摘要
目的:利用CT能谱成像(GSI)技术测定不同浓度含碘溶液在静止及运动状态下的碘含量,分析GSI碘基图像上碘浓度的测量值与真实值之间的关系。方法:采用GE公司标准体模,其内放置有9种不同浓度的碘溶液试管,浓度依次为0.4、0.7、2.0、5.0、10.0、20.0、30.0、50.0和100.0mg/ml。使用能谱CT GSI模式进行扫描,球管旋转一周时间分别为0.6、0.8及1.0s/r。利用碘基图,选择相同层面、相同大小兴趣区,测量在静止及运动状态下(振幅为10mm,频率为15bpm)体模试管内碘含量,采用相关分析及配对t检验分析碘含量的测量值与真实值间的关系。结果:球管转速为0.8及1.0s时,无论是静止还是运动状态下,碘含量的测量值与真实值之间均具有明显的相关性(r=0.999,P<0.001),且两者之间的差异无统计学意义(P>0.05);而球管转速为0.6s/r时,碘浓度测量值与真实值之间仅存在相关性(P<0.001,r=0.999),两者数值之间差异有统计学意义(P<0.05)。结论:能谱CT在球管转速为0.8及1.0s/r时能准确测量不同浓度溶液中的碘含量,即使在运动状态下亦可以用于定量分析,有望成为一种可靠的物质成分分析方法。
Objective：To assess the feasibility of quantification of iodine at static or pulsating status with gemstone spectral imaging（GSI）.Methods：The phantom containing nine test tubes of solution which varied in iodine concentrations（0.4,0.7,2.5,10,20,30,50 and 100mg/ml） underwent GSI examination with spectral CT（Discovery CT750 HD） at static status and pulsating with frequency of 15 bpm（beat per minute）,amplitude of 10mm,at the tube rotation speed of 0.6,0.8 and 1.0s/r,respectively.All data were transferred to GSI viewer to acquire iodine-based images at which the iodine concentrations were measured with the same size of regions of interest at the same level.The relation and discrepancy between measured iodine concentrations and real iodine concentrations were compared by paired t-test and the linear regression.Results：At the tube rotation speed of 0.8 and 1.0s/r,either at static status or pulsating status,the measured concentrations were obviously correlated to the real concentrations（r=0.999,P0.001） without significant difference between these two values（P0.05）.However,at the tube rotation speed of 0.6s/r,there was significantly statistical difference between the measured values and the real values（P0.05） with only linear correlation between the two concentrations（r=0.999,P0.001）.Conclusion：GSI of spectral CT is a reliable method to accurately quantify iodine with bobbing at the tube speed of 0.8 and 1.0s/r.Owing to its accurate quantification of iodine,GSI might be useful to characterize and differentiate tissues and lesions.
出处
《放射学实践》
2012年第3期264-267,共4页
Radiologic Practice
关键词
体层摄影术
X线计算机
能谱成像
定量分析
碘含量
Tomography
X-ray computed
Spectral imaging
Quantitative analysis
Iodine concentration
