3D position estimation using an artificial neural network for a continuous scintillator PET detector
3D position estimation using an artificial neural network for a continuous scintillator PET detector
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DOI：
10.1088/0031-9155/58/5/1375
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发表时间：
2013-03-07
影响因子：
3.5
通讯作者：
Li, D.
中科院分区：
文献类型：
--
作者：
Wang, Y.;Zhu, W.;Li, D.
基于连续晶体的PET探测器具有设计简单、成本低、能量分辨率好、探测效率高等特点。通过单端读出闪烁光，直接三维(3D)位置估计可能是连续晶体探测器的另一个优势。本文提出了利用人工神经网络同时估计入射平面坐标和DOI坐标的方法。探测到闪烁光的光子。利用我们的实验装置，采用‘8+8’简化的信号读出方案，获得了垂直辐照正面和侧面的训练数据，并对平面(x，y)网络和DOI网络进行了训练和评估。测试结果表明，人工神经网络对DOI的估计与平面估计一样有效。这两种估计器的性能是通过分辨率和偏差来表示的。在没有偏差校正的情况下，平面估计器的分辨率平均优于2 mm，DOI估计器的分辨率在整个探测器面积上约为2 mm。在偏差校正的情况下，像我们预期的那样，在用于平面估计的边缘区域或在用于DOI估计的远离读出PMT的块的末端，分辨率变得更差。通过斜射实验数据对神经网络三维定位的综合性能进行了评价。为了显示探测器整个区域的三维定位的综合效果，给出了倾斜照射的二维洪水图像和未进行偏置校正的图像。
Continuous crystal based PET detectors have features of simple design, low cost, good energy resolution and high detection efficiency. Through single-end readout of scintillation light, direct three-dimensional (3D) position estimation could be another advantage that the continuous crystal detector would have. In this paper, we propose to use artificial neural networks to simultaneously estimate the plane coordinate and DOI coordinate of incident. photons with detected scintillation light. Using our experimental setup with an '8 + 8' simplified signal readout scheme, the training data of perpendicular irradiation on the front surface and one side surface are obtained, and the plane (x, y) networks and DOI networks are trained and evaluated. The test results show that the artificial neural network for DOI estimation is as effective as for plane estimation. The performance of both estimators is presented by resolution and bias. Without bias correction, the resolution of the plane estimator is on average better than 2 mm and that of the DOI estimator is about 2 mm over the whole area of the detector. With bias correction, the resolution at the edge area for plane estimation or at the end of the block away from the readout PMT for DOI estimation becomes worse, as we expect. The comprehensive performance of the 3D positioning by a neural network is accessed by the experimental test data of oblique irradiations. To show the combined effect of the 3D positioning over the whole area of the detector, the 2D flood images of oblique irradiation are presented with and without bias correction.