Activity quantitation in SPECT: a study of prereconstruction Metz filtering and use of the scatter degradation factor.
Activity quantitation in SPECT: a study of prereconstruction Metz filtering and use of the scatter degradation factor.
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SPECT 中的活性定量：重建前 Metz 过滤和散射降解因子使用的研究。
DOI：
10.1118/1.596705
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发表时间：
1991
期刊：
影响因子：
3.8
通讯作者：
Glick,SJ
中科院分区：
文献类型：
--
作者：
King,MA;Coleman,M;Penney,BC;Glick,SJ
研究了用结构前Metz滤波和散射退化因子(SDF)对散射进行数值校正的活性定量方法。用30×23 cm水盆体模内的源位置的单位活度计数率与空气中摄取的已知活度的Tc-99m点源的单位活度计数率之比来判断活度测定的准确性。调查是在浴缸内的某些位置进行的，当浴缸中均匀地充满了Tc-99m活度时，以及在5、4、3和2厘米直径的中心的相同位置，在冷背景下成像的热球。震源位置是中心，以及长轴的四分之一、一半和四分之三。研究了将共轭视图与重构前衰减校正(算术和几何平均)相结合的各种方法，以及在滚动之前梅兹过滤器跟随逆过滤器以抑制噪声的程度。在没有梅兹滤波的情况下，使用包含累积的透射率曲线进行衰减校正。通过Metz滤波，使用良好的几何衰减系数，并通过计算平均身体厚度的SDF来缩放组合视图。根据球体的大小和遵循逆滤波的程度，Metz滤波和SDF的使用相结合提高了活动定量的准确性。
A study of activity quantitation with prereconstruction Metz filtering and use of the scatter degradation factor (SDF) to numerically correct for scatter was conducted. The ratio of the count rate per unit activity for source locations within a 30×23‐cm water‐filled tub phantom to the count rate per unit activity for Tc‐99m point sources of known activity imaged in air was used to judge the accuracy of activity determination. The investigation was conducted for certain locations within the tub when it was uniformly filled with Tc‐99m activity, and for the same locations at the center of 5, 4, 3, and 2‐cm diam, hot spheres imaged in a cold background. The source locations were the center, and one‐fourth, one‐half, and three‐fourths the major axis. Various methods of combining the conjugate views for use with prereconstruction attenuation correction (arithmetic and geometric mean), and extent to which the Metz filter followed the inverse filter before rolling off to suppress noise were investigated. Without Metz filtering, attenuation correction was performed using a transmission curve that included buildup. With Metz filtering, the good‐geometry attenuation coefficient was used and the combined views were scaled by the SDF calculated for the average body thickness. Depending on the size of the sphere and the extent to which the inverse filter was followed, Metz filtering combined with use of the SDF improved the accuracy of activity quantitation.