以多切面電腦斷層搭配回顧式心電圖偵測分析冠狀動脈重組影像在心週期的最佳影像。171位病患（男性103位，女性68位；平均年齡55±11歲；年齡範圍由28歲至豁歲）在接受多切面電腦斷層冠狀動脈檢查，其影像重組由心週期35%至85%，間隔10%。重組影像分段依美國心臟協會分段標準評估右冠狀動脈（第1~3段）、左主冠狀動脈（第5段）、左前降枝（第6~8段）及左迴旋枝（第11、13段）。重組完之影像品質評分標準由很好到很差分別由1分到5分分佈。1分表示很好，5分表示很差，影像由兩位心臟放射線專科醫師判讀評分。171位冠狀動脈之3D重組影像以SPSS ANOVA軟體分析出各冠狀動脈皆在75%心週期有最佳影像品質(p<0.05)。冠狀動脈重組影像最佳品質在心舒張期中末段有最佳品質。在此研究中，75%心週期爲重組最佳影像。

To investigate and analyze reconstructed images of retrospective ECG gating multi-detector row computed tomography (MDCT) for each of the major coronary arteries during the cardiac cycle. Multi-detector row coronary artery CT angiographies obtained in 171 patients (103 men, 68 women; mean age, 55 years �11; age range, 28-83 years) were reconstructed at 35%-85% of the cardiac cycle in increments of 10%. Two independent reviewers who specialize in cardiac radiology assessed the image quality, obtained with three-dimensional post-processing for segments 1-3 (right coronary artery), segments 5-8 (left main and left anterior descending coronary arteries), and segments 11 and 13 (left circumflex artery). Segments were defined according to American Heart Association (AHA) guidelines. The grades were assigned: 1, excellent; 2, good; 3, fair; 4, poor; and 5, very poor. The three-dimensional reconstructed image data were statistically analyzed with SPSS software version 10.0. The authors analyzed 171 patients' data with 2-way ANOVA and found the left anterior descending artery, left circumflex artery and right coronary artery all were best visualized at 75% of the cardiac cycle (p<.05). Our results demonstrated that the reconstructed images of coronary arteries usually performed optimally during mid-to-late diastole cardiac cycle. 75% of the cardiac phase was the best visualization phase for all coronary arteries in this study.