Abstract: Objective To evaluation the anatomy relationship between thoracic artery and coronary artery by using 256 layer spiral CT angiography. Methods The angiographic images of thoracic aortic and coronary artery angiography were re⁃ vealed in 200 patients with chest pain. Values of the major branch length, diameter, length of the aorta-coronary artery by⁃ pass on both sides of the thoracic artery and coronary artery were measured. Results The diameter of thoracic artery was (2.52±0.38) mm, and the length of thoracic artery from the starting point to terminal was (190.12 ±1.90) mm. There were no significant differences in the thoracic artery lumen diameter and length between both sides. The inner diameters of left anteri⁃ or descending coronary artery, left circumflex, diagonal branch, right coronary artery and the posterior interventricular branch were (2.82 ±0.25), (2.60±0.12), (2.22±0.25), (3.02±0.27) and (2.35±0.35) mm respectively. There were no significant differences in thoracic artery diameters except for the right coronary artery diameter, which was higher than that of the thorac⁃ ic artery. About free transplantation the length from 2cm above in the ascending aorta starting to the halfway point of anterior descending coronary artery, to the atrioventricular node along the left circumflex way, to the atrioventricular node along the right coronary artery and from the atrioventricular node to halfway point of posterior interventricular branch was shorter than that of thoracic artery (P < 0.05). About situ transplantation in addition to the length from the thoracic artery start department to the point of anterior descending compared with the thoracic artery length, there were no statistical significance (P > 0.05). The length from the thoracic artery start department to the left-hand atrioventricular node, to the right coronary artery atrio⁃ ventricular node was higher than that of the thoracic artery length (P < 0.05). Conclusion The branches of internal thoracic artery and coronary artery are similar. About situ transplantation is suitable for the wall blood vessels before the heart. With free thoracic artery transplantation, its length can meet any bridging from the ascending aorta to the coronary arteries.

Key words: thoracic artery, coronary artery, tomography, spiral computed, tomography, X-ray computed machine, angi?
ography, 256 slice spiral CT