Evaluation of the Functional Impact of Coronary Stenoses in Diabetics by Spectral CT

The optimal screening methods for coronary insufficiency, a frequent and pejorative complication in diabetics, are subject to debate, particularly in situations of silent myocardial ischemia. The contemporary strategy consists of pre-selecting asymptomatic patients at very high cardiovascular (CV) risk by performing a coronary calcium score. If this is found to be high \>300 AU (Agatston units), the patient is suspected of being at high risk of silent myocardial ischemia (SMI), and the assessment is completed to exclude the presence of coronary artery disease likely to benefit from revascularization. The complementary evaluation consists in evaluating the myocardial perfusion to judge the perfusion repercussions. The most common examination to date is myocardial scintigraphy, because stress tests are too frequently submaximal in diabetics. However, the reproducibility of scintigraphy is controversial and their sensitivity and specificity are debated in this indication. This problem is similar in stable symptomatic coronary diabetic patients for whom an indication for functional examinations is justified. The double-energy double-layer spectral scanner (SDEDC) could now become a relevant tool in this field, since it can combine not only anatomical data (identification of coronary stenosis) but also functional data (myocardial perfusion) during a stress protocol. thanks to the spectral images which make it possible to measure the tissue concentration of intramyocardial iodine downstream of the considered stenosis.