64层VCT冠脉成像单扇区图像重建算法与相位窗的优选

目的评价单扇区图像重建算法的相位窗优选。方法102例患者行64层VCT冠状动脉成像检查，采用回顾性心电门控、0.35s容积扫描、单扇区重建算法，静脉注射对比剂。在8个相位窗（心动周期的R波后45%、50%、55%、65%、70%、75%、80%和90%）上对冠状动脉进行CT图像重组。结果在冠状动脉内径大于1.6mm的1286个节段中，823个节段（占63.9%）在75%相位窗上显示最佳，267个节段（占20.8%）在70%相位窗上显示最佳，109个节段（占8.4%）在50%相位窗上显示最佳，31个节段（占2.4%）在80%相位窗上显示最佳，23个节段（占1.7%）在45%相位窗上显示最佳，15个节段（占1.1%）在55%相位窗上显示最佳，11个节段（占0.9%）在90%相位窗上显示最佳，7个节段（占0.5%）在65%相位窗上显示最佳。结论采用单扇区重建算法，冠状动脉多数在心动周期的R波后75%相位窗上显示最佳，其次为70%和50%相位窗。

Retrospectively ECG gated 64-slice CT coronary angiography with one sector reconstruction algorithm and optimization of the image reconstruction window

Objective To evaluate optimal window of image reconstruction within the R-R interval for the coronary arteries.Methods 102 patients were studied with 64-slice spiral CT(retrospectively ECG-gating;0.35 s rotation;one-sector reconstruction algorithm;intravenous contrast agent).Volume data set of the heart reconstructed at 45%,50%,55%,65%,70%,75%,80% and 90% window of the cardiac cycle in increments of 5% were analyzed with maximum intensity projection and 2D curve reformatting mode on a 3D imaging work station.Results In the 1286 coronary artery segments,823(63.9%)were best visualized at 75% image reconstruction window of the cardiac cycle.The optimal window of image reconstruction for the 267(20.8%),109(8.4%),31(2.4%),23(1.7%),15(1.1%),15(1.1%),11(0.9%)and 7(0.5%)coronary artery segments was at 75%,70%,50%,80%,45%,55%,90% and 65%,respectively.Conclusion The coronary arteries usually were best visualized at 75% image reconstruction window of the cardiac cycle if one-sector reconstruction algorithm was used.