Kuenzana kweMRI

Kuenzana kwesimba remagineti (homogeneity), inozivikanwawo sekuti magnetic field uniformity, zvinoreva kuzivikanwa kwesimba remagineti mukati memuganho wevhoriyamu chaiyo, kureva kuti, kana mitsetse yesimba remagineti munzvimbo yeyuniti yakafanana. Vhoriyamu chaiyo pano inowanzova nzvimbo yakatenderera. Yuniti yesimba remagineti yakafanana ippm (chikamu pamiriyoni), kureva kuti, musiyano uripo pakati pesimba guru resimba remagineti uye simba shoma resimba remagineti munzvimbo chaiyo yakakamurwa neavhareji yesimba remunda rakapetwa nemiriyoni imwe.

MRI inoda mwero wakakwira wekufanana kwesimba remagineti, izvo zvinosarudza resolution yenzvimbo uye chiyero chechiratidzo-kune-ruzha chemufananidzo munzvimbo yemifananidzo. Kusafanana kwakanaka kwesimba remagineti kuchaita kuti mufananidzo usanyatsojeka uye ukanganiswe. Kufanana kwesimba remagineti kunotsanangurwa nekugadzirwa kwesimba remagineti pachayo nenzvimbo yekunze. Nzvimbo yemifananidzo yemagineti yakakura, ndiko kudzikira kwekufanana kwesimba remagineti kunogona kuwanikwa. Kugadzikana kwesimba remagineti chiratidzo chekuyera mwero wekudonha kwesimba remagineti nekufamba kwenguva. Munguva yekutevera kwemifananidzo, kusvetuka kwesimba remagineti kunokanganisa chikamu chechiratidzo che echo chakayerwa kakawanda, zvichikonzera kukanganiswa kwemufananidzo uye chiyero chechiratidzo-kune-ruzha kudzikira. Kugadzikana kwesimba remagineti kwakabatana zvakanyanya nerudzi rwemagineti uye mhando yedhizaini.

Zvinodiwa zve magnetic field uniformity standard zvine chekuita nehukuru nechimiro chenzvimbo yekuyera inotorwa, uye zvinowanzo shandiswa nzvimbo yakatenderera ine dhayamita yakati uye pakati pemagineti senzvimbo yekuyera. Kazhinji, kumiririrwa kwe magnetic field uniformity kuri munzvimbo yekuyera yakati, nzvimbo yekuchinja kwesimba remagineti munzvimbo yakapihwa (ppm value), kureva kuti, chikamu chimwe chemiriyoni chesimba guru remagineti (ppm) sechikamu chekutsauka kuti chiratidze huwandu, kazhinji chikamu ichi chekutsauka chinonzi ppm, icho chinonzi absolute value representation. Semuenzaniso, kufanana kwe magnetic field mukati me silinda yese yekuongorora scanning check i5ppm; Kufanana kwe magnetic field munzvimbo ye sphere ye 40cm ne 50cm concentric ne magnet centre i1ppm ne 2ppm, zvichiteerana. Inogona zvakare kuratidzwa se: kufanana kwe magnetic field munzvimbo ye cube ye cubic centimeter yega yega munzvimbo ye sampuli iri kuyedzwa i 0.01ppm. Pasinei nemutemo, pasi pepfungwa yekuti saizi yebhora rekuyera yakafanana, ppm value diki inoratidza kuti magnetic field yakafanana zviri nani.

Pachishandiswa che1.5-tMRI, kuchinja kwesimba remagineti kunomiririrwa neyuniti imwe chete yekutsauka (1ppm) i1.5×10-6T. Nemamwe mashoko, musystem ye1.5T, kufanana kwesimba remagineti kwe1ppm zvinoreva kuti simba guru remagineti rine kuchinja kwe1.5×10-6T (0.0015mT) zvichibva pamashure esimba remagineti re1.5T. Zviri pachena kuti, mumidziyo yeMRI ine simba remagineti rakasiyana, kusiyana kwesimba remagineti rinomiririrwa neyuniti yega yega yekutsauka kana ppm kwakasiyana, kubva pamaonero aya, masisitimu epasi anogona kunge aine zvinodiwa zvishoma zvekufanana kwesimba remagineti (ona Tafura 3-1). Nechipo chakadaro, vanhu vanogona kushandisa chiyero chehumwe kuti vaenzanise zviri nyore masisitimu ane simba remagineti rakasiyana, kana masisitimu akasiyana ane simba remagineti rakafanana, kuitira kuti vaongorore mashandiro emagineti.

Usati wayera simba remagineti, zvakakosha kuti unyatsoona pakati pemagineti, wobva waronga chipimo chekuyera simba remagineti (Gauss meter) padenderedzwa renzvimbo reradius yakati, woyera simba remagineti point by point (24 plane method, 12 plane method), uye pakupedzisira wogadzirisa data kuti uverenge simba remagineti point mukati mevhoriyamu yese.

Kufanana kwesimba remagineti kuchachinja zvichienderana nenzvimbo yakapoteredza. Kunyangwe kana magineti yasvika padanho rakati (value yakavimbiswa nefekitori) isati yabuda mufekitori, Zvisinei, mushure mekuiswa, nekuda kwesimba rezvinhu zvakatipoteredza zvakaita sekudzivirira magineti (self-), kudzivirira magineti (RF shielding) (magonhi nemahwindo), waveguide plate (tube), chimiro chesimbi pakati pemagineti nezvitsigiro, zvinhu zvekushongedza zvekushongedza, magetsi, mapaipi emhepo, mapaipi emoto, mafeni emagetsi ekukurumidza, michina inofambiswa (kunyangwe mota, maelevator) ari pedyo nezvivakwa zvepamusoro nepazasi, kufanana kwayo kuchachinja. Saka, kana kufanana kwacho kuchizadzisa zvinodiwa zve magnetic resonance imaging kunofanirwa kubva pane zvabuda pakuyera panguva yekugamuchirwa kwekupedzisira. Kuenzanisa kwemunda usingashande uye kuenzana kwemunda unoshanda we superconducting coil inoitwa neinjiniya wekuisa wemugadziri we magnetic resonance mufekitori kana muchipatara ndiwo matanho makuru ekuvandudza kufanana kwesimba remagineti.

Kuti zviratidzo zvakaunganidzwa zvionekwe munzvimbo dzakasiyana-siyana panguva yekuskena, michina yeMRI inofanirawo kuisa simba remagineti regradient △B nekuchinja kunoramba kuchienderera mberi zvichibva pasimba guru remagineti B0. Zvinogoneka kuti munda wegradient △B wakaiswa pane imwe voxel unofanira kunge wakakura kupfuura kutsauka kwesimba remagineti kana kushanduka kwemvura kunokonzerwa nesimba guru remagineti B0, zvikasadaro ichachinja kana kutoparadza chiratidzo chekuisa nzvimbo chiri pamusoro apa, zvichikonzera zvinhu zvakagadzirwa uye kuderedza kunaka kwemifananidzo.

Kana kutsauka kukuru uye kushanduka-shanduka kwesimba remagineti rinogadzirwa nemunda mukuru wemagineti B0, kufanana kwesimba remagineti kwakaipa, kunaka kwemufananidzo kunoderedza, uye hukama hwakananga ne lipid compression sequence (musiyano we resonance frequency pakati pemvura nemafuta mumuviri wemunhu i200Hz chete) uye kubudirira kwekuongorora magnetic resonance spectroscopy (MRS). Saka, kufanana kwesimba remagineti chimwe chezviratidzo zvikuru zvekuyera mashandiro emidziyo yeMRI.

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Injector yekudhinda ine simba guruMidziyo iyi inokoshawo zvikuru muchikamu chemifananidzo yekurapa uye inowanzo shandiswa kubatsira vashandi vekurapa kupa mishonga yekudzivirira kuvarwere. LnkMed ikambani iri muShenzhen inogadzira michina iyi yekurapa. Kubva muna 2018, timu yehunyanzvi yekambani iyi yave ichinyanya kutarisa pakutsvaga nekugadzira majekiseni ekudzivirira kudzvinyirira anokonzera kushushikana kwakanyanya. Mutungamiriri wechikwata ichi chiremba ane ruzivo rweR&D rwemakore anopfuura gumi. Aya mabhenefiti akanaka ejekiseni reCT rimwe chete,jekiseni reCT remusoro miviri,Jekiseni reMRIuyeInjector yeAngiography ine pressure yakakwira(jekiseni reDSA) yakagadzirwa neLnkMed inosimbisawo hunyanzvi hwechikwata chedu chehunyanzvi - dhizaini diki uye iri nyore, zvinhu zvakasimba, Perfect inoshanda, nezvimwewo, zvakatengeswa kuzvipatara zvikuru zvemuno nemisika yekunze.