CT检查中辐射剂量的研究

Study of the radiation dosage in CT examination

目的：探讨CT检查中CT扫描基本参数对辐射剂量的影响。方法：随机抽取2006年1-5月与2005年同期、同部位各30例腹部常规CT、CT血管造影（CTA）两种检查的基本参数值（mAs、层数、层厚）及辐射剂量值进行回顾性比较。结果；2006年与2005年同期腹部CT检查人次相比，在常规扫描、CTA、三维成像方面分别增加了16．12％、84．15％、300％人次（P〈0．05）。腹部CTA较常规扫描层数增加135．35％（P〈0．01）、层厚减少16．12％（P〈0．02）、mAs增加10．46％（P〈0．01）、DLP增加33．28％（P〈0．01）。结论：CT检查2006年罗2005年同期人次增加且随着mAs增加或层数增加、层厚减薄，受检者所受辐射剂量增加。

Objective：To discuss radiation dosage in CT examination through statistics and analysis of basic parameters in CT scanning. Methods：In January to May of 2006 and same time and same position in 2005. the basic parameters （mAs, slice number, slice thick） and radiation dosage of 30 cases apiece random seltected with routine abdominal CT scanning and CT angiography （CTA） were compared retrospectively. Results： The man-time of routine abdominal CT scanning, CTA and three dimensional imaging increased 16.12%, 84.15% and 300% （ P 〈 0.05） respectively. Slice number of abdominal CTA increased 135.35% than in 2006 routine abdominal CT scanning,（ P 〈0.01）, slice thick decreased 16.12% （ P 〈0.02）, mAs increased 10.46% （ P 〈0.01） and DLP increased 33.28% （ P 〈 0.01 ）. Conclusion： The radiation dosage of patients is increased with the increasing of mAs or increaseing of slice number and thinning of slice thick in CT examination.