自动管电流调节低剂量CT在尘肺诊断中的应用

目的 探讨自动管电流调节低剂量CT在尘肺诊断中的可行性及应用价值.方法 45例经专业机构确诊的尘肺患者均行固定管电流（150 mA）常规剂量CT扫描（固定组）和自动管电流调节低剂量CT扫描（ATCM组,固定噪声指数为14,管电流50～200 mA）,记录两组不同扫描条件下患者的容积CT剂量指数（CTDIvol）和剂量长度乘积（DLP）,采用双盲法分别对两种扫描方法所获取图像的质量、尘肺影像特征（阴影大小、阴影密集度、尘肺分期）进行评价,并进行统计学分析.结果 在尘肺的CT影像征象显示率方面,ATCM组可清晰地显示各种尘肺特征性表现,与固定组相比,两者在显示尘肺影像特征（阴影大小、阴影密集度以及尘肺分期）、图像质量方面比较差异均无统计学意义（P＞0.05）.固定组的CTDIvol、DLP分别为13.53 mGy和（337.13±13.53） mGy/cm,ATCM组分别为（7.39±0.45） mGy和（188.78±1.80） mGy/cm,两者比较差异有统计学意义（P＜0.05）.结论 自动管电流调节低剂量CT能全面反映尘肺的特征,图像质量可满足辅助诊断要求,并且能显著降低患者的辐射剂量,可代替常规剂量CT用于尘肺的筛选与辅助诊断.

The application of low dose CT with automatic tube current modulation in the diagnosis of pneumoconiosis

Objective To explore the feasibility and application value of low dose CT with automatic tube current modulation （ATCM） in the diagnosis of pneumoconiosis.Methods Forty-five patients with pneumoconiosis confirmed by the occupational agency underwent standard dose CT scanning with a fixed tube current of 150 mA and low dose CT scanning with ATCM （50-200 mA） with noise index （NI） of 14.The CT dose index volume （CTDIvol） and dose length product （DLP） under the different scanning condition were recorded.The image quality,specific image manifestations of pneumoconiosis （shadow size,shadow concentration,pneumoconiosis stages） were reviewed in double-blind methods by two radiologists,and the statistical analysis was performed.Results CT characteristics of pneumoconiosis could be detected efficiently with low dose CT scanning with ATCM.There were no significant differences in showing the shadow size,shadow concentration,pneumoconiosis stages and the image quality between the two groups （P〉0.05）.The CTDIvol and DLP of standard dose CT scanning were 13.53 mGy and （337.13 ± 13.53） mGy/cm respectively,and CTDIvol and DLP of low dose CT scanning with ATCM were （7.39 ± 0.45） mGy and （188.78 ± 1.80） mGy/cm,there were statistical differences （P 〈 0.05）.Conclusions Low dose CT scanning with ATCM can reflect the characteristics of pneumoconiosis,and it also can significantly reduce the radiation dose with diagnostic acceptability of the image quality.So low dose CT scanning with ATCM can replace the standard dose CT scan in diagnosing and screening of the pneumoconiosis.