QUANTITATION OF THE HUMAN BASAL GANGLIA WITH POSITRON EMISSION TOMOGRAPHY - A PHANTOM STUDY OF THE EFFECT OF CONTRAST AND AXIAL POSITIONING
QUANTITATION OF THE HUMAN BASAL GANGLIA WITH POSITRON EMISSION TOMOGRAPHY - A PHANTOM STUDY OF THE EFFECT OF CONTRAST AND AXIAL POSITIONING
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DOI：
10.1109/42.79480
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发表时间：
1991-06-01
影响因子：
10.6
通讯作者：
VOLKOW, ND
中科院分区：
文献类型：
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作者：
BENDRIEM, B;DEWEY, SL;VOLKOW, ND
用正电子发射计算机进行小结构放射性同位素浓度的精确测量，需要对部分体积效应和散射辐射效应引起的定量损失进行校正。为了评估与人类基底节(BG)测量相关的误差，我们建立了一个单侧BG模型，我们将其插入一个20厘米的圆柱体中。我们的BG模型的恢复系数(RC=测量的活度/真实活度)已经在具有不同背景浓度(对比度)的CTI断层扫描仪(型号931-08/12型)上以及在龙门的不同轴向位置进行了测量。根据BG在门架中的位置和使用的对比度，在4或5个切片上显示BG。RC为0.75，无背景(对比度等于1.0)。当对比度为-0.7时，增加背景中的相对放射性浓度使RC从0.75增加到2.00(BG和lt；背景)。感兴趣区(ROI)的大小和形状对RC也有影响(RC为0.75~0.67，ROI为0.12~1.41 cm2)。这些结果表明，准确的RC校正不仅取决于结构的体积，还取决于其与周围环境的对比以及ROI的选择。他们还证明，对比度越高，BG中的轴向定位PET测量就越敏感。这些数据为我们提供了一些关于像BG这样的小结构的PET测量的可变性的信息，我们提出了一些改进重复性的策略。
The accurate measurement of the concentration of a radioisotope in small structures with PET requires a correction for quantitation loss due to the partial volume effect and the effect of scattered radiation. To evaluate errors associated with measures in the human basal ganglia (BG) we have built a unilateral model of the BG that we have inserted in a 20 cm cylinder. The recovery coefficient (RC = measured activity/true activity) for our BG phantom has been measured on a CTI tomograph (model 931-08/12) with different background concentrations (contrast) and at different axial locations in the gantry. The BG was visualized on 4 or 5 slices depending on its position in the gantry and on the contrast used. The RC was 0.75 with no background (contrast equal to 1.0). Increasing the relative radioactivity concentration in the background increased the RC from 0.75 to 2.00 when the contrast was -0.7 (BG < Background). The RC was also affected by the size and the shape of the region of interest (ROI) used (RC from 0.75 to 0.67 with ROI size from 0.12 to 1.41 cm2). These results show that accurate RC correction depends not only on the volume of the structure but also on its contrast with its surroundings as well as on the selection of the ROI. They also demonstrate that the higher the contrast the more sensitive to axial positioning PET measurements in the BG are. These data provide us with some information about the variability of PET measurements in small structure like the BG and we have proposed some strategies to improve the reproducibility.