1.
1. Truncation artifacts in PET/CT imaging are produced by
Correct Answer
B. Difference in size of FOV between PET and the CT
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.
2.
2. A PET system capacity to distinguish between two points after image reconstruction is called :-
Correct Answer
B. Resolution
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
3.
3. All of the following positron emission tomography myocardial perfusion tracers are cyclotron produced EXCEPT:
Correct Answer
B. Rubidium Rb-82
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
4.
4. In general, the best radiopharmaceutical to use for a suspected abdominal abscess is
Correct Answer
B. 111In-labeled leukocytes
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.
5.
5. In a patient with renal artery stenosis
Correct Answer
B. A post captopril study will show decreased GFR
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
6.
6. What imaging agent can be used to image the skeleton as well as myocardial infarction
Correct Answer
C. 99mTc PYP
Explanation
pyrophosphate can be used for bone scintigraphy, myocardial infarction, and blood pool imaging
7.
7. the dose calibrator quality control procedure performed with different sealed radionuclides is called:
Correct Answer
B. Accuracy
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
8.
8. The enormous decrease in photons detection efficiency by SPECT, when compared to that of PET, is caused by:
Correct Answer
C. Use of collimator
Explanation
image resolution is inferior to that of PET because emission of single photon requires the use of a collimator to acquire image data
9.
9. What should have been done to avoid the artifact illustrated in Fig.1 ?
Correct Answer
C. Keeping the patient warm during the uptake pHase after the FDG injection
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.
10.
10. When monitoring response to treatment with PET-FDG imaging is essential to obtain:
Correct Answer
A. Baseline PET-FDG scan
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