Comparison of Topogram-based Automated Selection of Tube Potential and Fixed Tube Potential in Imaging Solid Pancreatic Lesions / 中国医学科学院学报

Objective To evaluate the image quality and radiation exposure in multidetector computed tomography (MDCT) with automated topogram-based tube potential selection,compared to fixed tube potential,in patients with solid pancreatic lesions. Methods The preoperative pancreatic dual-source CT images of 113 patients who were confirmed as solid pancreatic lesions by postoperative pathology in the Peking Union Medical College Hospital from January 2014 to August 2016 were retrospectively analyzed.Among them,53 patients were examined on fixed tube potential at 120 kV,and tube current was automatically modulated (group 1). Sixty patients underwent topogram-based automatic tube potential selection (Tube voltage step:90,100 kV) and automated mA modulation (group 2). Two experienced radiologists measured the body sizes,assessed subjective and objective image quality of arterial phase and portal phase,and recorded radiation parameters including CT dose index volume (CTDI) and dose-length product (DLP). Results Of 60 patients in group 2,45 patients were scaned at 90 kV,15 patients were scaned at 100 kV.The average body diameter [(287±24) mm] in 90 kV group was significantly lower than that [(328±22) mm] in 100 kV group(t=0.731,P=0.0008). The mean CTDI[(3.9±1.0) mGy] in group 2 was significantly lower than in group 1 [(9.0±1.9) mGy],reduced by 56.7% (t=17.5,P=0.0003). The average DLP [(109±38) mGy·cm] in group 2 was significantly lower than that in group 1 [(276±83) mGy·cm],reduced by 60.5% (t=14.0,P=0.0007). In group 2,the standard deviations of images background noise in arterial and portal phase were (6.4±0.9) and (6.4±1.0)HU,respectively,which were significantly higher than those in group 1 [(5.6±1.4)HU,t=-3.757,P=0.0003;(5.5±1.4)HU,t=-3.828,P=0.0006]. In group 2,the signal to noise ratios of pancreatic lesions, abdominal aorta in arterial phase and pancreatic lesions, the portal vein in portal phase were 18.8±9.3,76.0±19.3 and 17.4±6.7,33.1±7.2,which were significantly higher than those in group 1 (13.1±8.7,t=-3.379,P=0.001;56.5±22.6,t=-2.268,P=0.025;14.1±8.1,t=-2.283,P=0.024;28.9±8.8,t=-2.613,P=0.009). Conclusion Compared with fixed tube voltage on the second-generation dual-source CT techniques,topogram-based automatic tube potential selection on third-generation dual-source CT can reduce radiation dose without decreasing image quality in imaging solid pancreatic lesions.

Bone Marrow Imaging by Third-generation Dual-source Dual-energy CT Using Virtual Noncalcium Technique for Assessment of Diffuse Infiltrative Lesions of Multiple Myeloma / 中国医学科学院学报

Objective To evaluate the value of bone marrow imaging by third-generation dual-source dual-energy CT(DSDECT) using virtual noncalcium(VNCa) technique for the assessment of diffuse infiltrative lesions of multiple myeloma(MM). Methods From December 2015 to June 2016,31 patients with plasma disorders at our center were prospectively recruited and received whole-body imaging with third-generation DSDECT and MRI. CT numbers of vertebrae were measured on VNCa images as well as regular CT images. Correlation between VNCa CT numbers and MRI signal intensities of the vertebrae was evaluated. The diagnostic ability of VNCa for MM infiltrative lesions was assessed by ROC analysis,using MRI as the reference standard. Results The mean VNCa CT numbers of vertebrae with MM diffuse infiltration (n=62) were (-13.27±18.96)HU,which were significantly higher than those of non-infiltrated vertebrae[(-63.31±26.75)HU,(n=117)] (Z=-9.731,P=0.000). VNCa CT numbers of vertebrae were negatively correlated with T1WI signal intensity normalized by non-degenerative vertebral discs (r=-0.592,P=0.000). ROC analysis showed the area under the curve of VNCa for the diagnosis of infiltrative lesions was 0.943. With the cut-off value of-37 HU,the sensitivity and specificity of VNCa were 90.32% and 87.18%,respectively. Conclusion Bone marrow imaging by third-generation DSDECT using VNCa technique is a valuable tool for assessing diffuse infiltrative lesions of MM.

Application Practice of JCI Standard in Pharmacy Intravenous Admixture Service of Our Hospital / 中国药房

OBJECTIVE:To discuss the application practice of PIVAS standardization in pharmacy intravenous admixture ser-vice(PIVAS)of our hospital. METHODS:Based on JCI,the design concept and management mode of PIVAS were analyzed and summarized from PIVAS design,management,job and medical order time arrangement,staff management,infusion quality or fault emergency plan,etc. RESULTS:After introducing JCI standards,the improvement was conducted in respects of management system and work flow design,purification system and logistics division design,information system design,etc. Working hour was arranged according to the workload or work flow and the actual needs of clinical departments. Medical orders,1 batch per hour,24 batches one day,were delivered to clinical departments according the time point. The positivity of the staff had been improved, and work quantization and performance appraisal had been achieved. Those improvement optimized drug dispensing process, cleared the responsibility of information management and guaranteed the quality of infusion. Work error analysis and summary were monthly conducted;the number of work error decreased from 562 cases before JCI introduction(2013)to 264 cases after JCI intro-duction (2014),decreasing by 112.87% annually. CONCLUSIONS:JCI standard is of significance to the promotion of PIVAS management,work level and quality,and safe and rational use of drugs in the clinic.

Three-dimension quantitative CT assessment of lung volume on paired inspiratory and expiratory CT scans in chronic obstructive pulmonary disease / 中华放射学杂志

Objective To evaluate the relationship between the lung volume (LV) in inspiration and expiration,pulmonary function tests(PFT),and other CT measurements of emphysema index (EI) and mean lung density (MLD) in patients with chronic obstructive pulmonary disease (COPD).Methods Seventy-six patients with COPD were included.Three-dimension analysis was performed to obtain the following CT parameters on the inspiratory and expiratory phases:EI,MLD,LV.The ratios and differencesof MLD and LV between the two phases were calculated(ΔMLD,ΔLV,MLDex/in,LVexin).Not only the linear correlations between the lung volume parameters and PFT but also the correlations of lung volume parameters with the other CT parameters were tested by the Spearman rank correlation test and multivariant step wise regression.Results LVex/in had negative correlations with forced expiratory volume in 1 second ％ predicted [FEV1 ％,(54.32 ± 7.11)] and the ratio of forced expiratory volume in 1 second to forced vital capacity [FEV1/FVC,(49.12 ±8.01)％] (r =-0.69,-0.56,P ＜0.01),but it had the positive correlation with the ratio of residual volume to total lung capacity [RV/TLC,(58.03 ± 8.55) ％,Spearman coefficients 0.66,P ＜ 0.01].LV/exin (0.67 ± 0.12) was positively correlated with MLDex/in (0.89 ± 0.04,r =0.88,P ＜0.01).The further multivariate step wise regression denonstrated that EI,LV and MLD could introduce a regression equation with R2 =0.77 and 0.73,respectively (P ＜ 0.01).Conclusions There is an association between LVex/in and the parameters of routine PFT,which can reflect the collapsibility of lung.Moreover,LVex/in can be considered to be equivalent to MLDex/in.Taking into account the impact of scanning parameters on MLDex/in,LVex/in may play a complementary role in the assessment of pulmonary function.