Ukujonga umfanekiso weMagnetic Resonance
I-MRI imele i -imagination magontic resonance imaging . Ngokwenene, igama elifanelekileyo le sifundo sisisithombe sombane we- nyukliya (i-NMRI), kodwa xa ubugcisa bephuhliswa ukusetyenziswa kwiinkonzo zempilo, igama elithi "nyukliya" lalibonakala libi kwaye lashiywa ngaphandle igama elamkelweyo.
I-MRI isekelwe kwimimiselo yenyama kunye nemikhemikhali ye-nuclear magnetic resonance (NMR), isetyenzisiwe esetyenziselwa ukufumana ulwazi malunga nohlobo lwemolekyuli.
Indlela iMRI esebenza ngayo
Ukuqala, makhe sibheke kwiindawo zomshini we-MRI. Izixhobo ezintathu ezisisiseko zomshini we-MRI zi:
- Umbane omkhulu
Inxalenye enkulu ye-MRI yiyona magnet . Ukuphuhlisa umbane wamandla okwaneleyo ukudala imifanekiso ye- MRI yayiyinkxalabo yokusinqoba ekuphuhliseni le teknoloji. - Amagnetta
Iimakethi ze-gradient ziyinxalenye "yokulungiswa kakuhle" inxalenye yomshini weMRI. Zivumela i-MRI ukuba igxile kwingxenye ethile yomzimba. Iimakethi ze-gradient nazo zinoxanduva lwe "ingxolo echukumisayo" kwi-MRI. - Ikhoyili
Emva kwesahlulo somzimba wakho ocingwa yikhoyili . Kukho iipilisi ezenzelwe amahlombe, amadolo kunye nezinye izixhobo zomzimba. Ikhoyili iya kukhupha i-radiofrequency eyenza i-MRI ibonakale.
Magnetti aPrayimari
Umtshini osisigxina (njengoluhlobo olusetyenziswayo kwisango sakho sefriji) olunamandla okwaneleyo ukusebenzisa iMRI luya kuba lukhulu kakhulu ukuvelisa kwaye lunzima ukugcina.
Enye indlela yokwenza i-magnet ukucoca ucingo lwamandla kwaye usebenze ngoku ngokutsha ngetambo. Oku kudala insimu yamagnetic ngaphakathi kwipilisi. Ukuze udale isiseko esinamandla esaneleyo sommandla ukwenza iMRI, iipilisi zentambo akumele zichaswe; Ngoko ke bayahlamba kwi-helium egazini kwiqondo lokushisa ama-450 degrees Fahrenheit ngaphantsi kwe-zero!
Oku kuvumela ukuba iikhoyili ziphuhlise amasimu ombane we-1.5 ukuya kwi-3 iTesla (amandla amaninzi e-MRIs yezokwelapha), ngaphezu kwamawaka angama-20,000 anamandla kunomhlaba wamagnetic.
Magnet Gradient
Kukho amatshini amathathu amancinci ngaphakathi komshini we-MRI obizwa ngamagnetta. Ezi zindlwana zincinci kakhulu ukuba i-magnet yokuqala (malunga ne-1/1000 inamandla), kodwa ivumela ukuba i-magnetic field iguqulwe ngokuchanekileyo. Zizo ziimakethi ze-gradient ezivumela "imifanekiso" yomzimba ukuba yenziwe. Ngokutshintsha ama-magnets, i-magnetic field ingagxininisa ngokukhethekileyo kwinqutyana ekhethiweyo yomzimba.
Ikhoyili
I-MRI isebenzisa izakhiwo zee-athomu ze-hydrogen ukuhlukanisa phakathi kwezicubu ezahlukeneyo emzimbeni womntu. Umzimba womntu uqulunqwe ngokuyinhloko kuma-athomu e-hydrogen (63%), ezinye izinto eziqhelekileyo zi-oxygen (26%), i-carbon (9%), i-nitrogen (1%), kunye nexabiso elincinci le-phosphorus, i-calcium, ne-sodium. I-MRI isebenzisa ipropathi yama-athomu ebizwa ngokuthi "spin" ukuhlukanisa umahluko phakathi kwezicubu ezifana nesisundu, i-fat, ne-tendon.
Ngesigulane kumatshini we-MRI kwaye i-magnet iyaqhubeka, i-nuclei yama-athomu e-hydrogen ihlala ijikeleza kwelinye lesibini. Ezi i-nuclei ze-athomu ze-hydrogen zinokuguqulwa kwe-oriental orientation, okanye i-prese, kwi-orientation echaseneyo.
Ukuze ujikeleze esinye isikhokelo, ikhoyili ikhupha i-radio-frequency (RF) eyenza lo tshintsho (ubukhulu bamandla obufunekayo ukwenza lolu tshintsho lucacile, kwaye lubizwa ngokuba yiLarmour Frequency).
Isibonakaliso esisetyenziselwa ukudala imifanekiso ye-MRI sithathwe kumandla akhululwe ngama-molecule aguqukayo okanye aqhubekele phambili, ukusuka kumandla abo aphezulu ukuya kwilizwe elisezantsi. Olu tshintshiselwano lwamandla phakathi kwamazwe ase-spin lubizwa ngokuba yi-resonance, kwaye ngoko igama elithi imagination magnetic imagination .
Ukuyibeka Konke
Ikhoyili iphinda isebenze ukufumanisa amandla anikwe amandla ngokufakelwa kwamagnetic ukususela ekuqaleni.
Ikhomputha iguqulela idatha kwaye idala imifanekiso ebonisa iimpawu ezahlukeneyo ze-resonance zeentlobo ezahlukeneyo zeethambo. Sibona oku njengomfanekiso wemibala yegrey - ezinye izicubu zomzimba zibonakalisa zibe mnyama okanye zikhanya, konke kuxhomekeke kule nkqubo ingentla.
Izigulane ezicwangciselwe ukufumana i-MRI ziya kubuzwa imibuzo ethile ukuze kuqinisekiswe ukuba i-MRI ikhuselekile kulo mguli. Eminye yemiba eya kuphendulwa iquka:
- Insimbi emzimbeni
Izigulane ezinezitshixo zetsimbi emzimbeni kufuneka ziqaphele abasebenzi be-MRI phambi kokuhlolwa kwe-MRI. Ezinye izimpembelelo zetsimbi ziyahambelana neMRI, kuquka neziplanyithi ezininzi zamathambo . Nangona kunjalo, ezinye izimpembelelo zithintela izigulane ukuba zingaba ne-MRI, njenge-aneurysm zicatshulwa ebuchosheni kunye nezilwanyana zesohlo zetsimbi . - Izixhobo ezifakiwe
Izigulane kunye nabadlali be- defibrillator zangaphakathi kufuneka baqaphele abasebenzi be-MRI, njengoko ezi zixhobo zithintela ukuhlolwa kwe-MRI. - Impahla / iingubo
Naluphina iingubo zensimbi okanye iigrafu kufuneka zisuswe ngaphambi kokuba ziqhube isifundo se-MRI.
Izinto zetsimbi ezikufutshane ne-MRI zingaba yingozi. Ngomnyaka we-2001, inkwenkwe eneminyaka emithandathu ubudala yabulawa xa itanki ye-oksijini yabetha umntwana. Xa i-MRI magnet ivuliwe, itanki ye-oksijini yanyulwa kwi-MRI, kwaye umntwana wabethwa yinto enzima. Ngenxa yale ngxaki inokuthi, abasebenzi be-MRI baqaphele kakhulu ekuqinisekiseni ukhuseleko lwezigulane.
Umsindo
Izigulane zihlala zikhalaza 'ngengxolo' yomsindo obangelwa yimishini yeMRI. Le ngxolo ivela kumagnet adibanisi ayechazwe ngaphambili. Ezi zikumakethi ze-gradient zincinci kakhulu xa zifaniswa nomlingo we-MRI oyintloko, kodwa zibalulekile ekuvumela ukuguqulwa okucokisekileyo kwintsimi yamagneti ukuze 'ubone' inxalenye efanelekileyo yomzimba.
Isikhala
Ezinye izigulane ziyi-claustrophobic kwaye azinqweneli ukungena kumshini we- MRI . Ngenhlanhla, kukho iindlela ezininzi ezikhoyo.
- I-MRIs eyingozi
Ii-MRIs ezintsha azifuni ukuba ulale ngaphakathi kwiphubhu. Kunoko, izigulane ezine-MRI zedolo, i-ankle, unyawo, i-elbow, okanye isandla, ziyakwazi ukubeka loo nxalenye yomzimba ngaphakathi komshini we-MRI. Olu hlobo lomshishini alusebenzi kwi-MRI yamagxa, umgudu, umlenze, okanye i-pelvis. - Vula i-MRIs
I-MRIs evulekileyo yayineengxaki eziphezulu ezibalulekileyo, kodwa ubugcisa bezithombe buye buphucula kakhulu kwiminyaka embalwa edlulileyo. Nangona ii-MRIs ezivaliweyo zikhethwa ngabagqirha abaninzi , i-MRI evulekile ingaba yinto efanelekileyo. - Ukuhlaliswa
Ezinye izigulane zinenkathazo zihleli zize ziphele imizuzu engama-45 ukugqiba i-MRI, ngokukodwa ngxolo. Ngako oko, kunokufanelekile ukuthatha imithi yokuphumula ngaphambi kokufunda i-MRI. Xoxa ngale ngcaciso nogqirha wakho ngaphambi kokuba uhlele ucwaningo lwe-MRI.