GII THIU Y HC HT NHN BS DNG PH TRIT DIM BV HYD*

NI DUNG1. nh ngha2. Phn bit vi Xray, CT, MRI3. Ch nh v chng ch nh4. Cc khi nim c bn5. Sn xut ng v phng x6. ng vo ca DCPX7. Hnh nh YHHN8. Cc k thut tiu biu9. An ton bc x

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YHHNChn on InvitroBnh nhnChn on Invivoiu Trng v phng xGC SPECT PET*

Y HC HT NHN*

LCH S HT NHN PHNG X1896Cht phng x thin nhinBecquerel1898RadiumCurie1911Ht nhn nguyn tRutherford1913Dng nguyn tBohr1930CyclotronErnest Lawrence NeutronChadwick Cht phng x nhn toJoliot-Curie1938 Tm ra ng v phng x 99mTc t 99MoSegre v Seaborg 1938Sn xut v nhn bit I-131Fermi v cs 1942l phn ng ht nhnFermi v cs1946Ht nhn phng x thng miHarwell196299mTc trong YHHNHarper*

NGI TIN PHONGHenri BecquerelErnest RutherfordMarie CurieFrederique Joliot-Irene Curie*

NGI TIN PHONG John Lawrence Hal Anger Georg Charles von Hevesy*

LCH S CHN ON1935o chuyn ha xng(P-32) Chiewitz-de Hevesy1939K thut ghi, o tuyn gip (I-131) Hamilton et al1948Ghi hnh tim (Na-24) Prinzmetal v cs1956Ghi hnh thn (I-131) Taplin, Winter1957X hnh gan (Au-198 colloid) Friedell v cs1961X hnh xng (Sr-85) Fleming v cs1962X hnh c tim (Rb-86, Cs-131) Carr v cs1964X hnh phi Taplin v cs1965X hnh no(Tc99m-pertechnetate) Bollinger v cs1971X hnh xng (Tc99m-MDP) Subramanian v cs*

LCH S IU TR Dng Na-24 iu tr bnh bch cu Hamilton v cs Dng P-32 iu tr bnh bch cu v Lawrence tng hng cu v cn Dng iode iu tr cng gipHamilton Dng iode iu tr ung th gip di cn iu tr di cn xng vi P-32Maxfield*

LCH S - THIT B1951 my ghi hnh vch thngCassen Gamma cameraHal Anger1976SPECTHal Anger1976 PETHenry Wagner*

B. CassenNGI TIN PHONGHal Anger H.O. Anger*

GAMMA CAMERA*

SPECT*

PET_CT*

CH NHCn nhc ch nh YHHN: li ch m YHHN mang li ln hn tc dng ph m YHHN gy raChng ch nh: Ph n c thaiPh n ang cho con b*

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KHI NIM C BNng v phng xHot phng xPhn rQui lut phn r*

NG V PHNG XNhn trng thi khng n nhGii phng nng lng thaHin tng phng xHai loai VPX:VPX thin nhinVPX nhn to

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HOT PHNG XL s phn r tm thi ca nhn phng xPht tia ,,n v o hot Curi (Ci)Becquerel (Bq)

(m) milli (10 ) 3 (m) micro (10 ) 6 (n) nano (10 ) 9 (p) pico (10 ) -12 (K) kilo (10 ) 3 (M) mega (10 ) 6 (G) giga (10 ) 9 (T) tera (10 ) 12*

LIN H GiA Bq VI Ci n v Bq n v Ci1 GBq = 109 Bq1 Ci = 37 GBq1 MBq = 106 Bq1 mCi = 37 MBq1 kBq = 103 Bq1 Ci = 37 kBq

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HOT PHNG XV d: Mt ngun phng x c hot 100mCi. Hi hot tnh theo n v becquerel l bao nhiu?

Gii p: do 1mCi= 37MBq 100 mCi = 37x100 MBq = 3,7x103 MBq = 3,7 GBq

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N V CA LIU HP THUl t s gia nng lng trung bnh d m bc x truyn cho vt cht trong th tch nguyn t v khi lng vt cht dm ca th tch :D = d/dmh SI l Gray (k hiu l Gy) 1 Gy = 1 J/kg n v thng dng trc y l rad: 1 rad = 0,01 Gy hay 1 Gy = 100 rad*

SUT LIU HP THUSut liu hp th l liu hp th trong mt n v thi gian.n v sut liu hp th trong h SI l Gy/s.n v khc l rad/s hay rad/h

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LIU HP THU TNG NG HL i lng nh gi mc nguy him ca cc loi bc xBng tch ca liu hp th D vi h s cht lng Wr H = D x WrMi loi tia c Wr khc nhau*

Loi bc xWrTia X, tia 1Tia 1Tia 20

n v ca liu hp th tng ng trong h SI l Sievert (Sv)1 Sv = 1 Gy x Wrn v ca liu hp th tng ng ngoi h SI l rem 1 rem = 1 rad x Wr1 Sv = 100 rem hay 1 rem = 0,01 Sv LIU HP THU TNG NG H*

LIU HP THU TNG NG HV d: Mt nhn vin bc x lm vic tip xc vi ngun phng x chu mt liu 20 mrem trong 1 ngy. Hi ngi chu liu bao nhiu theo n v Sv?Gii p:Do 1 mrem = 0,01 mSv nn 20 mrem = 0,01 x 20 mSv = 0,2 mSv*

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QUI LUT PHN R

Thi gian bn r vt lThi gian bn r sinh hcThi gian bn r hiu ng- Vi t = nT1/2 th ta c cng thc: N(t)/N0 = 1/2n

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QUI LUT PHN RHat nhan phong xa Co60 co thi gian ban ra la T1/2 = 5 nam. Hoi sau 10 nam so hat nhan con lai bao nhieu phan tram so vi so hat nhan ban au ?Gii t = 2T1/2 n = 2 N/N0 = 1/22 = Ngha l cn li hay 25% s ht nhn ban u

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CC KIU PHN Rphn r Phn r - Phn r +Thu ot electron (EC)Chuyn ni ti: (interne conversion)Qu ng phn (gm phn r )

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PHN R Ch din ra cho cc ht nhn nng (VPX thin nhin 235U, 226Ra)Ht chnh l ht nhn nguyn t Heli gm 2 proton v 2 ntron rt bn vngVPX nhn to khng c kiu phn r *

PHN R Ht nhn nguyn t tha ntron chuyn 1 ntron thnh proton v pht ra 1 electron v 1 ntrino ()Ntrino l mt tiu th trung ho inkhng cn xt n n trong vic tnh liu hp thu. Nng lng ca electron pht ra (k hiu: E -) khng ng u, ri ra t 0 n mt tr s cc i Emax. V d 32P phn r -, pht ra cc electron c ng nng E - ri ra t 0 n tr s cc i Emax = 1,7MeV. Nng lng trung bnh (xp x 1/3 Emax), nn tr s c gi tr thc hnh nht 32P c = 0,685 MeV.

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PHN R *

PHN R +Ht nhn nguyn t tha protonchuyn 1 proton thnh ntron pht 1 electron dng (ht +) v 1 ntron. Ht +(hay positron), so vi electron, th rt khng bn; ch tn ti trong khong thi gian ht sc ngn (khong 10-8 giy).Sau kt hp vi electron qu o no , ri chuyn t dng ht sang dng sng in t bng cch lm xut hin 2 lng t (quanta) bc x vi nng lng 0,51 MeV.

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PHN R + (tt)Ph nng lng ca positron tng ng nh electron trong phn r -.S pht positron hu ch trong YHHN do hai photon hay lng t c to ra trn cng mt s kin phn r ht nhn.Mi quan h nh hng chnh xc gia hai photon hy dit (annihilation photon) cho php ng dng k thut m trng phng (coincidence counting).

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PHN R + (tt)*

PHN R *

QU NG PHNPHN R Sau mt phn ng phn r, ht nhn thng trong trng thi kch thch- trng thi vng bn (metastable).Nng lng tha ny s chuyn thnh bc x in t gi l tia gamma.Tia gamma c th i c mt on t 1 n hng trm mili mt trong khng kh v d dng xuyn qua ngi.*

THU OT ELECTRON (EC)1 proton ca ht nhn nguyn t chuyn thnh ntron bng cch thu ot 1 electron ca qu o trong cng (K) (i khi c ca qu o L hay M). Thng gp nhn nng do trong nhng nguyn t nng, electron qu o c khuynh hng gn nhn hn nn d b by hn, nhng nguyn t nh hn thng xy ra phn r +. V d 18F 3% l phn r EC v 97% l phn r +.Vic thu ot electron i km vi vic pht tia X c hiu do electron cc qu o ngoi vo th ch.

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KH NNG M XUYN CA CC HT TRONG M*

Loi htMc nng lngKh nng m xuyn (iu tr khu tr)Vi MeV vi cm

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TNG TC CA BC X VI VT CHT*

TNG TC CA TIA X V TIA *

HIU NG QUANG INTia X truyn ton b nng lng cho electron qu o v y electron ny ra ngoi

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HIU NG COMPTOMS tng tc gia tia vi mt lectrn v ngoi cng ca nguyn t, nh bt lectrn ny ra cn tia gim nng lng v thay i hng bay.

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HIU NG TO CP Khi tia no c nng lng ln hn 1,02MeV th tia to nn mt cp lectrn v position trong trng ht nhn. Ht position sau hy cp vi mt lectrn to nn 2 tia vi nng lng 0,51 Mev mi tia, v chng bay ngc chiu nhau.

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S SUY GiM CA CHM TIA BC X KHI I QUA VT CHTQu trnh hp thuQu trnh tn x Cng tia b suy gim khi i qua vt cht s suy gim tun theo hm s m I (x) = I0 e-x I0 l cng chm tia i voI(x) l cng chm tia sau khi i qua qung ng X trong vt cht l h s suy gim tuyn tnh. Th nguyn ca l cm-1*

DY GIM MT NA d1/2L dy vt cht m cng chm tia i qua b suy gim hai ln, ngha l cn mt na cng ban u dy gim mt na lin h vi h s tuyn tnh nh sau d1/2 = 0,693/ Vi x = nd1/2ta c cng thcI(X)/I0 = 1/2n*

Mt tm ch dy x = 2,12cm che chn cc tia bc x ca ngun Co60. H s suy gim tuyn tnh ca ch i vi tia ngun Co60 l = 0.655 cm-1. Hi sau khi qua tm ch dy 2,12 cm, s tia gamma ca Co60 b gim i bao nhiu ln?Cch 1: I (x) = I0 e-x I (x) / I0 = e-x = e -0.655.2.12 = e-1.39 = Vy sau khi i qua tm ch dy 2cm s tia ca Co60 gim i 4 ln Cch 2:d1/2 = 0,693/ = 0,693/ 0.655cm-1 = 1.06cm

Tm ch dy x = 2,12 cm = 2 x 1,06 cm = 2d1/2. Vy cng chm tia gamma b gim i 4 ln.*

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SN XUT HT NHN PHNG XPhn ng phn hch (Fission product)L phn ng (reactor)My gia tc vng (cyclotron)My pht ng v (generator)*

SN XUT HT NHN PHNG X*

SN XUT HT NHN PHNG X*

L phn ng ht nhn Lt (Reactor)My gia tc vng (cyclotron)*SN XUT HT NHN PHNG X

SN XUT HT NHN PHNG XChng ta c th dng VPX c T1/2 di t l phn ng to thnh VPX c T1/2 ngn trong my pht ng v phng x di ng c (generator)*

CYCLOTRON*

CYCLOTRONDo chng ta dng s bn ph proton lm thay i nguyn t chuyn xung nm di ng n nh. V vy y l loi pht tia positronc lp t ti ch, cho php dng ng v c T1/2 ngn, gim liu cho bnh nhnChi ph lp t rt cao*

NG V C SN XUT T CYCLOTRON VPX ph bin nht l 18F trong 18F-FDG*

GENERATORKhc vi l phn ng ht nhn hay my gia tc , my pht ng v dng ng v m c i sng di phn r thnh ng v con c i sng ngn hn c dng cho ghi hnhng v m c sn xut t l phn ng ht nhn v sau c vn chuyn di dng generatorKhi cn ng v phng x con c chit tch v kt hp thnh dng dc cht phng x*

GENERATOR*

GENERATORMy pht 99mTc (ng v con) c dng ph bin trong YHHNMy pht c thay i hng thng*

HT NHN PHNG X T GENERATOR*

GENERATOR*

LA CHN VPXT1/2 ngn gim liu bc x cho bnh nhn

Khng ging nh thit b pht tia X, chng ta khng th dng s pht bc x t ng v

Phn r bc x gim theo hm mN(t)/N0 = 1/2n*

LA CHN VPXCn lu :- Thi gian bn r vt l (Tp): cn di chuyn ng v t ni sn xut n ni s dng v cho vic theo di v o c- Thi gian bn r sinh hc (Tb): l thi gian m trong mt na lng ca cht c a vo c loi ra ngoi c th- Thi gian bn r hiu ng (Tef): l khong thi gian trong cc nguyn t ng v phng x a vo c th gim i mt na (va do phn r vt l, va do loi tr sinh hc) Tef = Tp.Tb / (Tp+Tb).

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C CH HP THUVn chuyn ch ng (active transport)x hnh tuyn gip (thyroid scan)Tc mao mch (capillary blockage)x hnh phi (lung scan)Thc bo (phagocytosis)x hnh gan (liver scan)Tnh cht ha hc c th ca VPX i vi tng c quan(the localization of materials to an anatomical compartment)x hnh ng tiu ha (gastrointestinal scan), x hnh xng (bone scan), x hnh thn (renal scan)..Trao i khuch tn (exchange difusion)x hnh ti mu c tim (myocardioperfusion scan)*

NG VO CA DCPX1. Tim tnh mch: DCPX c tim vo tnh mch V d: Tc-99m MDP trong x hnh xng.2. Tim di da: DCPX c tim vo di da. Phng php ny dng trong ghi hnh h thng Lympho.3. Tim trong bao hot dch: DCPX c tim trc tip vo khp. V d ghi hnh khp gi dng Yttrium-90.

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NG VO CA DCPX4. Dng ht: Mt s DCPX v VPX c bnh nhn ht vo, in hnh trong nh gi chc nng phi dng Krypton-81m v acrosole cha Tc-99m.5. ng tiu ho: C th a DCPX qua ng ming. V d Tc-99m c cho vo trng ghi hnh d dy.6. Tim vo khoang di nhn: ghi hnh dch no tu.*

HNH NH YHHNHnh chc nng ca cc c quanCc bc ghi hnh:a DCPX vo c th bnh nhnMy GC ghi nhn s pht tia gamma t c th bnh nhn phn nh s phn b v mc hp thu VPX My tnh x l s liu v to nh chc nng

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X HNH XNG BONE SCAN- S hp thu 99mTc MDP ca xng phn nh chuyn ha ca xng cng nh lu lng mu n xng, cho php nh gi chc nng ca xng- Bt k s thay i trong chuyn ha xng c th gip pht hin tn thng xng nh:Di cn xng.U xng lnh tnh hay c tnh.Chn thng xng.- Ghi hnh xng 3 pha cn thit trong bnh l vim xng ty xng (osteomelitis)- X hnh xng cng gip theo di nhng ri lon khc ca xng nh bnh Paget- K thut: tim IV 400-600 MBq 99mTc MDP. Ghi hnh 3 gi sau tim VPX*

X HNH XNGANTPOSTX hnh xng bnh thng Bnh l*

X HNH PHILUNG SCAN1. Ti mu phi (Lung perfusion): - Mt s thuyn tc tng ng ca ging mao mch phi trn hnh phn nh s ti mu phi.Hnh nh ny gip chn on thuyn tc phi (pulmonary emboli).- Tim IV 100 MBq Tc99m MAA. Ghi hnh ngay sau tim 2. X hnh thng kh phi (Ventilation studies):- Phn nh thng kh vng hay phn thy phi. Gii thch hnh nh cn kt hp vi x hnh ti mu phi gip chn on phn bit c thuyn tc phi hay khng.- Cho bnh nhn ht 100 MBq Tc99m -aerosols. Ghi hnh ngay sau tim

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X HNH PHI Ti mu Thng kh *

X HNH TUYN GIP Thyroid scan*

DC CHT PHNG X DNG TRONG X HNH TUYN GIP99mTcGenerator6h 140KeV 123ICyclotron13.3h 159KeV 131IReactor8.1d 364KeV 132IGenerator2.3h 670KeV 760KeV *

CH NH X HNH TUYN GIPnh gi chc nng tuyn gip (bnh gip, cng gip, nhc gip)nh gi chc nng nhn gip (nhn lnh, nhn nng, nhn m)Xc nh tuyn gip lc chnh gi trc v sau iu tr ung th tuyn gip*

X HNH TUYN GIP Vim gip bnh thng cng gip*

X HNH TUYN GIP Nhn nng nhn lnh a nhn *

X HNH TUYN GIP Tuyn gip lc ch y li (Ectopic Lingual Thyroid)*

X HNH TUYN GIPV tr bnh thngTG sau xng cBu gip a nhn sau xng c Retrosternal thyroid*

X HNH THN (99mTc-DTPA)*

X HNH THN (99mTc-DMSA)*

X HNH TI MU C TIM STRESS REST*

X HNH TI MU C TIM QUA CNG IN TIM (ECG-GATED MYOCARDIAL PERFUSION)*

X HNH TI MU NOCEREBRAL BLOODFLOW99mTc HMPAO c gi li trong no t l vi ti mu no vng.VPX tp trung ch yu cht xm v khng c s ti phn b. Kh nng pht hin: Sa st tr tu (dementia) nh bnh Alzheimers, ng kinh cc b (seizure localization Foci), bnh l mch mu no nh thiu mu no, chn thng v cht no Tim IV 800 MBq 99mTc HMPAO. Ghi hnh ng 30 pht sau tim

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X HNH TI MU NOCEREBRAL BLOODFLOW Bnh thng Bnh sa st tr tu (Alzheimers disease)*

PETPositron Emission Tomography

My PET trong nhng nm u sn xut*

PETPositron Emission Tomography

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CYCLOTRONStanley Livingstone and Ernest Lawrence with their 8 MeV cyclotron (1935) CYCLOTRONS IN HOSPITALS*

F18-FDG*

FDG TRONG TIM MCH*

FDG TRONG UNG BU*

FDG TRONG BNH L THN KINH Bnh Alzheimers

Bnh thng*

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AN TON BC X*

PHNG PHP KIM SOT LIU BC XLP K HOCH (PLAN), KIM SOT (CONTROL), THI GIAN (TIME), KHONG CCH(DISTANCE), V CHE CHN (SHIELDING)Plan: thit lp chng trnh kim sot an ton gim liu chiu cng thp cng tt (As Low As Reasonably Achievable) (ALARA).Control: dng dng c thch hp v thit b an ton, theo di thng xuyn

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PHNG PHP KIM SOT LIU BC XLiu hp th = Liu chiu x thi giangim ti a thi gian thao tc bng tay hoc tip xc ngun bc x

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Distance: tng khong cch tip xc ngun bc x bng cch dng dng c h tr s gim liu nhn c do liu hp thu s gim theo hm m ca khong cch t ngun im.

PHNG PHP KIM SOT LIU BC X*

Shielding: bc x s b hp th bi vt liu che chn gia ngun bc x v ngi tip xc. S dng loi vt liu che chn no v vi dy bao nhiu ty thuc vo kh nng m xuyn ca loi bc x y.

PHNG PHP KIM SOT LIU BC X*

LIU CHIU TRONG YHHNLiu chiu trongQua ng n hoc ht DCPX

Liu chiu ngoing tim, bnh nhn.*

CHE CHN*

CHE CHN*

KH NNG M XUYN CA BC X*

CHT THI PHNG XCht thi lngCht thi rn*

QUESTION ?*

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*Part 5. Occupational protectionRadiation protection in nuclear medicine*Part 5. Occupational protectionRadiation protection in nuclear medicine*