Assessment of myocardial perfusion by radioisotopic methods : experimental validation and clinical applications

The thesis is divided into three parts.
Part 1 describes the methods of measuring myocardial perfusion in man. Among the non-radioactive methods, two approaches, he pulsed Doppler and the digital subtraction angiography have been recently introduced and represent a major advance in the field.
The advantages and disadvantages of the radioactive methods necessitating a cardiac catheterization are briefly reviewed.
Part 2 focuses on a noninvasive method of evaluating myocardial perfusion, based on the use of a diffusible indicator, T1-201, and of a gamma camera. In the first chapter, basic experiments studying T1-201 kinetics are described. The initial distribution of T1.201 uptake does correlate closely with the distribution of blood flow, under various experimental conditions. However, presently, absolute measurements of total or regional blood flow cannot be the “redistribution” phenomenon seen in patients, experiments are describe showing the difference between T1-201 clearance in normal and ischemic myocardium.
The second chapter of Part 2 centres on the current methodology of the T1-201 imaging. The value and limitations of quantification of planar images and of single photon emission tomography are discussed.
The first chapter of Part 2 deals with the clinical applications of rest and exercise T1-201 scintigraphy are detection of coronary disease in patients where stress ECG provides insufficient information, and the detection of exercise-induced ischemia in patients with known coronary disease, i.e. after bypass surgery or angioplasty or after myocardial infraction. Finally, rest T1-201 scientigraphy has been applied with success to study the prognosis and the value of therapy in acute myocardial infarction.
Part 3 draws the general conclusions of the use of T1-201 scintigraphy and calls attention to new approaches for studying myocardial perfusion