影响SUV值可控因素的比较研究

The Comparative Study of Controllable Factors influencing SUV of PET Imaging

目的：探讨影响标准吸收值（ＳＵＶ）的可控因素，以提高ＳＵＶ的准确性，材料与方法：ＰＥＴ照相机和质控模型，改变感兴趣区（ＲＯＩ）的大小，使用不同的滤波函数和截止频率，计算出各种条件下的ＳＵＶ与标准ＳＵＶ的比值。结果：扩大 ＲＯＩ明显降低 ＳＵＶ，缩小 ＲＯＩ区 ３～４个象元（ｐｉｘｅｌ），其 ＳＵＶ相对趋于稳定。不同滤波函数、不同截止频率对 ＳＵＶ影响很大，尤其是小病变更明显。结论：设置ＲＯＩ应略小于实际病变３－４个ｐｉｘｅｌ，以避开边缘部位的影响。各项检查要固定滤波函数和截止频率，保证ＳＵＶ结果的可比性。

Purpose: The comparative study was conducted on several controllable factors which influence SUV in order to appreciate the parameter correctly. Materials and methods: Siemens ECAT EXACT HR^+ PET camera and quality control phantom was used. The ratio was calculated between SUV determined at basic experimental setting and that after changing the size of ROI or using different filter and cutoff frequency. Results: There was a negative correlation between ROI size and SUV. The SUV tends to be stable if the ROI was set 3 -4 pixels smaller than the volume of target on reconstructed images. different filter and cutoff frequency will vary the SUV, especially on small lesion. Conclusion: The setup of ROI should be less by 3-4 pixels than the object, so as to avoid the influence of margin effect. The filter and cutoff frequency are better to be fixed on every study in order to warrant the comparability of SUV.