SPI CH. 13-14 QUESTION WITH
CORRECT ANSWERS
Staticvscanningv-vans✔✔imagesvdisplayedvonevframevatvavtime
Real-timevimagingv-
vans✔✔eachvframevisvcreatedvandvdisplayedvveryvquickly,vprovidingvthevimpressionvofvco
nstantvmotion
Framevratev-vans✔✔Thevsystemsvabilityvtovcreatevnumerousvframesveachvsecond
MeasuredvinvHz
Framevratevisvdeterminedvbyv-vans✔✔1.vspeedvofvsoundvinvthevmediumv(1.54vkm/s)
2.vimagingvdepth
Temporalvresolutionv-
vans✔✔Pertainsvtov"accuracyvinvtime,"vdescribesvthevabilityvtovpreciselyvpositionvmovingvs
tructuresvfromvinstantvtovinstant.
MeasuredvinvHz
Temporalvresolutionvisvdeterminedvbyv-vans✔✔framevrate
Tframev-vans✔✔TimevrequiredvtovmakeONEvsinglevimage/vframe
FramevratevandvTframevrelationshipv-vans✔✔Inverselyvrelatedv(reciprocals)
TframevxvFramevratev=v1
Thevtwovcontrolsvthatvsonographersvcanvadjustvthatvaffectvframevrightv-
vans✔✔1.vImagingvdepth
2.vNumbervofvpulsesvpervframev(adjustvwithvchangingvfocus)
Imagingvdepthvandvframevratevrelationshipv-vans✔✔Inverselyvrelated
Shallowvimagingvincreasesvframevratevandvimprovesvtemporalvresolution
Tframevformulav-vans✔✔Tframev=v#vpulsesvxvPRP
Pulsesvpervframevandvframevratevrelationshipv-vans✔✔Inverselyvrelated
Highervframevratesvarevpossiblevwhenveachvindividualvimagevisvmadevwithvfewervpulses.
, Threevfactorsvdeterminevthevnumbervofvpulsesvneededvtovcreateveachvimagev-
vans✔✔1.vNumbervofvpulsesvpervscanvlinev(Multi-focusvvs.vsingle-focus)
-vNumbervofvfocalvpoints
2.vSectorvsize
3.vLinevdensityv(Linesvpervanglevofvsector)
Thevmainvadvantagevofvmultiplevfocalvzonesv-vans✔✔Improvedvlateralvresolution
Sectorvsizev-vans✔✔Fieldvofvview
Whenvthevsonographervexpandsvthevsectorvsizevmorevpulsesvarevrequiredvtovcreatevanvim
age.vTemporalvresolutionvdecreases
Linevdensityv-vans✔✔Thevspacingvbetweenvthevsoundvbeams
-vLowvlinevdensityv(Linesvspacedvfarvapart)
-vHighvlinevdensityv(Linesvcloselyvpacked)
Whenvlinevdensityvisvlowvfewvpulsesvcreateveachvimagevandvthevframevratevisvhigh.vTemp
oralvresolutionvisvhigh
Mainvadvantagevofvhighvlinevdensityv-vans✔✔Increasedvspatialv(detail)vresolution
Temporalvresolutionvanvimagevqualityvrelationshipv-
vans✔✔Tradevoffvbetweenvexcellentvimagevqualityv"superiorvphotograph"vandvexcellentvte
mporalvresolutionv"superiorvmovie"
Operationalvsettingsvforvhighvframevratev(better)v-vans✔✔Shallowvimagingv
Singlevfocus
Narrowvsector
Lowvlinevdensity
Operationalvsettingsvforvlowvframevratev(worse)v-vans✔✔Deepervimaging
Multiplevfocalvpoints
Widevsector
Highvlinevdensity
Fundamentalvlimitationvofvtemporalvresolutionv-vans✔✔Speedvofvsoundvinvthevmedium
Twovmajorvfunctionsvofvthevultrasoundvsystemv-vans✔✔1.vPreparationvandvtransmission
-vIvhavevelectricalvsignalsvtovthevtransducervwhichvcreatesvavsoundvbeam
2.vReception
-
velectricalvelectricalvsignalsvfromvthevtransducervwithvsubsequentvprocessingvintovclinically
vmeaningfulvimagesvandvsounds
Ultrasoundvsystemsvcontainvthevsixvmajorvcomponentsv-vans✔✔1.vTransducer
2.vPulservandvbeamvformer
3.vReceiver
CORRECT ANSWERS
Staticvscanningv-vans✔✔imagesvdisplayedvonevframevatvavtime
Real-timevimagingv-
vans✔✔eachvframevisvcreatedvandvdisplayedvveryvquickly,vprovidingvthevimpressionvofvco
nstantvmotion
Framevratev-vans✔✔Thevsystemsvabilityvtovcreatevnumerousvframesveachvsecond
MeasuredvinvHz
Framevratevisvdeterminedvbyv-vans✔✔1.vspeedvofvsoundvinvthevmediumv(1.54vkm/s)
2.vimagingvdepth
Temporalvresolutionv-
vans✔✔Pertainsvtov"accuracyvinvtime,"vdescribesvthevabilityvtovpreciselyvpositionvmovingvs
tructuresvfromvinstantvtovinstant.
MeasuredvinvHz
Temporalvresolutionvisvdeterminedvbyv-vans✔✔framevrate
Tframev-vans✔✔TimevrequiredvtovmakeONEvsinglevimage/vframe
FramevratevandvTframevrelationshipv-vans✔✔Inverselyvrelatedv(reciprocals)
TframevxvFramevratev=v1
Thevtwovcontrolsvthatvsonographersvcanvadjustvthatvaffectvframevrightv-
vans✔✔1.vImagingvdepth
2.vNumbervofvpulsesvpervframev(adjustvwithvchangingvfocus)
Imagingvdepthvandvframevratevrelationshipv-vans✔✔Inverselyvrelated
Shallowvimagingvincreasesvframevratevandvimprovesvtemporalvresolution
Tframevformulav-vans✔✔Tframev=v#vpulsesvxvPRP
Pulsesvpervframevandvframevratevrelationshipv-vans✔✔Inverselyvrelated
Highervframevratesvarevpossiblevwhenveachvindividualvimagevisvmadevwithvfewervpulses.
, Threevfactorsvdeterminevthevnumbervofvpulsesvneededvtovcreateveachvimagev-
vans✔✔1.vNumbervofvpulsesvpervscanvlinev(Multi-focusvvs.vsingle-focus)
-vNumbervofvfocalvpoints
2.vSectorvsize
3.vLinevdensityv(Linesvpervanglevofvsector)
Thevmainvadvantagevofvmultiplevfocalvzonesv-vans✔✔Improvedvlateralvresolution
Sectorvsizev-vans✔✔Fieldvofvview
Whenvthevsonographervexpandsvthevsectorvsizevmorevpulsesvarevrequiredvtovcreatevanvim
age.vTemporalvresolutionvdecreases
Linevdensityv-vans✔✔Thevspacingvbetweenvthevsoundvbeams
-vLowvlinevdensityv(Linesvspacedvfarvapart)
-vHighvlinevdensityv(Linesvcloselyvpacked)
Whenvlinevdensityvisvlowvfewvpulsesvcreateveachvimagevandvthevframevratevisvhigh.vTemp
oralvresolutionvisvhigh
Mainvadvantagevofvhighvlinevdensityv-vans✔✔Increasedvspatialv(detail)vresolution
Temporalvresolutionvanvimagevqualityvrelationshipv-
vans✔✔Tradevoffvbetweenvexcellentvimagevqualityv"superiorvphotograph"vandvexcellentvte
mporalvresolutionv"superiorvmovie"
Operationalvsettingsvforvhighvframevratev(better)v-vans✔✔Shallowvimagingv
Singlevfocus
Narrowvsector
Lowvlinevdensity
Operationalvsettingsvforvlowvframevratev(worse)v-vans✔✔Deepervimaging
Multiplevfocalvpoints
Widevsector
Highvlinevdensity
Fundamentalvlimitationvofvtemporalvresolutionv-vans✔✔Speedvofvsoundvinvthevmedium
Twovmajorvfunctionsvofvthevultrasoundvsystemv-vans✔✔1.vPreparationvandvtransmission
-vIvhavevelectricalvsignalsvtovthevtransducervwhichvcreatesvavsoundvbeam
2.vReception
-
velectricalvelectricalvsignalsvfromvthevtransducervwithvsubsequentvprocessingvintovclinically
vmeaningfulvimagesvandvsounds
Ultrasoundvsystemsvcontainvthevsixvmajorvcomponentsv-vans✔✔1.vTransducer
2.vPulservandvbeamvformer
3.vReceiver
