ee enTee Se eh Bn ae ilRaia ee Ke Ailiarate Be
t-Cs'37 (9542 jac, 0.66 Mev)
|
4
iw
0,000 L{_
<i
=
|
=
4
a
:
—
=
,
Zn? (0.443 pc, 112 Mev)
/-
=
a
4
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{
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65 cgi
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SPECTRUM
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an Alderson phantom (REMCAL). Solutions of
known concentration of each radionuclide were
placed in the phantom to approximate theeffects
of tissue absorption and scatter. The spectrum of
the phantom for each of the isotopes was obtained
under conditions of counting geometry identical
with that used in counting the subjects. By this
techniqueit was possible to simulate quite closely
with the phantom the multicomponentspectra of
the Marshallese. A representative Marshallese
spectrum obtained by adding K, Cs’*’, and Zn
at average levels (as determined in the medical
: Mev) >_|
K**140gk",146
|
z
5
titated in this study were obtained with the use of
—
SPECTRUM
NET cs’? 7
o
SPECTRUM
io
20
44
68
q
92
116
ENERGY Mev
140
164
study of 1959) to the phantom is shown in Figure
55. The K, Cs'*", and Zn*° were distributed homo-
188
Figure 55. Gammaspectrum ofthe calibration phantom
containing Cs'**, Zn’, and K*"in the approximate range
found in Marshallese subjects. The dotted lines indicate
the results of spectral stripping of the higher energy
photopeaks.
TOT
A-MARSHALLESE MALE
t
COUNTS /30 MINUTES/20 kev CHANNEL
TT
AGE 45 YRS-WT=70 Kg
[
iO
A
=
=
B- U.S MALE,MEDICAL TEAM
AGE 41 YRS-WT-77Kq
e
Zt
L
~
-
—s
-
—
F
2r°°(98 myc]
10°
CAH 102 myc}
K{A=139.4g
a
uh
. \ cs712 5 myc)
|
“ss,
1? E-
i
\
t
ot
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LS
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i
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,
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B=140.3g)
9
+
4
7
/ \
i
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4
ey
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8
t
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1
\,
WAY
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}
by s---~- NLA
ee
a
4
/
|
48
38
58
398
118
ENERGY {Mev)
78
4
138
oj} _.
(158
_
eS
ci
tt
=
fot
RESULTS
__!
Figure 56. Spectrumof typical Marshallese aduit male
compared with that of memberof the U.S. medical team.
ae)
tota] spectrum (see Figure 55).
Individual 24-hr urine specimens were collected
and one pooled urine sample of 20 liters. The
radiochemical procedure for the Sr*" analysis has
been described previously.’
4
4
fot
subject), the computer performs a channel-bychannel subtraction of the normalized K"° spectrum. In a similar manner, the normalized spectra
for Zn"’, Co*", and Cs'** were subtracted from the
4
7
|
fey toi. dt
!
geneously throughout the phantom, while Co*°
wasplacedin theliver only.
Analyses of the complex spectra were performed
by subtracting the calibrated pulse-height spectrum for each gammaemitter to be quantified.
Although these spectra are obtained ideally from
a subject of identical build, an approximationis
obtained with the use of the plastic phantom.
Computation wascarried out by an IBM-704 computer. Starting with the highest energy photopeak,
that of K*° (after correction for background and
normalization of the K*" photopeak to thatof the
A spectrum for an average Marshallese adult
male, obtained in the 1961 study, is shown in
Figure 56, with the spectrum of a memberofthe
U.S. medical team of about the same bodyweight
eeante en
magnetic tape of a 704 computer. The task of
“spectral stripping” was carried out on the computer with a FORTRAN program. In this operation
the spectrum of each individualisotope is removed
from the total spectrum obtained for the subject,
which represents the combination of the contributions from all the isotopes deposited in that subject.
Spectra for each of the individual isotopes quan-
—
Rtlettin a LETaeANN ple
—
cnn
—
> GAMMA RAY SPECTRA OF PLASTIC MANS
ws eect lle e n cen Nn
100,000 &
2 an etme ot ence mee” Mla Naty
38