Saudi Nuclear Medicine Club " Quiz #2 " @saudi_nmc

1. 3. All of the following positron emission tomography myocardial perfusion tracers are cyclotron produced EXCEPT:

Water O-15

Rubidium Rb-82

Acetate C-11

Ammonia N-13

Rb-82 is produced from a strontium-82 (Sr-82)/Rb-82 generator, which can be eluted every 10 min. The half-life (T1/2) of Sr-82 is 25.5 days, which results in a generator life of 4–8 weeks

Explanation

Rb-82 is produced from a strontium-82 (Sr-82)/Rb-82 generator, which can be eluted every 10 min. The half-life (T1/2) of Sr-82 is 25.5 days, which results in a generator life of 4–8 weeks

2. 9. What should have been done to avoid the artifact illustrated in Fig.1 ?

Administer insulin

Administer glucose

Keeping the patient warm during the uptake phase after the FDG injection

Keeping the patient cool during the uptake phase after the FDG injection

Keeping the patient warm during the uptake phase after the FDG injection The MIP image demonstrates intense FDG uptake in brown fat, and excessive metabolism in the neck and paraspinal area. Keeping the patient warm and comfortable prior to injection can reduce such activity.

Explanation

Keeping the patient warm during the uptake phase after the FDG injection The MIP image demonstrates intense FDG uptake in brown fat, and excessive metabolism in the neck and paraspinal area. Keeping the patient warm and comfortable prior to injection can reduce such activity.

3. 2. A PET system capacity to distinguish between two points after image reconstruction is called :-

Contrast

Resolution

Attenuation

Emission

PET system resolution, according to NEMA guidelines, is assessed by imaging a point source in the air and reconstructing the images with no smoothing or transformation of images. The resolution of the system is affected by the annihilation ambiguities, the detector ring diameter and the size of the scintillation crystal

Explanation

PET system resolution, according to NEMA guidelines, is assessed by imaging a point source in the air and reconstructing the images with no smoothing or transformation of images. The resolution of the system is affected by the annihilation ambiguities, the detector ring diameter and the size of the scintillation crystal

4. 1. Truncation artifacts in PET/CT imaging are produced by

Contrast medium

Difference in size of FOV between PET and the CT

Patient may drink water but should not eat.

Difference in scanning time between PET and the CT

Discrepancy between ﬁelds of view (FOVs) in a PET/CT scanner—70 cm causes a truncation artifact when imaging extends beyond the CT FOV-50 cm; as a result no attenuation correction values for the truncated anatomy are being applied.

Explanation

Discrepancy between ﬁelds of view (FOVs) in a PET/CT scanner—70 cm causes a truncation artifact when imaging extends beyond the CT FOV-50 cm; as a result no attenuation correction values for the truncated anatomy are being applied.

5. 10. When monitoring response to treatment with PET-FDG imaging is essential to obtain:

Baseline PET-FDG scan

Interim PET-FDG scan

PET-FDG scan on the last day of therapy

PET-FDG scan two days after therapy

Baseline PET-FDG scan To monitor response to therapy and to reduce the risk of false-negative and false-positive readings, it is recommended that a baseline scan be available for assessment

Explanation

Baseline PET-FDG scan To monitor response to therapy and to reduce the risk of false-negative and false-positive readings, it is recommended that a baseline scan be available for assessment

6. 6. What imaging agent can be used to image the skeleton as well as myocardial infarction

99mTc MDP

99mTc HDP

99mTc PYP

201TL chloride

pyrophosphate can be used for bone scintigraphy, myocardial infarction, and blood pool imaging

Explanation

pyrophosphate can be used for bone scintigraphy, myocardial infarction, and blood pool imaging

7. 8. The enormous decrease in photons detection efﬁciency by SPECT, when compared to that of PET, is caused by:

Shorter imaging time

Lower injected dose

Use of collimator

Use of shielding

image resolution is inferior to that of PET because emission of single photon requires the use of a collimator to acquire image data

Explanation

image resolution is inferior to that of PET because emission of single photon requires the use of a collimator to acquire image data

8. 4. In general, the best radiopharmaceutical to use for a suspected abdominal abscess is

67Ga citrate

111In-labeled leukocytes

111In satumomab pendetide

111In octreotide

It is best to use a radiopharmaceutical with less gastrointestinal excretion; therefore, 67Ga should be excluded. Octreotide is used for tumors with somatostatin receptors, and satumomab pendetide is a monoclonal antibody used mainly for colorectal and ovarian cancers, so these are not helpful. 111In-labeled leukocytes would be useful; GI activity will not be present when disease is absent.

Explanation

It is best to use a radiopharmaceutical with less gastrointestinal excretion; therefore, 67Ga should be excluded. Octreotide is used for tumors with somatostatin receptors, and satumomab pendetide is a monoclonal antibody used mainly for colorectal and ovarian cancers, so these are not helpful. 111In-labeled leukocytes would be useful; GI activity will not be present when disease is absent.

9. 5. In a patient with renal artery stenosis

A post captopril study will show increased GFR

A post captopril study will show decreased GFR

A post captopril study will show GFR to be unchanged

Patients who have renal artery stenosis, when given an ACE (angiotensin-converting enzyme) inhibitor, will show a decrease in GFR. Therefore, captopril renography is an effective examination to determine whether renal artery stenosis is the cause of hypertension

Explanation

Patients who have renal artery stenosis, when given an ACE (angiotensin-converting enzyme) inhibitor, will show a decrease in GFR. Therefore, captopril renography is an effective examination to determine whether renal artery stenosis is the cause of hypertension

10. 7. the dose calibrator quality control procedure performed with different sealed radionuclides is called:

Geometry

Accuracy

Linearity

Constancy

A ccuracy testing is performed at installation and then annually, with at least two different sealed sources, e.g., Co-57, Cs-137, and Ba-133

Explanation

A ccuracy testing is performed at installation and then annually, with at least two different sealed sources, e.g., Co-57, Cs-137, and Ba-133