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ARDMS SPI EXAM LATEST 2023 - 2024 REAL
EXAM 150 QUESTIONS AND CORRECT
ANSWERS|AGRADE
Multiple echoes, equally spaced originating from a gas bubble is called: a. comet tail b. ring down c. slice thickness artifact d. multipath Correct Answer: b. ring down An increase in red blood cell velocity will the Doppler Shift: a. increase b. decrease c. not change d. cannot be predicted Correct Answer: a. increase The primary advantage of CW Doppler is: a. range resolution b. range discrimination c. range ambiguity d. range gating e. absence of sampling rate Correct Answer: e. absence of sampling rate The range for ultrasound begins: a. 20 Hz b. 20,000 Hz c. 2 MHz d. 15 MHz Correct Answer: b. 20,000 Hz (useful frequency range for clinical imaging is 2MHz-10MHz) Which instrument control affects the amplitude (dB) of the outgoing signal: a. gain b. receiver gain c. TGC d. transmit gain e. overall gain Correct Answer: d. transmit gain; amplitude can be affected by the sonographer Which of the following is used to convert Doppler shift information into color:
a. high PRF b. fast Fourier transform c. autocorrelation d. time interval histogram Correct Answer: c. autocorrelation
a. increase b. decrease c. not change d. cannot be predicted. Correct Answer: b. decrease Which gain will increase the risk of bioeffects? a. transmit b. receive c. gain d. overall gain Correct Answer: a. transmit Which of the following is considered the memory of an ultrasound instrument? a. pulser b. transducer c. receiver d. beam former e. digital scan converter f. display monitor Correct Answer: e. digital scan converter Spectral broadening suggest: a. laminar flow b. turbulent flow c. flow away from the transducer d. flow towards the transducer Correct Answer: b. turbulent flow With pulse wave Doppler axial resolution: Correct Answer: degrades What color is usually use in color flow Doppler variance map to indicate turbulent flow? Correct Answer: green Doppler high pass filter eliminates: Correct Answer: high amplitude signals; low velocity flow The Doppler wall filter is considered a: Correct Answer: high pass filter The Nyquist Limit is equal to: a. propagation speed x frequency b. propagation speed/ wavelength c. PRF/ d. 4xV^2 Correct Answer: c. PRF/
All of the following directly affect frame rate except: a. depth of penetration b. field of view c. number of focuses d. line density e. beam width Correct Answer: e. beam width A reflection will occur at the boundary of two media if the acoustic impedences of the two media are: a. equal b. different c. unchanged d. cannot be predicted Correct Answer: b. different A mechanical transducer utilizes: a. transmit focus b. receive focus c. fixed focus d. dynamic aperture focusing Correct Answer: c. fixed focus; sonographer cannot determine the location of # of foci. mechanical transducer uses cross sectional imaging, rotating wheel, wobbler, oscillating mirror The transducer frequency is primarily determined by the transducer element: a. diameter b. thickness c. propagation speed d. type Correct Answer: b. thickness A strongly focused transducer implies a: a. short focal length; decreased beam divergence b. medium focal length; increased beam divergence c. long focal length; no beam divergenc d. short focal length; increased beam divergence Correct Answer: d. short focal length; increased beam divergence
e. intensity Correct Answer: e. intensity= mW/cm What are the four acoustic variables: Correct Answer: 1. temperature, density, particle motion, pressure Frequency is Correct Answer: Cycles per second (Hz) not affected by sonographer increase frequency; decrease depth Pulse duration Correct Answer: period (ms) x # of cycles in a pulse Wavelength Correct Answer: the length of one cycle wavelength= propagation speed/ frequency 1.54/3MHz= .5mm An increase in packet size will the frame rate Correct Answer: Decrease The range for audible sound is: Correct Answer: 20 Hz- 20kHz The wavelength of a 1MHz transducer is: Correct Answer: 1.54/1= 1.54mm The average speed of sound in soft tissue is: Correct Answer: 1540m/s; 1.54km/s; 1.54mm/us An increase in overall gain will result in all of the following except: a. increase in image brightness b. increase in output power c. increase in amplification of the returning signal d. decrease risk in bioeffects Correct Answer: b. increase in power Reject eliminates: Correct Answer: low amplitude signals There have been no proven biological effects for unfocused transducers for intensities below: Correct Answer: 100mW/cm2 SPTA The primary cause of attenuation of ultrasound in soft tissue is caused by: Correct Answer: absorption Resolution artifact Correct Answer: When two structures parallel to the ultrasound beam are displayed as one reflector.
Damping does not decrease: Correct Answer: bandwidth Spectral Broadening Correct Answer: The widening of the doppler shift spectrum. Meaning the increase of the range of doppler shift frequencies present, owing to a broader range of flow speeds encountered by the sound beam. Refraction Correct Answer: Change in direction of a wave when it changs speed as in travels from one material to another. The change in the direction of sound as it crosses a boundary. autocorrelation Correct Answer: used to convert Doppler shift information into color. PRF Correct Answer: Pulse Repetition Frequency. The rate at which pulses are transmitted, given in hertz or pulses per second; reciprocal of pulse-repetition time. Period Correct Answer: the time per cycle 1 - 10usec Period Calculation Correct Answer: 1/frequency 1/5MHz=. How do you decrease period? Correct Answer: Increase frequency Impedance Correct Answer: the opposition of sound propagation The unit for impedance? Correct Answer: Rayls What type of wave is sound? - ANSWER- mechanical and longitudinal The frequency ranges for ultrasound are: - ANSWER- >20 kHz The speed of sound in soft tissue is: - ANSWER- 1540 m/s which of the following transducers fires the elements in groups? A. Linear sequenced array B. Phased array C. Continuous-wave transducer D. Single-element transducer - ANSWER- A
spatial pulse length is a product of the _____ & the number of _______ in a pulse? - ANSWER- wavelength & Cycles 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? ** - ANSWER- 15dB (1/2=-3dB therefore, 18dB- 3dB=15dB) True or False: SPTP is always equal to or greater than SPTA ** - ANSWER- True If the amplitude of a wave is increased threefold, the power will: ** - ANSWER- Increase NINEfold (amp squared) ultrasound attenuates an average of ____ dB/cm of travel for each megahertz of frequency. ** - ANSWER-. If the intensity transmission coefficient is 0.74, the intensity reflection coefficient will be: ** - ANSWER- .26 (IRC & ITC must =100) Acoustic impedance is a product of: ** - ANSWER- speed of sound in tissue & density of the tissue reflector whose size is smaller than the wavelength ** - ANSWER- Rayleigh Scattering Total attenuation of a 3.5MHz pulse after passing thru 2cm of soft tissue?** - ANSWER- 3.5dB The thinner the piezoelectric element: ** - ANSWER- the higher the frequency The unit for impedance is ________. - ANSWER- Rayl A sound beam encounters an interface at a 90* angle. If the speed of sound in the first tissue is 1540m/s & speed of sound in second tissue is 1450 m/s, what is approximate angle of beam transmission? - ANSWER- 90* (no refraction) A decibel describes the: - ANSWER- RATIO of 2 sound intensities Attenuation coefficient of sound in soft tissue can be defined by what equation? ** - ANSWER- frequency/2 (1/2 of freq)
The intensity transmission coefficient is equal to: - ANSWER- 1 - intensity reflection coefficient The range equation explains: ** - ANSWER- distance to reflector The typical value for attenuation coefficient for 6 MHz ultrasound in soft tissue is - ANSWER- 3dB/cm (1/2 the freq) What must be known to calculate the distance to a reflector? - ANSWER- Travel time, propagation speed Specular reflection occurs when - ANSWER- interface(border) is larger than the wavelength The layers material within the transducer which has an intermediate impedance between the transducer element & human tissue is known as: ** - ANSWER- Matching Layer What relates bandwidth to operating frequency? ** - ANSWER- Quality Factor (OF/bandwidth) the piezoelectric effect can be best described as: - ANSWER- piezoelectric crystals subject to pressure resulting in an electrical charge appering on their surface. Spreading out of the ultrasound beam** - ANSWER- diffraction Preferred method of sterilizing transducers: - ANSWER- Cold Sterilization Transducer with which a frequency would have the thickest element? A. 2MHZ B.3.5MHZ C.5MHZ D.7.5MHZ - ANSWER- A (thicker the element=lower freq) Best defines ability to discriminate between 2 closely spaced reflectors? ** - ANSWER- Spatial Resolution which of the following is an effect on Focusing? ** A. Improved lateral resolution B. Improved axial resolution C. Increased beam divergence in the near zone
echo intensity on a grayscale of 32 shades is represented by the binary number: - ANSWER- 100000 What does grayscale system typically use as means of signal dynamic range REDUCTION? - ANSWER- Compression If frequency of a transducer in increased, what decreases? - ANSWER- Wavelength What has Decreased artifacts in the near field ** - ANSWER- Harmonics Infrasound is defined as sound with a frequency of ______. A. greater than 20,000 kHz B. less than 20 Hz C. greater than 10 Mhz D. less than 0.02 MHz - ANSWER- B Which of the following can be changed by the operator? A. Frequency B. Wavelength C.Propogation Speed D. Pulse Repetition Frequency - ANSWER- D. PRF-by adjusting depth- A 5MHz wave travels thru 5cm of soft tissue. If a 3.5 MHz transducer is selected instead, what happens to the propagation speed of the medium ** - ANSWER- NO change. Prop speed only determined by medium The SLOWEST propagation speed is found in which medium ** - ANSWER- AIR! What is the unit of pressure amplitude ** - ANSWER- Pascal What else changes with a change in amplitude ** - ANSWER- Output Power What is along the x-axis on a spectral doppler waveform? ** - ANSWER- TIME What testing device measures acoustic output (intensity)? - ANSWER- Hydrophone Principle that states sound waves are the result of the interference of many wavelets produces at the face of transducer - ANSWER- Huygen's Principle When using tissue harmonics, the frequency is ____ the fundamental frequency ** - ANSWER- DOUBLE
In B-Mode, amplitude is located on the ___-axis of image - ANSWER- Z-axis what determines the radial resolution of a system - ANSWER- Spatial Pulse Length (radial=axial) The axial resolution can be improved by DECREASING the _______ or INCREASING the ______. ** - ANSWER- Number of cycles in a pulse, frequency The larger the aperture, the ____ the ____ zone - ANSWER- longer, near (aperture=element diameter) The ability to resolve 2 reflectors that lie parallel to the beam is _____ resolution of a system. ** - ANSWER- AXIAL What is the maximum temperature increase below which there should be NO thermally induced biologic effects? - ANSWER- 2*C 2 sound beams with different frequencies are traveling thru soft tissue. which beam will travel faster? - ANSWER- Both will travel at the same speed What is the relationship between spatial pulse length & pulse duration? ** - ANSWER- Directly Which is true about axial resolution. ** A. Decreases w/depth B. Increases w/depth C. Does not vary w/depth D. Best at focal zone - ANSWER- C. Does NOT vary with depth If the _______ is increased, the flow increases. - ANSWER- Pressure Differential Law describing relationship between flow and pressure differential, viscosity & length? - ANSWER- Poiseuille's Law Most common type of flow found in the body is: - ANSWER- Laminar smallest amount of digital storage - ANSWER- bit what preserves the pixel density when enlarging the image? -
