Determination of Coronary Flow Reserve by Dynamic Myocardial Perfusion Scintigraphy

Because of its availability, non-invasiveness, and high diagnostic performance, myocardial perfusion tomoscintigraphy has become a standard tool for the detection, characterization and monitoring of coronary artery disease. Standard analysis, based on the reversibility of regional myocardial hypoperfusion between stress (physiological or pharmacological) and rest, has good sensitivity and negative predictive value in the search for myocardial ischemia. However, two major obstacles persist. First, because of the relative nature of the normalization of cardiac activity, this approach may underestimate the extent of the damage, especially when the territory with the most activity is itself pathological. Thus myocardial perfusion scintigraphy can only detect 40 to 50% of tri-truncal patients. To overcome these disadvantages, several indexes have been proposed to improve the diagnostic performance of perfusion scintigraphy in multi-truncal patients based in particular on kinetic analysis. Secondly, the review does not provide any guarantee as to the quality and reproducibility of use of the coronal reserve during stress, in particular during submaximal stress tests and pharmacological stress, the latter being easily antagonized by xanthine derivatives contained in tea and coffee in particular (abstinence of at least 12 to 24 hours being recommended). In recent years and thanks to the advent of CZT semiconductor cameras dedicated to cardiology - to perform a dynamic tomographic acquisition - a study of the coronal reserve is feasible by perfusion tomoscintigraphy in current practice. This study of the coronary reserve mainly consists of a computer post-processing of the myocardial perfusion scintigraphy data and does not therefore require any additional irradiation (the only difference with respect to the old protocols is the start of the images at the time of publication. injection of the radiotracer). However, the diagnostic benefit gained from the coronary reserve study compared to conventional stress / rest perfusion scintigraphy has not been clearly studied, particularly in the multi-truncal patients.