The proposed study is to validate a new non-invasive imaging technique for evaluation of cardiac microciculation in coronary artery disease with a comparison with validated technique invasive, which is measure of index of myocardial resistance.

Coronary microvascular dysfunction is closely associated with coronary artery disease, it is an independent risk factor and predicts future coronary events or clinically manifest disease up to 10 years later.

Index of microcirculatory resistance (IMR) is a validated method to Assessment of the Coronary Microcirculation but this is an invasive technique.

In this study, we use a new mathematic technique from homogeneity analysis to provide precise, objective, automated quantification of perfusion heterogeneity at stress with new camera CZT SPECT. We compare the results with those of the measurement of IMR.

Inclusion Criteria:

• Stable angina
• Cadmium-zinc-telluride gamma camera SPECT
• Coronarography

Exclusion Criteria:

• Pregnant woman
• Patient with terminal illness,
• Terminal Renal failure
• Allergy to iodine
• Contraindications for adenosine: Asthmatic patients, Second- or third-degree AV block without a pacemaker or sick sinus syndrome, Systolic blood pressure less than 90mm Hg, Recent use of dipyridamole or dipyridamole-containing medications, Methyl xanthenes such as aminophylline caffeine or theobromine block the effect of adenosine and should be held for at least 12 hours prior to the test, Known hypersensitivity to adenosine, Unstable acute myocardial infarction or acute coronary syndrome