SPECT平面显像中不同矩阵与距离下影像分析

Analysis of SPECT planar imaging in different matrixes and distances

目的:研究SPECT平面显像中不同矩阵与距离下图像质量影响。方法:依据标准制作甲状腺模型与双点源模型,对不同距离、矩阵采集数据做分析。结果:对相同距离下128×128、256×256、512×512矩阵60s采集计数做两两比较q检验,30mm、50mm、100mm、150mm、200mm处的q值分别为0.80、0.82、0.76;0.79、0.83、0.85;0.80、0.82、0.83;0.82、0.83、0.85;0.83、0.85、0.89,以上均P<0.01,尚不能认为相同距离时不同矩阵的采集计数有差别。在空气介质中一定距离下矩阵128×128、256×256、512×512的径向半高宽(mm)为12.53±2.26、10.87±0.80、7.06±1.80。高矩阵、点源与探头距离近的图像可调节的宽容度大。结论:在相同距离、相同时间下不同采集矩阵的总采集计数没有差别。随着矩阵的每次上升,灵敏度不会下降,系统分辨率略有上升。平面显现中通过简单的函数滤波,可使图像表现的更完美。

Objective：To explore the differences of SPECT planar imaging quality in different matrixes and distances. Methods：Making model of the thyroid and the two-point source and then analyzing SPECT planar imaging in different matrixes and distances. Results： The data of counts collected by 128 × 128,256 × 256,512 × 512 matrix for 60 seconds in 30 mm, 50 mm, 100 mm, 150 mm, 200 mm were analyzed by q test （ 0.80,0.82,0.76, P0.01; 0.79,0.83,0.85, P0.01; 0.80,0.82,0.83, P0.01; 0.82,0.83,0.85, P0.01; 0.83,0.85,0.89, P0.01 ）. Still can’t say that there were significant. The FWHM （mm） with 128×128, 256×256, 512×512 matrix were respectively 12.18±2.26, 10.98±0.80, 9.58±1.80 in a certain distance in the air medium. Image adjustable range was large when matrixes are high and the point source closes to the probe. Conclusion：There is no significant differences among the total collected counts in different matrixes. With each increase in the matrix, the sensitivity will not decrease and the system resolution will increase slightly with the increase of matrixes. Planar imaging will become more perfect through simple function filtering.