Rusinek H, Reich T, Youdin M, Clagnaz M, Kolwicz R
J Nucl Med. 1980 Aug;21(8):777-82.
A new stationary 200-element ultrapure germanium (HPGe) array has been tested for accuracy and sensitivity in quantitating the distributed concentration of single-gamma-emitting radionuclides in phantoms approximating the size of the human brain. The phantoms consisted of 42 blocks of 39.1 cm3 average volume. Fourteen different permutations were studied. The concentrations in the blocks varied from 0i to 4.64 muCi/cm3. This first-generation instrument makes it possible to reconstruct the distributed concentration with a mean relative error of 8.3% at 200,000 counts per sample (1,000 counts/detector), and has sensitivities of 6,200 and 12,000 cps, respectively, for 1 muCi/cm3 of Xe-133 and Tc-99. The reconstruction algorithm is based on the conjugate gradient method of solving the set of linear equations that account for geometric, attenuation, and scatter factors. The results have implications for measuring the distribution of the partition coefficients, blood flow, blood volume, and concentration of tracers emitting single gamma photons in 42 anatomic subvolumes (30 cm3 average) of the entire brain simultaneously.
一种新型的固定 200 元素高纯锗（HPGe）阵列已针对在模拟人脑大小的体模中定量单伽马发射放射性核素的分布浓度的准确性和灵敏度进行了测试。这些体模由 42 个平均体积为 39.1 cm³ 的模块组成。研究了 14 种不同的排列。模块中的浓度范围从 0 到 4.64 μCi/cm³。这台第一代仪器能够以每个样本 200,000 次计数（每个探测器 1,000 次计数）时 8.3% 的平均相对误差重建分布浓度，对于 1 μCi/cm³ 的 Xe - 133 和 Tc - 99，灵敏度分别为 6,200 和 12,000 cps。重建算法基于求解考虑几何、衰减和散射因素的线性方程组的共轭梯度法。这些结果对于同时测量整个大脑 42 个解剖子体积（平均 30 cm³）中示踪剂的分配系数、血流量、血容量以及发射单伽马光子的浓度分布具有重要意义。
