NCT 2026 Exam Prep: Nuclear Cardiology
Practice Questions with Answer Rationales
Myocardial Perfusion Stress Testing |
Cardiac Imaging | Radiopharmaceuticals |
Clinical Cases Review
DOMAIN 1: RADIOPHARMACEUTICALS (~15-20 questions)
Question 1: Which radiopharmaceutical is most commonly used for SPECT
myocardial perfusion imaging?
A. Tl-201 thallous chloride
B. Tc-99m sestamibi
C. F-18 FDG
D. Rb-82 chloride
Answer: B
Rationale: Tc-99m sestamibi is the most commonly used radiopharmaceutical for
SPECT MPI due to its favorable 140 keV photon energy, 6-hour half-life, and
minimal redistribution. Tl-201 was historically used but has been largely replaced
due to its lower energy (69-83 keV) and higher radiation dose. F-18 FDG and Rb-82
are PET agents .
Question 2: The physical half-life of Tc-99m is:
A. 4 hours
B. 5 hours
C. 6 hours
D. 7 hours
Answer: C
,Rationale: Tc-99m has a physical half-life of approximately 6 hours, which allows
sufficient time for same-day imaging protocols while minimizing radiation
exposure. This is ideal for diagnostic imaging .
Question 3: In a rest-stress Tc-99m sestamibi protocol, what is the typical rest
dose and stress dose?
A. 5 mCi rest / 10 mCi stress
B. 8-12 mCi rest / 24-36 mCi stress
C. 20 mCi rest / 20 mCi stress
D. 15 mCi rest / 15 mCi stress
Answer: B
Rationale: The standard same-day rest-stress Tc-99m sestamibi protocol uses 8-12
mCi for rest and 24-36 mCi for stress (approximately 3x the rest dose) to
overcome residual background activity from the rest injection and optimize count
statistics .
Question 4: Which radiopharmaceutical is most suitable for evaluating cardiac
sympathetic innervation?
A. 99mTc-pyrophosphate
B. 123I-mIBG
C. 82Rb
D. 18F-FDG
Answer: B
Rationale: 123I-mIBG (meta-iodobenzylguanidine) is a norepinephrine analog that
evaluates cardiac sympathetic innervation. It is used in heart failure imaging and
to assess conditions such as Lewy body disease and Parkinson's disease, where
cardiac sympathetic denervation occurs.
Question 5: Which radiopharmaceutical is used for Tc-99m pyrophosphate (PYP)
cardiac imaging to detect transthyretin cardiac amyloidosis?
,A. Tc-99m sestamibi
B. Tc-99m pyrophosphate (PYP)
C. F-18 FDG
D. I-123 MIBG
Answer: B
Rationale: Tc-99m pyrophosphate (PYP) is specifically used for cardiac amyloidosis
imaging. It binds to calcium deposits in the myocardium, which are present in
transthyretin (ATTR) amyloidosis .
Question 6: During a PET myocardial viability study with F-18 FDG, what
physiological condition must be met to ensure accurate assessment of metabolic
activity?
A. Patient must fast for at least 12 hours
B. Blood glucose level must be <200 mg/dL
C. Administration of heparin before tracer injection
D. Use of a high-dose potassium protocol
Answer: B
Rationale: Elevated glucose competes with FDG uptake, reducing myocardial
signal. A blood glucose level <200 mg/dL is generally required for reliable viability
imaging. In diabetic patients, glucose loading or insulin adjustment may be
necessary .
Question 7: Which of the following are potassium analogs?
A. Tl-201 chloride
B. Rb-82 chloride
C. F-18 FDG
D. Tc-99m sestamibi
Answer: A and B
, Rationale: Both Tl-201 chloride and Rb-82 chloride are potassium analogs. Their
uptake by myocardial cells occurs via active transport mechanisms similar to
potassium, making them suitable for perfusion imaging .
Question 8: The metabolic equivalent task (MET)—a unit of oxygen uptake in a
sitting, resting person—corresponds to:
A. 3.5 ml O2/kg/h of body weight
B. 3.5 ml O2/kg/min of body weight
C. 7.0 ml O2/kg/h of body weight
D. 7.0 ml O2/kg/min of body weight
Answer: B
Rationale: One MET corresponds to 3.5 ml O2/kg/min of body weight. This is the
standard unit used to quantify exercise workload in stress testing protocols .
Question 9: In PET imaging, a "blank scan" is performed to:
A. Measure background radiation for scatter correction
B. Verify patient positioning
C. Calibrate the dose calibrator
D. Test the high-resolution collimator
Answer: A
Rationale: A blank scan (no source) records ambient and intrinsic detector counts,
which are subtracted during reconstruction to improve quantitative accuracy .
Question 10: Which of the following cardiac radiopharmaceuticals is considered a
myocardial metabolism agent?
A. Tc-99m sestamibi
B. I-123 fatty acid
C. Tc-99m Myoview
D. Tl-201 chloride
Answer: B
Practice Questions with Answer Rationales
Myocardial Perfusion Stress Testing |
Cardiac Imaging | Radiopharmaceuticals |
Clinical Cases Review
DOMAIN 1: RADIOPHARMACEUTICALS (~15-20 questions)
Question 1: Which radiopharmaceutical is most commonly used for SPECT
myocardial perfusion imaging?
A. Tl-201 thallous chloride
B. Tc-99m sestamibi
C. F-18 FDG
D. Rb-82 chloride
Answer: B
Rationale: Tc-99m sestamibi is the most commonly used radiopharmaceutical for
SPECT MPI due to its favorable 140 keV photon energy, 6-hour half-life, and
minimal redistribution. Tl-201 was historically used but has been largely replaced
due to its lower energy (69-83 keV) and higher radiation dose. F-18 FDG and Rb-82
are PET agents .
Question 2: The physical half-life of Tc-99m is:
A. 4 hours
B. 5 hours
C. 6 hours
D. 7 hours
Answer: C
,Rationale: Tc-99m has a physical half-life of approximately 6 hours, which allows
sufficient time for same-day imaging protocols while minimizing radiation
exposure. This is ideal for diagnostic imaging .
Question 3: In a rest-stress Tc-99m sestamibi protocol, what is the typical rest
dose and stress dose?
A. 5 mCi rest / 10 mCi stress
B. 8-12 mCi rest / 24-36 mCi stress
C. 20 mCi rest / 20 mCi stress
D. 15 mCi rest / 15 mCi stress
Answer: B
Rationale: The standard same-day rest-stress Tc-99m sestamibi protocol uses 8-12
mCi for rest and 24-36 mCi for stress (approximately 3x the rest dose) to
overcome residual background activity from the rest injection and optimize count
statistics .
Question 4: Which radiopharmaceutical is most suitable for evaluating cardiac
sympathetic innervation?
A. 99mTc-pyrophosphate
B. 123I-mIBG
C. 82Rb
D. 18F-FDG
Answer: B
Rationale: 123I-mIBG (meta-iodobenzylguanidine) is a norepinephrine analog that
evaluates cardiac sympathetic innervation. It is used in heart failure imaging and
to assess conditions such as Lewy body disease and Parkinson's disease, where
cardiac sympathetic denervation occurs.
Question 5: Which radiopharmaceutical is used for Tc-99m pyrophosphate (PYP)
cardiac imaging to detect transthyretin cardiac amyloidosis?
,A. Tc-99m sestamibi
B. Tc-99m pyrophosphate (PYP)
C. F-18 FDG
D. I-123 MIBG
Answer: B
Rationale: Tc-99m pyrophosphate (PYP) is specifically used for cardiac amyloidosis
imaging. It binds to calcium deposits in the myocardium, which are present in
transthyretin (ATTR) amyloidosis .
Question 6: During a PET myocardial viability study with F-18 FDG, what
physiological condition must be met to ensure accurate assessment of metabolic
activity?
A. Patient must fast for at least 12 hours
B. Blood glucose level must be <200 mg/dL
C. Administration of heparin before tracer injection
D. Use of a high-dose potassium protocol
Answer: B
Rationale: Elevated glucose competes with FDG uptake, reducing myocardial
signal. A blood glucose level <200 mg/dL is generally required for reliable viability
imaging. In diabetic patients, glucose loading or insulin adjustment may be
necessary .
Question 7: Which of the following are potassium analogs?
A. Tl-201 chloride
B. Rb-82 chloride
C. F-18 FDG
D. Tc-99m sestamibi
Answer: A and B
, Rationale: Both Tl-201 chloride and Rb-82 chloride are potassium analogs. Their
uptake by myocardial cells occurs via active transport mechanisms similar to
potassium, making them suitable for perfusion imaging .
Question 8: The metabolic equivalent task (MET)—a unit of oxygen uptake in a
sitting, resting person—corresponds to:
A. 3.5 ml O2/kg/h of body weight
B. 3.5 ml O2/kg/min of body weight
C. 7.0 ml O2/kg/h of body weight
D. 7.0 ml O2/kg/min of body weight
Answer: B
Rationale: One MET corresponds to 3.5 ml O2/kg/min of body weight. This is the
standard unit used to quantify exercise workload in stress testing protocols .
Question 9: In PET imaging, a "blank scan" is performed to:
A. Measure background radiation for scatter correction
B. Verify patient positioning
C. Calibrate the dose calibrator
D. Test the high-resolution collimator
Answer: A
Rationale: A blank scan (no source) records ambient and intrinsic detector counts,
which are subtracted during reconstruction to improve quantitative accuracy .
Question 10: Which of the following cardiac radiopharmaceuticals is considered a
myocardial metabolism agent?
A. Tc-99m sestamibi
B. I-123 fatty acid
C. Tc-99m Myoview
D. Tl-201 chloride
Answer: B
