Kwi-PW Doppler scanning yemithambo ejikelezayo, ukuhamba kwegazi okuya kwicala elinye kubonwa ngokucacileyo, kodwa umfanekiso wesipili ocacileyo unokufunyanwa kwi-spectrogram.Ukunciphisa amandla okuhambisa isandi kunciphisa kuphela ukujikeleza kwegazi okuya phambili kunye nokubuyisela umva kwinqanaba elifanayo, kodwa akwenzi ukuba umoya unyamalale.Kuphela xa i-frequency emission ilungelelaniswa, umahluko unokufunyanwa.Okukhona iphezulu i-frequency yokukhutshwa, kokukhona ibonakala ngakumbi i-spectrum yomfanekiso wesipili.Njengoko kubonisiwe kulo mfanekiso ulandelayo, i-blood flow spectrum kwi-carotid artery ibonisa i-spectra yesipili esicacileyo.Amandla esipili somqukuqelo wegazi ongalunganga anamandla kancinane kuphela kunomthamo wegazi ovumayo, kwaye nesantya sokuhamba siphezulu.Kutheni kunje?
Ngaphambi kokufunda iziporho, makhe sihlolisise umqa we-ultrasound scan.Ukuze ufumane i-directivity engcono, umqadi we-ultrasonic scanning kufuneka ugxininiswe ngolawulo lokulibaziseka olwahlukileyo lwezinto ezininzi.I-beam ye-ultrasonic emva kokugxila ihlulwe ibe yi-lobe ephambili, i-lobe yecala kunye nesango lesango.Njengoko kubonisiwe ngezantsi.
I-lobes eziphambili kunye necala zihlala zikhona, kodwa kungekhona i-lobes ye-gating, oko kukuthi, xa i-angle ye-gating lobe inkulu kune-90 degrees, akukho zi-gating lobes.Xa i-engile ye-lobe yesango incinci, i-amplitude ye-lobe yesango idla ngokuba nkulu kakhulu kune-lobe yecala, kwaye inokuba yi-odolo yobukhulu efanayo njengeyona ndawo iphambili.Icala-isiphumo se-lobe ye-grating kunye ne-side lobe kukuba isignali yokuphazamiseka ephuma kumgca wokuskena ibekwe phezulu kwi-lobe eyintloko, enciphisa isisombululo sokuchasana komfanekiso.Ngoko ke, ukwenzela ukuba kuphuculwe isisombululo sokuchasana nomfanekiso, i-amplitude ye-lobe yecala kufuneka ibe yincinci kwaye i-angle ye-lobe yokungena kufuneka ibenkulu.
Ngokutsho kwefomula ye-angle ye-lobe engundoqo, i-angle enkulu ye-lobe (W) kunye ne-frequency ephezulu, i-lobe ephambili ilungile, eyinzuzo ekuphuculweni kwesisombululo secala le-imaging ye-B-mode.Kwimeko yokuba inani lemijelo aliguquguqukiyo, okukhona isithuba se-elementi sikhulu (g), kokukhona sikhulu i-aperture (W) iya kuba.Nangona kunjalo, ngokwefomula ye-angle ye-gating, i-angle ye-gating nayo iya kuncipha ngokunyuka kwe-frequency (i-wavelength iyancipha) kunye nokwanda kwesithuba sezinto (g).Incinci i-engile yelobe yokumasango, kokukhona iphezulu i-lobe ye-lobe yesango.Ngokukodwa xa umgca wokuskena uphambukisiwe, i-amplitude ye-lobe ephambili iya kuncipha kunye nesikhundla se-lobe ephambili iphambuke kwiziko.Ngelo xesha, indawo ye-lobe ye-gating iya kuba kufuphi neziko, ukwenzela ukuba i-amplitude ye-gating lobe iya kwanda ngakumbi, kwaye ide yenze ii-lobes ze-gating ezininzi kwi-imaging field of view.
Ixesha lokuposa: Feb-07-2022
