Objective To explore the application value of multi-model adaptive statistical iterative reconstruction-Veo (ASiR-V) in ultra-low dose chest CT examination of children in the plateau area. Methods The children who underwent chest CT examination in Xizang Autonomous Region People's Hospital were enrolled in this study and assigned into two groups according to the scanning conditions.Group A underwent scanning at a tube voltage of 100 kV and ASiR-V 50% reconstruction,and group B underwent scanning at a tube voltage of 80 kV and ASiR-V 0 (Group B1) and ASiR-V 50% (Group B2) reconstruction.The image quality of each group was evaluated objectively and subjectively.The radiation dose and image quality were compared between groups. Results Groups A and B showed the volume CT dose indexes of (2.33±0.62) mGy and (0.86±0.01) mGy and the dose length products of (65.01±25.12) mGy·cm and (23.55±3.38) mGy·cm,respectively,which presented differences between groups (both P<0.001).The image noise in the bilateral upper and middle lung areas in group B2 was lower than that in group B1 but higher than that in group A (all P<0.001).There was no significant difference in image quality score of the lung window among groups (all P>0.05).Groups A,B1,and B2 had no significant differences in ascending aorta (P=0.538) or liver CT value (P=0.175) in the mediastinal window.The signal-to-noise ratios and contrast-to-noise ratios of ascending aorta and liver in group B2 were higher than those in group B1 (all P<0.001) and lower than those in group A (all P<0.05).The image quality score of the mediastinal window followed a descending order of group A>group B2>group B1 (all P<0.001)。Conclusion ASiR-V combined with low tube voltage can effectively reduce the radiation dose and guarantee the image quality of chest CT of children in the plateau area.
Humans ; Radiation Dosage ; Tomography, X-Ray Computed/methods* ; Child ; Male ; Female ; Child, Preschool ; Radiography, Thoracic/methods* ; Infant ; Models, Statistical ; Image Processing, Computer-Assisted/methods*

Objective To investigate the predictive value of chest CT imaging characteristics for risk stratification of acute pulmo-nary embolism(APE)in the plateau area.Methods A total of 202 patients diagnosed with APE for the first time were retrospec-tively selected.According to clinical risk stratification criteria,all patients were categorized into low-risk group(104 cases)and medium/high-risk group(98 cases).Demographic characteristics and chest CT image parameters of patients were collected,including gender,age,ascending aorta diameter(AAd),main pulmonary artery diameter(MPAd),the ratio of main pulmonary artery diameter to ascend-ing aorta diameter(r PA),pulmonary artery obstruction index(PAOI),PAOI grade,emphysema,atelectasis,pulmonary consolida-tion,pleural effusion,pericardial effusion,and pulmonary atelectasis.All these parameters between the two groups were compared and statistically analyzed.Results There was a statistically significant difference between the two groups in age,MPAd,r PA,PAOI grade,emphysema,and pericardial effusion(P<0.05).No statistically significant difference was showed in gender,AAd,PAOI,ate-lectasis,pulmonary consolidation,pleural effusion,and pulmonary atelectasis between the two groups(P>0.05).The logistic regres-sion analysis showed that age,r PA,PAOI grade,and pericardial effusion were independent factors for risk stratification of APE.The area under the curve(AUC)of the receiver operating characteristic(ROC)curve was 0.654,0.699,0.669,and 0.616,respectively.The combined AUC was 0.843,with a sensitivity of 76.5%and a specificity of 77.9%.Conclusion Chest CT imaging characteris-tics such as r PA,PAOI grade,and pericardial effusion combined with patient age have important predictive value for risk stratification of APE in the plateau area.

Objective To investigate the predictive value of chest CT imaging characteristics for risk stratification of acute pulmo-nary embolism(APE)in the plateau area.Methods A total of 202 patients diagnosed with APE for the first time were retrospec-tively selected.According to clinical risk stratification criteria,all patients were categorized into low-risk group(104 cases)and medium/high-risk group(98 cases).Demographic characteristics and chest CT image parameters of patients were collected,including gender,age,ascending aorta diameter(AAd),main pulmonary artery diameter(MPAd),the ratio of main pulmonary artery diameter to ascend-ing aorta diameter(r PA),pulmonary artery obstruction index(PAOI),PAOI grade,emphysema,atelectasis,pulmonary consolida-tion,pleural effusion,pericardial effusion,and pulmonary atelectasis.All these parameters between the two groups were compared and statistically analyzed.Results There was a statistically significant difference between the two groups in age,MPAd,r PA,PAOI grade,emphysema,and pericardial effusion(P<0.05).No statistically significant difference was showed in gender,AAd,PAOI,ate-lectasis,pulmonary consolidation,pleural effusion,and pulmonary atelectasis between the two groups(P>0.05).The logistic regres-sion analysis showed that age,r PA,PAOI grade,and pericardial effusion were independent factors for risk stratification of APE.The area under the curve(AUC)of the receiver operating characteristic(ROC)curve was 0.654,0.699,0.669,and 0.616,respectively.The combined AUC was 0.843,with a sensitivity of 76.5%and a specificity of 77.9%.Conclusion Chest CT imaging characteris-tics such as r PA,PAOI grade,and pericardial effusion combined with patient age have important predictive value for risk stratification of APE in the plateau area.