The Clinical Application Of Adenosine-stress Magnetic Resonance Myocardial Perfusion Imaging And Computed Tomographic Coronary Angiography In The Diagnosis Of Early Stage Of Coronary Artery Disease

Selective coronary angiography is regard as a gold diagnostic standard for arterial luminal stenosis in coronary artery disease. Although the cost of this method is higher and the technique is invasive to the patient with 1.5% complications and 0.5% mortalities, it is still extensively used for the clinical diagnosis and treatment of coronary artery disease. But with the advance of clinical research on coronary artery disease, including the novel concept of acute coronary syndrome, it is required to identify stablity of atherosclerotic plaque and to evaluate myocardial ischemia induced by coronary artery stenosis, all of which can not be done by selective coronary angiography. the advent and development of multislice spiral CT (MSCT) and magnetic resonance imaging (MRI) may be the best way to solve this problem. At present, numerous studies focus on the use of these two equipments in the diagnosis of coronary artery disease. But, strict comparative and relative studies is rare. In the present study, diagnostic test of CT coronary arterial imaging in diagnosis with early stage of coronary artery disease was performed. The relationship of myocardial ischemic degree with coronary artery stenosis evaluated by cardiac magnetic imaging (CMRI) and CAG was studied to investigate clinical feasibilty of coronary arterial angiography and cardiac MRI in earlier diagnosis of coronary artery disease.Objective: To study the effect of CT coronary artery imaging on coronary artery stenosis in earlier diagnosis of coronary artery disease. To study the manifestation of myocardial ischemia demonstrated by adenosine-stress and resting cardiac MRI and to evaluate the value of adenosine-stress cardiac MR imaging in the earlier diagnosis of coronary artery disease. Methods: Thirty-four patients without acute coronary syndrome underwent selective coronary angiography, dual-source CT coronary angiography and 3.0T myocardial magnetic resonance imaging respectively. The diagnostic test were performed to evaluate diagnostic value of CT coronary imaging for early stage of CAD. The relative study between cardiac magnetic perfusion imaging and coronary angiography were also performed.1. CT coronary artery imaging was conducted according to 15 segments of coronary artery recommended by American heart association and each segment of coronary arteries were evaluated and the sensitivity, specificity, predictive value and negative predictive value of CT coronary artery imaging were calculated.2. Magnetic resonance myocardial perfusion and delayed scan were conducted and the wall of left ventricle in axial view was divided to 17 segments according to the standard presented by American heart association. The changes of blood supply in all left ventricular segments before or after adenosine-stress were compared to confirm if there was reversible myocardial ischemia . Then we compared the changes of myocardial ischemia in groups of different coronary arterial stenosis and investigated the relation between change of myocardial ischemia and degree of coronary arterial stenosis.Results:1. Sensitivity of CT coronary artery imaging was 68%, specificity was 97%, positive predictive value was 89% and negative predictive value was 90% compared with CAG for the evaluation of coronary artery stenosis.2. The results of CT coronary artery imaging showed that the quality of 65 pictures of coronary artery segments was bad (accounting for 12%). The main reason is due to calcification, breathing and cardiac movement artifacts and another reason is that arterial lumen is not clear to show for a few cases.3. The changes of myocardial ischemia in MRI appeared the decrease of myocardial perfusion and no enhancement of delay scanning.4. Adenosine can aggravate the degree of myocardial ischemia and increased positive rate of detecting myocardial perfusion. Positive rate increase in patient group of 50% 75% arterial stenosis was significant compared with that in lower 50% arterial stenosis group and higher 75% arterial stenosis group.Conclusion:1. CT coronary artery imaging may be conducted before coronary angiography for screening of coronary artery disease. The patient with negative CT coronary artery imaging is not necessary to do coronary angiography. The patient with positive CT coronary artery imaging need it to confirm pathological changes if coronary endoarterial intervention was to be needed.2. Adenosine can be used to evaluate degree of myocardial ischemia for earlier diagnosis of coronary artery disease by MR myocardial perfusion imaging and delayed scan. The degree of myocardial ischemia is a sensitive marker. Myocardial segment with decrease of MR myocardial perfusion imaging and no enhancement of delay scanning is considered supplying coronary artery stenosis.3. Dual-source CT and 3.0T magnetic resonance imaging can not replace coronary angiography to evaluate coronary arterial luminal stenosis, but these methods can identify stability of atheromatous plaque and evaluate myocardial ischemia and help to make clinical diagnosis and treatment strategy of CAD.