1
1. 1.
..
1. 1. -- AngerAnger
(H. Anger, Berkeley, 1958)
NaI
x
z
y
..
--::
(collimator), NaI (scintillator), (photomultipliers) ( )
( )
..
90
..
--
, ( ) .
.
, (light guide)(light guide), , (x,y) .
, .
..
--
.
--.
- .
99m99mTcTc, 140 keV140 keV, 10%, 130 keV 150 keV.
, -- .
..
.
.
(FFieldield OOff VViewiew -- FOVFOV).
..
((parallelparallel--hole collimatorhole collimator))
..
((pinhole collimatorpinhole collimator)) 3-5 mm.
b, a -, .
:
/ = / / = / bb
..
((diverging multihole collimator)diverging multihole collimator)
40-50 cm .
A : f, b t
/ / = (f= (f -- t) / (ft) / (f ++ b)b)
..
(converging multihole collimator)
40-50 cm .
, .
/ = ( / = (ff ++ tt) / () / (f + t f + t -- bb))
..
H H
:
.
:
..
-.
, -:
RRcc d(Ld(L ++ z)z) // LL
..
gg ( ) .
:
gg [kd[kd22 // L(dL(d ++ t)]t)]22 k .
: zz >>>> LL dd >>>> tt : gg RRcc22
, -- .
..
.
[15] -- 40 cm40 cm:
1.460003.4Medium Energy High Sensitivity (MEHS)
0.390003.4Low Energy High Sensitivity (LEHS)
0.3180002.5Low Energy General Purpose (LEGP)
0.3300001.8Low Energy High Resolution (LEHR)
(mm)
(mm)
..
((scintillatorsscintillators)) ( ) .
NaINaI TlTl, .
.
- NaI(Tl)NaI(Tl) 150 keV150 keV
..
((photomultiplier tube photomultiplier tube -- PMPM)).
.
.
..
//(())
: , : , : , : , : , : , : ( ), ee--: , : , :
..
37 -
..
- , RRxx++, , RRxx--, , RRyy++, , RRyy--
, - - ++, , --, , ++, , --, -.
= = +++ + --+ + +++ + --
x = k(x = k(+++ + --)/Z)/Z y = k(Yy = k(Y+++ Y+ Y--)/Z)/Z , k = .
..
((pulse height pulse height analyzeranalyzer)) - .
- () .
..
TcTc9999mm MDP () () 140 keV
..
-
(spatial resolution)
.
RRss :
RRcc RRii ,
22cis RRR +=
..
(temporal resolution)
- , .
, (dead timedead time).
= ,
nn = ,
= , :
nTnN = 1
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