宝石CT能谱成像140keV单能图结合水基图检查肝脏

140 keV monochromatic energy images combined with water-based images in gemstone spectral imaging of liver

目的探讨宝石CT能谱成像(GSI)140keV单能图结合水基图扫查肝脏的价值。方法对45例接受肝脏平扫和增强扫描CT患者,在完成常规平扫及三期增强扫描后,采用肝脏能谱后处理分析软件生成140keV单能图和水基图;比较平扫图像、140keV单能图和水基图对肝内病灶的显示情况,对比分析平扫图像与140keV单能图中肝脏、肌肉的CT值、SNR以及单期和总容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)。结果在显示病灶方面,140keV单能图、水基图与平扫图像无明显差异;肝脏CT值140keV单能图略高于平扫图像,而SNR 140keV单能图低于平扫图像(P均<0.05);140keV单能图和水基图的总CTDIvol和DLP均低于平扫图像(P均<0.05)。结论 GSI肝脏三期增强扫描中,利用140keV单能图结合水基图有可能取代平扫图像,以利于降低辐射剂量。

Objective To explore the clinical value of 140 keV monochromatic energy images combined with water-based images in gemstone spectral imaging （GSI） of liver. Methods 140 keV monochromatic energy images and water-based images were obtained in 45 patients underwent liver CT scan after conventional plain, arterial, portal and equilibrium phase enhanced scan. The visualization and display of lesions in plain images, 140 keV monochromatic energy images and water- based images were compared. CT values of liver and muscle, image SNR as well as volumetric CT dose index （CTDIvol） and dose length product （DLP） were compared among 140 keV monochromatic energy images, water-based images and plain CT images. Results There was no significant difference of lesions display among 140 keV monochromatic energy im- ages or water-based images and conventional plain images, while CT value in 140 keV monochromatic energy images was higher and SNR was lower than those in plain images （both P〈0. 05）. In 140 keV monochromatic energy imaging and water-based imaging, the total CTDIvol and DLP were lower than those in plain scanning （both P〈0.05）. Conclusion For three-phase liver scanning using GSI, 140 keV monochromatic energy imaging combined with water-based imaging may replace the conventional plain scanning, being helpful to decrease radiation dose in clinical application.