Effect of Truncation in Quantitative Cardiac Imaging with Small Field-of-View Pinhole SPECT
Effect of Truncation in Quantitative Cardiac Imaging with Small Field-of-View Pinhole SPECT
复制标题
小视场针孔 SPECT 定量心脏成像中截断的影响
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
H. Iida
中科院分区：
文献类型：
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作者：
T. Zeniya;H. Watabe;A. Sohlberg;T. Inomata;H. Kudo;H. Iida
针孔SPECT可以以高空间分辨率成像小动物的生理功能。在分辨率较高的心脏成像中，可以通过将准直器放置在靠近对象的位置来提高分辨率，但由于周围器官中的放射性同位素而导致截断。本研究旨在通过计算机模拟来评估截断在小视野针孔SPECT心脏定量成像中的效果。假设一只大鼠，一个数字体模由直径10 mm、高度10 mm的圆柱体和直径36 mm、高度70 mm的圆柱体组成，作为心脏区域和周围区域(背景)。心脏区域计数为10个，背景计数为1个、2个、4个或8个。在该仿真中，重建视场被定义为直径30 mm的球体。采用针孔3D-OSEM算法重建截断后的投影数据。将重建图像与原始图像的计数结果进行比较。背景计数为1、2、4和8时，重建图像心脏区域的计数分别被高估了14.5%、17.6%、20.5%和23.2%。这些结果表明，在针孔SPECT心脏定量成像中需要考虑截断的影响。
Pinhole SPECT allows to image physiological functions in small animals with high spatial resolution. In case of cardiac imaging with higher resolution, the resolution can be improved by positioning a collimator close to an object, but truncation arises from radioisotope in the surrounding organs. This study was intended to evaluate the effect of truncation in quantitative cardiac imaging with small field-of-view pinhole SPECT by a computer simulation. Assuming a rat, a numerical phantom consists of cylinder with 10-mm diameter and 10-mm height, and cylinder with 36-mm diameter and 70-mm height as the cardiac region and the surrounding region (Background). The counts of the cardiac region and the background were 10 and 1, 2, 4 or 8, respectively. In this simulation, the field-of-view of reconstruction was defined as a sphere with 30-mm diameter. The projection data with truncation were reconstructed using pinhole 3D-OSEM algorithm. The counts on the reconstructed images were compared with that on original image. The counts on the cardiac regions in reconstructed images were overestimated 14.5%, 17.6%, 20.5% and 23.2% for the background counts of 1, 2, 4 and 8, respectively. These results suggest that the effect of truncation needs to be considered in quantitative cardiac imaging with pinhole SPECT.