Center for Advanced Imaging, Department of Radiology, 1 Medical Center Dr., West Virginia University, Morgantown, WV, 26506, USA.
Xoran Technologies Inc., 5210 S State Rd., Ann Arbor, MI, 48108, USA.
Med Phys. 2018 Apr;45(4):1603-1613. doi: 10.1002/mp.12780. Epub 2018 Feb 23.
Application of advanced imaging techniques, such as PET and x ray CT, can potentially improve detection of breast cancer. Unfortunately, both modalities have challenges in the detection of some lesions. The combination of the two techniques, however, could potentially lead to an overall improvement in diagnostic breast imaging. The purpose of this investigation is to test the basic performance of a new dedicated breast-PET/CT.
The PET component consists of a rotating pair of detectors. Its performance was evaluated using the NEMA NU4-2008 protocols. The CT component utilizes a pulsed x ray source and flat panel detector mounted on the same gantry as the PET scanner. Its performance was assessed using specialized phantoms. The radiation dose to a breast during CT imaging was explored by the measurement of free-in-air kerma and air kerma measured at the center of a 16 cm-diameter PMMA cylinder. Finally, the combined capabilities of the system were demonstrated by imaging of a micro-hot-rod phantom.
Overall, performance of the PET component is comparable to many pre-clinical and other dedicated breast-PET scanners. Its spatial resolution is 2.2 mm, 5 mm from the center of the scanner using images created with the single-sliced-filtered-backprojection algorithm. Peak NECR is 24.6 kcps; peak sensitivity is 1.36%; the scatter fraction is 27%. Spatial resolution of the CT scanner is 1.1 lp/mm at 10% MTF. The free-in-air kerma is 2.33 mGy, while the PMMA-air kerma is 1.24 mGy. Finally, combined imaging of a micro-hot-rod phantom illustrated the potential utility of the dual-modality images produced by the system.
The basic performance characteristics of a new dedicated breast-PET/CT scanner are good, demonstrating that its performance is similar to current dedicated PET and CT scanners. The potential value of this system is the capability to produce combined duality-modality images that could improve detection of breast disease. The next stage in development of this system is testing with more advanced phantoms and human subjects.
应用先进的成像技术，如 PET 和 X 射线 CT，有可能提高乳腺癌的检测能力。不幸的是，这两种方式在检测某些病变方面都存在挑战。然而，这两种技术的结合可能会导致诊断性乳房成像的整体改善。本研究的目的是测试一种新型专用乳腺 PET/CT 的基本性能。
PET 组件由一对旋转探测器组成。其性能使用 NEMA NU4-2008 协议进行评估。CT 组件利用安装在与 PET 扫描仪相同的龙门架上的脉冲 X 射线源和平板探测器。其性能使用专门的体模进行评估。通过测量自由空气中的比释动能和在 16cm 直径 PMMA 圆柱体中心测量的空气比释动能，研究了 CT 成像过程中乳房的辐射剂量。最后，通过微热棒体模成像展示了系统的综合能力。
总的来说，PET 组件的性能与许多临床前和其他专用乳腺 PET 扫描仪相当。其空间分辨率为 2.2mm，使用单切片滤波反投影算法生成的图像，距离扫描仪中心 5mm 处的分辨率为 2.2mm。最大计数率为 24.6kcps；最大灵敏度为 1.36%；散射分数为 27%。CT 扫描仪的空间分辨率在 10% MTF 时为 1.1lp/mm。自由空气中的比释动能为 2.33mGy，而 PMMA-空气比释动能为 1.24mGy。最后，通过对微热棒体模的联合成像，说明了该系统产生的双模态图像的潜在应用价值。
新型专用乳腺 PET/CT 扫描仪的基本性能良好，表明其性能与当前的专用 PET 和 CT 扫描仪相似。该系统的潜在价值在于能够生成联合双模态图像，从而提高对乳腺疾病的检测能力。该系统的下一阶段开发是使用更先进的体模和人体进行测试。
