电子束CT血管三维重建技术与冠状动脉成像

目的　分析电子束CT(EBT)三维血管重建技术对冠状动脉及其狭窄的最佳显示方法。方法　对 40例分别行EBT冠状动脉增强扫描及常规冠状动脉造影 (CAG)的病例图像行回顾性三维重建。重建方法主要是最大密度投影法 (MIP)、曲面重建法(CPR)、多平面重组法 (MPR)及容积再现法 (VR)。所有三维重建图像由 2名不知CAG结果的医师按左主干、前降支、回旋支及右冠4支血管进行分析 (分支血管未包括在内 ) ,狭窄程度以 >5 0 %为标准与CAG结果对照。结果　MIP及CPR成像清晰 ,对 48支正常冠状动脉的评价准确率达 91.7%和 93 .8% ,对 5 9支狭窄 >5 0 %血管的评价准确率分别为 83 .1%和 88.1%。VR法重建立体效果好 ,但图像易造成正常血管狭窄的假象 ,48支正常血管中有 2 9支显示狭窄改变。对有狭窄血管的程度也较CAG夸大了约 10 %～3 0 %。MPR重建图像粗糙 ,无法评价冠状动脉。结论　MIP与CPR是显示冠状动脉及其狭窄的最佳三维重建方法 ,诊断准确性高 ,VR可作为补充显示方法 ,MPR可不采用

Three-dimensional Reconstruction of Electron Beam Tomographic Angiography in the Evaluation of Coronary Arterial Stenosis

Objective To investigate the optimal three-dimensional reconstruction method of showing coronary artery and lesion with contrast material-enhanced electron beam tomography(EBT). Methods All coronary arteries were retrospectively reconstructed in 40 patients who underwent both EBT and conventional coronary angiography (CAG).Three-dimentional reconstruction methods were maximum intensity projection (MIP), multiple planar reformat (MPR), curved planar reformat (CPR) and volume rendering (VR). All three-dimensional reconstruction images were analysed by two observers who had no knowledges of the coronary angiographic results.Electron beam tomography findings were then compared with coronary angiographic findings.Results MIP and CPR imaging were clear and the accuracy of MIP and CPR in evaluating 48 normal coronary arteries was 91.7% and 93.8% respectively. The accuracy of MIP and CPR in assessing 59 more than 50% stenoses coronary arteries was 83.1% and 88.1% respectively.Images reconstructed with VR were found cause normal coronary artery stenosis and increase the grade of stenoses for 10 or 30 persent. MPR showed coronary artery unclear and not permitted the observing of stenoses. Conclusion The optimal three-dimension reconstructional method in evaluating coronary artery and stenoses was MIP and CPR.