Visualization of colorectal polyps with spiral CT colography: evaluation of processing parameters with perspective volume rendering.
Visualization of colorectal polyps with spiral CT colography: evaluation of processing parameters with perspective volume rendering.
复制标题
螺旋 CT 结肠成像的结直肠息肉可视化：通过透视体积渲染评估处理参数。
DOI：
10.1148/radiology.205.3.9393524
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发表时间：
1997
期刊：
影响因子：
19.7
通讯作者：
Vannier,MW
中科院分区：
文献类型：
--
作者：
McFarland,EG;Brink,JA;Loh,J;Wang,G;Argiro,V;Balfe,DM;Heiken,JP;Vannier,MW
目的：评价螺旋CT结肠成像与透视容积再现（PVR）检测结肠息肉的两个关键处理步骤：图像重建和不透明度分配的衰减data.MATERIALS和METHODSSpiral CT在10例结肠镜检查证实的已知息肉患者中进行，并进行详细的定量分析，在四个获得的数据。首先，将从具有相等体素尺寸（87%-90%重叠）的二维（2D）源图像生成的三维（3D）图像的解剖保真度与从具有不相等体素尺寸（0%-80%重叠）的2D源图像生成的3D图像进行比较。接下来，针对不同的不透明度阈值设置，评估结直肠息肉与相邻结构的相对尺寸。然后，步骤和S形不透明度函数进行了比较，相对于图像的平滑度和边缘sharpness. SPRTSPVR图像重建的图像数据插值后产生的至少60%的重叠是等效的图像质量的PVR图像从源图像具有相等的体素尺寸。息肉到吸器褶皱的相对尺寸表现出实质性的扭曲，不透明度阈值低于-700 HU。使用S形不透明度函数生成的3D PVR图像明显比使用阶梯不透明度函数生成的图像更平滑（配对t检验，P < .02），在边缘锐度方面存在微小差异。使用适当的不透明度阈值和S形不透明度函数抑制了图像伪影，而边缘清晰度没有实质性损失。
PURPOSETo evaluate two key processing steps for detection of colon polyps with spiral computed tomographic (CT) colography with perspective volume rendering (PVR): image reconstruction and opacity assignment of the attenuation data.MATERIALS AND METHODSSpiral CT was performed in 10 patients with known polyps confirmed at colonoscopy, and detailed quantitative analyses were performed of data obtained in four. First, anatomic fidelity of three-dimensional (3D) images generated from two-dimensional (2D) source images with equal voxel dimensions (87%-90% overlap) was compared with 3D images generated from 2D source images with unequal voxel dimensions (0%-80% overlap). Next, the relative dimensions of colorectal polyps to adjacent structures were evaluated for various opacity threshold settings. Then, step and sigmoidal opacity functions were compared with respect to image smoothness and edge sharpness.RESULTSPVR images generated after interpolation of image data reconstructed with at least 60% overlap were equivalent in image quality to PVR images generated from source images with equal voxel dimensions. Relative polyp-to-haustral fold dimensions demonstrated substantial distortions with opacity thresholds below -700 HU. The 3D PVR images generated with the sigmoidal opacity function were significantly smoother than those generated with the step opacity function (paired t test, P < .02), with small differences noted in edge sharpness.CONCLUSIONUse of highly overlapping source images (87%-90%) was not necessary to generate 3D PVR images of colorectal polyps. Image artifacts were suppressed with use of an appropriate opacity threshold and a sigmoidal opacity function without substantial loss in edge sharpness.