The clinical value of anteroposterior and lateral scout image combined with Care Dose 4D and Care kV in reducing radiation dose of chest CT scanning

Objective To investigate the feasibility and clinical value of anteroposterior and lateral scout scan combined with Care Dose 4D and Care kV in chest CT scan. Methods A total of 60 patients of clinical diagnosis with lung tumor were enrolled. Those patients were randomly divided into test group and control group. Control group underwent a scan protocol with lateral scout scan combined with Care Dose 4D and Care kV, while anteroposterior and lateral scout scan combined with Care Dose 4D and Care kV were performed in test group. The signal-to-noise ration (SNR) , contrast-to-noise ratio (CNR) , and overall image quality of two groups of images and diseased tissues were analyzed and evaluated by two high-grade radiologists using double-blind method. Effective doses (E) were also calculated. Results All the 60 patients had successfully completed the chest CT scans. Test group overall image quality (4.57±0.45) and control group overall image quality (4.73±0.45) had no statistically significant difference (P>0.05) . The control group image SNR, CNR and diseased tissue SNR, CNR compared with test group had no statistical significance difference (P>0.05) . The difference of the volume CT dose index (CTDIvol) , dose-length product (DLP) and effective dose (E) of test group and control group was statistically significant (t=8.514, 8.464, 8.464, P<0.001) . Compared with control group, the effective dose of test group decreased by 33.3%. Conclusions Compared with lateral scout scan, the technology of anteroposterior and lateral scout scan combined with Care Dose 4D and Care kV can decrease radiation dose without reducing the image quality. This technology can therefore be considered as a regular imaging modality for chest CT scan. Key words: Chest; Radiation dose; Care Dose 4D; Care kV; Scout image