DESIGN STUDIES FOR A PET DETECTOR MODULE USING A PIN PHOTODIODE TO MEASURE DEPTH OF INTERACTION
DESIGN STUDIES FOR A PET DETECTOR MODULE USING A PIN PHOTODIODE TO MEASURE DEPTH OF INTERACTION
复制标题
DOI：
10.1109/23.322929
复制
发表时间：
1994-08-01
影响因子：
1.8
通讯作者：
DERENZO, SE
中科院分区：
文献类型：
--
作者：
MOSES, WW;DERENZO, SE
我们目前的设计研究的多层PET探测器模块，使用一个8 × 8阵列的3毫米平方PIN光电二极管，以确定相互作用的晶体和测量相互作用的深度。 每个光电二极管耦合到3 × 3 × 30 mm BGO晶体的一端，64个这种晶体的相对端连接到单个1“正方形光电倍增管，该光电倍增管提供定时信号和能量鉴别。 每个BGO晶体涂覆有损耗反射器，因此在光电二极管和光电倍增管中检测到的光的比率取决于晶体中的相互作用深度，并且用于基于逐个事件来确定该相互作用深度。具有一个3x 3x 30 mm BGO晶体、一个3 mm正方形PIN光电二极管、一个光电倍增管在-20 ℃下工作，放大器峰值时间为4 μ s，测量的相互作用深度分辨率为5 - 8 mm fwhm。 模拟预测，这实际上消除了60厘米直径的BGO断层摄影径向伸长。 对应于511 keV能量存款的光电二极管信号随激发位置线性变化，范围从最靠近光电二极管的一端的1250电子（e-）到相对端的520电子。 电子噪声是位置无关的330 e-fwhm，因此信噪比足以可靠地识别64元件模块中的相互作用晶体。
We present design studies of a multi-layer PET detector module that uses an 8x8 array of 3 mm square PIN photodiodes to both identify the crystal of interaction and measure the depth of interaction. Each photodiode is coupled to one end of a 3x3x30 mm BGO crystal, with the opposite ends of 64 such crystals attached to a single 1'' square photomultiplier tube that provides a timing signal and energy discrimination. Each BGO crystal is coated with a lossy reflector, so the ratio of light detected in the photodiode and photomultiplier tube depends on the interaction depth in the crystal, and is used to determine this depth of interaction on an event by event basis.A test module with one 3x3x30 mm BGO crystal, one 3 mm square PIN photodiode, and one photomultiplier tube is operated at -20-degrees-C with an amplifier peaking time of 4 mus, and a depth of interaction resolution of 5 to 8 mm fwhm measured. Simulations predict that this virtually eliminates radial elongation in a 60 cm diameter BGO tomograph. The photodiode signal corresponding to 511 keV energy deposit varies linearly with excitation position, ranging from 1250 electrons (e-) at the end closest to the photodiode to 520 e- at the opposite end. The electronic noise is a position independent 330 e- fwhm, so the signal to noise ratio is sufficient to reliably identify the crystal of interaction in a 64 element module.