Part 9: Mechanisms of
Localization of Radiopharmaceuticals
1.
For Tc-MAA localization in the lungs, the mechanism is based upon
a)
Phagocytosis of the albumin
particles
b)
Microembolization of capillaries
using precipitated human serum albumin particles
c)
Chemisorption
d)
Capillary filtration
2. The uptake of Tc-MDP in
bone tissue is based upon
a)
Passive diffusion and exchange
with hydroxide ions
b)
Surface adsorption of the labeled
phosphate on hydroxyapatite crystals
c)
Phagocytosis by the bone matrix
d)
Metabolic trapping
3. F-18 FDG localizes in malignant tumors because
a)
It undergoes phagocytosis in the
mitochondria
b)
It is a fatty acid analog and is
readily taken up by tumors
c)
It undergoes metabolic trapping
d)
It is organified by a fluorination
reaction
4. The mechanism of
localization of In-111 Octreoscan in an insulinoma is called
a)
Antigen-antibody reaction
b)
Metabolic trapping
c)
Chemisorption
d)
Receptor binding
5. Imaging of the airways
in the lungs is an example of
a)
Chemisorption
b)
Simple diffusion
c)
Compartmental localization
d)
Active transport
6. Imaging of tubular
secretory function of the kidneys is an example of
a)
Chemisorption
b)
Simple diffusion
c)
Compartmental localization
d)
Active transport
7. Imaging of the blood
pool in a MUGA study is an example of
a)
Chemisorption
b)
Simple diffusion
c)
Compartmental localization
d)
Active transport
8. Imaging of the
cerebrospinal fluid in a Cisternogram is an example of
a)
Chemisorption
b)
Simple diffusion
c)
Compartmental localization
d)
Active transport
9. Imaging of the urinary
bladder immediately after filling with Tc-99m is an example of
a)
Chemisorption
b)
Simple diffusion
c)
Compartmental localization
d)
Active transport
10. Imaging of the thyroid
24 hr after oral administration of I-123 NaI is an example of
a)
Chemisorption
b)
Simple diffusion
c)
Compartmental localization
d)
Active transport
11.
Therapy of thyroid carcinoma following oral administration of I-131 NaI is an
example of
a)
Chemisorption
b)
Simple diffusion
c)
Compartmental localization
d)
Active transport
12. Liver/spleen imaging with
Tc-99m SC is an example of
a)
Passive diffusion and exchange
with hydroxide ions
b)
Capillary blockade
c)
Phagocytosis by the bone matrix
d)
Metabolic trapping
e)
None of the above
13. Y-90
Zevalin and I-131 Bexxar are effective therapies for certain types of lymphoma
because they are taken up by
a)
Passive diffusion and exchange
with hydroxide ions
b)
Surface adsorption of the labeled
phosphate on hydroxyapatite crystals
c)
Antigen/antibody reaction
d)
Metabolic trapping
e)
Phagocytosis
14. Cerebral blood flow may
be measured following inhalation of Xe-133 gas. The mechanism of localization in
which Xe crosses capillary membranes in the lungs and is carried away by the
blood stream is called
a)
Passive diffusion
b)
Chemisorption
c)
Lipophilic transfer
d)
Metabolic trapping
e)
Phagocytosis
15. Imaging the myocardium
with Rb-82 ion or Tl-201 ion is based on
a)
Passive diffusion
b)
Chemisorption
c)
Active transport
d)
Metabolic trapping
e)
Phagocytosis
16. The mechanism of uptake
of Myoview and Cardiolite is the same as for Rb-ion. True/False?
