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Physics Registry

zoe021601 Inglês 270 flashcards

Flashcards do conjunto (270)

  1. 1What is the average PS in soft tissues?1540 m/sec or 1.54 mm/microsecond
  2. 2PS in air330 m/sec
  3. 3PS in bone4000 m/s
  4. 4The inability of the sound wave to travel through a mediumImpedance
  5. 5The higher the frequency, the lower or higher the periodlower
  6. 62 types of wavesLongitudinal and Transverse
  7. 7A wave in which the particle motion is perpendicular to the direction of the waveTransverse waves
  8. 8Transverse waves are AKAShear waves
  9. 9This wave can represent simple harmonic motion and areas of high or low pressureSine wave
  10. 10What do waves not carry from one place to another and what do they carry?Do not carry matter, do carry energy
  11. 11What is the range of frequency for audible sound?20-20,000 Hz
  12. 12Longitudinal waves are AKACompressional waves
  13. 13These variables identify sound waves as well as making a difference in how well the sound travelsacoustic variables
  14. 14What does sound require to travel?A medium
  15. 15A wave in which the particle motion is parallel to the direction of the waveLongitudinal/Compressional wave
  16. 16The time it takes one cycle to occurPeriod
  17. 17Which type of waves are sound waves?Longitudinal/Compressional
  18. 18This is a wave produced by vibrating objectsSound waves
  19. 19The rate at which work is done or the rate at which energy is transferedPower
  20. 20Stiffness is more important than what in regards to PS?Density
  21. 21Does stiffness increase or decrease propagation speed?Increases
  22. 22The speed at which a wave moves through a mediumPropagation Speed/ PS
  23. 23The length of space over which one cycle occursWavelength
  24. 24Areas of low particle concentrationRarefaction/Troughs
  25. 25Numerical description on how far apart objects areDistance
  26. 26+10 dB = ____ times louder +20 dB = ____ times louder +30 dB = ____ times louder10 times
    100 times
    1000 times
  27. 27Used to express very large or very small numbers in exponential formscientific notation
  28. 28The speed and direction of an object in motionVelocity
  29. 29The rate at which the velocity is changingAcceleration
  30. 30Not only is the volume flow rate constant, but the ____ must also remain constantEnergy
  31. 31Abnormal narrowing of a vesselStenosis
  32. 32Hemodynamic changes begin to occur with a ____% stenosis50%
  33. 33____ and/or ____ flow may be present at a stenosisDisturbed and/or turbulent
  34. 34____ rate remains constantVolume Flow
  35. 35Constant volume flow rate occurs in response to structure at the end of vessel demanding a ____.Constant supply of blood
  36. 36Which rule says that volume flow rate must remain the same proximal to, at, and distal to a stenosis?Continuity Rule
  37. 37At a ____, flow speeds can be significantly increased.Stenosis
  38. 38The high velocity flow through a stenosis is known as the ____.Jet
  39. 39____ stenosis have extremely high velocities.High-grade
  40. 40Power doppler has a slower ____ rate/ ____ resolution than color doppler.Fram rate/ Temporal resolution
  41. 41Color map w/power doppler defines ____ regions vs. ____ regions of flow. NOT VELOCITIES.High vs. low
  42. 423 colors used in variance mapsCyan, magenta, yellow
  43. 43Variance color maps are used to display ____ and/or ____ flow.Disturbed and/or Turbulent
  44. 44A ____map can be used to display blood flow at different speeds.Variance color map
  45. 45Amount of hue mixed w/ whiteSaturation
  46. 46Less white = ____ saturationgreater
  47. 47Brightness of a colorLuminance
  48. 48The color perceived. Red, blue, green, yellow.Hue
  49. 493 Color characteristicsHue, Saturation, Luminance
  50. 50Color closest to neutral color represents ____ velocity. Color farthest away represents ____ velocity.Low; Peak
  51. 51With color doppler ____ is the neutral colorBlack
  52. 52The mathematical process commonly used to detect doppler shifts in color doppler measurementsAutocorrelation
  53. 53Equals the distance between the average value and the maximum value of an acoustic variableAmplitude
  54. 54Power is proportional to?Waves amplitude squared
  55. 55majority type of attenuation. Sound is converted to heat.Absorption
  56. 56Amount of material (medium) required to decrease the intensity to 1/2 its original value.1/2 Value Layer
  57. 57The concentration of energy of a sound beamIntensity
  58. 58In CW, SPTA = ____SPPA
  59. 59Describes the distribution of the sound beam in spaceBUR
  60. 60What is the range of frequency for US?>20,000 Hz
  61. 61What 2 things does plasma consist of?Water & Proteins
  62. 62Hematocrit makes up what % of blood?40%
  63. 63What is the equation for reflector speed with angle?RS=PS x doppler shift/2x OF x Cosine theta
  64. 64If PS is increased, what happens to frequency?Unchanged
  65. 65The time it takes for a single pulse to occurPulse Duration
  66. 66In real life, the listening time is ____ of times longer than the talking time.Hundreds
  67. 67PRP is determined by what?Sound source
  68. 68The PRF can be changed by the sonographer by adjusting the what?Depth
  69. 69What is the PRF determined by?Sound source
  70. 70Can the SPL be changed by the sonographer?NO
  71. 71The length of space over which a pulse occursSPL
    Spatial Pulse Length
  72. 72In CW ultrasound, the sound is always on = ____% DF100
  73. 73DF can be changed by sonographer by adjusting the what?Depth
  74. 74DF is ____ and expressed as a ____Unitless; percentage
  75. 75Advantage of PW Disadvantage of PWAdvantage = range resolution
    Disadvantage = aliasing
  76. 76PW receiver gate is AKASample volume
  77. 77CW can cause ____ due to different vessels detected along the beam. This is called ____.artifact; range ambiguity
  78. 78A CW doppler detects reflector motion flow from the ____ of the transmit and receive beamsIntersection
  79. 79CW must use a ____ element & a ____ element.Source & Receiver
  80. 804 types of doppler instrumentsCW, PW, Color & Power doppler
  81. 81On most US units, the sonographer can position an "____" cursor on the image that allows the system to estimate the angle between the blood flow and sound beamAngle correct
  82. 82What is the cosine? 0 60 90 1800=1
    60=.5
    90=0
    180=-1
  83. 83If the sound is parallel to flow, you don't need to use the angle, because cosine of 0=?1
  84. 84If vessel demonstrates neutral color, flow could exist but is ___ to beam.Perpendicular
  85. 85PW doppler operates w/ a single element in a transducer used as a ____ & ____Source & Receiver
  86. 863 types of visual displayColor doppler, Power doppler, spectral analysis
  87. 87Doppler shift is converted to ____ & ____.Audible sound & Visual display
  88. 88Doppler instruments respond to moving ____ by detecting the ____.Reflectors; doppler shift
  89. 89When the sonographer just wants to identify presence of flow doppler angle is unimportant, as long a the incident angle isn't ____ degrees90
  90. 90Plasma makes up what percentage of blood?60%
  91. 91Can doppler US detect perfusion?NO
  92. 92Where does perfusion occur?In the capillaries
  93. 93What is blood perfusion?The exchange of oxygen and nutrients for carbon dioxide and waste products in the body's cells
  94. 94Doppler US can detect flow in the ___, ___, & ___heart, arteries, veins
  95. 95The circulatory system consists of these 6 things:Heart, arteries, arterioles, capillaries, venules, veins
  96. 96For parabolic flow, the averag flow speed across the entire vessel = ?1/2 the max flow speed
  97. 97Flow is forward but not parallel; occurs at bifurcation or stenosis.Disturbed
  98. 98Type of flow found at entrance or within a large vesselPlug
  99. 99Pressure gradient is AKAEnergy gradient
  100. 100What is volume flow rate?Amount of blood passing a specific point per unit of time
  101. 101What is the force against flow?Resistance
  102. 102What is the driving force behind flow?Pressure
  103. 103What is the equation for pressure?Force/area
  104. 104What is required for flow?A pressure difference
  105. 105Flow = ___/how much Velocity = ___/how fastvolume; speed
  106. 106What is the term for thick blood? What is the term for thin blood?Polycythemia; Anemia
  107. 107Blood is comprised of these four things:Plasma
    Red Blood Cells
    White Blood Cells
    Platelets
  108. 108RBC's cause ___ and can often be visualized on USReflection
  109. 109What do the RBCs contain that transports oxygen?Hemoglobin
  110. 110RBCs make up what % of the hematocrit?99%
  111. 111With lesser angles, ___ & ___ may inhibit the doppler signalRefraction and critical angle
  112. 1123 Disadvantages of power dopplerCannot detect flow speed/direction
    Slower FR/Temporal Resolution
    Susceptible to flash artifact
  113. 113Doppler shift info is received from a designated region containing many small ___.receiver gates
  114. 114Color doppler is a type of what?PW
  115. 115This is the angle between sound propagation and blood flowDoppler angle
  116. 116If reflector speed increases, doppler shift:Increases
  117. 117If operating frequency increases, doppler shift:increases
  118. 118Doppler shift is usually ____ of the source, therefore it falls into the audible range of hearing1/1000
  119. 119A change in frequency of a wave as a result of motionDoppler shift
  120. 120Doppler intensities are usually ___ than 2d USMuch higher
  121. 121Veins rely on ___ & ___ for movementmuscle contraction and respirations
  122. 122Pressure pulses are dampened or reduced before reaching the veins resulting in:low constant pressure
  123. 123Arterial pressure depends on 3 thingsCardiac output, compliance of vessel, and peripheral resistance
  124. 124A compliant vessel has the ability to store blood and continue flow during:Diastole
  125. 125Stretchability of a vessel which allows it to expand under pressureCompliance
  126. 126Peak pressure during Systole120 mmHg
  127. 127Cardiac output is approximately ___L/min5
  128. 128It is important in Echo to determine a ___ across a ___Pressure drop across a stenotic valve
  129. 129At a significant stenosis, usually 80-99%, increase turbulence seen ___ can produce a decrease in ___ resulting in a decrease in volume flow rate.Distally, pressure
  130. 130The bernoulli principle states that when ___ decreases, ___ increases.Pressure decreases, velocity increases
  131. 131Through a stenosis there is a ___, this is called the ___.Pressure drop; Bernoulli Effect
  132. 132The total energy of blood is a sum of what 3 energies?Potential, Kinetic, and gravitational
  133. 133A typical pattern at a stenosis includes ___ flow proximally, ___ flow at the stenosis, and ___ flow distal to the stenosis.Disturbed; increased, disturbed/turbulent
  134. 134Related to motion, working energyKinetic energy
  135. 135Stored energy, ability to do workPotential energy
  136. 136The ___ energy proximal to the stenosis is converted to ___ energy through the stenosis, and back to ___ energy distal to the stenosis.potential, kinetic, potential
  137. 137Units for attenuation CoefficientdB/cm
  138. 138Units for amplitudedB
  139. 139Unit for workJ
  140. 140Unit for pressurePascal
  141. 141Unit for densitykg/mass cubed
  142. 142The loudness or strength of sounddB
  143. 143Unit for stiffnessN/m squared
  144. 144Units for intensityW/cm squared; mW/cm squared
  145. 145Units for attenuationdB
  146. 146PS is measure inm/sec or mm/microsecond
  147. 147Units for impedanceRayls
  148. 148Unit for accelerationm/sec squared
  149. 149Unit for forcenewtons
  150. 150Unit for powerWatts
  151. 151Unit for PDseconds, miliseconds, microseconds
  152. 152Units for PRFHz, MHz
  153. 153Units for SPLm, cm, mm
  154. 154Kinematic velocity is measured in ___ or ___cm/sec or stoke
  155. 155BUR is AKA: (2 things)SP/SA Factor; beam uniformity coefficient
  156. 156The measure of an object's resistance to accelerationmass
  157. 1573 examples of wavessound, light, radio
  158. 158What is diagnostic medical US range of Frequency?1-15 MHz
  159. 159The capability to do workEnergy
  160. 160Another name for stiffnessBulk modulus
  161. 1612 opposites of stiffnessCompressibility and elasticity
  162. 162The concentration of massdensity
  163. 163number of cycles occurring in 1 secondfrequency
  164. 164Controls pitchfrequency
  165. 165What is IRC?Intensity reflection coefficient
  166. 166In soft tissue, approximately ___ dB of attenuation per ___ for each ___ of frequency..5 dB of attenuation per cm for each Mhz of frequency.
  167. 167Is attenuation higher or lower in air than soft tissue?Higher
  168. 168Direction of sound travel is not perpendicular to the boundary between the 2 mediaoblique incidence
  169. 169With oblique incidence, the incident angle = ?reflected angle
  170. 170With oblique incidence, which angle varies?Transmission
  171. 171The critical angle is surpassed when the transmission angle is equal to or greater than:90 Degrees
  172. 172When the critical angle is surpassed total ___ is produced and no ___ into second medium.reflection; transmission
  173. 173What are the 3 types of attenuation?Absorption, reflection, scattering
  174. 174Redirection of sound in many directions by a rough surface or boundaryScattering
  175. 175Several scatterers generate simultaneous echoes which partially or totally cancel each other outDestructive interference
  176. 176It is the ___ difference between media that causes reflection.Impedance
  177. 177What is ITC?Intensity Transmission Coefficient
  178. 178Perpendicular incidence is AKA: (4 things)Right angle, Orthogonal, 90 degrees, normal
  179. 179A ___ HVL has low attenuation and low frequencythick
  180. 180ALWAYS 50% attenuation at ___ dB loss3
  181. 181IN CW, SATA = ?SAPA
  182. 182The larger the BUR, the ___ the center is compared to edgesBrighter
  183. 183If a wave's amplitude is halved, the power is ___Quartered
  184. 184Formula for BURSP/SA
  185. 185Describes the volume of a waveAmplitude
  186. 186Measurement of how tall the wave isAmplitude
  187. 187Amplitude ___ as sound travels through the bodyDecreases
  188. 188If a wave's amplitude is doubled, the power increases by:4x
  189. 189BUR must be > ___1
  190. 190Amount of time US is actually onDF
  191. 191Reduction or loss of amplitude and intensity as a sound wave travels through a mediumAttenuation
  192. 192The average attenuation coefficient in dB/cm = ___ of frequency in MHz1/2
  193. 193Attenuation limits the ___ at which we can imagedepth
  194. 194The fraction of time the sound is actually onDF
  195. 195The amount of resistance a material or object has to compressionStiffness
  196. 196The loss of sound power as it travels through the bodyAttenuation
  197. 197Formula for powerwork/time
  198. 198Formula for calculating PDPeriod x # of cycles in a pulse
  199. 199Another formula for calculating PD# of cycles/frequency
  200. 200Formula for workForce x distance
  201. 201Formula for calculating DFPD/PRP
  202. 202Equation for calculating doppler shiftDS = RF - OF
  203. 203What is the equation for kinematic viscosity?viscosity/density
  204. 204Equation for doppler shift with angle2 x OF x Reflector Speed x Cosine theta/ PS
  205. 205Formula for pressureForce/area
  206. 206Formula for speeddistance/time
  207. 207Formula for frequencycycles/seconds
  208. 208Formula for period1/frequency
  209. 209Formula for attenuationAttenuation (dB)=1/2f(MHz) x Path Length
  210. 210Formula for calculating SPLWavelength x number of cycles in a pulse
  211. 211Formula for velocitydisplacement/time
  212. 212Formula for impedancedensity x PS
  213. 213Formula for PSFrequency x wavelength
  214. 214Formula for wavelengthPS/Frequency
  215. 215Formula for forceF = ma
  216. 216Formula for finding Amplifier GaindB = 10log(power 1/power 2)
  217. 217Formula for densitymass/volume
  218. 218Formula for stiffnesspressure/volume change
  219. 219Formula for calculating the PRP1/PRF
  220. 220Equation for 1/2 intensity depth6/frequency
  221. 221Formula for intensityPower/area
  222. 222Formula for calculating PRF# of pulses/total time
  223. 223What is the refraction equation?Transmission angle = incident angle x c2/c1
  224. 224Equation fr IRC with impedencesIRC = (imp. 2-imp. 1/imp. 2 + imp. 1)squared
  225. 225What is the equation for ITCITC = transmitted intensity/incident intensity
  226. 226Equation for calculating IRCIRC = reflected intensity/incident intensity
  227. 2272 formulas for temporal averagingTA = DF x TP
    TA = DF x PA
  228. 228Formula for attenuation coefficientattenuation coefficient = 1/2 frequency
  229. 229Formula for accelerationvelocity change/time
  230. 230What is the pulse duration determined by?sound source
  231. 231Power can be changed by thesound source
  232. 232What is the amplitude initially determined by?sound source
  233. 233What is the SPL determined by?Sound source and medium
  234. 234Power is initially determined by thesound source
  235. 235What is frequency determined by?Sound source
  236. 236What is propagation speed determined by?medium
  237. 237Is wavelength determined by the medium, sound source, or both?both
  238. 238What is period determined by?sound source
  239. 239What is DF determined by?sound source
  240. 240Type of reflection; Ex. cellular tissue. Non-specular reflectors cause backscatter. Provides internal texture of organs.Diffuse/non-specular reflection
  241. 241___ echoes provide image textureweek
  242. 242Sound scatters when the tissue interface is ___, ___, or ___ than the wavelengthsmall, equal, or less than
  243. 243Specific type of scattering. Reflector is much smaller than wavelength. Ex. RBC. Sound is diverted in many directions equally.Rayleigh scattering
  244. 244The transmission angle is sometimes called the ___ anglerefraction
  245. 245A change in direction of sound when crossing a boundryrefraction
  246. 246The intensities of the reflected and transmitted sound depend on the incident intensity and the ___ of the 2 media.Impedances
  247. 247A ___ 1/2 value layer has high attenuation and frequency.thin
  248. 2483 types of attenuationabsorption, reflection, scattering
  249. 249power loses ___ as it travelspower
  250. 250Intensity is proportional to?wave's amplitude squared
  251. 251___ is not uniform across the sound beamIntensity
  252. 252What is the intensity range for doppler? what is it for 2d?.2-2,000 mW/cm squared
    1-200 mW/cm squared
  253. 253Volume flow rate = ?Flow speed x vessel area
  254. 254What does power doppler measure?Energy differences in flow
  255. 2553 flow characteristics that doppler is used to measurevelocity, variance, energy
  256. 256What are the 3 forms of energy loss as blood flows?frictional, viscous, and inertial loss
  257. 257What is the impedance of blood? What is the attenuation?Impedence = 1,620,000 rayls
    Attenuation = .21 dB/cm/MHz
  258. 258What is the kinematic velocity of blood? What is the PS?KV = .033 stoke
    PS = 1.57 mm/microsecond
  259. 259Attenuation per cm of sound travelAttenuation coefficient
  260. 260This is a key in regard to bioeffectsIntensity
  261. 261This describes the volume and strength of a sound waveMagnitude
  262. 262___ & ___ describe the strength of a wavepower and intensity
  263. 263The time from the beginning of one pulse to the beginning of anotherPRP
  264. 264IS attenuation higher or lower in bone than soft tissuehigher
  265. 265Waht is BURBeam Uniformity Ratio
  266. 266The closer the BUr is to one, the more even or ___ the beam is over space.Homogeneous
  267. 267This type of reflection is caused by large, smooth, boundaries or interfaces. Interface is longer than the wavelength.Specular reflection
  268. 268Intensity averaged over total timeTemporal Average
  269. 2695 characteristics of pulsed USPRF, PRP, PD, DF, SPL
  270. 270PRP is AKAPulse Repetition time; on time and off time

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FlashCards sobre Physics Registry , criado por zoe021601 em 02-04-2014.
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zoe021601
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