Positron Emission Tomography in nuclear cardiology and detection of coronary artery disease
Positron Emission Tomography in nuclear cardiology and detection of coronary artery disease
Mohammad Hossein Jamshidi,1,*Aida Karami,2
1. Department of Medical Imaging and Radiation Sciences, School of Allied Medical Sciences, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. 2. Department of Medical Imaging and Radiation Sciences, School of Allied Medical Sciences, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Introduction: Early detection and treatment of coronary artery disease (CAD) remain paramount, given its morbidity, mortality, and economic consequences. Over the past few years, we have witnessed a rapid evolution of PET instrumentation, which now offers higher sensitivity and hybrid scanners integrating PET and computed tomography (CT). Hybrid PET-CT scanners account for approximately 80% of the new PET units installed.
Methods: Different terms explored in PubMed and Google Scholar databases: Nuclear cardiology, Coronary artery, and Positron Emission Tomography. The obtained results were selected for the title and abstracts. Finally, 21 relevant papers were selected and reviewed in full text.
Results: Experience with radionuclide assessments of myocardial perfusion can be measured over decades. Single-photon emission computed tomography (SPECT) myocardial perfusion scintigraphy (MPS) has been validated for the diagnosis and prognosis of cardiac disease, and the technique is embedded in national and international guidelines. Positron emission tomography (PET) has been used to assess myocardial viability, but it is now used increasingly to detect flow limiting CAD. Although previously used mainly to assess myocardial viability, PET is now more commonly used to assess myocardial perfusion, and it is generally considered the non-invasive gold standard for this. Although cyclotron-produced radiotracers, such as N-ammonia or O-water, are regularly used, recent efforts have also focused on the use of rubidium-82. This tracer is produced by a generator, compares favorably with other PET tracers for myocardial perfusion and perfusion reserve measurements, and is an attractive option for hospitals without easy access to a cyclotron. PET offers higher resolution images and provides quantification of perfusion in absolute terms (ml/g/min). PET may have better sensitivity and specificity than SPECT MPS for detecting CAD, particularly where there is a severe multi-vessel disease and in obese patients. Two meta-analyses with PET demonstrated 90–93% sensitivity and 81–88% specificity for CAD detection, superior to myocardial perfusion SPECT.
Conclusion: Myocardial perfusion in absolute units measured by PET further improves diagnostic accuracy, especially in patients with multi-vessel disease, and can be used to monitor the effects of various therapies. The method also has significant prognostic value. Despite the demonstration of cost-effectiveness in high-throughput centers, the clinical utility of PET is still constrained by high upfront cost and low availability compared with SPECT.