - RIGHT ANSWER -spatial pulse length B-mode - RIGHT ANSWER -What mode is displayed in this diagram? B-mode display denotes - RIGHT ANSWER -brightness modulation B-mode ultrasound includes all the following except? A. STATIC SCANS B. M-MODE SCANS C. REAL-TIME SCANS D. ALL THE ABOVE - RIGHT ANSWER -M-mode scans backing material - RIGHT ANSWER -#124 Bandwidth can be increased by - RIGHT ANSWER -increasing damping Beam steering is achieved in a linear phased array by - RIGHT ANSWER -electronic time-delay pulsing Beam thickness artifact is primarily dependent on - RIGHT ANSWER -beam angle binary digit - RIGHT ANSWER -bit Bioeffects at medium intensity levels on laboratory animals have resulted in? - RIGHT ANSWER -growth retardation bit denotes - RIGHT ANSWER -binary digit By using a waterpath offset - RIGHT ANSWER -The focal zone can be moved to the skin surface call for service - RIGHT ANSWER -While using the AIUM test object to test an articulated-arm scanner you obtain an image similar to scan A. You should cathode - RIGHT ANSWER -#132 Compounding, in the context of real-time ultrasound scanners, refers to - RIGHT ANSWER -steering the beam to achieve larger echoes at a specific image location. Continuous wave Doppler has a duty factor of - RIGHT ANSWER -100% Continuous wave doppler uses how many piezoelectric elements? - RIGHT ANSWER -2 Continuous wave ultrasound is used in - RIGHT ANSWER -some Doppler instruments Continuous-wave (CW) ultrasound is used in - RIGHT ANSWER -some Doppler systems control grid - RIGHT ANSWER -#134 control the upward incline of the TGC, used to display an even texture - RIGHT ANSWER -slope control used to delay the start of a slope - RIGHT ANSWER -delay control used to suppress or increase echoes in the far field - RIGHT ANSWER -far gain control used to suppress or increase echoes in the near field - RIGHT ANSWER -near gain controls the point where the slope ends - RIGHT ANSWER -knee conversion of sound to heat - RIGHT ANSWER -absorption Conversion of sound to heat - RIGHT ANSWER -absorption CPU denotes - RIGHT ANSWER -central processing unit damping material - RIGHT ANSWER -#125 dB = 10 log₁₀ (I₂ / I₁) - RIGHT ANSWER -attenuation equation dead zone - RIGHT ANSWER -The row of wires on top is used to check? dead zone - RIGHT ANSWER -Which AIUM test object function utilizes the D group of wires in the AIUM 100 mm test object? Decreasing the pulse repetition period - RIGHT ANSWER -decreases the maximum depth imaged delay - RIGHT ANSWER -What is B? Demodulation is a function performed by the - RIGHT ANSWER -receiver Demodulation is a process of - RIGHT ANSWER -converting the voltage delivered to the receiver from one form to another Density is defined as - RIGHT ANSWER -mass per unit volume density multiplied by sound propagation speed - RIGHT ANSWER -impedance depth calibration - RIGHT ANSWER -Which AIUM test object function utilizes the C or E groups of wires in the AIUM 100 mm test object? Digital computers use a special number system called - RIGHT ANSWER -binary numbers Digital memory can be visualized as - RIGHT ANSWER -squares on a checkerboard Doppler effect - RIGHT ANSWER -the change in frequency as a result of reflector motion between the transducer and the reflector Dynamic focusing is made possible by - RIGHT ANSWER -array based systems Each binary digit in a binary number is represented in memory by a memory element, which at any time is in one of ____ states. - RIGHT ANSWER -two Echoes of higher amplitude than the normal surrounding tissue - RIGHT ANSWER -hyperechoic Echoes of lower amplitude than the normal surrounding tissues - RIGHT ANSWER -hypoechoic electrical connector - RIGHT ANSWER -#123 electron beam - RIGHT ANSWER -#138 electron gun - RIGHT ANSWER -#133 elimination of small amplitude echo - RIGHT ANSWER -rejection energy transported per unit time - RIGHT ANSWER -acoustic power Enhancement is caused by - RIGHT ANSWER -weakly attenuating structures Enhancement occurs posterior to - RIGHT ANSWER -weak diffractors evacuated glass - RIGHT ANSWER -#139 Example of nonspecular reflector - RIGHT ANSWER -red blood cells face material - RIGHT ANSWER -#128 False echoes are produced by - RIGHT ANSWER -reverberation far gain - RIGHT ANSWER -What is D? focusing lens - RIGHT ANSWER -#135 For a specular reflector - RIGHT ANSWER -angle of incidence = angle of reflection For normal incidence, if the intensity reflection coefficient is 30%, the intensity transmission coefficient will be - RIGHT ANSWER -70% For real-time systems, which of the following is not related to the other? A. FRAME RATE B. LINES PER FRAME C. PULSE REPETITION FREQUENCY D. FREQUENCY - RIGHT ANSWER -frequency Frequency is a significant factor in - RIGHT ANSWER -tissue attenuation Gain compensation is necessary due to - RIGHT ANSWER -attenuation Generally, ultrasound transducers have - RIGHT ANSWER -better axial resolution than lateral resolution glass screen - RIGHT ANSWER -#140 Grating lobes in electronic array systems - RIGHT ANSWER -increase with increased steering angle Gray-scale systems typically use _____ as a means of signal dynamic range reduction. - RIGHT ANSWER -compression Harmonic imaging relative to conventional pulse-echo imaging has - RIGHT ANSWER -better lateral resolution Having two stages - RIGHT ANSWER -bistable High-frequency transducers have ___ wavelengths and ____ penetration - RIGHT ANSWER -shorter, less horizontal caliper check - RIGHT ANSWER -The row of wires on the bottom is used to check for housing - RIGHT ANSWER -#127 How many frames per second are displayed by a video monitor? - RIGHT ANSWER -30 How many gray levels (echo amplitude levels) can a 4-bit deep digital scan converter store? - RIGHT ANSWER -(2⁴ = )16 How many shades of gray can be displayed using a scan converter with 8 bits per memory element - RIGHT ANSWER -256 How many shades of gray can the human eye distinguish? - RIGHT ANSWER -about 16 How many times each second does the electron beam scan each field on a standard video monitor to produce a flicker-free display? - RIGHT ANSWER -60 How much will a 3.5 MHz pulse be attenuated after passing through 2 cm of soft tissue? - RIGHT ANSWER -3.5 dB Huygens' principle describes - RIGHT ANSWER -multiple point sources If a 2 MHz frequency is used in human soft tissue, the wavelength is approximately - RIGHT ANSWER -0.75 mm If frequency decreases, the wavelength will - RIGHT ANSWER -increase If frequency increases, the wavelength will - RIGHT ANSWER -decrease If it takes 0.01 second for a pulse emitted by the transducer to reach an echo source of soft tissue, what distance must the pulse travel to be recorded? - RIGHT ANSWER -(Distance = velocity × time, so 1540 × 0.01 = 15.4 m × 2 =) 30.8 m If the actual propagation speed in soft tissue is 1700 m/s, current diagnostic scanners will display a reflector at a location _____ the transducer - RIGHT ANSWER -too close to If the amount of acoustic coupling medium is insufficient, what changes could result? - RIGHT ANSWER -decrease in amplitude of the returning echo If the amplitude is doubled, the intensity is - RIGHT ANSWER -quadrupled If the amplitude of a wave is increased threefold, the intensity will - RIGHT ANSWER -increase ninefold If the frequency doubles, what happens to the wavelength? - RIGHT ANSWER -decreases by ½ If the frequency is increased, the velocity (propagation speed) will be _____. - RIGHT ANSWER -unchanged If the frequency of sound is above 20 kHz it is called - RIGHT ANSWER -ultrasound If the frequency of sound is below 16 Hz it is called - RIGHT ANSWER -subsonic infrasound If the frequency of sound is between 16 Hz and 20 kHz it is called - RIGHT ANSWER -audible sound If the gain of an amplifier is 18 dB, what will the new gain setting be if the gain setting is reduced by one-half? - RIGHT ANSWER -15 dB If the lines per degree in a mechanical sector scanner remain constant, a decreased sector angle can result in - RIGHT ANSWER -increased frame rate If the media boundary is moving away from the source, the result will be - RIGHT ANSWER -lower frequency than incident frequency If the media boundary is moving toward the source, the reflected sound wave will have - RIGHT ANSWER -higher frequency than the incident frequency If the power output of an amplifier is 100 times the power at the input, the gain is - RIGHT ANSWER -20 dB If the transducer Q factor is low, the bandwidth will be - RIGHT ANSWER -broad If the ultrasound beam passes through a mass in the liver that contains fat, how might the diaphragmatic echo posterior to it appear? - RIGHT ANSWER -farther than it really is imaginary surface passing through particles of the same vibration as an ultrasound wave - RIGHT ANSWER -wavefront Improper location of an echo may be attributed to - RIGHT ANSWER -propagation speed error In a mechanical wave, there are material particles that - RIGHT ANSWER -oscillate around an equilibrium point In a pulse-echo system, a 3.5 MHz beam of 2 cm of tissue will be attenuated by - RIGHT ANSWER -(0.5 × 3.5 = 1.75 × 2 =) 3.5 dB In a pulse-echo system, as the ultrasound beam becomes more perpendicular to the organ interface - RIGHT ANSWER -the received echoes become larger In binary numbers, how many values are used for each digit? - RIGHT ANSWER -two In harmonic imaging, received echoes used for the image have _____ than in ordinary pulse-echo imaging. - RIGHT ANSWER -higher frequencies In most soft tissue, the attenuation coefficient varies approximately? A. INVERSELY WITH FREQUENCY B. WITH THE SQUARE OF THE FREQUENCY C. LOGARITHMICALLY WITH FREQUENCY D. DIRECTLY WITH FREQUENCY - RIGHT ANSWER -Directly with frequency in physical science, the word period denotes - RIGHT ANSWER -time to complete one cycle In the study of bioeffects, cavitation denotes - RIGHT ANSWER -production and behavior of gas bubbles Increasing axial resolution by increasing frequency also results in - RIGHT ANSWER -decreasing half-intensity depth Increasing the frequency of an ultrasonic longitudinal wave will result in ______ in the velocity of that wave. - RIGHT ANSWER -no change Increasing the pulse repetition period - RIGHT ANSWER -increases the maximum depth that can be imaged Lambda (λ) represents - RIGHT ANSWER -wavelength lateral resolution - RIGHT ANSWER -Which AIUM test object function utilizes the B group of wires in the AIUM 100 mm test object? Lateral resolution is dependent on? - RIGHT ANSWER -beam diameter Lateral resolution is equal to - RIGHT ANSWER -beam diameter living human tissue - RIGHT ANSWER -in vivo Longitudinal or axial resolution is directly dependent on - RIGHT ANSWER -spatial pulse length Longitudinal waves are characterized by - RIGHT ANSWER -motion of particles parallel to the axis of wave propagation M-mode - RIGHT ANSWER -What mode is displayed in this diagram? mass divided by volume - RIGHT ANSWER -density matching layer - RIGHT ANSWER -#131 Mechanical deformation that results from high voltage applied on faces of the crystal, and, as a result, generate ultrasound - RIGHT ANSWER -reverse piezoelectric effect Microspheres filled with this material is currently used as an ultrasound contrast agent. - RIGHT ANSWER -perfluorocarbon Most of the scan converters currently in use are of the _____ type? - RIGHT ANSWER -digital motor - RIGHT ANSWER -#464 Name 3 natural piezoelectric materials. - RIGHT ANSWER -tourmaline, quartz, Rochelle salt Name 4 examples of a transducer - RIGHT ANSWER -battery, loudspeaker, light bulb, human being Name 5 synthetic piezoelectric materials. - RIGHT ANSWER -lead zirconate titanate, barium titanate, lithium sulfate, lead metaniobate, ammonium dihydrogen phosphate near gain - RIGHT ANSWER -What is A? Near zone length may be increased by increasing - RIGHT ANSWER -frequency & transducer diameter Normal incidence occurs when the ultrasound beam travels ____ to the boundary between the two media - RIGHT ANSWER -perpendicular number of cycles per unit time - RIGHT ANSWER -frequency Occur when the interface is larger than the wavelength - RIGHT ANSWER -specular reflections occur when the interface is smaller than the wavelength - RIGHT ANSWER -nonspecular reflections On some sonographic equipment, adjusting the compression will affect which of the following processes? A. SLOPE POSITION B. DYNAMIC RANGE C. OUTPUT D. BALANCE - RIGHT ANSWER -dynamic range One of the acoustic parameters that determines intensity of an ultrasound wave is? A. WAVEFORM B. PARTICLE DISPLACEMENT C. PERIOD D. POWER - RIGHT ANSWER -particle displacement operating frequency divided by bandwidth - RIGHT ANSWER -quality factor Other than azimuthal, angular, and transverse resolution, what is another term for the ability to distinguish two objects perpendicular to the ultrasound beam? - RIGHT ANSWER -lateral resolution Other than depth, longitudinal, and range/radial resolution, what is another term for the ability to distinguish two objects parallel to the ultrasound beam? - RIGHT ANSWER -axial resolution Period is inversely proportional to - RIGHT ANSWER -frequency picture element - RIGHT ANSWER -pixel piezoelectric ceramic material - RIGHT ANSWER -# 129 piezoelectric crystal - RIGHT ANSWER -#462 Piezoelectric crystals subject to pressure resulting in an electrical charge appearing on their surfaces - RIGHT ANSWER -piezoelectric effect pixel - RIGHT ANSWER -picture element Plastic material placed in front of the transducer face to reduce the reflection at the transducer surface - RIGHT ANSWER -matching layer power divided by area - RIGHT ANSWER -intensity Power is defined as energy per unit - RIGHT ANSWER -time Progression or travel - RIGHT ANSWER -propagation Progressive weakening of the sound beam as it travels - RIGHT ANSWER -attenuation Progressive weakening of the sound beam as it travels through a medium - RIGHT ANSWER -attenuation Propagation speed errors result in - RIGHT ANSWER -improper axial position Pulse duration is the _____ for a pulse to occur. - RIGHT ANSWER -time R = [(Z₂ − Z₁) / (Z₂ + Z₁)]² × 100 - RIGHT ANSWER -percentage of reflection range of frequencies contained in the ultrasound pulse - RIGHT ANSWER -bandwidth rate at which work is done - RIGHT ANSWER -power rayl - RIGHT ANSWER -unit of impedance Rayleigh scattering occurs if the particle dimensions are - RIGHT ANSWER -less than the wavelength Real-time imaging is similar to - RIGHT ANSWER -fluoroscopy Real-time scanners are generally classified as either - RIGHT ANSWER -electronic or mechanical Real-time ultrasound instrumentation can be classified as - RIGHT ANSWER -sector, linear, and annular scanners Redirection of a portion of the ultrasound beam from a boundary is called - RIGHT ANSWER -reflection Redirection of the sound beam in several directions - RIGHT ANSWER -scattering Reduction in echoes from a region distal to an attenuating structure - RIGHT ANSWER -shadowing Reflection factor at an interface between two materials depends primarily on the change in ______ across the interface. - RIGHT ANSWER -acoustic impedance Refraction occurs because of difference in ______ across an interface between two materials - RIGHT ANSWER -wave velocity Refraction will not occur at an interface with _____ incidence of the ultrasound beam. - RIGHT ANSWER -normal registration or B-mode alignment - RIGHT ANSWER -Which AIUM test object function utilizes all the groups of wires in the AIUM 100 mm test object? Reverberation artifacts are a result of - RIGHT ANSWER -two or more strong reflecting surfaces Reverberation artifacts occur with - RIGHT ANSWER -multiple strong reflecting structures ring down artifact - RIGHT ANSWER -What does the arrow point to? rods for measuring "ring-down" - RIGHT ANSWER -In this image, which represents a tissue-equivalent phantom, the small open arrows point to? scan C - RIGHT ANSWER -Which of the diagrams shows correct arm registration? scanner head - RIGHT ANSWER -#463 Scanning a test object from three sides without erasing would be used to check - RIGHT ANSWER -registration sector - RIGHT ANSWER -pie shaped Shadowing occurs with - RIGHT ANSWER -highly attenuating structures shield - RIGHT ANSWER -#130 single-frame imaging - RIGHT ANSWER -static imaging slope - RIGHT ANSWER -What is C? Snell's Law - RIGHT ANSWER -the ratio between the angle of incidence and the angle of refraction Sound will travel ____ in 1 µs in soft tissue - RIGHT ANSWER -1.54 mm Spatial peak intensity / spatial average intensity - RIGHT ANSWER -beam uniformity ratio Specular reflection occurs when - RIGHT ANSWER -the reflector surface is small and smooth as compared with wavelength Specular reflections occur when the reflecting surface is ______ with respect to the wavelength - RIGHT ANSWER -large and smooth Split image artifact is more noticeable in - RIGHT ANSWER -athletic patients and mesomorphic habitus patients SPPA denotes - RIGHT ANSWER -spatial peak pulse average Spreading out of the ultrasound beam - RIGHT ANSWER -diffraction Temporal peak intensity is measured at - RIGHT ANSWER -the time the pulse is present The _____ relates bandwidth to operating frequency. - RIGHT ANSWER -quality factor, Q Factor The abbreviation 5 MHz denotes - RIGHT ANSWER -five million cycles per second The ability of a system to detect low-amplitude echoes accurately is referred to as - RIGHT ANSWER -sensitivity The ability of an imaging system to detect weak reflections is called - RIGHT ANSWER -sensitivity The ability to resolve structures lying perpendicular to the axis of the ultrasound beam is called - RIGHT ANSWER -lateral resolution The acoustic impedance of a material is - RIGHT ANSWER -equal to the product of density and velocity The acoustic impedance of the matching layer - RIGHT ANSWER -can be chosen to improve transmission into the body The acronym BASIC denotes - RIGHT ANSWER -beginner's all-purpose symbolic instruction code The acronym RAM denotes - RIGHT ANSWER -random access memory The acronym ROM denotes - RIGHT ANSWER -read only memory The acronym SATA denotes - RIGHT ANSWER -spatial average temporal average The acronym SPTA denotes - RIGHT ANSWER -spatial peak temporal average The advantage that PZT-5 has over other ceramic materials is that it is A. EASY TO SHAPE B. EFFECTIVE AT LOW VOLTAGE C. INEXPENSIVE - RIGHT ANSWER -all the above The AIUM 100 mm test object measures - RIGHT ANSWER -spatial resolution The AIUM Committee on Biological Effects (1982) stated that _____ biologic effects have been observed for ultrasound intensities below 100 mW/cm². - RIGHT ANSWER -no confirmed The amount of dispersion in the far field of an ultrasound beam can be decreased by - RIGHT ANSWER -using a larger diameter transducer The amount of energy transmitted and/or reflected at the boundary between two media depends on - RIGHT ANSWER -acoustic impedance mismatch The amount of splitting that occurs in a split image artifact for a given structure - RIGHT ANSWER -can be calculated using Snell's law The angle at which an ultrasound beam is bent as it passes through a boundary between two different materials is described mathematically by - RIGHT ANSWER -Snell's law The angle at which total reflection occurs is called - RIGHT ANSWER -critical angle The attenuation coefficient is expressed in units of - RIGHT ANSWER -dB/cm The attenuation for soft tissue is - RIGHT ANSWER -increased with tissue thickness The average propagation speed of ultrasound in soft tissue is - RIGHT ANSWER -1.54 mm/µs The average speed of propagation of ultrasound in soft tissue is - RIGHT ANSWER -1.54 mm/µs The average velocity of ultrasonic waves in soft tissue is - RIGHT ANSWER -1540 m/s The axial resolution of a system is determined by - RIGHT ANSWER -SPL The axial resolution of a transducer can be improved with _____ but at the expense of _____. - RIGHT ANSWER -increased damping, sensitivity The backing material that is usually constructed in a continuous wave Doppler transducer is - RIGHT ANSWER -air The binary number 1010 equals the decimal number - RIGHT ANSWER -10 The change in direction of an ultrasonic beam, when it passes from one medium to another, in which elasticity and density differ from those of the first medium is called - RIGHT ANSWER -refraction The characteristic acoustic impedance of a material is equal to the product of the material density and - RIGHT ANSWER -propagation speed The comet tail artifact can be seen posterior to an object that has - RIGHT ANSWER -either a much lower or a much higher acoustic impedance than its surroundings The confirmed bioeffects on pregnant mice exposed to continuous wave ultrasound in a laboratory setting have resulted in - RIGHT ANSWER -neurocranial damage The confirmed bioeffects on pregnant women with the use of real-time diagnostic instruments is - RIGHT ANSWER -no known effect The contents of EPROM can be completely erased by what application? - RIGHT ANSWER -ultraviolet light The CRT used in ultrasound usually encloses - RIGHT ANSWER -vacuum The density of tissue × the speed of sound in tissue - RIGHT ANSWER -impedance The device that produces the ultrasound beam is commonly called a - RIGHT ANSWER -transducer The difference between real-time ultrasound and fluoroscopy is - RIGHT ANSWER -Ultrasound - no contrast media, Fluoroscopy - potential biologic effects; whereas ultrasound - no known biologic effects at normal intensity level, ultrasound - nonionizing The digital memory representts a picture element called a - RIGHT ANSWER -pixel The digital scan converter will generally have a dynamic range that is ____ than other components of the system - RIGHT ANSWER -smaller The Doppler shift frequency is - RIGHT ANSWER -directly proportional to the velocity of the reflector The Doppler shift frequency is zero when the angle between the receiving transducer and the flow direction is - RIGHT ANSWER -90° The duty factor for a system with a pulse duration of 5 µs and a pulse repetition period of 500 µs is - RIGHT ANSWER -(5/500 =) 1% The duty factor of a pulsed echo system is normally less than - RIGHT ANSWER -1% The dynamic range of a pulse-echo ultrasound system is defined as - RIGHT ANSWER -the ratio of the maximum to the minimum intensity that can be processed The dynamic range of a system is - RIGHT ANSWER -the ratio of smallest to largest power level that the system can handle The dynamic range of the dots on the average oscilloscope or CRT monitor is - RIGHT ANSWER -20-25 dB The effects of diagnostic ultrasound on human soft tissue are called - RIGHT ANSWER -biologic effects The equation for measuring the relationship among velocity (or propagation speed), frequency, and wavelength is - RIGHT ANSWER -V = ƒλ The equation that describes the relationship among propagation, wavelength, and frequency is - RIGHT ANSWER -λ = c/ƒ The extraneous beams of ultrasound generated from the edges of individual transducer elements and not in the direction of the main ultrasonic beam are called - RIGHT ANSWER -side lobes The factor that determines the amount of reflection at the interface of two dissimilar materials is - RIGHT ANSWER -difference in acoustic impedances The first vertical deflection on the A-mode that corresponds to the transducer face is called - RIGHT ANSWER -main bang The five major components of a pulse-echo ultrasound system are - RIGHT ANSWER -pulser, transducer, receiver, image memory, display The fraction of time that a pulsed ultrasound system is actually producing ultrasound is called the - RIGHT ANSWER -duty factor The fraction of time that pulsed ultrasound is actually on is the - RIGHT ANSWER -duty factor The frame rate of a real-time scanner will not depend on - RIGHT ANSWER -the frequency The frequency bandwidth may be determined by which of the following? A. SPECTRAL ANALYSIS B. SCHLIEREN SYSTEM C. HYDROPHONE ANALYSIS D. CATHOD ANALYSIS - RIGHT ANSWER -spectral analysis The frequency of a transducer depends primarily on - RIGHT ANSWER -element thickness The function of the damping material in the transducer housing is to - RIGHT ANSWER -reduce pulse duration, improve axial resolution, reduce spatial pulse length The general range of intensities in diagnostic ultrasound is - RIGHT ANSWER -0.002 W/cm²−0.5 W/cm² SPTA The general range of intensities in therapeutic ultrasound is - RIGHT ANSWER -0.5 W/cm²−2.0 W/cm² SPTA The gray-scale resolution for a 5-bit digital instrument that has a dynamic range of 42 dB is - RIGHT ANSWER -(2⁵ = 32 then 42/32 =) 1.3 dB/gray level The greatest Doppler angle is achieved when the beam strikes a vessel at a ____ angle - RIGHT ANSWER -30° The height of the vertical spike on the A-mode display corresponds to - RIGHT ANSWER -strength of the echo The hydrophone is made up of - RIGHT ANSWER -transducer elements The instrument used to detect frequency shift is called - RIGHT ANSWER -Doppler The intensity of a focused beam is generally highest at the - RIGHT ANSWER -focal zone The intensity of the ultrasound beam depends on - RIGHT ANSWER -beam diameter The intensity of the ultrasound beam is usually greater at the focal zone because of - RIGHT ANSWER -the smaller beam diameter The intensity of ultrasound is measured in - RIGHT ANSWER -W/cm² The lateral resolution of a system - RIGHT ANSWER -is equal to beam diameter The level below which signals are not transmitted through an ultrasound receiver system is the - RIGHT ANSWER -threshold, negative, reject level The lower useful range of diagnostic ultrasound is determined primarily by ____; whereas, the upper useful range is determined by _____. - RIGHT ANSWER -resolution, penetration The major factor in determining the acoustic power output of the transducer is the - RIGHT ANSWER -magnitude of the voltage spike The method for sterilizing transducers is - RIGHT ANSWER -recommended by the transducer manufacturer The mirror image artifact is commonly seen around what structure? - RIGHT ANSWER -diaphragm The mode not applicable to a Doppler instrument is - RIGHT ANSWER -static The most common binary word length in microprocessors is - RIGHT ANSWER -8, 16, 32, or 64 bits The most common result of high intensity ultrasound is - RIGHT ANSWER -heat The most common type of artifact encountered in patients with shotgun wounds is - RIGHT ANSWER -comet tail artifact The most commonly used programming language for personal computer is - RIGHT ANSWER -BASIC The most likely cause for a beam thickness artifact is - RIGHT ANSWER -partial volume effect The most recent digital storage emplys what size memory? - RIGHT ANSWER -512 × 512 × 6-bit deep The near zone is also referred to as - RIGHT ANSWER -Fresnel zone The near zone length of an unfocused transducer depends on - RIGHT ANSWER -frequency and diameter The near-zone length of a transducer depends on - RIGHT ANSWER -frequency and transducer diameter The negatively charged CRT terminal is called the - RIGHT ANSWER -cathode The normal range of intensities used in Doppler instruments is - RIGHT ANSWER -0.2−400 mW/cm² The normal range of wavelength in medical application is - RIGHT ANSWER -0.1−1.5 mm The number 30 in binary is - RIGHT ANSWER -11110 The number of frames per second necessary for a real-time image to be flicker free is - RIGHT ANSWER -more than 15 The number of intensity levels between black and white - RIGHT ANSWER -gray scale The number of known human injuries resulting from diagnostic ultrasound exposure is - RIGHT ANSWER -NONE The operating frequency is dependent on - RIGHT ANSWER -thickness of the crystal The percentage of an ultrasound beam reflected at an interface between fat and muscle is approximately - RIGHT ANSWER -1-10% The percentage of an ultrasound beam reflected at an interface between gas and soft tissue is approximately - RIGHT ANSWER -90-100% The period of an ultrasound wave is - RIGHT ANSWER -the time of one wavelength The piezoelectric properties of a transducer will be lost if the crystal is heated above the - RIGHT ANSWER -Curie point the portion of the sound beam outside of the main beam - RIGHT ANSWER -side lobe The positively charged CRT terminal is called the - RIGHT ANSWER -anode The prefix piezo- is derived from a Greek word that denotes - RIGHT ANSWER -pressure The primary mechanisms whereby ultrasound can produce biologic effects are - RIGHT ANSWER -thermal and cavitation The principle that states that all points on a wavefront can be considered as point sources for the production of sperical secondary wavelets was postulated by - RIGHT ANSWER -Huygens The process of making the impedance values on either side of a boundary as close as possible to reduce reflections is called - RIGHT ANSWER -matching the product of pulse duration and pulse repetition frequency - RIGHT ANSWER -duty factor The product of the period and the number of cycles in the pulse is the - RIGHT ANSWER -pulse duration The production and behavior of bubbles in sound - RIGHT ANSWER -cavitation The propagation speed for fat is A. HIGHER THAN 1540 m/s B. LOWER THAN 1540 m/s C. EQUAL TO 1540 m/s D. CANNOT BE MEASURED - RIGHT ANSWER -lower than 1540 m/s The property of a medium characterized by energy distortion in the medium and irreversibly converted to heat - RIGHT ANSWER -viscoelasticity The pulse repetition frequency is - RIGHT ANSWER -pulse emitted per second The pulse repetition frequency is the number of pulses occurring per - RIGHT ANSWER -second The pulse repetition frequency of an ultrasound unit is typically - RIGHT ANSWER -1000 Hz The range equation explains - RIGHT ANSWER -distance to reflector The range equation relates - RIGHT ANSWER -distance, velocity, and time The range of frequencies contained in an ultrasound pulse is called - RIGHT ANSWER -bandwidth The range of pulse repetition frequencies used in diagnostic ultrasound is - RIGHT ANSWER -0.5−4 kHz The ratio of output of electric power to input electric power is termed - RIGHT ANSWER -gain The ratio of particle pressure to particle velocity at a given point within the ultrasonic field is - RIGHT ANSWER -impedance The ratio of the largest power to the smallest power that the ultrasound system can handle is the - RIGHT ANSWER -dynamic range The recommended orientation for a transverse scan. - RIGHT ANSWER -all transverse scans should be viewed from the patient's feet The recommended orientation for longitudinal scans is - RIGHT ANSWER -the patient's head to the left of the image and feet to the right of image The reflection coefficient between water and air is - RIGHT ANSWER -nearly 100% The refractive index of water is slightly altered when a sound beam passes through it, thus causing compression and rarefaction of the water molecules. The phenomenon is the basis for the _____ technique of beam measurement. - RIGHT ANSWER -Schlieren The role of sound attenuation in tissue is expressed in terms of - RIGHT ANSWER -half-value layer The spectrum of ultrasonic frequency is - RIGHT ANSWER -above 20,000 Hz The speed at which ultrasound propagates within a medium depends primarily on - RIGHT ANSWER -the compressibility of the medium The SPL is defined as the product of the ____ multiplied by the number of ____ in a pulse - RIGHT ANSWER -wavelength, cycles The strength of the echo is related to the height of the deflection on the oscilloscope for the ____ display. - RIGHT ANSWER -A-mode The substance typically used as a matrix on the imaging surface of an analog scan converter tube is - RIGHT ANSWER -silicon oxide The surface forming the boundary between two media having different acoustic impedance - RIGHT ANSWER -interface The technique of passing an ultrasound beam through water so that compression and rarefaction of the water molecules allow the beam pattern to be measured is referred to as the - RIGHT ANSWER -Schlieren method The technique that uses an optical system to produce a visible image of an ultrasonic beam is the _____ technique. - RIGHT ANSWER -Schlieren The term Hertz denotes - RIGHT ANSWER -frequency, cycle per second The term matrix, when referring to digital memory denotes - RIGHT ANSWER -number of rows and columns The threshold control is equivalent to the - RIGHT ANSWER -reject control The time it takes to complete a single cycle is called - RIGHT ANSWER -period The time-gain or depth-gain compensation control - RIGHT ANSWER -compensates for attenuation effects The trade name for lead zirconate titanate is - RIGHT ANSWER -PZT-5 The transducer ____ determines its ______. - RIGHT ANSWER -thickness, resonance frequency The transducer _____ is equal to the ratio of the operating frequency to the frequency bandwidth. - RIGHT ANSWER -Q factor The transducer crystal most likely to be employed in high-frequency work, above 18 MHz, is - RIGHT ANSWER -quartz The transducer that would be best suited for intercostal scanning is - RIGHT ANSWER -mechanical sector real-time transducer The two types of cavitation are - RIGHT ANSWER -stable and transient The type of programmable memory that allows the user to write, store, or erase data is called - RIGHT ANSWER -EPROM The type of real-time system that employs a combination of electronic and mechanical means is called - RIGHT ANSWER -annular-array real-time The type of reverberation echo that usually results from a small gas bubble and appears as a high-amplitude echo occurring at regular intervals is called a - RIGHT ANSWER -ring-down artifact The typical value for attenuation coefficient for 6 MHz ultrasound in soft tissue is - RIGHT ANSWER -3 dB/cm The typical value of attenuation in soft tissue is - RIGHT ANSWER -0.5 dB/cm/MHz The unit applied to the Q factor (quality factor) that describes the ratio of operating frequency to bandwidth is called - RIGHT ANSWER -none; unitless The unit for measuring the speed of data communication is called - RIGHT ANSWER -baud rate The unit of measure of SPTA is - RIGHT ANSWER -W/cm² The unit used for the duty factor is - RIGHT ANSWER -unitless The velocity of sound waves is primarily dependent on - RIGHT ANSWER -medium and mode of vibration The wave equation relates - RIGHT ANSWER -wavelength, velocity, and frequency The wavelength in a material having a wave velocity of 1500 m/s emplying a transducer frequency of 5 MHz is - RIGHT ANSWER -0.3 mm The wavelength of a 5 MHz wave passing through soft tissue is approximately - RIGHT ANSWER -0.3 mm There is no known adverse biologic effect in tissue at intensities below - RIGHT ANSWER -100 mW/cm² SPTA This type of scan converter stores any increment of signal amplitude - RIGHT ANSWER -analog tissue cultures in a test tube - RIGHT ANSWER -in vitro To achieve the best possible digital representation of an analog system, the echo signals should undergo - RIGHT ANSWER -preprocessing Transducers are focused by two major methods: internal focusing and external focusing. These methods can be accomplished by - RIGHT ANSWER -cutting a curved transducer element (subdicing) and/or using an acoustic lens Transducers with continuous wave operation are commonly used in which applications? - RIGHT ANSWER -surgical, therapeutic, and Doppler Transmit-delay focusing in a linear array transducer will - RIGHT ANSWER -improve lateral resolution Transonic regions are always - RIGHT ANSWER -uninhibited to propagation Transverse waves are characterized by - RIGHT ANSWER -motion of particles perpendicular to the axis of wave propagation True/False: A linear sequenced array cannot be dynamically focused. - RIGHT ANSWER -False True/False: A mechanical real-time scanner will always produce images at a slower frame rate than does an electronic real-time scanner. - RIGHT ANSWER -false True/False: A pulse-echo system should have a high Q factor (quality factor). - RIGHT ANSWER -false True/False: A videotape recorder records at a rate of 30 frames/s and therefore cannot be used to record images from a mechanical scanner operating at lower frame rates. - RIGHT ANSWER -false True/False: An annular array scanner uses mechanical beam steering. - RIGHT ANSWER -True True/False: Changes in the preprocessing controls will not affect the numbers stored in the scan converter. - RIGHT ANSWER -false True/False: Color Doppler systems are not subject to aliasing. - RIGHT ANSWER -false True/False: Electronically steered scanners always produce higher resolution images than do mechanically steered scanners. - RIGHT ANSWER -False True/False: For a focused transducer, the beam intensity will remain constant through the scan field - RIGHT ANSWER -false True/False: Grating lobes are essential for the proper operation of a linear phased array. - RIGHT ANSWER -False True/False: In a pulse-echo system, the quality factor should be made as large as possible. - RIGHT ANSWER -False True/False: It is not possible to steer an annular phased array electronically. - RIGHT ANSWER -True True/False: Linear phased array scanners need no form of mechanical focusing because focusing is performed electronically. - RIGHT ANSWER -False True/False: No refraction can occur at an interface if the media impedances are equal. - RIGHT ANSWER -False True/False: Quality assurance measurements are not required with electronic scanners with digital scan converters. - RIGHT ANSWER -false True/False: Real-time imaging is impossible without electronic arrays. - RIGHT ANSWER -false True/False: Receiver-angle values in CW Doppler analysis do not influence the final Doppler shift. - RIGHT ANSWER -False True/False: Smaller transducers always produce smaller beam diameters. - RIGHT ANSWER -False True/False: The beam diameter is constant in the near zone. - RIGHT ANSWER -False True/False: The fram rate of real-time scanners depends on the number of lines used to form the image. - RIGHT ANSWER -True True/False: The frame rate of real-time scanner that uses an electronic array will be limited only by the speed of the scan converter memory. - RIGHT ANSWER -false True/False: The gray-scale display was made possible when digital scan converters replaced analog scan converters. - RIGHT ANSWER -False True/False: The intensity of an ultrasonic beam can be measured with radiation force balance. - RIGHT ANSWER -True True/False: The near zone length should be kept as short as possible. - RIGHT ANSWER -False True/False: The pulsed-Doppler system yields better depth resolution than the continuous wave (CW) system. - RIGHT ANSWER -True True/False: The SPTA intensity will always be larger than the SATA intensity. - RIGHT ANSWER -True True/False: The ultrasound beam profile can be measured with a hydrophone. - RIGHT ANSWER -True True/False: Videotape recorders operating at 30 frames per second cannot be used with mechanical real-time units because the fram rate is too slow. - RIGHT ANSWER -False tuning coil - RIGHT ANSWER -#126 Two primary mechanisms that produce tissue biological effects are - RIGHT ANSWER -thermal and cavitational Ultrasonic waves are - RIGHT ANSWER -mechanical Ultrasound absorption in a medium results in - RIGHT ANSWER -conversion of ultrasound into heat Ultrasound absorption is directly proportional to - RIGHT ANSWER -viscosity, frequency, distance Ultrasound beams can be focused and defocused with the use of - RIGHT ANSWER -a concave/convex mirror, acoustic lenses Ultrasound bioeffects - RIGHT ANSWER -are not confirmed below 100 mW/cm² SPTA Ultrasound can be described as a - RIGHT ANSWER -mechanical vibration that can be transmitted through matter Ultrasound CANNOT travel in - RIGHT ANSWER -a vacuum Ultrasound has difficulty in propagating through which of the following? A. AIR B. BONE C. BaSO₄ D. IVP CONTRAST - RIGHT ANSWER -air, bone, BaSO₄ Ultrasound is defined as sound with frequencies above - RIGHT ANSWER -20 kHz Ultrasound wave propagation causes displacement of particles in a medium. The regions of greatest particle concentration are - RIGHT ANSWER -compressions Ultrasound wave propagation causes displacement of particles in a medium. The regions of lowest particle concentration are called - RIGHT ANSWER -rarefactions Ultrasound waves in tissue are referred to as - RIGHT ANSWER -longitudinal compression waves; longitudinal mechanical waves Ultrasound waves in tissues are called _____ waves. - RIGHT ANSWER -longitudinal units for attenuation - RIGHT ANSWER -dB units for density - RIGHT ANSWER -kg/m³ units for frequency - RIGHT ANSWER -Hz units for intensity - RIGHT ANSWER -W/cm² units for speed - RIGHT ANSWER -m/s units for wavelength - RIGHT ANSWER -m units for work - RIGHT ANSWER -J (joules) Video monitors normally have how many horizontal lines? - RIGHT ANSWER -525 Voltage pulses from the pulser go to the - RIGHT ANSWER -transducer and receiver Wavelength is a measure of - RIGHT ANSWER -distance What are methods of restricting the dynamic range of the signal? - RIGHT ANSWER -suppression, rejection, compression What are the functions performed by the receiver in the ultrasound machine? - RIGHT ANSWER -amplification, compensation, compression, rejection What happens to axial resolution when spatial pulse length is decreased? - RIGHT ANSWER -improves What happens to spatial pulse length when frequency increases? - RIGHT ANSWER -decreases What happens to the ultrasound beam beyond the critical angle? - RIGHT ANSWER -100% reflected What image shape is produced by a linear sequenced array transducer? - RIGHT ANSWER -rectangular What is the distinction between real-time scans and B-scans? - RIGHT ANSWER -no distinction What is the effect of ultrasound absorption on tissues at normal intensity levels? - RIGHT ANSWER -dissipation of heat by conduction What is the following formula used to determine? (2 × velocity of reflector × original frequency) / velocity of sound - RIGHT ANSWER -Doppler shift frequency What is the least likely cause for a split image artifact? - RIGHT ANSWER -gas bubble What is the reflected intensity from a boundary between two materials if the incident intensity is 1mW/cm² and the impedances are 25 and 75 - RIGHT ANSWER -{R = [(75-25) / (75+25)]² = (50/100)² = 0.5² =} 0.25 mW/cm² What is the type of permanent memory that is produced at the time of manufacture and cannot be changed by the computer user? - RIGHT ANSWER -ROM What is the velocity of ultrasound in human soft tissue at 37°C? - RIGHT ANSWER -1540 m/s What parameters CANNOT be evaluated by the AIUM test object? - RIGHT ANSWER -gray scale, dynamic range What percentage of intensity of an ultrasound pulse incident on an interface of 0.25 and 0.75 rayls is reflected? - RIGHT ANSWER -25% What percentage of the time is a typical pulsed ultrasound system capable of receiving echoes? - RIGHT ANSWER -99.9% What three things can occur when an ultrasonic beam reaches the interface of two dissimilar materials? - RIGHT ANSWER -reflection, refraction, mode conversion What type of artifacts result from echoes that take an indirect path back to the transducer? - RIGHT ANSWER -Multipath When an ultrasound beam passes obliquely across the boundary between two materials, ____ will occur if there is a difference in ____ in the two materials. - RIGHT ANSWER -refraction, propagation speed When attempting to identify fetal heart motion, the frame rate of the real-time system should be set at a ______ rate - RIGHT ANSWER -fast When electric voltage is applied on both faces of a piezoelectric crystal, the crystal will - RIGHT ANSWER -increase or decrease in size depending on the voltage polarity When particle motion of a medium is parallel to the direction of a wave propagation, the wave being transmitted is called a - RIGHT ANSWER -longitudinal wave When the FOV is reduced by decreasing the PRP, the following is more likely to occur - RIGHT ANSWER -greater range ambiguity artifacts When the peizoelectric crystal continues to vibrate after the initial voltage pulse, this is referred to as - RIGHT ANSWER -ring-down time When the pressure peaks of two waves coincide at a point to produce a new pressure that is larger than either of the two initial waves, the effect is called - RIGHT ANSWER -constructive interference When using the AIUM test object, which of the following should be kept constant for comparisons? A. OUTPUT POWER B. TGC C. REJECT D. TRANSDUCER MHz & FOCUS - RIGHT ANSWER -all the above Where does the beam of an unfocused transducer diverge? - RIGHT ANSWER -Fraunhofer zone Which contrast media used in x-ray do not obscure the propagation of ultrasound? - RIGHT ANSWER -hypaque for IVP examination, telepaque for oral cholecystogram Which control is used to minimize the effects of attenuation? - RIGHT ANSWER -TGC, DGC Which imaging modality is audible? - RIGHT ANSWER -Doppler Which mode requires two crystals: one for transmitting, and one for receiving? - RIGHT ANSWER -continuous wave Which modes are one dimensional? - RIGHT ANSWER -A-mode, M-mode Which of the following are effects seen in tissue at high ultrasound intensities? A. FUSION, IONIZATION B. HEATING, CAVITATION C. EXPANSION, ENCRUSTATION D. REABSORPTION, DEHYDRATION - RIGHT ANSWER -heating, cavitation Which of the following are not operator adjustable? A. COMPENSATION & REJECTION B. AMPLIFICATION & COMPENSATION C. DEMODULATION & COMPRESSION D. REJECTION & AMPLIFICATION - RIGHT ANSWER -demodulation & compression Which of the following CANNOT be checked when the AIUM test object is scanned from the top only? A. AXIAL RESOLUTION B. LATERAL RESOLUTION C. VERTICAL DISTANCE CALIBRATION D. HORIZONTAL DISTANCE CALIBRATION - RIGHT ANSWER -lateral resolution Which of the following cannot be distinguished on diagnostic ultrasound? A. TISSUE B. SOLID MASS C. INDIVIDUAL CELLS D. MALE / FEMALE GENETALIA - RIGHT ANSWER -individual cells Which of the following cannot be measured by a hydrophone? A. PRESSURE AMPLITUDE B. SPL C. IMPEDANCE D. INTENSITY - RIGHT ANSWER -impedance Which of the following CANNOT be used as a coupling medium? A. WATER B. SALINE C. BARIUM SULFATE D. AQUEOUS GELS - RIGHT ANSWER -barium sulfate Which of the following characteristics does NOT apply to diagnostic ultrasound at normal diagnostic intensity levels? A. NONINVASIVE B. ATRAUMATIC C. IONIZING D. NONTOXIC - RIGHT ANSWER -ionizing Which of the following combinations of frequency and intensity would most likely result in cavitation? A. HIGH FREQUENCY AND LOW INTENSITY B. LOW FREQUENCY AND HIGH INTENSITY C. HIGH FREQUENCY AND HIGH INTENSITY D. INTENSITY HAS NO EFFECT ON CAVITATION - RIGHT ANSWER -low frequency and high intensity Which of the following disks has the highest storage capacity and fastest access time? A. 3½-IN MICROFLOPPY DOUBLE DENSITY B. HARD DISK C. 5¼-IN MINIFLOPPY D. 3½-IN MICROFLOPPY HIGH DENSITY - RIGHT ANSWER -hard disk Which of the following does not display a sector format? A. LINEAR-SEQUENCED B. ELECTRONIC-PHASED ARRAY C. MECHANICAL ROTATING WHEEL D. MECHANICAL WOBBLER - RIGHT ANSWER -linear-sequenced array Which of the following has a higher acoustic impedance coefficient? A. SOLID B. LIQUID C. GAS D. ALL HAVE EQUAL ACOUSTIC IMPEDANCE COEFFICIENT - RIGHT ANSWER -solid Which of the following has a propagation speed closest to the average soft tissue? A. BONE B. AIR C. FAT D. MUSCLE - RIGHT ANSWER -muscle Which of the following has the highest sound velocity? A. SOFT TISSUE B. BONE C. AIR D. WATER - RIGHT ANSWER -bone Which of the following has the lowest intensity? A. SPTP B. SATP C. SPTA D. SATA - RIGHT ANSWER -SATA Which of the following is a true definition for a highly damped transducer? A. INCREASED EFFICIENCY, SENSITIVITY, AND SPL B. DECREASED EFFICIENCY, SENSITIVITY, AND SPL C. INCREASED EFFICIENCY AND SENSITIVITY, BUT DECREASED SPL D. DECREASED EFFICIENCY, BUT INCREASED SENSITIVITY AND SPL - RIGHT ANSWER -DECREASED EFFICIENCY, SENSITIVITY AND SPL Which of the following is determined by the medium? A. INTENSITY B. PERIOD C. PROPAGATION SPEED D. AMPLITUDE - RIGHT ANSWER -propagation speed Which of the following is likely to produce a comet tail artifact? A. BONE INTERFACE B. METALLIC SURGICAL CLIPS C. GALLSTONES D. GAS INTERFACE - RIGHT ANSWER -metallic surgical clips (or shotgun pellets) Which of the following is most commonly used in ultrasound transducers? A. LEAD ZIRCONATE TITANATE (PZT) B. BARIUM SULFATE C. METANIOBATE D. QUARTZ - RIGHT ANSWER -lead zirconate titanate Which of the following is not a component of the time-gain compensation (TGC) curve? A. GRAY SCALE B. FAR GAIN C. KNEE D. DELAY - RIGHT ANSWER -gray scale Which of the following is not a hard copy? A. X-RAY FILM B. POLAROID FILM C. DYE SUBLIMATION COLOR PRINT D. VIDEOTAPE RECORDER - RIGHT ANSWER -videotape recorder Which of the following is not a role of the pulser? A. DRIVING THE TRANSDUCER B. TELLING RECEIVER WHEN ULTRASOUND PULSES ARE PRODUCED C. TELLING MEMORY WHEN ULTRASOUND PULSES ARE PRODUCED D. BEAM STEERING - RIGHT ANSWER -beam steering Which of the following is not among the spectrum of electromagnetic waves? A. X-RAYS B. ULTRASOUND C. ULTRAVIOLET D. INFRARED E. VISIBLE LIGHT - RIGHT ANSWER -ultrasound Which of the following is not an acoustic variable? A. DENSITY B. PRESSURE C. TEMPERATURE D. FORCE - RIGHT ANSWER -force Which of the following is NOT an essential part of the cathode-ray tube (CRT)? A. ELECTRON GUN B. FLUORESCENT SCREEN C. SILICON D. DEFLECTION SYSTEM (HORIZONTAL & VERTICAL PLATES) - RIGHT ANSWER -silicon Which of the following is not an example of computer hardware? A. MONITOR B. PROGRAM C. DISK DRIVE D. PRINTER - RIGHT ANSWER -program Which of the following is not an input device? A. KEYBOARD B. PRINTER C. DISK DRIVE D. MAGNETIC DISK - RIGHT ANSWER -printer Which of the following is not related to real-time? - RIGHT ANSWER -static imaging Which of the following is NOT true for side lobe artifact? A. CAUSED BY MULTIPLE SIDE LOBES OF THE TRANSDUCER B. APPARENT IN REAL-TIME IMAGE C. MAY BE DIFFUSE OR SPECULAR IN APPEARANCE D. NOT VISIBLE ON REAL-TIME IMAGE - RIGHT ANSWER -may be diffuse or specular in appearance Which of the following is the least likely cause for attenuation? A. ABSORPTION B. REFLECTION C. REFRACTION D. SCATTERING - RIGHT ANSWER -refraction Which of the following is the least obstacle to the transmission of ultrasound? A. MUSCLE B. FAT C. BONE D. BLOOD - RIGHT ANSWER -blood Which of the following is true? A. SPTA IS ALWAYS ≥ SPTP B. SPTP IS ALWAYS ≥ SPTA C. SATA IS ALWAYS ≥ SATP D. SPTA IS ALWAYS ≥ SATP - RIGHT ANSWER -SPTP is always ≥ SPTA Which of the following materials are used to make acoustic lenses? - RIGHT ANSWER -aluminum, Perspex (acrylic plastic), polystyrene Which of the following materials would NOT be suitable as acoustic insulators for transducer backing? A. CORK B. RUBBER C. OIL D. ARALDITE W/ TUNGSTEN POWDER E. EPOXY RESIN - RIGHT ANSWER -oil Which of the following may produce the comet tail artifact? A. LIVER−KIDNEY INTERFACE B. SPLEEN−KIDNEY INTERFACE C. TISSUE−GAS INTERFACE D. GAS−FLUID INTERFACE - RIGHT ANSWER -tissue−gas interface Which of the following statements about ultrasound waves is not true? A. ULTRASOUND WAVES ARE MECHANICAL VIBRATING ENERGY B. ULTRASOUND WAVES CAN BE POLARIZED C. ULTRASOUND WAVES ARE NOT PART OF THE ELECTROMAGNETIC SPECTRUM D. ULTRASOUND WAVES CANNOT TRAVEL IN A VACUUM - RIGHT ANSWER -ultrasound waves can be polarized Which of the following transducers would be most useful for good penetration on an obese patient? A. 5 MHz, SHORT FOCUS B. 3 MHz, LONG FOCUS C. 5 MHz, LONG FOCUS D. 2.5 MHz, SHORT FOCUS - RIGHT ANSWER -3 MHz, long focus Which of the following transducers would be most useful for imaging superficial structures A. 5 MHz, SHORT FOCUS B. 3 MHz, LONG FOCUS C. 5 MHz, LONG FOCUS D. 2.5 MHz, SHORT FOCUS - RIGHT ANSWER -5 MHz, short focus Which of the following type(s) of ultrasound machine can be used with AIUM test object? A. LINEAR ARRAY B. STATIC SCANNER C. PHASED ARRAY D. ANNULAR ARRAY E. SECTOR SCANNER - RIGHT ANSWER -all the above Which of the following utilize a TGC? A. STATIC SYSTEM B. REAL-TIME SYSTEM C. BISTABLE SYSTEM - RIGHT ANSWER -all the above Which of the following varies with distance from the transducer? A. LATERAL RESOLUTION B. FREQUENCY C. AXIAL RESOLUTION D. SPATIAL PULSE LENGTH - RIGHT ANSWER -lateral resolution Which of the following waves are visible under normal conditions? A. WATER WAVES B. X-RAY WAVES C. RADIO WAVES D. SOUND WAVES - RIGHT ANSWER -water waves Which of the following will improve both axial and lateral resolution? A. SHORT PULSE LENGTH B. NARROW BEAM WIDTH C. INCREASE BEAM DIAMETER D. INCREASE TRANSDUCER FREQUENCY - RIGHT ANSWER -increase transducer frequency Which of the following will not affect the echo intensity in the image? A. OUTPUT POWER B. OVERALL GAIN C. TIME GAIN CURVE - RIGHT ANSWER -all the above Which of the following would be most likely to cause acoustic enhancement? A. A SOLID MASS B. A FLUID-FILLED MASS C. A CALCIFIED MASS D. A GALLSTONE - RIGHT ANSWER -fluid-filled mass Which of the following would be most likely to cause acoustic shadowing? A. GALLBLADDER B. FLUID-FILLED MASS C. CALCIFIED MASS D. URINARY BLADDER - RIGHT ANSWER -calcified mass Which quantity is unitless? - RIGHT ANSWER -Q factor, Duty factor Which statement about Doppler application is not true? A. COLOR DOPPLER IS NOT BENEFICIAL B. DOPPLER CAN PRODUCE AUDIBLE SOUND C. DOPPLER INSTRUMENTS USE BOTH PULSED AND CONTINUOUS WAVE D. DOPPLER CAN DISPLAY AN IMAGE - RIGHT ANSWER -color Doppler is not beneficial Which statements about bioeffects are unconfirmed? A. ULTRASOUND EXPOSURE IN HUMANS IS ACCUMULATIVE B. MOST HARMFUL BIOEFFECTS THAT OCCURRED IN EXPERIMENTAL CONDITIONS HAVE BEEN CONFIRMED IN HUMANS IN A CLINICAL SETTING C. INTENSITY, FREQUENCY, AND EXPOSURE TIME USED ON EXPERIMENTAL ANIMALS WERE COMPATIBLE THOSE USED IN A CLINICAL SETTING D. CONTINUOUS WAVE USED IN EXPERIMENTAL STUDIES GIVES THE SAME TISSUE EXPOSURE AS PULSED ULTRASOUND USED IN A CLINICAL SETTING E. THE EXPOSURE OF PREGNANT WOMEN TO HIGH INTENSITY LEVELS RESULTED IN GROWTH RETARDATION OF THEIR OFFSPRING - RIGHT ANSWER -all are false or unconfirmed Whose principal states "All points on an ultrasound waveform can be considered as point sources for the production of secondary spherical wavelets"? - RIGHT ANSWER -Huygens' Without echoes - RIGHT ANSWER -anechoic X-plate - RIGHT ANSWER -#137 Y-plate - RIGHT ANSWER -#136 Z = ρV - RIGHT ANSWER -impedance formula