Quantification of radiotracer uptake with a dedicated breast PET imaging system
Quantification of radiotracer uptake with a dedicated breast PET imaging system
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DOI：
10.1118/1.2990781
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发表时间：
2008-11-01
期刊：
影响因子：
3.8
通讯作者：
Majewski, Stan
中科院分区：
文献类型：
--
作者：
Raylman, Raymond R.;Smith, Mark F.;Majewski, Stan
乳腺断层成像技术可用于量化乳腺和肿瘤组织中的放射性示踪剂摄取。然而，PET成像常见的物理过程可能会混淆准确的定量。在这项研究中，我们评估了这些现象的影响，并测试了我们的新的正电子发射乳腺X射线摄影-断层扫描系统（PEM-PET）的校正方案。PEM-PET扫描仪使用两组旋转平面探测器头。每个单元由一个4x 3阵列的Hamamatsu H8500平板位置敏感光电倍增管组成，该光电倍增管与一个96 x72阵列的2x2 x15 mm（3）LYSO检测器元件（间距=2.1 mm）耦合。图像重建与3D-OSEM算法并行运行在多处理器计算机系统上进行。重建的视野为15 x15 x15 cm（3）。大部分测试程序基于NEMA-NU 2/2001方案。测量了由于脉冲堆积引起的计数率损失、由于接受随机符合和康普顿散射引起的图像污染以及由光子衰减产生的图像伪影。结果发现，由于事件触发电子器件的当前设计，当扫描仪中存在中等水平的辐射时，系统易受计数率损失的影响。康普顿散射，光子衰减和死时间的校正的应用导致在简化的幻影研究中的（18）F浓度的估计得到改善。这些初步研究的结果表明，PEM-PET扫描仪将用于定量乳腺肿瘤中的放射性示踪剂摄取，可能有助于癌症治疗的早期评估。(C)2008年美国医学物理学家协会。[DOI 10.1118/1.2990781]
Tomographic breast imaging techniques can be used to quantify radiotracer uptake in breast and tumor tissue. However, physical processes common to PET imaging can confound accurate quantification. In this investigation, we assessed the effects of these phenomena and tested correction schemes for our new positron emission mammography-tomography system (PEM-PET). The PEM-PET scanner utilizes two sets of rotating planar detector heads. Each unit consists of a 4x3 array of Hamamatsu H8500 flat panel position sensitive photomultipliers coupled to a 96x72 array of 2x2x15 mm(3) LYSO detector elements (pitch=2.1 mm). Image reconstruction is performed with a 3D-OSEM algorithm parallelized to run on a multiprocessor computer system. The reconstructed field-of-view is 15x15x15 cm(3). Much of the testing procedures were based on NEMA-NU2/2001 protocols. Count rate losses due to pulse pile-up, image contamination due to acceptance of random coincidences and Compton scatter, and image artifacts produced by photon attenuation were measured. It was found that the system was susceptible to count rate losses when moderate levels of radiation were present in the scanner due to the current design of the event trigger electronics. Application of corrections for Compton scattering, photon attenuation and dead time resulted in improved estimations of (18)F concentration in simplified phantom studies. Results from these preliminary studies indicate that the PEM-PET scanner will be useful for the quantification of radiotracer uptake in breast tumors, possibly facilitating early assessment of cancer treatments. (C) 2008 American Association of Physicists in Medicine. [DOI: 10.1118/1.2990781]