三维图像重建在头颈胸部螺旋CT中的应用进展

The advances about 3-D spiral CT imaging reconstruction in head,neck and thorax

目的分析与评价三维 CT 图像重建在头、颈、胸部扫描中的应用价值,寻找影响 CT图像三维显示的主要因素。方法 103例螺旋扫描(日立 PRATICO SPIRAL CT,层厚2～5mm)且行三维重建,分别应用 SSD、MPR 及3D VOLUME DISPLAY 法。结果 3D 比2D 法较好显示骨的立体感,较好显示气管、支气管及纵隔大血管及病变、累及的肋骨和胸膜、周围血管情况,较好显示肿块的轮廓,但显示内部结构差于2D 图像,影响3D 图像的主要因素有扫描层厚、螺距、滤波函数及视角及 CT 阈值,其中 CT 阈值不但影响3D 图像的显示立体效果,也影响病变的大小。结论 3D 对术前评价分期治疗有重要价值,该技术 CT 值范围的应用原则是窗宽调至1时,仅显示兴趣区结构时窗中心为下限,上限在600至3000之间。

Objective To analyze and evaluate clinical application value of 3-D spiral CT in head. neck and thorax to find out many important factors that affecting 3-D CT imaging display.Methods 103 patients were examined by PRATICO spiral CT(2mm～5mm slice thickness),the imaging,reconstrution methods such as SSD.,MIP and MPR,were used.Results 3-D volume display and SSD were superior to 2-D CTdisplay in showing the stereoscopic images of bone.SSD and MIP were superior in showing larger blood vessels of mediastinum and lung,so superior in showing principal bronchus and showing the relation- ship of focus to ribs,pleura and vessels around the focus,showing the whole outline of tumor,without showing internal structure of focus.There were may important factors,that affecting 3-D CT imaging display such as the slice thickness,pitch filter.The last one of this factors did have relationship with size of focus and the effect of 3-D imaging display.Conclusions Imaging reconstruction has important value in surgical treamtent,classifying and evaluating examination before operation.The principle about CT value is to adjust window level,till RoI image is shown best only while the window width can be adjusted to 1 Hu.Ranging from 600 to 3000.