IMPLEMENTING CONE BEAM ALGORITHMS FOR CLINICAL SPECT

单光子发射计算机断层扫描（SPECT）已成为一种重要的 核医学中的诊断工具，用于对心脏，大脑，肝脏， 骨骼和其他器官，因为它是非侵入性的， 比其他方式（例如正电子发射断层扫描（PET））更有效。 SPECT使用锥形束准直器增加了灵敏度 用于成像像大脑和心脏这样的小器官， 大视场旋转伽马相机将小器官放大到 一个大的探测器区域。锥束准直器的使用已经证明 与使用平行孔相比提高了灵敏度和分辨率 准直器，并导致更好的检测和大小，为 例如，扫描时间没有增加的心脏病变。但随着 目前的SPECT系统仅具有单个平面轨道， 锥束层析成像对某些结构的应用表明， 切片串扰。对于像大脑这样的器官， 在冠状面中，头部顶部附近沿旋转轴沿着伸长 和矢状位视图。为了获得足够的数据， 焦点的扫描轨迹必须具有 任何平面通过的至少一个交点 重建感兴趣区域。这可能需要修改硬件 然而，即使有足够的数据采样， 不能保证可用的、有效的分析算法。 该研究将发展用于重建锥束的算法 有足够数据采样的预测。特别强调的是 开发适用于SPECT系统的算法， 而很少或没有额外的成本来提供临床系统。整体 该项目的目标是开发有效的锥束重建 提供无伪影三维SPECT的算法 临床使用的重建。结果将有可能 显著提高核医学诊断能力 程序. 项目完成后，将开发和测试软件。的 研究将为设计制定工程原则和指导方针 SPECT系统可为锥形束断层扫描采集足够的数据， 用于采集和处理足够的锥形束数据的临床协议。

Single-photon emission computed tomography (SPECT) has become an important diagnostic tool in nuclear medicine for imaging the heart, brain, liver, bones, and other organs because it is non-invasive and is less expensive than other modalities--for example, positron emission tomography (PET). The use of cone-beam collimators with SPECT has increased the sensitivity for imaging small organs like the brain and heart by taking advantage of the large field-of-view rotating gamma camera to magnify small organs onto a large detector area. The use of cone-beam collimators has demonstrated improved sensitivity and resolution over the use of parallel hole collimators, and has resulted in better detection and sizing of, for example, cardiac lesions with no increase in scanning time. However, with present SPECT systems, which have only single planar orbits, the application of cone-beam tomography to some structures shows slice-to- slice cross-talk. For organs like the brain this system shows image elongation along the axis of rotation near the top of the head in coronal and sagittal views due to insufficient data. To achieve sufficient data it is necessary for the scanning trajectory of the focal point to have at least one point of intersection for any plane passing through the reconstructed region of interest. This may require hardware modifications of present SPECT systems; however, even if sufficient data sampling is available, efficient analytical algorithms are not guaranteed. The proposed research will develop algorithms for reconstructing cone-beam projections with sufficient data sampling. Of special emphasis is the development of algorithms applicable to SPECT systems that can be modified with little or no additional cost to present clinical systems. The overall goal of the project is to develop efficient cone-beam reconstruction algorithms that provide artifact-free three-dimensional SPECT reconstructions for clinical use. The results will have the potential to significantly improve the diagnostic capability of nuclear medicine procedures. Upon completion of the project, software will be developed and tested. The research will develop engineering principles and guidelines for the design of SPECT systems that acquire sufficient data for cone-beam tomography and clinical protocols for acquiring and processing sufficient cone-beam data.