Breast Cancer Imaging Using Non-Parallel Beam SPECT

描述(申请人提供)：该项目的长期目标是开发和评估新的单光子发射计算机断层扫描(SPECT)成像配置，以改善早期乳腺癌放射性药物摄取的特征和量化。这些配置包括：i)配备针孔(Pinh)或会聚光束(CVB)准直器的传统大视场(FOV)相机和ii)配备Pinh准直、CVB或组合Pinh(或CVB)和倾斜平行光束准直的新型中型FOV可倾斜相机。这些相机围绕着位于下垂的俯卧乳房内的旋转中心旋转。该项目的主要假设是，早期乳腺癌期间小肿瘤(直径8毫米，摄取6：1)的放射性药物摄取的特征和量化可以通过结合以下各项来实现：i)利用现有的和/或新的核医学SPECT照相机的适当的三维(3D)轨道构型；ii)Pinh、CVB或组合准直器配置；以及iii)改进的重建算法。这项提案的目的不是评估目前用于乳腺癌成像的现有放射性药物的性能，也不是开发一种SPECT系统来执行乳腺癌检测的常规筛查。拟议设计的优点包括：i)通过在大型FOV相机和/或紧凑型相机上使用Pinh准直器，使旋转半径最小；ii)由于可能使用多个特别设计的相机和准直器，提高了系统的灵敏度和分辨率；iii)减少了专用乳房成像轨道造成的光子衰减；以及iv)可倾斜相机，将成像区域扩展到包括乳房的腋下尾巴。根据第一个项目期的结果，5-8年的下一个项目期包括以下具体目标：i)使用现有的临床SPECT系统用于专用乳腺肿瘤成像，研究Pinh和倾斜垂直旋转轴CVB准直器配置；ii)开发和评估新的3D Pinh和CVB轨道，充分采样或几乎充分采样乳房，包括其腋下尾巴；三)与杰斐逊实验室(JLab)合作开发专用SPECT乳腺成像相机，该相机可执行倾斜相机、3D PINH和CVB轨道，并作为获取PINH(或可能是CB)/PARH SPECT联合投影数据的测试机架。在最初项目期间开发的迭代重建程序将得到增强，以包括对Pinh和锥束CVB准直器的空间变化分辨率进行建模。

DESCRIPTION (provided by applicant): The long-term goal of this project is to develop and evaluate new single photon emission computed tomography (SPECT) imaging configurations for improved characterization and quantification of radiopharmaceutical uptake in early-stage breast cancer. The configurations include: i)conventional, large field of view (FOV) cameras equipped with either pinhole (PinH) or convergent beam (CvB) collimators and ii) novel, medium FOV tiltable cameras, equipped with either PinH collimation, CvB, or combined PinH (or CvB) and tilted-parallel beam collimation. These cameras revolve around a center of rotation located within a pendulous, prone-dependent breast. The main hypothesis of this project is that characterization and quantification of radiopharmaceutical uptake in small tumors (<8 mm dia., 6:1 uptake) during early-stage breast cancer can be achieved by combining: i) appropriate three-dimensional (3D) orbital configurations utilizing available and/or novel nuclear medicine SPECT cameras; ii) PinH, CvB or combined collimator configurations; and iii) improved reconstruction algorithms. It is not a goal of this proposal to evaluate the performance of currently available radiopharmaceuticals used for breast cancer imaging, nor is it a goal to develop a SPECT system to perform routine screening for breast tumor detection. Advantages of the proposed designs include: i) minimal radius of rotation by using PinH collimators on large FOV cameras and/or compact cameras; ii) improved system sensitivity and resolution due to the potential use of multiple specially designed cameras and collimators; iii) reduced photon attenuation due to dedicated breast imaging orbits; and iv) tiltable cameras to extend the imaged region to include the axillary tail of the breast. Guided by the results of the first project period, the next project period in Years 5 - 8 includes the following Specific Aims: i)Investigate PinH and tilted vertical-axis-of-rotation CvB collimator configurations using available clinical SPECT systems for dedicated breast-tumor imaging; ii) Develop and evaluate novel 3D PinH and CvB orbits that sufficiently sample, or nearly sufficiently sample, the breast, including its axillary tail; iii) Develop, in collaboration with Jefferson Laboratory (JLab), a dedicated SPECT breast-imaging camera that performs tilted-camera, 3D PinH and CvB orbits and serves as a test-gantry for acquisition of combined PinH (or possibly CB)/ParH SPECT projection data. The iterative reconstruction programs developed during the initial project period will be enhanced to include modeling spatially varying resolution of PinH and cone beam CvB collimators.