CT扫描参数对人体组织CT值影响的研究

目的 探索不同CT扫描参数对人体同一种组织CT值的影响。方法 通过在同一台CT机上,分别改变其中1个扫描参数,如X线管电压、毫安秒和重建函数等,而保持其他扫描参数不变,多次扫描标准体模,测量和分析体模中不同物质的CT值。结果 X线管电压的改变对物质的CT值影响具有显著意义。聚乙烯、聚碳酸酯、有机玻璃的CT值与管电压成正相关;聚四氟乙烯的CT值与管电压成负相关。毫安秒和重建函数对CT值的影响差异无统计学意义。结论 同一个人体组织在不同的X线管电压条件下CT值是变化的。因此,在临床影像诊断和放疗中应该考虑图像扫描参数的设置对诊断和治疗结果的影响。

Effect of CT scanning parameters on CT number

Objective To study the effects on tissue CT number caused by scan protocols. Methods The phantom was repeatedly scanned in different protocols by changing only one of parameters, such as X-ray tube voltage,mAs and recon kernel, while other parameters were ketp unchanged. The CT number of different materials in phantom were measured and analyzed. Results The CT numbers of tissues changed remarkably with the tube voltage and had different relativity for different tissues. The CT numbers had positive correlation with kV for such maierials as polyethyle, lexan, perspex,but for teflon the correlation was negative. The mAs and recon kernel had no effects on CT number. Conclusions The CT number of tissue changes with scanning X-ray tube voltage, so the setting of scan parameters should be taken into account in image diagnosis and radiotherapy.