| Objective:To investigate the relationship between intersection angles among left main coronary artery (LM), left anterior descending branch (LAD) and left circumflex branch (LCX) and formation and distribution of atherosclerotic plaques in the left coronary artery by employing 320-row CT angiography (CTA).Methods:127 patients underwent CTA examinations were retrospectively reviewed, including the normal group (n=44) and left coronary artery lesion group (n=83) which were divided into three sub-groups:the LM group (n=18), the proximal group (n=57) and the middle and distal group (n=8). The original data of every branch of coronary artery were reconstructed into images of volume rendering and curved planar reconstruction in the workstation using the soft-ware of Cardiac CTA Analysis. The intersection angles among LM, LAD and LCX should be measured on the reconstructed images, and then the relationships between intersection angles among LM, LAD and LCX and formation and distribution of atherosclerotic plaques were analyzed.Results:In 127 patients, the angles of LM-LAD negatively correlated with the angle of LAD-LCX (the bifurcation angle); and the correlation coefficient is-0.356(P< 0.05); the angles of LM-LCX negatively correlated with the bifurcation angle also, and the correlation coefficient is-0.662(P< 0.05). There was significant difference in the bifurcation angle between the proximal group (90.9°±20.0°) and the normal group (72.7°±16.7°)(P<0.05). Comparing the mean angle of LM-LCX between the proximal group (117.8°±16.0°) and the normal group (129.5°±15.9°),there was significant difference between the two groups(P < 0.05). The formation of plaques in the proximal segment of LAD and LCX, especially in the proximal segment of LAD, is positively related to the angle of LAD-LCX and negatively related to the angle of LM-LCX. When the angle of LAD-LCX is more than 70°, the probability of plaque formatted in left coronary artery is increased.Conclusion:There is a correlation between the angles of LAD-LCX and LM-LCX and formation and distribution of plaques in the proximal segment of LAD, CTA can provide non-invasive, accurate and fast relevant feature information of plaque formatted, risk prediction and preoperative interventional therapy in left coronary artery. |
