Determination of exact reconstruction regions in composite-circling cone-beam tomography.
Determination of exact reconstruction regions in composite-circling cone-beam tomography.
复制标题
复合环形锥形束断层扫描中精确重建区域的确定。
DOI：
10.1118/1.3158733
复制
发表时间：
2009
期刊：
影响因子：
3.8
通讯作者：
Wang,Ge
中科院分区：
文献类型：
--
作者：
Ye,Lena;Yu,Hengyong;Wang,Ge
使用纵向截断锥束数据对长物体的短部分进行图像重建对于主要的医学计算机断层扫描（CT）应用非常重要，尤其是心脏CT。心脏CT是心脏缺陷、心血管疾病和肺部疾病的诊断和治疗评估的重要成像工具，但它仍然受到次优图像质量的限制。最近，鞍曲线和复合循环扫描模式已被提出来解决这个问题，使用精确的重建公式。然而，鞍形曲线扫描同时涉及圆周运动和线性运动，而复合圆扫描仅涉及圆周运动。由于鞍形曲线扫描难以机械实现，因此复合环绕扫描提供了另一种可能更简单的方法：在X射线管中的X射线焦点在面向心脏的平面上旋转，而X射线管和探测器可能同时在机架平面上旋转。本文确定了复合循环扫描模式下基于弦的精确重建区域，并将其与鞍曲线扫描模式下的区域进行了比较。对于不同的扫描参数组合，本文找到了可以嵌入精确重建区域内的以原点为中心的最大球体。这篇文章还表明，当X射线焦斑以可变速度旋转时，嵌入的球体会变得更大，从而使扫描曲线能够覆盖更大的物体。总之，这篇文章得出了一个新的心脏CT扫描仪的原型，以满足减少辐射剂量和增加空间和时间分辨率的目标的指导方针。
Image reconstruction of a short portion of a long object using longitudinally truncated cone‐beam data is important for major medical computed tomography (CT) applications, especially cardiac CT. Cardiac CT is an essential imaging tool for the diagnosis and therapeutic assessment of heart defects, cardiovascular diseases, and lung diseases, but it is still limited by suboptimal image quality. Recently, saddle‐curve and composite‐circling scanning modes have been proposed to solve this problem using exact reconstruction formulas. However, saddle‐curve scanning involves both circular and linear motions, while composite‐circling scanning conveniently involves just circular motions. Because saddle‐curve scanning is difficult to implement mechanically, composite‐circling scanning provides another, hopefully easier, approach: An x‐ray focal spot in an x‐ray tube is rotated on a plane facing the heart, while the x‐ray tube and possibly the detector are simultaneously rotated on the gantry plane. This article determines regions for chord‐based exact reconstruction in the composite‐circling scanning mode and compares them to those in the saddle‐curve scanning mode. For different scanning parameter combinations, this article finds the largest sphere centered at the origin that can be embedded inside the exact reconstruction region. This article also shows that the embedded spheres become larger when the x‐ray focal spot rotates at variable speeds, allowing the scanning curve to cover a larger object. In summary, this article derives guidelines for prototyping a new cardiac CT scanner to meet the goals of reducing radiation dose and increasing spatial and temporal resolution.