Sonography Physics 2 Midterm

Contrast harmonics are created by what type of microbubble behavior? a. perpendicular vibrations b. in-synce oscillations c. nonlinear behavior d. linear behaviorc. nonlinear behaviorAll of the following are disadvantages of pulse inversion harmonics except.... a. frame rate is doubled b. increased Tframe c. frame rate is cut in half d. temporal resolution is cut in halfa. frame rate is doubledWhen are tissue harmonics created? a. reflection b. transmission c. listening time d. when the sound beam is weakb. transmissionwhere are harmonics created? a. in the pulser b. in the transducer c. in the tissue d. in the receiverc. in the tissueTrue or false ? with pulse inversion, a positive and then a negative pulse is transmitted down each scan line.Truefor pulse inverson harmonics when the sound is created it contains? a. harmonic frequencies. b. fundamental frequencies c. kinetic energy d. both a & Bd. both a & b1.54 mm-Us / Frequency represents the equation for what ? a. propagation speed b. wavelength. c. intensity d. pulse durationb. wavelengthIf we see a picture of blood flow aliasing, how do we fix it? a. increase color scale b. decrease color scale c. move the color box to the leftA. increase the color scale -The color scale is set to low.2 x velocity of blood x transducer x frequency x cos / propagation speed is the equation for what ? A. Doppler spectrum B. blood cell velocity C. Doppler shift d. mechanical indexC. doppler shiftTrue or false. Turbulent flow is the same as laminar flow?FalsePower is determined by? A. sound source only b. media c. sound source and mediaA. sound source onlyPeriod is determined by? A. sound source only b. media c. sound source and mediaa. sound source ONLYIntensity is determined by? . A. sound source b. medium c. sound source and mediaA. sound sourcewavelength is determined by? A. sound source only b. medium c. sound source and mediumc. sound source and media (This is the only parameter that is determined by both th=e sound source and the medium)Propagation speed is determined by? A. sound source only b. medium c. sound source and mediab. mediumPulse duration is determined by? A. sound source only b. media c. sound source and mediumA. Sound source onlyspatial pulse length is determined by? A. sound source only b. media c. both the sound source and mediumc. Both the source and the mediumpulse repetition period is determined by ? A. sound source only b. media c. both the sound source and mediumA, sound source only.PRF is determined by ? A. sound source b. media c. both the sound source and mediumA. the sound sourcewhat is the relationship between duty factor and PRF? A. Directly B. Inversely C. Not relatedB. InverseWhat is the relationship between PRF and PRP? A. Directly B. Inversely C. Not relatedB. Inversewhat is the relationship between depth and PRP? A. Directly B. Inversely C. Not relatedA. DirectlyAll of the following are in the range of human hearing except.... A. 22 Hz B. 19,854 Hz C. 18 kHz D. 22 kHzD. 22kHzYou are scanning a patient and increase your imaging depth from 4cm to 6 cm. What does this do to the pulse repetition frequency? a. decreases it b. increases it c. nothinga. decreases itFour pulses have pulse repetition periods as listed below. Which of the following four waves has the highest PRF? a. 8 s b. 80 ms c. 5 ms d. 400 ksc. 5 ms The PRP with the shortest pulse duration will have the highest PRF.The horizontal (x-axis ) on spectral display represents? A. time b. depth c. velocities d. m/sA. timeAnother term for flow is.... a. inertia b. volume flow rate c. frequency in motion d. velocity flowb. volume flow rateWhat is Ohm's Law? a. voltage = current x resistance b. Resistance = voltage x current c. Current = resistance x voltagea. voltage = current x resistancePatient's who have anemia have high viscosity blood. True FalsefalseThe thickness or stickiness of a fluid that is measured in units of Poise is....... a. density b. viscosity c. hematocrit d. red blood cell contentb. viscositySmall, hurricane-like, swirling, rotational patterns that appear in turbulent flow are called..... a. eddy currents b. flow separations c. stenosis d. viscous changeseddy currentsThis is a type of laminar flow in which all of the layers and blood cells travel at the same velocity. a. parabolic flow b. turbulent flow c. plug flow d. steady flowplug flowPhasic flow is typically found in what vascular system? a. venous b. arterial c. both venous and arteriala. venousWhen blood flow steamlines are aligned and parallel it is said to be....... a. laminar b. pulsatile c. turbulent d.phasicA. laminarParabolic flow has a bullet-shaped profile and velocity is the highest in the center of the lumen. True FalsetrueWhich of the following do not belong? a. negative Doppler shift b. blood cells move away from the transducer c. the reflected frequency is higher than the transmitted frequencyc. the reflected frequency is higher than the transmitted frequencyBlood flow moving away from the transducer appears where in relation to the baseline? a. above b. to the side c. in front of d. beneathd. beneathReflected frequency - transmitted frequency is the equation for.... a. Nyquist limit b. PRF c. pulse repetition period d. Doppler shiftd. doppler shiftThe effects of the medium upon the sound wave is referred to as what? A. biologic effects b .acoustic propagation properties c. bad luck d. amplitude overloadB. acoustic propagation properties.If you have a positive doppler shift which way does blood cells travel? A. away from the transducer B. toward the transducerB. toward the transducerSynonyms for power doppler.energy mode, color angioHow is doppler shift related to the velocity of the blood cells? A. Directly B. InverseA. DirectlyMaximizing the pulse repetition frequency raises the Nyquist limit and aliasing is less likely to appear. True FalsetrueGenerally, crosstalk result from what? A. Doppler gain is set too low B. Doppler gain is set to high C. the incident angle is near 90 degrees between the sound beam and the flow direction, when flow is at the beam's focus D. Both B and CD. Both B and CTurbulent blood flow would most likely be found ?The time it takes a wave to vibrate a single cycle is referred to as...... a. wavelength b. pulse duration c. period d. spatial pulse lengthc. periodwhich of the following principles describe the relationship between velocity and pressure in a moving fluid. This principle states that, with a steady flow, the sum of all forms of energy is the same everywhere. Simply stated the sum of kinetic energy and pressure energy remains constant. A. frank starling b. Bernoulli's c. Maslow's d. Currie'sB Bernoulli's principalAutocorrelation is the digital technique used to analyze what? a. pulsed wave Doppler b. color flow Doppler c. spectral waveforms d. low flow statesb. color flow dopplerDoppler shift is inversely related to the cosine of the angle between the direction of flow and the direction of sound. True FalseFalse.what are the two fast Fourier advantages?1. exceedingly accurate 2. displays all individual velocity components that make up the complex reflected signal.On a variance mode color map, colors on the left side of the map indicate what? a. laminar flow b. higher velocities c. turbulent flow d. lower velocitiesa. laminar flowwhat is the relationship between the speed of sound in PZT and the frequency of sound ? A inverse B. proportional C. directlyC. DirectlyAt what angle between the direction of flow and the direction of sound would the cosine be 0? a. 30 degrees b. 0 degrees c. 90 degrees d. 150 degreesc. 90 degreesPulse Doppler transducers have a high Q-factor. True FalsefalseAll of the following are techniques that may be used to avoid aliasing artifact except.... A. use baseline shift b. use continuous wave Doppler c. Adjust the scale to its minimum d. select a lower frequency transducerc. Adjust the scale to its minimumPeak rarefaction pressure / the square root of frequency is the equation for what? a. pulsatility index b. acceleration time c. mechanical index d. Doppler shiftc. mechanical indexIf you have an image and the color is outside of the vessel, how do you fix this ?Decrease color gain.When a patient is laying supine, what is the hydrostatic pressure at all locations in the body? A. 0 mmHg B. 140 mmHg C. 100 mmHgA 0 mmHgIn the circulatory system, the resistance vessels are called A. veins b. arterioles c. capillariesb. arteriolesWhen line density is high, the number of pulses per image increases, frame rate drops, and the temporal resolution decreases. True FalseTRUE high line density has tightly packed lines pulses increase longer tframe lower frame rate lower temporal resolution excellent spatial resolutionWhen line density is low, what happens to the frame rate and temporal resolution?Temporal resolution increases and the frame rate is higherWhat is the main advantage of high line density?smaller gaps improve the accuracy of each individual image. Each image contains more detail, also known as improved spatial resolution.What is the equation for the Nyquist limit? a. PRP / 2 b. wavelength / 2 c. PRF / 2 d. propagation speed / 2c. PRF / 2All of the following are techniques that may be used to avoid aliasing artifact except.... a. use baseline shift b. use continuous wave Doppler c. Adjust the scale to its minimum d. select a lower frequency transducerc. adjust the scale to its minimumPulse Doppler transducers have a high Q-factor. True Falsefalsewhat term describes a wider range of velocities and doppler shifts within the sample volume? A. fast fourier b. autocorrelation c. spectral broadeningc. spectral broadeningwhich of the following terms is synonyms with spectral broadening? A. plug flow b. parabolic flow c. laminar flow d. turbulent flowd. turbulent flow. Turbulence causes spectral broadening. with turbulence, blood flow is chaotic. Many different directions and speeds are within the sample volume. With turbulent flow, the pulsed doppler spectral window is filled in.Hydrostatic pressure in a patient who is standing up, in locations above the heart are..... positive negativenegativeBlood pressures taken in an extremity that is below the level of the heart will be..... falsely diminished falsely elevatedfalsely elevatedSound with a frequency of 12 MHz is created by a transducer. What is the harmonic frequency? 12 MHz 6 MHz 24 MHz 10 MHz24 MHzHarmonic imaging has less distortion than fundamental imaging. True FalseTruemeasured pressure = circulatory pressure + ? gravitational pressure hydrostatic pressure kinetic pressure potential pressurehydrostatic pressureDensity is measured in units of pascals. True Falsefalse kg/cm^3Pressure is measured with units of pascals? true falsetrueperiod is mesured with units of microseconds (Us) true falsetrueThe time it takes to vibrate a single cycle ? A. period B. frequency C. wavelengthA. Periodthe distance or length of one complete cycle. A. spatial pulse length b. wavelength c. period d. pulse durationb. wavelengthA sound beam with a frequency of 8 MHz is emitted from a transducer that has a diameter of 4 cm. What is the fundamental frequency? 6 MHz 8 MHz 4 MHz 2 MHz8 MHzWhich of the following statements about a stenosis is correct? A. velocity is highest and pressure is lowest within a stenosis B. velocity is lowest and pressure is highest within a stenosis C. velocity and pressure are both low within a stenosis D. velocity and pressure are both high within a stenosisA. velocity is highest and pressure is lowest within a stenosisMicrobubbles the size of red blood cells resonate when exposed to sound in the 2 to 4 MHz range. True FalseTrueThis type of flow occurs when a fluid moves at a constant speed or velocity. pulsatile flow turbulent flow steady flow rouleaux flowsteady flowWith relation to a stenosis, where is pressure the lowest? Where the velocity is the highest Where the velocity is the lowestwhere the velocity is the highestFlow is measured in units of.... distance/time power/area decibels volume/timevolume/ timeVelocity and pressure have what type of relationship? a. inverse b. direct c. unrelateda. inverse Velocity and pressure are inversely related so if velocity goes up, pressure goes down.Decreasing the diameter of a vessel causes an increase in velocity. What affect does this have on pressure? Pressure drops Pressure goes up There is no affect on pressurepressure dropswhat are the 3 types of energy loss in the circulatory system?1. viscous energy loss 2. frictional energy loss 3. inertial energy loss (FIV) Pneumonic.The tendency of a fluid to resist changes in its velocity is known as.... resistance inertia friction pressureinertiaWhat predicts whether flow is laminar or turbulent? Nyquist limit Rictor scale Reynolds number Bernoulli's PrincipleReynold's numberAll of the following are reynold's numbers for laminar flow except.... 1250 1000 1450 21002100 The Reynolds number predicts whether flow is laminar or turbulent. The Reynolds number for laminar flow is less than 1500.The term when flow energy is converted to heat as one object rubs against another. Blood sliding across the vessel walls creates heat, and is and example of? A. Inertial energy loss B. Viscous energy loss C. frictional energy lossC. frictional energy lossKinetic energy is associated with a moving object. What two factors are kinetic energy determined by ?1. the objects mass 2. the speed at which it movesWhat type of energy is a form of stored or potential energy? A. kinetic energy B. pressure energy C. gravitational energy D. both B and CD. both B & CThe term _________ describes the property of certain materials to create a voltage when they are mechanically deformed or when pressure is applied to them. A. PZT B. decreased sensitivity c. piezoelectric effect d. doppler effectc. piezoelectric effectwhat is the relationship between doppler shift and frequency?Directly related (pg. 321)what two conditions create aliasing?1. aliasing occurs only with pulsed doppler never with continuous doppler 2. when the doppler sampling rate is too low in comparison to the measured blood velocities (Pg.316)true or false when the blood cells are moving parallel to the sound beam, the entire velocity is measured. The doppler shift represents 100% of the true velocity when blood flow is parallel to the sound beam ?TrueTrue or false ? Doppler shift is directly related to the cosine of the angle between the direction of flow and the direction of sound.Trueif the angle was 0 degrees what would the cosine be? A. 1.0 B. -1.0 C. 0.87 D. -0.5A 1.0If the angle was 180 degrees what would the cosine be ? A 1.0 B. -1.0 C. 0.87 D. -0.5B -0.1what is power doppler?only identifies presence of doppler shift. > all vessels have the same color, regardless of the direction of blood flow .Advantages & Disadvantages of power doppler.Advantages > increased sensitivity > unaffected by doppler angles, unless the angle is exactly 90 degrees >NO aliasing Disadvantages >no measurement of velocity or direction >lower frame rate (decreased temporal resolution) >susceptible to motion of the transducer, patient, or soft tissues, which may result in a burst of color, or flash artifact.a digital (computer based) technique, used to process both pulsed and continuous wave doppler signals? A. spectral window B. analog C. post processing D. Fast Fourier transformD. Fast Fourier transformA digital (computer-based) technique used to analyze color flow doppler? A. Color analog B. Color gain C. Autocorrelation D. spectral broadening.C. Auto correlation

Sonography Physics 2 Midterm

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