Ukuqonda ukusebenza kwe-Neuroimaging
I-Magnetic Resonance Imaging (MRI) inike odokotela amandla okuthola izithombe ezinhle kakhulu zezakhiwo zobuchopho. Inqubo entsha eyaziwa ngokuthi i-MRI esebenzayo ingahamba ngisho nangaphezulu ngokungalingani ngokulinganisa umsebenzi wobuchopho. Nakuba iningi le nqubo le ndlela isetshenziselwa izifundo zokwenza ucwaningo, kuyaba yinto evamile kakhulu esimweni semitholampilo.
Cishe uthola izithombe ezidalwe usebenzisa i-MRI esebenzayo ngesikhathi esithile.
Babonisa ubuchopho ngezizinda ezinemibala ebonisa izindawo zobuchopho ezihlobene nomsebenzi othile njengolimi noma ukunyakaza. Lezi zifundo zithandwa kakhulu: Amakhulu ama-athikili esayensi asebenzisa lobu buchwepheshe ashicilelwa njalo ngenyanga, eziningi zazo ezikhulunywe ngazo ekucindezelweni kwezinto. Kodwa lezi zithombe zenziwe kanjani, futhi ziyini ngempela?
Indlela i-MRI esebenzayo isebenza ngayo
I-MRI esebenzayo isebenzisa isignali ekhethekile ebizwa ngokuthi i-blood oxygen level dependant (BOLD). Igazi eligeleza ebuchosheni lithwala oksijeni kumamolekyu okuthiwa i- hemoglobin . Ama-molecule e-Hemoglobin nawo athatha insimbi ngakho-ke anesignali yamagnetic. Kuvela ukuthi ama-molemomu e-hemoglobin anezici ezihlukahlukene zamagnetic uma zihlanganiswa ne-oksijeni kunalokho uma zingathwali i-oksijeni, futhi lokhu umehluko omncane kungatholakala ngomshini we-MRI.
Uma indawo yobuchopho isasebenza kakhulu, okokuqala isebenzisa i-oksijeni eningi egazini.
Ngokushesha ngemva kwalokho, ubuchopho buxosha imithwalo yegazi yendawo ukuze ubuyisele umoya we-oxygen. Ubuchopho bungenza ngisho lomsebenzi kancane kakhulu ukuze igazi elingaphansi kwe-oksijeni lingene kule ndawo kunalokho okwakusetshenziswe ekuqaleni. Umshini we-MRI ungathola umehluko embonini ukuthi imiphumela yalokho ukwanda kwegazi oksijini.
Ngakho-ke izifundo ezisebenzayo ze-MRI empeleni azibheki umsebenzi we-neuronal ngqo, kodwa zibuka indlela amazinga e-oksijeni egazi aguquka ngayo futhi ahlobanisa lo msebenzi ukuze aqhubekele ukuqhuma. Ucwaningo luye lwabonisa ukuthi lokhu kucabangela kuvame ukulungile, nakuba izifo ezinjengobuhlungu bezinthambo, izikhumba , kanye nokuguga okujwayelekile kungashintsha ubuhlobo phakathi kwemisebenzi ye-neural nokugeleza kwegazi kwendawo okwenza isignali ye-BOLD.
Odokotela Bangayisebenzisa Kanjani I-MRI esebenzayo?
Ngenxa yokuthi ubuchwepheshe obusha futhi ngoba amanye amasu angaphendula imibuzo efana ne-FMRI, i-fMRI ayisetshenzisiwe ngokujwayelekile emitholampilo noma esibhedlela. Noma kunjalo, ingasetshenziswa ukusiza ukuhlinzeka ngokuhlinzwa okubalulekile kobuchopho. Isibonelo, uma i-neurosurgeon ifuna ukususa isisu sobuchopho esihlala eduze nezikhungo zolimi zobuchopho, zingase zihlele ucwaningo lwe-FMRI ukuze luze lubonise ukuthi yiziphi izindawo zobuchopho ezihilelekile ngolimi. Lokhu kusiza i- neurosurgeon ukugwema ukulimaza lezo zifunda ngenkathi kwenziwa ukuhlinzwa. Noma kunjalo, ukusetshenziswa okuvame kakhulu kwe-fMRI kukucwaninga lwezokwelapha.
Yiziphi izinhlobo zokucwaninga ezenziwayo usebenzisa i-fMRI?
Kunezindlela ezimbili eziyinhloko zokusebenzisa i-fMRI ukubona ngeso lengqondo ukusebenza kobuchopho. Enye indlela igxile ekutholeni izindawo ezithile zobuchopho ezithinta umsebenzi othile noma isisusa.
Isibonelo, umuntu osesithombeni se-MRI angaboniswa i-checkerboard ekhanyayo kwamanye amaphuzu, futhi ngezinye izikhathi isikrini esingenalutho. Bangase baceliwe ukuba basunduze inkinobho noma nini lapho bebona i-checkerboard ebhanya. Isibonakaliso phakathi nomsebenzi sizobe siqhathaniswa nesignali uma umsebenzi ungenziwanga, futhi umphumela uzoba uhlobo lwezithombe zeziphi ubuchopho ezihilelekile ekuboneni i-checkerboard ekhanyayo bese uphonsa inkinobho.
Enye indlela i-fMRI ingasetshenziswa ukuhlola amanethiwekhi we-neural. Lokhu kuhilela ukuhlola ukuthi yiziphi izindawo zobuchopho ezikhulumisanayo. Uma indawo eyodwa yobuchopho ivame ukukhanya ngesikhathi esifanayo nenye, lezi zindawo ezimbili zobuchopho zingaxhunyaniswa.
Akukho msebenzi ongase udingeke ukuze wenze lolu hlobo lokutadisha. Ngenxa yalesi sizathu, lezi zifundo ngezinye izikhathi zibizwa ngokuthi ukuphumula kwesimo sombuso se-resonance magnetic.
Ukwaziswa okuvela kwizifundo ze-MRI esebenzayo kuyinkimbinkimbi kakhulu futhi kudinga ukuhlaziywa kwezibalo eziningi kube nenjongo. Lokhu ekuqaleni kwaholela abantu abaningi ukuba bangathembi imiphumela yezinhlelo zokusebenza ze-MRI, njengoba kubonakala sengathi kunamathuba amaningi okuba nephutha ekuhlaziyweni. Kodwa-ke, njengoba bobabili abacwaningi nababuyekezi sebejwayelene kakhulu nobuchwepheshe obusha, imiphumela iyathembeka futhi ithembekile.
Yini Ikusasa Elibhekene neMRI Esebenzayo?
Ucwaningo lwe-MRI olusebenzayo seluvele lubonise izinto eziningi ngokuphathelene nobuchopho, ngaphezu kokuqinisekisa lokho esasiwazi kakade mayelana nezindlela ze-neural kanye nokwakhiwa kwendawo. Nakuba kunzima ukusho ukuthi ngabe i-fMRI izoke isetshenziswe kaningi esimisweni somtholampilo, ukuthandwa kwayo kanye nokusebenza njengethuluzi lokucwaninga yedwa kwenza kube kubalulekile kokubili odokotela kanye nabalandeli ukuba babe nokuqonda okuyisisekelo ukuthi leli thuluzi lisebenza kanjani.
Imithombo:
I-Pressman P, iGitelman D. I-MRI esebenzayo: I-primer yezakhamuzi ze-neurology. Neurology 2012 March 06, 78 (10) e68-e71
Faro SH, Mohamed FB, I-Self-Self V. I-MRI esebenzayo: Izimiso eziyisisekelo kanye nezicelo zomtholampilo: I-Oxford Univrsity Press, e-USA, 2006.