血管造影系统噪声等价量子数NEQ和检测量子效率DQE的测试

NEQ and DQE test of two medical imaging systems

我们对我院现有的德国西门子公司NEUOSTARPLUS血管造影系统和北京万东医疗装备股份有限公司CGO -2100C血管造影系统的调制传递函数 (MTF) ,噪声功率谱 (NPS) ,噪声等价量子数 (NEQ )和检测量子效率 (DQE)分别进行了测试。我们发现虽然两系统的MTF相差不多 ,但由于万东系统图像噪声特性较差 ,导致系统NPS增加 。

We compared two angiography systems in our hospital,Siemens NEUOSTAR PLUS and CGO-2100C made by Beijing Wandong Medical Equipment limited Company.We individually test their modulation transfer function(MTF),noise power spectrum(NPS),noise equivalent number of quanta(NEQ)and detective quantum efficiency(DQE).We found that the cut-off frequency of two systems is about3lp/mm,the50%MTF and10%MTF do not have significant difference.But the DQE of Siemens is much higher than that of Wandong,because of the noise characteristic of Wandong is not good,its NPS is high,which results in the decreasing of DEQ.This also shows the importance of using NPS and DQE to evaluate the imaging quality of a system.