Subvoxel processing: A method for reducing partial volume blurring with application to in vivo MR images of trablecular bone
Subvoxel processing: A method for reducing partial volume blurring with application to in vivo MR images of trablecular bone
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DOI：
10.1002/mrm.10138
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发表时间：
2002-05-01
影响因子：
3.3
通讯作者：
Wehrli, FW
中科院分区：
文献类型：
--
作者：
Hwang, SN;Wehrli, FW
部分体积模糊妨碍了在有限分辨率范围内精确测量结构尺寸，其中图像体素尺寸大于要解析的典型结构元素。由于以更高的分辨率获取图像通常会带来不可接受的信噪比 (SNR) 损失，因此减轻部分体积模糊不利影响的方法有助于准确测量应用中的结构参数，例如预测小梁骨网络的机械能力。在当前的工作中，描述了一种称为“子体素处理”的新型后处理方法，用于提高表观图像分辨率。该方法适用于包含两个离散信号强度的材料相的感兴趣体积。主要策略包括细分体素并根据局部邻域标准和严格的质量守恒为每个子体素分配体素强度。在当前的工作中，已使用人体骨小梁的微计算机断层扫描图像（22 x 22 x 22 mum(3) 体素大小）评估了该方法的准确性。结果表明，在减小表观体素尺寸方面，子体素处理明显比三线性插值更准确，尤其是在存在噪声的情况下。此外，通过体内采集的 137 x 137 x 350 mum(3) 体素尺寸的人体骨小梁 MR 图像说明了该方法的有效性。亚体素处理的图像显示出具有以较高空间分辨率获取的图像的结构特征特征。 (C) 2002 Wiley-Liss, Inc.
Partial volume blurring precludes accurate measurement of structural dimensions in the limited-resolution regime In which Image voxel size is larger than the typical structural element to be resolved. Since acquiring images at increased resolution often exacts an unacceptable signal-to-noise ratio (SNR) penalty, methods to alleviate the adverse effects of partial volume blurring are instrumental for the accurate measurement of architectural parameters in applications such as predicting the mechanical competence of trabecular bone networks. In the current work, a novel post-processing method, referred to as "subvoxel processing," is described for increasing apparent image resolution. The method is applicable to volumes of interest containing material phases of two discrete signal intensites. The principal strategy consists of subdividing voxels and assigning voxel intensities to each subvoxel on the basis of local neighborhood criteria and strict mass conservation. In the current work, the method's accuracy has been evaluated using microcomputed tomography images (22 x 22 x 22 mum(3) voxel size) of human trabecular bone. The results demonstrate that subvoxel processing is significantly more accurate than trilinear interpolation in decreasing apparent voxel size, especially in the presence of noise. In addition, the method's effectiveness is illustrated with MR images of human trabecular bone acquired in vivo at 137 x 137 x 350 mum(3) voxel size. The subvoxel-processed images are shown to have architectural features characteristic of images acquired at higher spatial resolution. (C) 2002 Wiley-Liss, Inc.