الفهرس 
ANATOMY OF CORONARY ARTERIESOnly 14 pages are availabe for public view
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Abstract
ntroduction
Atherosclerotic cardiovascular diseases are the leading cause of death worldwide responsible for nearly 30% of the mortalities. In Egypt, 27% of the annual death causes is caused by these diseases exceeding the deaths caused by the endemic HCV.
Coronary atherosclerotic plaques are classified into stable and unstable. Unstable plaques increase the risk of the acute coronary syndrome and early detection will help that. Evaluation of plaque vulnerability is done best by intravascular ultrasound but this is an invasive modality and so, this study aims to evaluate the possible use of CT for plaque characterization.
Material and methods
Thirty-eight plaques were divided based on their clinical history into two groups, stable –plaque group and unstable-plaque group. Patients with conditions that might affect that may affect the study were excluded. The standard protocol for patient preparation was followed before imaging them. The reconstructed images were transferred to a workstation (Vitrea FX, Vital Images, USA) to review axial images and also to obtain multiplanar reformatted images at sagittal and coronal planes. Also, maximum intensity projection images, 3D-volume rendered images, semitransparent 3D volume-rendered images, and curved planar reformations were obtained for a detailed assessment of coronary plaques. To arrange the variables according to their diagnostic performance in the differentiation of unstable plaques from stable plaques, the area under their ROC curves (AUC) were compared.
Results
Napkin ring sign and plaque attenuation characters were better than spotty calcification in prediction of future clinical instability. There was also an association between unstable patients clinically and low plaque burden and nature of plaque. There was no correlation between the remodeling index, calcium scoring and stenosis with patient future clinical outcome.
Conclusion
The study showed that Napkin ring sign and plaque attenuation pattern both had the largest AUC followed by plaque-type and finally spotty calcifications. However, Napkin ring sign and plaque attenuation pattern were better than spotty calcifications in the differentiation of unstable and stable plaques. No significant difference was seen between the AUCs of plaque-type and spotty calcifications.
MDCT has an important role in identification of HRP thus early identification of future cardiac events. In this study there is a strong association between different plaque characters and the clinical stability of the patients after a year of follow up. Accurate identification and quantification of coronary plaque components on CT is challenging because of the limited temporal, spatial, and contrast resolutions of current scanners. Nonetheless, CT may provide valuable information that has potential for characterization of coronary plaques and may serve as a non-invasive screening tool in the near future.