ABSTRACT
A complete evaluation of the patient with ischemic heart disease requires an anatomical and functional assessment of the myocardium and coronary arteries. Recent technological advances have allowed a quantitative and physiological evaluation of the cardiovascular system with Positron Emission Tomography (PET). This method is a valuable tool for the assessment of heart metabolism, myocardial perfusion, ventricular function, coronary blood flow, myocardial viability and endothelial function. One of the major limitations of a PET study is its low spatial resolution. Cardiac Computed Tomography (CCT) is an anatomic study used for coronary calcium quantification, evaluation of wall and lumen of coronary arteries, study of vascular permeability and assessment of composition, extension and severity of atherosclerotic plaques. The main limitation of CCT is the lack of functional information that is obtained with this technique. Both methods are complementary in many ways. That is the reason of the wide spread of PET-CT hybrid equipments that can provide very useful functional and anatomic information of patients with ischemic heart disease in a single exploration.
Subject(s)
Humans , Myocardial Ischemia , Myocardial Ischemia , Positron-Emission Tomography , Tomography, X-Ray Computed , Atherosclerosis , Capillary Permeability , Coronary Angiography , Coronary Circulation , Calcinosis , Coronary Disease , Imaging, Three-Dimensional , Myocardial Ischemia , Positron-Emission Tomography/methods , Ventricular Function, Left/physiologyABSTRACT
PET (positron emission tomography) as a non-invasive imaging method for studying cardiac perfusion and metabolism has turned into the gold standard for detecting myocardial viability. The utilization of 18 FDG as a tracer for its identification permits to spot the use of exogenous glucose by the myocardium segments. By studying and comparing viability and perfusion results, for which the latter uses tracers such as 13N-ammonia, three different patterns for myocardial viability evaluation arise:. transmural concordant pattern, non-transmural concordant pattern, and the discordant pattern; the last one exemplifies the hibernating myocardium and proves the presence of myocardial viability. The importance of its detection is fundamental for the study of an ischemic patient, since it permits the establishment of and exact diagnosis, prognosis, and the best treatment option. It also allows foreseeing functional recovery of the affected region as well as the ejection fraction rate after revascularization treatment if this is determined as necessary. All these elements regarding viability are determinant in order to reduce adverse events and help improving patients' prognosis.