Developing a low-radiation-dose high-image-quality intelligent contrast-enhanced CT system in the era of multidetector-row CT

我国每个公民的辐射照射量约为世界平均水平的3.7倍。减少CT中的辐射暴露是迫切的问题，并且已经报道了低管电压CT的有用性。然而，放射线剂量的减少往往会导致图像噪声增加和对比度降低，从而导致图像质量劣化，并且已经开发了降噪滤波器来进行补偿。另一方面，过敏反应或肾功能不全等副作用与碘给药有关，但500 mg/kg -750 mg/kg左右的碘量与这些不良事件之间没有明显关系。我们用600 mg/kg的碘负荷进行了上腹部CT检查，但认为521 mg/kg的剂量足以进行对比增强。基于这样的背景，我们尝试在我院的两台CT上开发多对比期团注跟踪技术。我还开发了一个程序，使成像在对比度增强峰值的器官，同时设置ROI的主动脉，胰腺和肝实质。在此基础上，根据患者的体型，优化CT检查，降低辐射剂量，优化最佳对比时相。我们还尝试将该系统连接到智能造影剂注射器。我们在2012年北美放射学会上展示了这些结果。

The radiation exposure per a citizen in our country leads to approximately 3.7 times of the world average. Reduction of radiation exposure in CT is urgent issue, and the usefulness of low tube voltage CT has been reported. However, the reduction of radiation dose often leads to image quality deterioration by increased image noise and the contrast decrease, and the noise reduction filter has been developed for the compensation. On the other hand, side effects such as anaphylaxis or renal dysfunction related to iodine administration, but there is not evident relation between the iodine amount of 500 mg/kg - around 750 mg/kg and such adverse events. We have conducted upper abdominal CT examinations with the iodine load of 600 mg/kg, but it is believed that the dose of 521 mg/kg is sufficient for the contrast enhancement. Based on such backgrounds,we attempted to develop bolus-tracking techniques for multiple- contrast phase using two CT s in ourhospital. I also developed a program to enable the imaging at the contrast enhancement peak of organs while setting ROIs to the aorta, pancreas, and liver parenchyma. Based on the research data,we optimized the CT examinations adjusting with body habitus of patients, decreasing radiation dose, optimizing the most effective contrast phase. We also attempted to connect the system to theintelligent contrast injector. We present these results at Radiological Society of North America in2012.