Magnetic field uniformity (homogeneity), inozivikanwawo semagnetic field uniformity, inoreva kuzivikanwa kwesimba remagineti mukati meiyo vhoriyamu yakatarwa, kureva kuti, kana mitsetse yemagineti yakayambuka nzvimbo yeyuniti yakafanana. Vhoriyamu chaiyo pano kazhinji inzvimbo yedenderedzwa. Iyo unit yemagnetic field uniformity ndeye ppm (chikamu pamiriyoni), ndiko kuti, mutsauko pakati pehukuru hwesimba remunda uye diki simba remunda remagineti mune imwe nzvimbo yakakamurwa neavhareji simba remunda rakapetwa nemiriyoni imwe.
MRI inoda dhigirii yakakwirira yemagnetic field kufanana, iyo inosarudza kugadzirisa kwepakati uye chiratidzo-ku-ruzha chiyero chemufananidzo muhuwandu hwekufungidzira. Kusafanana kwakashata kwemagnetic field kuchaita kuti chifananidzo chive chisina kujeka uye chinokanganisa. Iyo magnetic field uniformity inotarirwa nekugadzirwa kwemagineti pachayo uye nekunze kwezvakatipoteredza. Iyo yakakura nzvimbo yekufungidzira yemagineti, iyo yakaderera iyo magnetic field kufanana inogona kuwanikwa. Kugadzikana kwemagnetic field indekisi yekuyera dhigirii rekukukurwa kwesimba remagineti nekufamba kwenguva. Munguva yekutevedzana kwekufungidzira, kudonha kwesimba remagineti kuchakanganisa chikamu cheiyo yakadzokororwa kuyerwa echo chiratidzo, zvichikonzera kukanganisa kwemufananidzo uye chiratidzo-ku-ruzha reshiyo. Kugadzikana kwemagnetic field kunoenderana zvakanyanya nemhando yemagineti uye kunaka kwekugadzira.
Izvo zvinopihwa zvemagnetic field uniformity standard zvine hukama nehukuru uye chimiro cheyero nzvimbo yakatorwa, uye kazhinji shandisa nzvimbo yedenderedzwa ine imwe dhayamita uye nepakati pemagineti seyeyero renji. Kazhinji, kumiririrwa kweiyo magineti yekufanana kuri mune imwe nzvimbo yekuyera, shanduko yemhando yesimba remagineti munzvimbo yakapihwa (ppm kukosha), ndiko kuti, miriyoni imwe yesimba guru remagineti (ppm) sechikamu chekutsauka kuratidza huwandu, kazhinji chikamu ichi chekutsauka chinodaidzwa kuti ppm, inodaidzwa kuti absolute value representation. Semuenzaniso, kufanana kwemagnetic field mukati mese scanning check aperture cylinder ndeye 5ppm; Iyo magineti yemagineti yakafanana munzvimbo yepasirendi ye40cm uye 50cm yakatarisana ine magineti centre i1ppm uye 2ppm, zvichiteerana. Inogona zvakare kuratidzwa se: kufanana kwesimba remagineti munzvimbo yecubic yega yega cubic centimita munzvimbo yemuenzaniso inoedzwa ndeye 0.01ppm. Pasinei nechiyero, pasi pechikonzero chekuti kuyerwa kwepasirendi kwakafanana, iyo diki kukosha kweppm inoratidza zviri nani iyo magnetic field kufanana.
Muchiitiko che 1.5-tMRI chigadziro, kudonha kushanduka kwesimba remagineti rinomiririrwa nechikamu chimwe chekutsauka (1ppm) ndeye 1.5 × 10-6T. Mune mamwe mazwi, mune 1.5T system, iyo magineti yakafanana ye1ppm inoreva kuti iyo huru magineti ine dhift fluctuation ye1.5 × 10-6T (0.0015mT) zvichienderana nekumashure kweiyo 1.5T yemagineti simba. Sezviri pachena, muMRI michina ine simba rakasiyana-siyana remunda, kuchinja kwemagnetic field intensity inomiririrwa nechikamu chimwe nechimwe chekutsauka kana ppm yakasiyana, kubva pane iyi maonero, maitiro epasi pasi anogona kuva nezvinodiwa zvishoma zvemagnetic field uniformity (ona Tafura 3-1) . Negadziriro yakadai, vanhu vanogona kushandisa chiyero chakafanana kuenzanisa masisitimu ane masimba akasiyana emumunda, kana masisitimu akasiyana ane simba remumunda rakafanana, kuitira kuti vatarise mabatiro anoita magineti.
Pamberi pekuyera chaiko kweiyo magnetic field kufanana, zvinodikanwa kunyatsoona pakati pemagineti, uyezve kuronga iyo munda intensity yekuyeresa chiridzwa (Gauss mita) probe pane space sphere yeimwe radius, uye kuyera iyo magineti simba. point by point (24 plane method, 12 plane method), uye pakupedzisira gadzira iyo data kuverenga iyo magnetic field uniformity mukati mevhoriyamu yose.
Kufanana kwemagnetic field kuchachinja nenharaunda yakapoteredza. Kunyangwe kana magineti yasvika pane imwe chiyero (fekitari yakavimbiswa kukosha) isati yabuda mufekitori, Nekudaro, mushure mekuiswa, nekuda kwesimba rezvakatipoteredza zvinhu zvakaita semagineti (self-) kudzivirira, RF shielding (magonhi neWindows), waveguide plate. (tube), chimiro chesimbi pakati pemagineti uye zvitsigiro, zvekushongedza zvekushongedza, zvigadziriso zvemwenje, pombi dzekufemesa, pombi dzemoto, mafeni emhepo yekukurumidzira, nharembozha (kunyangwe mota, zvikwiriso) padivi pezvivakwa zvekumusoro nepasi, kufanana kwayo kuchachinja. Nokudaro, kana iyo yakafanana inosangana nezvinodiwa zvemagnetic resonance imaging inofanira kubva pamigumisiro chaiyo yekuyera panguva yekugamuchirwa kwekupedzisira. Iyo passive field leveling uye inoshingaira yemunda kuenzana kweiyo superconducting coil yakaitwa neanogadzira mainjiniya weiyo magineti resonance mugadziri mufekitori kana muchipatara ndiwo matanho akakosha ekuvandudza kufanana kweiyo magineti.
Kuti uwane masaini akaunganidzwa munzvimbo yekuvheneka, michina yeMRI inodawo kukwirisa gradient magineti △B nekuenderera uye kuwedzera shanduko pahwaro hweiyo huru magineti B0. Zvinogoneka kuti gradient munda △B yakakwirirwa pavoxel imwe chete inofanira kunge yakakura kudarika magineti kutsauka kana kudonha kunokonzerwa neiyo main magnetic field B0, zvikasadaro inoshandura kana kutsakatisa chiratidzo chenzvimbo chiri pamusoro, zvichikonzera zvinhu zvekare. kuderedza mufananidzo wemhando.
Iyo yakakura kutsauka uye kudonha kudonha kweiyo magineti inogadzirwa neiyo huru magineti B0, zvakanyanya kufanana kweiyo magineti, kuderera kwemhando yemufananidzo, uye zvakanyanya kuenderana neiyo lipid compression kutevedzana (iyo resonance frequency musiyano pakati mvura nemafuta mumuviri wemunhu ingori 200Hz) uye kubudirira kwemagineti resonance spectroscopy (MRS) yekuongorora. Nokudaro, magnetic field uniformity chimwe chezviratidzo zvakakosha zvekuyera kushanda kweMRI michina.
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High-pressure musiyano media injectors zvakare yakakosha kwazvo midziyo yekubatsira mumunda wekufungidzira kwekurapa uye inowanzoshandiswa kubatsira vashandi vekurapa kuburitsa midhiya yakasiyana kune varwere. LnkMed inogadzira iri muShenzhen inonyanya kugadzira iyi michina yekurapa. Kubva 2018, timu yekambani tekinoroji yanga yakatarisana nekutsvagisa uye kugadzirwa kweyakanyanya-kudzvanya majekiseni ejenti. Mutungamiri wechikwata chiremba ane anopfuura makore gumi eruzivo rweR&D. Aya maonero akanaka eCT jekiseni rimwe chete,CT kaviri musoro jekiseni,MRI jekiseniuyeAngiography high pressure injector(DSA jekiseni) inogadzirwa neLnkMed inosimbisawo hunyanzvi hwechikwata chedu chehunyanzvi - dhizaini yakabatana uye iri nyore, zvinhu zvakasimba, zvinoshanda Zvakakwana, nezvimwewo, zvakatengeswa kuzvipatara zvikuru zvepamba nemisika yekunze.
Nguva yekutumira: Mar-28-2024
