BREAST CANCER IMAGING USING NONPARALLEL BEAM SPECT

描述（改编自申请人的摘要）：本发明的长期目标是： 研究项目是开发新的单光子发射计算 用于改进成像和表征的断层摄影（SPECT）系统设计 Tc-99 m放射性药物摄取在早期乳腺癌中的作用。 的 正在考虑的概念有多个可倾斜的相机，配备有 会聚光束或针孔准直器，围绕单个乳房旋转， 患者处于俯卧位，与相机的垂直方向对齐， 旋转轴（VAOR）。 主要假设是多摄像机VAOR 具有会聚束准直器的SPECT系统可以改善病变 与平面放射性乳腺成像相比， SPECT（即，需要大半径的水平轴旋转装置 旋转）。 此外，假设VAOR SPECT在用于 结合图像重建算法， 衰减，检测到的康普顿散射事件和准直器分辨率，是 能够检测直径小于8 mm的小乳腺癌， 肿瘤与背景活性浓度比小于6：1。 与传统的SPECT系统相比， 建议的设计是：i）通过包括一个乳房的最小旋转半径 ii）改进的系统灵敏度和分辨率 由于使用多个照相机和会聚光束或针孔 专门设计用于乳房成像的准直器，iii）减少的衰减 对于从乳房发射的光子，iv）较少覆盖和下层 如果存在心肌，则在摄像机的视野中的躯干活动 使用成像药物，以及v）可倾斜的相机提供了 扩展成像区域以包括近胸壁组织的灵活性 几乎不受摄像机的干扰 我们建议调查这些 假设通过评估备选系统配置， 首选系统配置的重建算法，评估 通过传导接收器操作特性的损伤检测能力 研究，并将VAOR SPECT与平面闪烁乳腺成像进行比较， 常规水平轴旋转SPECT。 具体目标是 建议是：i）设计VAOR采集系统配置， 乳腺癌成像，ii）开发新的图像重建算法 对于选定的配置，以及iii）评估选定的配置，以及 图像重建算法 虽然建立一个VAOR SPECT系统是 超出本初步提案的范围，临床适用性将 使用具有可倾斜的水平旋转轴SPECT设备进行演示 探测器作为初始VAOR可行性扫描的测试设施。

DESCRIPTION (Adapted from Applicant's Abstract): The long term goal of this research project is to develop new single photon emission computed tomography (SPECT) system designs for improved imaging and characterization of Tc-99m radiopharmaceutical uptake in early-stage breast cancer. The concepts being considered have multiple tiltable cameras, equipped with convergent beam or pinhole collimators, revolving around a single breast, with the patient in a prone position, aligned with the camera's vertical axis of rotation (VAOR). The main hypothesis is that a multiple-camera VAOR SPECT system with convergent beam collimators can improve lesion detectability over planar scintimammography, as well as over conventional SPECT (i.e., horizontal axis of rotation devices requiring a large radius of rotation). Also, it is hypothesized that VAOR SPECT, when used in conjunction with image reconstruction algorithms which compensate for attenuation, detected Compton scatter events and collimator resolution, is capable of detecting small breast cancers less than 8 mm in diameter and with a tumor-to-background activity concentration ratio less than 6 to 1. Compared with conventional SPECT systems, the primary advantages of the proposed design are: i) minimal radius of rotation by including one breast alone in the field-of-view, ii) improved system sensitivity and resolution due to the use of multiple cameras and convergent beam or pinhole collimators specially designed for breast imaging, iii) reduced attenuation for the photons emitted from the breast, iv) less overlying and underlying torso activities in the camera's field-of-view if existing myocardial imaging pharmaceuticals are used, and v) tiltable cameras provide a flexibility to extend the imaged region to include near-chest-wall tissue with little camera-patient interference. We propose to investigate these hypotheses by evaluating alternative system configurations, deriving reconstruction algorithms for preferred system configurations, evaluating lesion detectability by conducting receiver operating characteristics studies, and comparing VAOR SPECT with planar scintimammography and conventional horizontal axis of rotation SPECT. The specific aims of this proposal are: i) designing VAOR acquisition system configurations for breast cancer imaging, ii) developing new image reconstruction algorithms for selected configurations, and iii) evaluating selected configurations and image reconstruction algorithms. Although building a VAOR SPECT system is beyond the scope of this initial proposal, clinical applicability will be demonstrated using a horizontal axis of rotation SPECT device with tiltable detectors to serve as a test facility for initial VAOR feasibility scans.