MuPW Doppler scanning yemidziyo yekutenderera, iyo yakanaka-imwe nzira yekuyerera kweropa inoonekwa zvakajeka, asi pachena girazi mufananidzo spectrum inogona kuwanikwa mu spectrogram.Kuderedza simba rekufambisa kwenzwi kunongoderedza kumberi nekudzosera kumashure kuyerera kweropa kusvika pamwero wakafanana, asi hazviiti kuti chipoko chinyangarike.Chete kana iyo emission frequency ikagadziriswa, musiyano unogona kuwanikwa.Iyo yakakwirira iyo emission frequency, zvakanyanya kuoneka yegirazi mufananidzo spectrum.Sezvinoratidzwa mumufananidzo unotevera, kuyerera kweropa mutsinga ye carotid inopa girazi rekuona.Iyo simba reiyo negative blood flow girazi image spectrum inongoderera zvishoma pane yakanaka yekuyerera kweropa, uye kuyerera kwevelocity kwakakwira.Sei izvi?
Tisati tadzidza zvipoko, ngationgororei danda re ultrasound scan.Kuti uwane kutungamira kurinani, danda re ultrasonic scanning rinoda kutariswa nekusiyana kunonoka kutonga kweakawanda-element.Iyo ultrasonic danda mushure mekutarisa yakakamurwa kuita main lobe, side lobe uye gedhi lobe.Sezvinoratidzwa pasi apa.
Iwo makuru uye eparutivi lobes anogara aripo, asi kwete iwo gating lobes, ndiko kuti, kana gating lobe angle yakakura kupfuura 90 madhigirii, hapana gating lobes.Kana iyo gating lobe angle iri diki, iyo amplitude yegeti lobe inowanzova yakakura kupfuura iyo yedivi lobe, uye inogona kunge iri iyo yakafanana kurongeka kwehukuru seyo huru lobe.Iyo yedivi-mhedzisiro ye grating lobe uye yeparutivi lobe ndeyekuti chiratidzo chekukanganisa chinotsauka kubva pamutsetse we scan inoiswa pamusoro peiyo huru lobe, iyo inoderedza kusiyanisa kugadzirisa kwemufananidzo.Nokudaro, kuitira kuti uvandudze kusiyana kwekugadzirisa kwemufananidzo, rutivi rwobe amplitude inofanira kuva duku uye gating lobe angle inofanira kuva yakakura.
Zvinoenderana nechimiro cheiyo main lobe angle, iyo yakakura aperture (W) uye yakakwira frequency, iyo yakanakisa lobe huru, iyo inobatsira pakuvandudza kwe lateral resolution yeB-mode imaging.Papfungwa yekuti huwandu hwemachaneti hunogara huripo, iyo yakakura iyo element spacing (g) ndeye, yakakura iyo aperture (W) ichave.Nekudaro, zvinoenderana neformula yegating angle, iyo gating angle inodererawo nekuwedzera kweiyo frequency (wavelength inodzikira) uye nekuwedzera kwechinhu spacing (g).Iyo idiki iyo gating lobe angle, inokwidza gating lobe amplitude.Kunyanya kana mutsara wekuongorora uchinge watsauka, iyo amplitude yeiyo huru lobe inoderera nenzvimbo yeiyo huru lobe inotsauka kubva pakati.Panguva imwecheteyo, nzvimbo yegeti lobe ichave pedyo nechepakati, kuitira kuti amplitude ye gating lobe iwedzere kuwedzera, uye kunyange kuita akawanda gating lobes mundima yekufungidzira yekuona.
Nguva yekutumira: Feb-07-2022
