NMTCB PET Exam Study Guide Questions & Answers 100% Correct(RATED A+)

The exposure rate of an activity of 1 millicurie (mCi) measured at 1 centimeter (cm) is called - ANSWER-- The exposure rate constant (ERC) For positron emitters, the exposure rate constant (ERC) is about 6 R/h per milli- curie at 1 cm. The exposure rate of a 10 mCi dose of F-18 is approximately six times greater than that of a 10 mCi dose of Tc-99 m at a distance of approxi- mately 8 inches. Quantitative bias that refers to the underestimation of counts density which differs from what they should be is called: - ANSWER-Partial-volume effect PVE is caused by the finite spatial resolution of the imaging system which reveals how far the signal "spills out" around its actual location. The signal spreading falsely increases the object size and volume. Image sampling, where voxels in ROI include the signal from underlying tissues, also contributes to the phenomenon known as partial-volume effect. Truncation artifacts in PET/CT imaging are produced by - ANSWER-Difference in size of FOV 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. Dental fillings, hip prosthetics, or chemotherapy port are examples of PET/CT imaging artifacts described as: - ANSWER-Metallic implants artifacts Metallic implants create streaking artifacts on CT images because of their high photon absorption. Higher Hounsfield numbers consequently produce high PET attenuation coefficients and an overestimation of PET findings. The Property of PET detectors that allows them faster timing signals for coincidence detection and to work at high count rates is called: - ANSWER-The decay constant The decay constant decides how long the scintillation flashes in the crystal; a short decay time reduces detector dead time and as a result higher annihilation rates can be accepted. The picturing, description, and measurement of biological processes at the particle and cellular level is known as - ANSWER-Molecular imaging Radionuclide originated molecular imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) capture functional or phenotypic changes associated with pathology and unfold the molecular abnormalities responsible to form basis of many diseases. A PET system capacity to distinguish between two points after image reconstruction is called: - ANSWER- Allergic reaction that begins within seconds/minutes of contrast media admin- istration and rapidly progresses to cause airway constriction, skin and intestinal irritation, and altered heart rhythms is called: - ANSWER-Anaphylaxis The first PET radiopharmaceutical to receive the U.S. Food and Drug Administration approval in 1989 was: - ANSWER-Rb-82 The dose calibrator quality control procedure performed to assess the device's ability to measure accurately a range of a low to high activities is called: - ANSWER-Linearity The following positron-emitting radionuclides are isotopes of natural elements present in most biochemical processes EXCEPT: (A) O-15