| Objective:Coronary heart disease is based on the pathophysiology of coronary atherosclerotic plaque formation. Coronary artery calcification is formed by calcium deposition of coronary atherosclerosis Department,which is an important indicator of coronary atherosclerosis Accurate detection of coronary atherosclerosis can significantly improve the prediction of cardiovascular disease incidence.Coronary angiography can direcely determine the extent of the Artery stenosis In the clinical aspects.which has unique advantages in the diagnosis and treatment of coronary heart disease and is considered the gold standard for diagnosis of coronary heart disease. But it has some limitations ,for it is a noninvasive examination and has a threat to the health of patients.With the invention of MSCT, its scanning speed, combined with the ECG-gated triggering technology, rule out the possibility of cardiac pulsatility and effects produced by respiratory .And it has high time and spatial resolution,which can be carried out on the quantitative detection of CAC.The high sensitivity and non-invasive examination of CAC64 layer CT (MSCT) detection allows is increasingly becoming an important methods for early prediction and provides a new reliable method for the patients with coronary artery disease for the early diagnosis of coronary heart disease.Studies have shown that detection of CAC of MSCT is the independent factor of prediction of coronary heart disease and future cardiovascular events. The effectiveness of early prediction of coronary heart disease is stronger than all the combined traditional risk factors. Investigate the detection to coronary calcium score of 64-slice CT can diagnosis the coronary artery disease and is an evaluation of reliability.studing on determination of 64-slice spiral CT coronary artery calcification score reliability and the best coronary artery of reconstruction phase, and understanding the relations of coronary artery calcification score with diabetes, high blood pressure, high cholesterol and other factors can ultimately determine the best threshold of diagnosis of coronary artery calcification score. Methods:86 patients with suspected coronary heart disease in newly diagnosed patients and for treatment and medical examination to our hospital,and some patients with previous non-coronary angioplasty and bypass grafting in their history take the post-coronary 64-slice MSCT (41 cases in which the heart rate more than 70 times/min before CT scan have atenolol 12.5 ~ 25 mg 30 minutes before of MSCT to sublingual the heart rate to 70 times / min or less)①Scanning method of detection of coronary artery calcification: used ECG-gated MSCT scan of the patient from the bottom to the apex of heart , 0.8s spiral scanning, 2.75mm thick, the range of Z-axis is 120-150mm (40-50 layers). After scanning the image is reconstructed by segment, matrix 512×512, field of vision 26cm pixel 0.26mm, requires patients to complete the scan in a breath-hold. Before that it should be connected with the EKG, to synchronize record and image acquisition at the same time.②The technical methods and parameters of MSCT coronary angiography : first ,positioning the chest and heart CT scan,calculatiing the delay time of coronary artery scan.After that complete the breath-hold 64-slice MSCT scanning according to a certain delay time . After scaning the restructuring data can be transmitted to the AW4 image processing workstation.The use of retrospective ECG-gated reconstruction of the RR of 45-85% during the reconstruction (between 5%) can restruct the cross-sectional images, and then proceed to the reconstruction of coronary artery volume, select the best images to take CACS measurements.CACS measured using Agatston to learn the various branches of coronary artery calcification and coronary artery calcification rate, calcification score in terms of gender, age distribution; and to analyze the rate of coronary artery calcification, calcium score and coronary heart disease. The selected patients in the intervention of our hospital center take the coronary angiography, we can determine the predictive value of coronary heart disease according to MSCT angiography.Results:1.Coronary artery calcification rate and calcification score in people who have coronary aryery disease is higher than who havein non-coronary heart disease. Coronary heart disease increases with age increasing continuously. The rate of coronary artery calcification and calcium score in after-60-year-old age group are above the before-60-year-old age group, and the calcification rate and calcification score in anterior descending artery were the highest, LCX and right coronary artery followed by ,the left main trunk is the minimum.2.The rate of coronary artery calcification and calcification score of male slightly higher than the female. This study P = 0.106 showed that no significant difference between men and womem.3.The image of of all the 344 coronary vascular of 86 patients in MSCT examination image shows well and meet the imaging evaluation. 234 blood vessels is normal,mild stenosis (<50%) of vascular is 37, moderate and severe stenosis (≥50%) is 73 .Compared with results using CGA checking, the two homology rate is 96.6%, 83.3%, 95.7 %.Conclusion:1.When the heart rate is less than 70 times / min, we should use the application of multi-phase reconstruction, (usually at intervals of 5%). 75 percent of reconstruction phase of the majority show the backbone of coronary artery and its branches of 2-3 level, as well as the extent of the open cavity of tube; varying degrees of coronary artery calcification has high sensitivity and can be the reconstruction of blood vessels, and calculated the degree of coronary heart disease risk in accordance with the luminal diameter stenosis. This can be used as a screening tool. If coronary artery of special patients is poor we can use the other phase reconstruction to obtain the best results. Generally using 45% -85% of the reconstruction phase neither would be too many images, but also to ensure that image quality.2.Multi-slice spiral CT (MSCT) is a safe and non-innovative method of qualitative and quantitative researching CAC.The use of coronary calcium score to diagnostic disease has a higher sensitivity and specificity.This can be a method of clinical assessment and gradually become a new diagnostic imaging of coronary heart disease. Therefore, 64-slice spiral CT is ideal for the census means of coronary heart disease and can guide the further diagnosis and treatment, and for the diagnosis of coronary heart disease provide many rich dignosis basis. |
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