Tổng Quan Về Máy MRI.doc

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Tng quan v my MRI1./ L ch s pht trinFelix Block v Edward Purcell pht hin ra hin tng cng hng t ht nhn vo nm 1946 v t nhng nm 1950 n nm 1970 cng hng t c ng dng v pht trin rng ri. Thnh qu c chng nhn bng gii Nobel Vt l vo nm 1952 cho 2 nh vt l Felix Block v Edward Purcell. V l c s vt l quan trng cho s pht trin MRI.n nm 1970, nn to nh y hc th gii c mt s thay i ng k vi s cng b kt qu nghin cu ca tin s Raymond Damidian. ng pht hin ra cu trc c th ngi bao gm phn ln nc v l cha kha cho to nh cng hng t, v rng nc pht ra mt tn hiu m c th d v ghi li c. Sau tin s Damidian v cc cng s tip tc nghin cu mit mi trong 7 nm v thit k, ch to ra chic my qut cng hng t u tin dng trong vic to nh y t ca c th ngi.n nm 1980 chic my cng hng t u tin c a vo p dng. n nm 1987 k thut Cardiac MRI c a vo s dng cho vic chn on cc bnh v tim mch. n nm 1993 th FMRI dng chn on cc chc nng v hot ng ca no b

K thut to nh cng hng t (MRI) hin tr thnh mt phng php ph thng trong y hc chn on hnh nh. Cc thit b MRI u tin ng dng y hc xut hin vo u nhng nm 1980. Vo nm 2002, c gn 22.000 camera MRI c s dng trn ton th gii. Trn ton th gii mi nm c hn 60 triu ca chn on bng MRI v phng php ny vn ang pht trin nhanh. MRI thng tt hn cc k thut hnh nh khc v c ci thin ng k v chnh xc trong vic chn on nhiu cn bnh. N thay th mt s phng php kim tra theo kiu a thit b vo c th, do gim au n, ri ro cng nh s bt tin cho nhiu bnh nhn. Chng hn nh s dng phng php ni soi kim tra tuyn ty hoc tuyn mt c th gy mt s bin chng nghim trng.Li th ca MRI l tnh v hi ca n. MRI khng s dng bc x ion ho ging nh phng php chp X quang thng quy (Nobel Vt l -1901) hoc chp CT (Nobel Y hc -1979). Tuy nhin, n c mt nhc im l bnh nhn no phi tim kim loi t hoc mang my iu ho nhp tim khng th c kim tra bng MRI bi MRI c trng t tnh mnh. Ngy nay, MRI c s dng kim tra gn nh mi c quan trong c th. K thut ny c bit c gi tr trong vic chp nh chi tit no hoc dy ct sng. K t khi MRI mang li nhng hnh nh 3 chiu, bc s c th nm c thng tin v a im thng tn. Nhng thng tin nh vy rt c gi tr trc khi phu thut chng hn nh tiu phu no.2./ Nguyn l to nh phng php chp nh cng hng t ht nhn MRI (Magnetic Resonnance Imaging), ngi ta a c th bnh nhn vo vng c t trng mt chiu rt mnh, hin nay ph bin l dng t trng sinh ra do cun dy siu dn c dng in rt ln chy qua. Trong c th c nhng nguyn t m ht nhn c momen t tng t nh c gn mt thanh nam chm cc nh. Di tc dng ca t trng ngoi, momen t ca ht nhn nguyn t quay o tng t nh con quay di tc dng ca trng trng trn mt t. Nu ht nhn ang quay o vi tn s w m c thm sng v tuyn cng tn s w tc dng, ht nhn s quay o cc mnh v c hin tng cng hng. l cng hng t ht nhn. Khi ngng tc dng sng v tuyn, ht nhn s t trng thi quay o cc mnh tr v trng thi quay o bnh thng. Ht nhn c momen t quay nh vy s sinh ra sng in t pht ra khng gian xung quanh, c th o c sng in t nu t vo y mt cun dy in.

Vic ht nhn t trng thi quay o mnh do cng hng tr v trng thi quay o bnh thng nhanh hay chm cn ty thuc vo cc nguyn t quanh ht nhn cn tr chuyn ng quay t hay nhiu. V d, ht nhn ca nguyn t H trong phn t nc (H2O) ca mu, t trng thi cng hng quay v trng thi thng rt nhanh nu mu ang lu thng trong mch mu, tri li quay v rt chm nu mu chy thm ra ngoi tht, m. my MRI, ngi ta c th to ra cng hng ng vi mt loi ht nhn no (v d ht nhn hyr) trong tng th tch c milimet khi ca no v theo di trng thi cng hng. Ln lt qut th tch c cng hng ny, s c c hnh nh cng hng t ht nhn tng lp. C th theo di nh bit c cu to bn trong ca no lc c th ang sng (bit c c chy mu trong no hay khng, chy ch no). C th dng MRI theo di hot ng ca no, v d nh khu vc no ca no hot ng, mu a oxy v vng mnh hay yu...c im MRI phn gii khng gian rt cao, cn phn gii thi gian va phi: Phn gii khng gian: 3 mm v phn gii thi gian: 3 giyy l phng php hiu nghim v d s dng nht hin nay nghin cu v no. Ngi ta pht trin phng php chp nh cng hng t chc nng (FMRI Function MRI) nghin cu khng ch v cu to m cn v chc nng hot ng ca no.Tuy nhin, phng php ny kh tn km do phi dng hli lng lm lnh cun dy siu dn.u imnh cu trc cc m mm trong c th nh tim, phi, gan v cc c quan khc r hn v chi tit hn so vi nh c to bng cc phng php khc.MRI gip cho cc bc s nh gi c cc chc nng hot ng cng nh l cu trc ca nhiu c quan ni tng trong c thS chi tit lm cho MRI tr thnh cng c v gi trong chn on thi k u v trong vic nh gi cc khi u trong c th.To nh bng MRI khng gy tc dng ph nh trong to nh bng chp X quang thng quy v chp CTMRI cho php d ra cc im bt thng n sau cc lp xng m cc phng php to nh khc kh c th nhn ra.MRI c th cung cp nhanh v chun xc so vi tia X trong vic chn on cc bnh v tim mch.Khng pht ra cc bc x gy nguy him cho con ngi.Nhc imCc vt bng kim loi cy trong c th khng c pht hin c th b nh hng bi t trng mnhKhng s dng vi cc bnh nhn mang thai 12 tun u tin. Cc bc s thng s dng cc phng php to nh khc, v d nh siu m, vi cc ph n mang thai tr phi tht cn thit bt buc phi s dng MRI.3./ p dngCc bnh l thn kinh : ng kinh , bnh mt Myelin, bnh no bm sinh, u bu , vim nhim, .. . ca no v ty sng .Mch Mu : D dng , x va , teo hp mch mu no b v tn thng.C xng khp : bnh l vim c xng khp, dy chng, c bp.Mt, tai mi hng : U hc mt, u ni nh, u hu hng, vim nhim, p xe ...Tim mch : bnh l c tim, ng mch c, ng mch ch, ng mch ngoi viC quan ni tng : cc bnh l gan, thn ty, lch ...U buu : pht hin, nh gi mc xm ln theo iu tr.4./ So snh MRI vi CTChp ct lp in ton (CT Scan) s dng tia X v h thng detector thu thp tn hiu khc nhau ca tng im trn c th sau ti to li hnh nh theo tng lt ct.Chp cng hng t (MRI) s dng t trng lm phn cc cc nguyn t Hydro c trong phn t nc ca c th. Khi cc nguyn t H o cc s cho cc tn hiu in t c ghi nhn. V hm lng nc khc nhau trn mi loi m nn tn hiu nhn c s khc nhau, to ra hnh nh khc nhau ca cc vng m trong c th.CT v MRI u l phng tin chn on hnh nh cao cp, thu nhn cc hnh nh bnh l nm su trong c th chn on bnh. Hnh nh thu c c th ti to thnh hnh 3 chiu, lt ct rt mng v chi tit rt nh gip ch rt nhiu trong chn on.CT s dng tia X nn c tc hi do c th b nhim tia, gi r hn MRI.MRI s dng t trng, hon ton khng tn hi c th nh gi mc hn.5./ ng dng Vit NamNgy 14/7/1996, ti Medic khnh thnh my MRI u tin ti Vit Nam vi s hin din ca GS. Trn Vn Giu, my MRI hiu Toshiba Access loi m (open).ngy 14-07-1996 khai trng MRI..u tin ca MEDIC. My MRI u tin ny hot ng khi m ngi bnh cn cha sn lng xt nghim bng k thut ny v qu mi, gi cao,, bc s cha bit r ch nh khi no cn chp MRI.i ng bc s chn on s dng cng hng t (MRI) c o to ti Singapore v M Lai, ri M dn uy tn v nhu cu chn on vi MRI trong lnh vc no v ct sng, lm nn cho 2 chuyn khoa ny pht trin. Nhu cu chp MRI tng ln cao, MRI th 2 ra i bnh vin Vit X v sau l bnh vin ch Ry ri ph bin rng ra ton quc.Ti Medic, TPHCM, nhu cu chp MRI tng nhanh, my MRI th 2 ca Medic ra i, loi siu dn 1,5T GE LX. Ri tip tc li cn thm my th 3 MRI siu dn 1,5T CVI GE Hin ti, mi ngy Medic chp 50 bnh nhn vi nhiu k thut, nht l ct sng v no.Hin ti trn ton quc c 23 my MRI phn b nh sau :H Ni : 9 myBV Bch MaiBV Vit cBV Saint-PaulBV Qun Y 103TT AmticTT chn on (178 Thi H)TT chn on (107 Tn c Thng)BV Vit X (1T)BV 108 (1,5T)Hu Nng : 3 myBV Trung ng Hu (1,5T China)BV a khoa Nng (open Hitachi)BV Hon M Nng (open Toshiba)

TPHCM : 11 myMedic (3 my : 2 GE 1,5T v 1 open)BV Ch Ry (2 my : 1T v 1,5T Siemens)BV i hc Y (1,5T Siemens)BV Thng nht (1,5T Philip)BV 115 (1,5T Siemens)BV Vn Hnh (open - Siemens)BV Chn thng Chnh hnh (open Hitachi)BV 175 (open Philip)

ng bng Sng Cu Long : 1 myBV a khoa Kin Giang (open Hitachi)TNG CNG : 23 MY (C 11 MY LOI SIU DN)Tng lai s cn nhiu my MRI ra i na, ko theo cc chuyn khoa su pht trin nh thn kinh, ct sng, khp, v mt tin vui cho ngnh ung th l c th pht hin ra ung th sm vi cht cn t nano c bit, mt ng r ca cng hng t tng lai cnh tranh vi k thut PET trong truy tm ung th sm.Sau 10 nm pht trin (1996 2006), t 1 my nay c 23 my, ngi bnh Vit Nam gi y khng cn phi ngh l phi i Singapore chp MRI na, c ai bit chi ph chp ti Vit Nam ch l 20% so vi gi chp nc ngoi, khng cn chi ph v my bay v khch sn, khng cn i ch xp hng lu na. Tt c s thun li cho bnh nhn c cht lng iu tr cao v chi ph r phi cn 10 nm qua pht trin.(Trch bo co ca K47 TYS H BK Hhn 4: Chp cng hng t l g?

MRINguyenTriPhuong- Chp cng hng t ( MRI scan ) ph bin trn th gii cng nh Vit Nam bi tnh u vit ca n so vi cc phng php to nh y hc khc, nhng phn lnchng tavn cha c hiu bit c bn v phng php chp cng hng t, tuy nhin hiu chi tit v phng php ny th l cng vic ca cc nh vt l vchng tach cn hiu c bn v n tn hng nhng thnh tu ca khoa hcm nmang li nhng lich cho cuc sng. Vy cng hng t l g? Chp cng hng t hay cn gi l chp MRI (Magnetic Resonnace Imaging) l phng php a c th vo vng t trng mnh ng ha chiu chuyn ng ca cc nguyn t Hydro trong cc phn t nc ca c th v mt ng ten thu pht sng radio tn s thp (tn s radio ny c thay i trong vng t trng n nh ca nam chm chnh ty theo mc ch kho st ca s phn bit m, nc, v v) c s dng gi tn hiu n c th gp cc nguyn t Hydro ca c th sau nhn li tn hiu v chiu chuyn ng ca cc nguyn t ny, tn hiu ca ng ten c truyn v trung tm my tnh x l tn hiu s sau cc tn hiu c truyn v my tnh iu khin v cc hnh nh cu trc c th c m phng ti y.N) Nguyn l ca chp cng hng tng lc: Th ba - 15/04/2014 13:50 - Ngi ng bi vit:admin

Nguyn l ca chp cng hng tBnh vin a khoa tnh k Lk va a vo s dng h thng chp cng hng t (Magnetic Resonance Imaging: MRI). c phim ng, thy thuc phi tip cn vi mt s khi nim i khi kh tru tng. V th, chng ti xin trnh by khi qut mt s khi nim thng dng ca phng tin ni trn. Cc vn c th v vai tr ca phng tin ny trong chn on cc bnh l ca nhng c quan khc nhau s c trnh by trong lot bi khc.Nguyn l hot ng ca MRI (Magnetic Resonance Imaging)Chng ta u bit mi vt th u c cu to t nguyn t. Ht nhn nguyn t c cu to t cc proton (mi proton mang in tch +1) v cc neutron (khng mang in tch). Quay quanh ht nhn l cc electron (mang in tch m). Trong nguyn t trung ha in tch, s proton ca ht nhn bng ng s electron ca nguyn t . Tt c cc tiu th ny u chuyn ng. Neutron v proton quay quanh trc ca chng, electron quay quanh ht nhn v quay quanh trc ca chng. S quay ca cc tiu th ni trn quanh trc ca chng to ra mt mmen gc quay gi lspin. Ngoi ra, cc ht mang in tch khi chuyn ng s sinh ra t trng. V proton c in tch dng v quay nn n t