CT扫描不同图像后处理技术对主动脉夹层破口检出率的影响研究

目的研究CT扫描不同图像后处理技术对主动脉夹层破口检出率的影响。方法对106例主动脉夹层病人行多层螺旋CT血管成像检查，采用最大密度投影（MIP）、容积重建（VR）、多平面重建（MPR）、曲面重建（CPR）、表面遮盖成像（SSD）等技术进行图像后处理。结果原始横轴位图像的夹层动脉瘤破口检出率为37.7%，MIP、CPR、MPR、VR、SSD的夹层破口检出率分别为0.0%、46.2%、69.8%、65.1%、39.6%。最终97例能明确显示夹层破口，夹层破口的检出率为91.5%，9例因破口直径太小、升主动脉根部伪影或假腔完全血栓化等原因而显示欠佳。MPR、CPR、VR对夹层破口的总检出率明显高于SSD与MIP（P < 0.01）。根据DeBakey分型，Ⅰ型47例（44.3%），Ⅱ型17例（16.0%），Ⅲ型42例（39.6%）。MPR、VR对Ⅰ型、Ⅱ型的检出准确率优于MIP、CPR及SSD（P < 0.01），CPR、MPR对Ⅲ型的检出准确率优于MIP与SSD（P < 0.01）。结论CT扫描结合图像后处理技术在显示主动脉夹层破口方面具有一定的优势，不同图像后处理技术各有优缺点，其中MPR操作简单、对夹层破口的显示能力强及准确分型，可作为首选。

Study on the effects of different image post-processing techniques on the detection rate of aortic dissection

ObjectiveTo study the effects of different image post-processing techniques on the detection rate of aortic dissection.MethodsOne hundred and six patients with aortic dissection were detected using the multi-slice spiral CT.The maximum intenstity projection(MIP), volume rendering(VR), multiplanar reconstruction(MPR), curved planar reconstruction(CPR)and surface cover imaging(SSD)were used for image post-processing.ResultsThe fracture detection rate of original horizontal axis images was 37.7%, and the detection rates of interlayer fracture of MIP, CPR, MPR, VR and SSD were 0.0%, 46.2%, 69.8%, 65.1% and 39.6%, respectively.The break in 97 cases could be clearly showed, and the detection rate of break was 91.5%.The poor show in 9 patients were identified due to the small diameter of the rupture, artifact of the ascending aortic root or complete thrombosis of pseudolumen.The detection rate of MPR, CPR and VR for fracture were significantly higher than that of SSD and MIP(P < 0.01).According to DeBakey type, 47 cases(44.3%)were type Ⅰ, 17 cases(16.0%)were type Ⅱ and 42 cases(39.6%)were type Ⅲ.The detection accuracy of MPR and VR for type Ⅰ and Ⅱ was better than those of MIP, CPR and SSD(P < 0.01), and the detection accuracy of CPR and MPR for type Ⅲ was better than that of MIP and SSD(P < 0.01).ConclusionsThe CT scanning combined with image post-processing technique has certain advantages in showing the rupture of aortic dissection.Different image post-processing techniques have different advantages and disadvantages, and the MPR is simple to operate, and has strong displaying ability for interlayer fracture and accurate typing, and can be taken as the first choice.