Objective To observe the value of advanced patient motion correction(APMC)technology for improving imaging quality of low-dose pediatric chest CT.Methods Ninety-six children who received low-dose chest CT scan were retrospectively enrolled.CT images were reconstructed using full reconstruction technique(FULL)or APMC for both lung window and mediastinal window.Then the imaging qualities were subjectively evaluated according to image clarity,degree of motion artifacts,sharpness of structural edges and overall quality.The indexes of objective evaluation of imaging quality included the mean CT values of unit density pixel within ROI on lung window and mediastinal window,the standard deviation of CT values(SDCT)representing image noise,as well as signal-to-noise ratio(SNR).Sobel operator edge detection was performed on images,recording the mean gray level(G)and the standard deviation of gray value in Sobel(SDsobel)within ROI.Comparisons were made between FULL reconstruction and corrected images with APMC reconstruction in terms of subjective and objective evaluations,as well as parameters obtained from Sobel output images.Results Compared to FULL reconstruction,APMC corrected images showed reduced motion artifacts,improved edge structure sharpness and enhanced overall image quality(all P＜0.05),while there was no significant difference of image clarity(P＞0.05).Meanwhile,with APMC reconstructions,the mean CT values,SDCT on lung window and SDCT on mediastinal window increased(all P＜0.05),but there was no significant difference for the mean CT values on mediastinal window(P＞0.05),and SNR on both lung window and mediastinal window decreased(both P＜0.05).Besides,for Sobel output images,compared to FULL reconstruction,APMC reconstruction had increased G and SDsobel on both lung window and mediastinal window(all P＜0.05).Conclusion APMC technology applicated in low-dose chest CT scan of children could effectively reduce motion artifacts,improve edge clarity and imaging quality,hence enhance diagnostic sensitivity.

Objective To observe the value of advanced patient motion correction(APMC)technology for improving imaging quality of low-dose pediatric chest CT.Methods Ninety-six children who received low-dose chest CT scan were retrospectively enrolled.CT images were reconstructed using full reconstruction technique(FULL)or APMC for both lung window and mediastinal window.Then the imaging qualities were subjectively evaluated according to image clarity,degree of motion artifacts,sharpness of structural edges and overall quality.The indexes of objective evaluation of imaging quality included the mean CT values of unit density pixel within ROI on lung window and mediastinal window,the standard deviation of CT values(SDCT)representing image noise,as well as signal-to-noise ratio(SNR).Sobel operator edge detection was performed on images,recording the mean gray level(G)and the standard deviation of gray value in Sobel(SDsobel)within ROI.Comparisons were made between FULL reconstruction and corrected images with APMC reconstruction in terms of subjective and objective evaluations,as well as parameters obtained from Sobel output images.Results Compared to FULL reconstruction,APMC corrected images showed reduced motion artifacts,improved edge structure sharpness and enhanced overall image quality(all P＜0.05),while there was no significant difference of image clarity(P＞0.05).Meanwhile,with APMC reconstructions,the mean CT values,SDCT on lung window and SDCT on mediastinal window increased(all P＜0.05),but there was no significant difference for the mean CT values on mediastinal window(P＞0.05),and SNR on both lung window and mediastinal window decreased(both P＜0.05).Besides,for Sobel output images,compared to FULL reconstruction,APMC reconstruction had increased G and SDsobel on both lung window and mediastinal window(all P＜0.05).Conclusion APMC technology applicated in low-dose chest CT scan of children could effectively reduce motion artifacts,improve edge clarity and imaging quality,hence enhance diagnostic sensitivity.

Objective To establish a method for determining the amount of silicone oil on the surface of rubber closures,which is one of the packaging material standards in the Pharmacopoeia of the People's Republic of China.Methods The development process of the method for determining silicone oil content on the surface of rubber closures was described,taking the infrared transmission mode as example.Through method validation,the scientific and rational aspects of the method were examined.Key points of the determination method were analyzed,including the selection of quantitative peaks,selection of measurement solvent,selection of extraction solvent and conditions,selection of instrument measurement methods,selection of liquid cell windows for infrared transmission mode,selection of quantification methods,and selection of dimethyl silicone oil reference standards.Results The infrared spectroscopy mode was chosen to determine the amount of polydimethylsiloxane on the surface of rubber closures based on the peak height of the Si-CH3 bond vibration absorption at 1 260 cm-1.Cyclohexane was used as the measurement solvent.The same concentration of polydimethylsiloxane reference solution was measured using both infrared transmission mode and attenuated total reflection mode,and quantification was performed based on peak height.The results from the two measurement modes were essentially the same.The linear range of polydimethylsiloxane was about 0.3-10.0 mg·mL-1,and its correlation coefficient was 0.999 8.The average recovery of the method was 102.3%-105.6%.The LOD of polydimethylsiloxane was 0.1 mg·mL-1.The silicone oil measurement results of seven batches for rubber closures were consistent with the silicone oil amounts provided by the manufacturer.Conclusion Enterprises can choose either the infrared transmission mode or the attenuated total reflection mode to measure the amount of polydimethylsiloxane on the surface of rubber closures based on their actual conditions.

Objective:To establish a method for the determination of antioxygen 1178 in 5-layer co-extrusion bags used for infu-sion. Methods:A Uitimat XB-C8 (250 mm × 4. 6 mm,5μm) column was used,the mobile phase was methanol-water with gradient elu-tion, the flow rate was 1. 0 ml·min-1 ,the detection wavelength was 223 nm,the column temperature was 35℃ and the injection vol-ume was 20 μl. Results:The concentration of antioxygen 1178 had the linear relationship within the range of 1. 64-205. 10 μg·ml-1 (r=0. 999 9),and the average recovery was 92. 05% (RSD=1. 94%, n=9). Conclusion:The method is accurate,stable and spe-cific,and can be used to determine antioxygen 1178 in 5-layer co-extrusion bags used for infusion.