Isilinganiso sokugeleza kwegazi sasivame ukuba umsebenzi onzima ku-Doppler ultrasound yombala.Manje, ngokusakazwa okuqhubekayo kwe-ultrasound emkhakheni wokufinyelela kwemithambo ye-hemodialysis, sekuyisidingo esiqinile futhi esiqinile.Nakuba kuvame kakhulu ukusebenzisa i-ultrasound ukukala ukugeleza koketshezi kumapayipi ezimboni, akuzange kunakwe kakhulu esilinganisweni sokugeleza kwegazi emithanjeni yegazi emzimbeni womuntu.Kunesizathu salokho.Uma kuqhathaniswa namapayipi ezimboni, imithambo yegazi emzimbeni womuntu ingcwatshwa ngaphansi kwesikhumba esingabonakali, futhi ububanzi beshubhu buhluka kakhulu (ngokwesibonelo, ububanzi beminye imikhumbi ngaphambi kwe-AVF bungaphansi kuka-2mm, kanti amanye ama-AVF angaphezulu. kuno-5mm ngemva kokuvuthwa), futhi ngokuvamile anwebeka kakhulu, okuletha ukungaqiniseki okukhulu ekulinganisweni kokugeleza.Leli phepha lenza ukuhlaziya okulula kwezici ezinethonya zokulinganisa ukugeleza, futhi liqondise ukusebenza okungokoqobo okuvela kulezi zici, ngaleyo ndlela kuthuthukiswe ukunemba nokuphindaphinda kokulinganisa ukugeleza kwegazi.
Ifomula yokulinganisa ukugeleza kwegazi:
Ukugeleza kwegazi = isilinganiso sokugeleza kwesikhathi × indawo enqamula izingxenye × 60, (iyunithi: ml/min)
Ifomula ilula kakhulu.Ivolumu nje yoketshezi olugeleza engxenyeni enqamulayo yomkhumbi wegazi ngesikhathi seyunithi ngayinye.Okudingeka kulinganiswe yiziguquguquki ezimbili-- indawo ephambanayo kanye nesilinganiso sokugeleza esimaphakathi.
Indawo ye-cross-sectional kufomula engenhla isekelwe ekucabangeni ukuthi umkhumbi wegazi uyithubhu eliyindilinga eliqinile, kanye nendawo ye-cross-sectional = 1/4 * π * d*d, lapho u-d kuwububanzi bomkhumbi wegazi. .Nokho, imithambo yegazi yangempela yomuntu iyanwebeka, okulula ukuyikhama futhi ikhubazekile (ikakhulukazi imithambo).Ngakho-ke, lapho ukala ububanzi beshubhu noma ukala izinga lokugeleza, udinga ukuqinisekisa ukuthi imithambo yegazi ayicindezelwa noma ikhubazekile ngangokunokwenzeka.Uma siskena isigaba se-longitudinal, amandla angase asetshenziswe ngokungazi ezimweni eziningi, ngakho ngokuvamile kuyanconywa ukuqedela isilinganiso sobubanzi bepayipi esigabeni esiphambene.Esimeni lapho indiza ephambanayo ingaminyanisiwe ngamandla angaphandle, umkhumbi wegazi ngokuvamile uwundingiliza ocishe ufane, kodwa esimweni esiminyanisiwe, uvame ukuba yi-ellipse evundlile.Singakwazi ukukala ububanzi bomkhumbi esimweni semvelo, futhi sithole inani elilinganiselwe lokulinganisa ububanzi njengereferensi yezilinganiso zesigaba sobude bobude obulandelayo.
Ngaphandle kokugwema ukucindezela imithambo yegazi, kuyadingeka futhi ukuthi unake ukwenza imithambo yegazi ihambisane nesigaba se-ultrasound imaging lapho kulinganiswa ingxenye yesiphambano semithambo yegazi.Ungahlulela kanjani ukuthi imithambo yegazi iqondile njengoba ingaphansi kwesikhumba?Uma ingxenye ye-imaging ye-probe ingeyona i-perpendicular to the blood vessel (futhi isitsha segazi singaminyanisiwe), isithombe esitholakala esiphambanweni sizophinde sibe i-ellipse eqondile, ehlukile ku-ellipse evundlile eyakhiwe yi-extrusion.Lapho i-engeli yokutsheka ye-probe inkulu, i-ellipse ibonakala kakhulu.Ngesikhathi esifanayo, ngenxa yokutsheka, amandla amaningi e-ultrasound yesigameko aboniswa kwezinye izikhombisi-ndlela, futhi inani elincane kuphela lama-echoes elitholwa yi-probe, okuholela ekukhanyeni kwesithombe kwehliswa.Ngakho-ke, ukwahlulela ukuthi i-probe i-perpendicular to the blood vessel ngokusebenzisa i-engeli isithombe esikhanya kakhulu futhi kuyindlela enhle.
Ngokugwema ukuhlanekezela umkhumbi kanye nokugcina i-probe perpendicular emkhunjini ngangokunokwenzeka, ukulinganisa okunembile kobubanzi bomkhumbi engxenyeni ephambanayo kungafinyelelwa kalula ngokuzijwayeza.Nokho, kusazoba khona ukuhluka okuthile emiphumeleni yesilinganiso ngasinye.Kungenzeka kakhulu ukuthi umkhumbi awulona ithubhu lensimbi, futhi uzokhula noma uvumelane nezinguquko zomfutho wegazi phakathi nomjikelezo wenhliziyo.Isithombe esingezansi sibonisa imiphumela ye-carotid pulses ku-B-mode ultrasound kanye ne-M-mode ultrasound.Umehluko phakathi kobubanzi be-systolic ne-diastolic obukalwe ku-M-ultrasound ungaba cishe u-10%, futhi umehluko we-10% ububanzi ungabangela umehluko we-20% endaweni ye-cross-sectional.Ukufinyelela kwe-hemodialysis kudinga ukugeleza okuphezulu futhi ukushaya kwemikhumbi kuzwakala kakhulu kunokujwayelekile.Ngakho-ke, iphutha lokulinganisa noma ukuphindaphindwa kwale ngxenye yesilinganiso kungabekezelelwa kuphela.Asikho iseluleko esihle kakhulu, ngakho vele uthathe izilinganiso ezimbalwa uma unesikhathi bese ukhetha isilinganiso.
Njengoba ukulungiswa okuqondile komkhumbi noma i-angle enesigaba se-probe ayikwazi ukwaziwa ngaphansi kokubuka okuphambene, kodwa ekubukeni kwe-longitudinal yomkhumbi, ukulungiswa komkhumbi kungabonwa kanye ne-angle phakathi kokuqondisa komkhumbi kanye umugqa wokuskena we-Doppler ungalinganiswa.Ngakho-ke ukulinganisa kwejubane lokugeleza kwegazi eliphakathi komkhumbi kungenziwa kuphela ngaphansi kokushanela kwe-longitudinal.Ukushanela isikhathi eside komkhumbi kuwumsebenzi oyinselele kwabaqalayo abaningi.Njengalapho umpheki esika imifino yekholomu, ummese uvamise ukusikwa endizeni evundlayo, ngakho-ke uma ungangikholwa, zama ukusika i-asparagus endizeni yobude.Lapho usika i-asparagus ubude, ukuhlukanisa i-asparagus ibe izingxenye ezimbili ezilinganayo, kubalulekile ukubeka ummese ngokucophelela phezulu, kodwa futhi uqinisekise ukuthi indiza yommese ingawela nje i-axis, ngaphandle kwalokho ummese uzoba nzima, i-asparagus kufanele igibele eceleni.
Okufanayo kuyiqiniso ngokushanela kwe-longitudinal ultrasound yomkhumbi.Ukuze ulinganise ububanzi bomkhumbi we-longitudinal, isigaba se-ultrasound kufanele sidlule e-axis yomkhumbi, futhi kuphela lapho isigameko se-ultrasound perpendicular to the front and posterior izindonga zomkhumbi.Inqobo nje uma uphenyo luseceleni kancane, enye yesigameko se-ultrasound izobonakala kwezinye izikhombisi-ndlela, okuholela ekwenanela okubuthakathaka okutholwe uphenyo, futhi kuhlanganiswe neqiniso lokuthi izingcezu zangempela ze-ultrasound beam (i-acoustic lens focus) ziwugqinsi, kukhona okuthiwa "umphumela wevolumu eyingxenye", okuvumela ukuthi ama-echoes avela ezindaweni ezahlukene kanye nokujula kodonga lomkhumbi kuhlanganiswe ndawonye, okuholela ekutheni Isithombe sifiphale futhi udonga lweshubhu lungabonakali bushelelezi.Ngakho-ke, ngokubheka isithombe sesigaba se-longitudinal esiskeniwe somkhumbi, singakwazi ukunquma ukuthi ingxenye ye-longitudinal eskeniwe ilungile yini ngokubheka ukuthi udonga lubushelelezi, lucacile futhi lukhanya yini.Uma i-artery iskenwa, i-intima ingabonwa ngokucacile ekubukeni kwe-longitudinal ekahle.Ngemva kokuthola isithombe esikahle se-2D se-longitudinal, ukukalwa kobubanzi kunembe uma kuqhathaniswa, futhi kuyadingeka ukuze kuthathwe isithombe sokugeleza kwe-Doppler esilandelayo.
Isithombe sokugeleza kwe-Doppler ngokuvamile sihlukaniswa sibe yisithombe sokugeleza kombala esinezinhlangothi ezimbili kanye nesithombe esibukwayo se-pulsed wave Doppler (PWD) esinendawo yesampula yesampula engashintshi.Singasebenzisa isithombe sokugeleza kombala ukuze senze ukushanela kwe-longitudinal okuqhubekayo kusukela emithanjeni kuya ku-anastomosis bese kusuka ku-anastomosis kuya emthanjeni, futhi imephu yesivinini yokugeleza kombala ingakwazi ukukhomba ngokushesha izingxenye ze-vascular ezingavamile ezifana ne-stenosis nokuvala.Kodwa-ke, ukuze kulinganiswe ukugeleza kwegazi, kubalulekile ukugwema indawo yalezi zingxenye zemikhumbi ezingavamile, ikakhulukazi ama-anastomoses nama-stenoses, okusho ukuthi indawo ekahle yokulinganisa ukugeleza kwegazi ingxenye yomkhumbi oyisicaba uma kuqhathaniswa.Lokhu kungenxa yokuthi kuphela kumasegimenti amade ngokwanele aqondile lapho ukugeleza kwegazi kuvame ukugeleza okuzinzile kwe-laminar, kuyilapho ezindaweni ezingavamile njengama-stenoses noma ama-aneurysms, isimo sokugeleza singashintsha kungazelelwe, okuholela ekugelezeni kwe-eddi noma okuyaluzayo.Emdwebeni wokugeleza kombala womthambo ovamile we-carotid kanye nomthambo we-carotid we-stenotic oboniswe ngezansi, ukugeleza esimweni se-laminar kubonakala ngesivinini sokugeleza okuphezulu phakathi nendawo yomkhumbi kanye nokunciphisa isivinini sokugeleza eduze kodonga, kuyilapho kusigaba se-stenotic ( ikakhulukazi ezansi ne-stenosis), isimo sokugeleza asijwayelekile futhi indlela yokugeleza kwamangqamuzana egazi ayihlelekile, okuholela ekuhlukeni kokubomvu okuluhlaza okwesibhakabhaka emfanekisweni wokugeleza kombala.
Isikhathi sokuthumela: Feb-07-2022
