POSITRON EMISSION MAMMOGRAPHY SCANNER

正在开发一种正电子发射乳房X光照相(PEM)仪器，以 作为诊断和规划的临床和研究工具 乳腺癌治疗的最新进展。PEM专用仪器是 在标准的x射线乳房X光照相装置中通过定位两个 伽马相机，一个在上面，一个在压缩的乳房下面。这个 患者接受放射性示踪剂氟代脱氧葡萄糖(FDG)治疗。 众所周知，FDG集中在乳腺肿瘤中，因此使它们 可在正电子发射断层扫描(PET)系统中检测到。FDG发射 伽马射线，由伽马相机探测到。每个摄像头都有 连接到事件重合电路的最后一个动态节点输出 扳机。来自每个摄像机的数据被分析并存储在存储器中。 实时获取并显示分布的图像。 系统参数包括：(1)实时成像能力，因此 在30秒内可以看到1厘米的热点；(2)分辨率 体模中直径1厘米的热点，所以热 点与背景的比例为8：1或更高；以及(3)高 单人速率在100 kHz范围内，最小间隔为 脉冲，以避免重叠，范围在1.0秒到1.5秒之间。这个 仪器开发包括设计和制造 探测器、信号处理和数据采集电子设备，以及 用于采集、显示和存储事件的实时编程。

A positron emission mammography (PEM) instrument is being developed to be used as a clinical and research tool for the diagnosis and planning of treatment for breast cancer. Dedicated instrumentation for PEM was implemented in a standard x-ray mammography unit by positioning two gamma cameras, one above and one below a compressed breast. The radiotracer fluorodeoxyglucose (FDG) is administered to the patient. FDG is known to concentrate in breast tumors, thus making them detectable in positron emission tomagraphy (PET) systems. FDG emits gamma rays, which are detected by the gamma cameras. Each camera has a last-dynode output connected to a coincident circuit for event trigger. The data from each camera is analyzed and placed in memory. Images of the distribution are obtained in real time and displayed. The system parameters include: (1) real-time image capability, so that a 1-cm hot spot can be seen within 30 seconds; (2) resolution of a 1-cm-diameter hot spot in a phantom, so that a hot spot-to-background ratio will be 8:1 or greater; and (3) a high singles rate in the range of 100 KHz with a minimum separation of pulses, to avoid overlap, in the 1.0- to 1.5-sec range. The instrument development includes the design and fabrication of the detectors, signal-processing and data-acquisition electronics, and real-time programming for acquisition, display, and storage of events.