Section 4: Applications and Indications of Nuclear Cardiology
Which one of the following has the highest specificity for diagnosis of coronary artery disease?
a. dipyridamole echocardiography.
b. dobutamine Tc-99m sestamibi SPECT imaging.
c. pharmacologic stress rubidium PET imaging.
d. dipyridamole Tc-99m sestamibi SPECT imaging.
c. Bateman et al. compared 82Rubidium PET and 99mTc sestamibi SPECT in two matched patient cohorts undergoing clinically indicated pharmacologic-stress perfusion imaging using SPECT and PET. Differences in diagnostic accuracy reflected primarily the increased specificity (with an advantage in sensitivity) of PET vs. SPECT, and applied to both men and women, and to obese and non-obese individuals.
Early screening of asymptomatic type II diabetic patients for CAD has been shown to prevent:
a. myocardial infarction.
d. The Detection of Ischemia in Asymptomatic Diabetics (DIAD) study was a randomized controlled trial in which 1123 participants with type 2 diabetes and no symptoms of CAD were randomly assigned to be screened with adenosine-stress radionuclide myocardial perfusion imaging (MPI) or not to be screened. Screening did not show a reduction in cardiac death and non-fatal myocardial infarction.
A 63-year-old woman with hypertension and hypercholesterolemia presents to your clinic with several months' history of exercise-induced (minimum) chest discomfort associated with dyspnea. Baseline ECG demonstrates non-specific ST/T changes in the lateral leads. Which one of the following is the most appropriate modality to diagnose coronary artery disease?
a. Tc-99m exercise SPECT.
b. vasodilator Tc-99m SPECT.
c. exercise treadmill test.
b. Baseline ST/T-wave ECG changes decrease the sensitivity and specificity of regular exercise treadmill stress tests. Given this patient's minimal exercise capacity, there is a high chance that ETT alone will be inconclusive. Vasodilator SPECT imaging has been shown to be more sensitive in patients unable to exercise.
A 54-year-old diabetic patient presents with exertional chest pain, relieved by stress. He has hypercholesterolemia, but no smoking history. Which of the following is the best test for this patient?
a. exercise treadmill testing.
b. exercise SPECT imaging.
c. cardiac catheterization.