[Exercise 13NH3-positron emission computed tomography (PET) versus exercise single photon emission computed...

Area of Science:

• Cardiology
• Nuclear Medicine
• Diagnostic Imaging

Background:

• Coronary artery disease (CAD) diagnosis relies on accurate myocardial perfusion imaging.
• Exercise stress testing combined with imaging modalities like SPECT and PET aids in detecting significant coronary artery stenosis.

Purpose of the Study:

• To compare the diagnostic value of exercise positron emission tomography (PET) with exercise T1-201 single photon emission computed tomography (SPECT).
• To assess the accuracy of PET and SPECT in identifying and quantifying myocardial ischemia in patients with left anterior descending (LAD) coronary artery involvement.

Main Methods:

• Ten patients with anginal symptoms and significant LAD stenosis underwent graded ergometer exercise with both N-13 ammonia PET and T1-201 SPECT.
• Circumferential profile curve (CPC) analysis was used to determine ischemic areas (%C), accuracy in diagnosing coronary involvement, and identification of coronary branch involvement.

Main Results:

• Exercise PET demonstrated higher accuracy (9/10) than SPECT (7/10) in diagnosing proximal LAD involvement, though not statistically significant.
• PET showed a significantly higher percentage of ischemic area (%C) during exercise compared to SPECT (56% vs. 35%, p < .01).
• PET was more reliable in evaluating regional ischemia and semiquantifying the ischemic burden, even with lower double products during exercise.

Conclusions:

• Exercise N-13 ammonia PET is a more reliable imaging modality than T1-201 SPECT for evaluating regional myocardial ischemia in patients with CAD.
• PET provides superior semiquantification of ischemic areas, aiding in more accurate assessment of coronary artery disease severity.