自动毫安CT扫描在埋伏牙诊断中的应用

目的探讨埋伏牙螺旋CT扫描时运用不同模式的自动毫安技术,患者接受的射线剂量及其对图像质量的影响。方法将30例埋伏牙患者随机分成3组,分别以IQ、Normal、Lowdose3种自动毫安模式进行螺旋CT扫描,扫描时记录容积CT剂量指数（CTDI）及扫描长度,计算出平均剂量长度乘积（DLP）。对不同扫描参数的图像质量评分,并进行统计学分析。结果 IQ、Normal、Lowdose模式组的CTDI值分别为14.0、13.3和11.4mGy,DLP分别为（122.50±5.17）、（113.58±7.34）和（98.15±5.39）mGycm,各组图像质量评分无统计学差异。结论埋伏牙低剂量自动毫安螺旋CT扫描技术简便易行,既显著降低辐射剂量,又能满足诊断要求。

Clinical Application of Auto-Milliampere Technique of Spiral CT for Impacted Tooth

Objective To investigate the effect of different modes of auto-mA technique on the image quality and the radiation dose of the patients accepted undergoing spiral CT for impacted tooth.Methods Thirty patients with impacted teeth were divided into three groups and underwent dental CT using IQ,normal,and lowdose modes of auto-mA respectively. The volume CT dose index （CTDI） was recorded and the average dose-length produce （DLP） was calculated in the three groups respectively. Image quality of three groups were compared and scored by a radiologist and a dentist,and the results were performed statistic analysis. Results The CTDI and DLP of IQ-mode group were 14.0mGy and 122.50±5.16mGycm,those of normal-mode group were 13.3mGy and 113.58±7.34mGycm,and those of lowdose-mode group were 11.4mGy and 98.15±5.39mGycm. There was no significant difference among three groups in diagnostic image quality. Conclusion Lowdose auto-mA CT technique is easy to operate,and not only significantly reduce the radiation dose,but also satisfy the diagnostic requirements.