Biomedical Engineering Reference
In-Depth Information
Time (d)
Net Counts
0
1129
7
589
14
314
21
156
10
5
Bq of
86
Y, is ingested
19.
A drug, containing
4.27
×
10
-4
)
at time
t
=
(
f
1
=
1
×
0
. After 10 h, what is the activity of
the
86
Yin
(a)
the stomach,
(b)
the small intestine,
(c)
the upper large intestine?
20.
What is the rate of transfer of activity from the GI tract into the
body fluids at time
t
10 h in the last problem?
=
21.
At what time after ingestion does the activity in the small
intestine reach a maximum in Problem 19?
22.
What is the equivalent dose to the kidneys of an adult male per
transformation from a source in the lungs that emits a single
500-keV photon per transformation, if the specific effective
energy (kidney
←
lung) is
5.82
10
-9
MeV g
-1
?
×
23.
What is the absorbed fraction (kidney
←
lung) in the last
problem? (Mass of the kidneys is given in Table 16.1.)
24.
The specific absorbed fraction for irradiation of the red bone
marrow by 200-keV photons from a source in the liver is
4.64 × 10
-6
g
-1
. Calculate the specific effective energy for the
liver (source organ) and red marrow (target tissue) for a
gamma source in the liver that emits only a 200-keV photon in
85% of its transformations.
25.
What is the committed equivalent dose to the red marrow from
the source in the liver in the last problem if
2.23
10
15
transformations occur in the liver over a 50-y period?
×
26.
What are the specific absorbed fractions for various target
organs for the pure beta emitter
14
Cintheliver
(mass = 1800 g) as source organ?
27.
What are the corresponding values of the specific effective
energies in the last problem?
28.
A certain radionuclide emits a 1-MeV photon in 62% of its
transformations. Use Table 16.2 to compute the equivalent
dose delivered to the lungs by these photons as a result of
10
6
transformations of the nuclide, located in the thyroid.
29.
The specific absorbed fraction for the testes for 1-MeV photons
emitted in the thyroid is
2.46
10
-8
g
-1
(Table 16.2).
×
