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

Abstract

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. Key words: Tomography X-ray computed; Pneumoconiosis; Automatic tube current modulation technique