X线管电压对生物组织CT值影响的实验研究

目的：探讨X线管电压对兔器官组织CT值的影响。方法：在同一台CT机上采用4组x线管电压80、100、120和140kV（头部模式只有前3组管电压，体部模式4组管电压）扫描12只实验兔，在切换管电压时保持其它扫描参数不变。用头颅序列扫描实验兔的头部，用体部序列扫描实验兔的胸部和腹部，测量实验兔的皮质骨、脑组织、肌肉、肝脏、肾脏、脂肪、肺组织的CT值。结果：X线管电压的改变对兔器官组织的CT值影响不一致。脂肪、肝脏、肾脏和皮质骨不同管电压下的CT值差异有统计学意义（P值均〈0．05），肺组织、脑组织和肌肉不同管电压下的CT值差异无统计学意义（P值均〉0．05）。结论：兔部分器官组织的CT值与X线管电压有一定相关性。临床中可根据组织器官的扫描参数来设定参考CT值。

The effects of X-ray tube voltage on tissue CT value

Objective：To explore the effects on CT values of rabbit organs and tissues caused by X-ray tube voltage variation. Methods： Four groups of X-ray tube voltage （80kV, 100kV, 120kV, 140kV） were used for scanning of 12 rabbits with the other parameters unchanged. The head was scanned with 80,100 and 120kV, and the abdomen was scanned with 80,100,120 and 140kV. The CT values of different tissues were measured and analyzed including bone, brain,muscle,liver, kidney,fat and lung. Results：The fat,liver, kidney, bone were affected significantly by the X-ray tube voltage （P〈0.05）. The CT numbers changed remarkably with tube voltage changing. The high density bone,liver and kidney had negative rela tivity to tube voltage, while the fat has positive relativity to tube voltage. The lung, brain and muscle, had no significant effect on X-ray tube voltage （P〉0.05）. Conclusions： Some rabbit organs and tissues have different CT values with different X-ray tube voltage and have their own special relativities to the X ray tube voltage. We can set up reference CT values ac-cording to the scan parameters of tissues.