Segmented-Parallel-Beam Stationary Cardiac SPECT

描述（由申请人提供）：本项目的目的是使用安装在大面积NaI（Tl）探测器上的新型分段平行孔准直器开发固定心脏SPECT（单光子发射计算机断层扫描）系统。这种固定式SPECT系统建造成本低，无运动，并且能够获得一致的SPECT。该系统可获得真实的动态SPECT图像。 光谱动力学公司研制了一种用于心脏SPECT的“固定式”γ照相机，称为D-SPECT。D-SPECT中没有机架旋转;但是，探测器持续扫描。因此，D-SPECT不是真正的固定系统。 加州大学旧金山分校弗朗西斯科和西方心脏病学协会联合提出了一种真正的固定心脏SPECT系统。他们的系统是一个改进的三探测器SPECT系统，安装了三个多针孔准直器。他们已经成功地使用此设置采集了心脏SPECT图像。GE还开发了一种固定的多针孔专用心脏SPECT系统，称为Alcyone。我们的研究是用我们原来设计的分段平行孔准直器代替多针孔准直器。在分段平行孔准直器中，整个检测区域被划分成许多更小的子区域。每个节段中的准直器孔指向心脏。 我们用分段平行孔技术取代针孔技术的动机是基于以下事实。针孔的分辨率/灵敏度折衷是极好的（良好的分辨率和良好的灵敏度），但仅在小对象中（例如，小动物）成像。在大对象中（例如，当针孔在图像缩小模式下操作时或者当图像和物体具有相同的尺寸时，分辨率/灵敏度折衷差（差的分辨率和差的灵敏度）。此外，在固定系统中，角度视图的数量是有限的，因此，为了获得更多的视角，图像不能被放大。在这种情况下，分段平行孔准直能够提供比针孔准直更好的分辨率和检测灵敏度。 本研究将仔细研究和比较传统的旋转系统、多针孔系统和分段平行孔系统，并将验证我们的假设：对于人体心脏研究，分段平行孔系统在图像分辨率和检测灵敏度方面将优于多针孔系统和传统旋转系统。还计划进行患者可行性研究。在这项研究为使用普通临床SPECT相机的分段平行孔系统奠定了坚实的基础之后，患者研究，具有时间一致投影的动态成像和运动校正技术将在未来的R 01资助下开发。 公共卫生相关性：该项目开发了一种固定式心脏SPECT（单光子发射计算机断层扫描）。心脏SPECT可以检测许多心脏疾病。这个新系统是固定的，没有移动部件。这使得该系统的建造和维护成本更低。这一新系统还将具有比当前系统更高的检测灵敏度，这将在更短的成像时间内产生更清晰的图像。

DESCRIPTION (provided by applicant): The objective of this project is to develop a stationary cardiac SPECT (single photon emission computed tomography) system using a novel segmented parallel-hole collimator mounted on a large-area NaI(Tl) detector. This stationary SPECT system is inexpensive to build, motion-free, and able to acquire consistent SPECT. This system can obtain true dynamic SPECT images. A "stationary" gamma camera for cardiac SPECT has been developed by Spectrum Dynamics, called D- SPECT. There is no gantry rotation in D-SPECT; however, the detectors are continuously sweeping. Therefore, D-SPECT is not a truly stationary system. A genuine stationary cardiac SPECT system has been proposed jointly by UC San Francisco and Western Cardiology Associates. Their system is a modified three-detector SPECT system, mounted with three multi- pinhole collimators. They have successfully acquired cardiac SPECT images using this setup. GE has also developed a stationary, multi-pinhole dedicated cardiac SPECT system called Alcyone. Our proposed research is to replace the multi-pinhole collimators with our original-design segmented parallel-hole collimators. In a segmented parallel-hole collimator, the entire detection area is partitioned into many smaller sub-regions. The collimator holes in each segment point to the heart. Our motivation for replacing the pinhole technology by segmented parallel-hole technology is based on the following facts. The resolution/sensitivity trade-off for the pinhole is excellent (good resolution and good sensitivity), but only in small object (e.g., small animal) imaging when it is operating in the image magnifying mode. In large object (e.g., human) imaging when the pinhole is operating in the image-reducing mode or when image and object have the same size, the resolution/sensitivity trade-off is poor (poor resolution and poor sensitivity). In addition, the number of angular views is limited in a stationary system, thus, in order to obtain more view angles, the images cannot be magnified. In this situation, segmented parallel-hole collimation is able to provide better resolution and detection sensitivity than pinhole collimation. The proposed research will carefully study and compare the conventional rotational systems, the multi- pinhole systems, and segmented parallel-hole systems, and will verify our hypothesis: For human cardiac studies, the segmented parallel-hole system will outperform the multi-pinhole systems and the conventional rotational systems in terms of image resolution and detection sensitivity. Patient feasibility studies are also planned. After this research establishes a solid foundation for the segmented parallel-hole system using a common clinical SPECT camera, patient studies, dynamic imaging with temporally consistent projections, and motion correction techniques will be developed under a future R01 grant. PUBLIC HEALTH RELEVANCE: This project develops a stationary cardiac SPECT (single photon emission computed tomography). A cardiac SPECT can detect many heart diseases. This new system is stationary with no moving parts. This makes this system cheaper to build and to maintain. This new system will also have much higher detection sensitivity than the current systems, which will results in much clear images with a shorter imaging time.