Objective To confirm the interference effect of heparin lithium on turbidimetry method for detecting total protein , and to conduct performance evaluation of it .Methods Eight different concentrations of total protein urine specimen with and with ‐out heparin lithium were detected respectively ,to confirm the interference of heparin lithium on the experiment .Adding different concentration of heparin lithium solution to the prepared total protein samples with concentration of 0 .172 ,0 .427 g/L(a series of interference experiment samples ,with heparin lithium concentrations of 0 .000 ,0 .025 ,0 .030 ,0 .035 ,0 .040 ,0 .045 ,0 .050 mg/L ) , repeat four times detection ,and then conduct the dose‐effect experiment of interference .Results The biggest bias of the testing re‐sults in the two paired samples was 159 .37% ,the mini‐bias was 11 .37% ,the difference of the results in two groups was statistical significant(t= 17 .24 ,P< 0 .05) .95% confidence interval of the interference effect in the total protein samples with concentration of 0 .172 g/L was 0 .034 ~ 0 .062 ,while in the total protein samples with concentration of 0 .427 g/L was 0 .043 - 0 .053 .When the heparin lithium were 0 .025 mg/mL and 0 .050 mg/mL respectively ,the results of bias of the total protein samples with concentra‐tion of 0 .172 g/L were 27 .33% ,58 .14% respectively .But in the 0 .427 g/L total protein samples ,the results of bias were 11 .24% 、18 .74% respectively .Dose effect of interference both showed a linear relationship in the series concentration of the hepa ‐rin lithium and interference of sample of 0 .172 g/L and 0 .427 g/L ,and the linear equations were Y = 1 .974X - 0 .001 03 ,Y = 1 .599 X - 0 .000 5 respectively .Conclusion Heparin lithium is the exogenous interfering substance to the detection of total protein in tur ‐bidimetry method ,it is the positive interference to the determination results of total proteins ,especially for the low level of total pro‐tein detection ,and as heparin lithium concentration increases ,the stronger the interference effect .

Objective To compare the role of CTE and CE on the diagnosis of small bowel diseases and evaluate their advantages in patients with different indications.Methods Patients underwent both CTE and CE(interval time <2 weeks)at our institution in recent 3 years were enrolled.The positive detection rates,lesion properties and characteristics of CTE and CE were compared.The diagnostic accuracy of combined method was also analyzed.Results A total of 47 patients were enrolled and the indications included suspected or established Crohn′s disease (28 cases),unexplained abdominal pain (14 cases), obscure gastrointestinal bleeding(3 cases),insufficient small bowel obstruction(1 case)and protein losing enteropathy(1 case).Diagnostic yield of CTE and CE for whole small bowel disorders showed no significant difference(CE 83.0% VS CTE 78.7%,P =0.791).For suspected or established CD,CE had a higher diagnostic accuracy than CTE (78.6% VS 35.7%,P =0.002 ),especially in detecting lesions in the jejunum(CE 50.0% VS CTE 7.1%,P =0.002).The diagnostic accuracy reached 100.0% when two meth-ods were combined.For unexplained abdominal pain,no significant difference was found in the diagnostic ac-curacy of CE and CTE(CTE 42.8% VS CE 50.0%,P =1.000).Diagnostic accuracy of combining CTE and CE was 85.7%.Conclusion CTE and CE are both valuable in detecting small bowel lesions.For pa-tients with suspected or established CD,CE is better than CTE.For patients with unexplained abdominal pain,a combination of CTE and CE may be a better strategy than use CTE or CE alone.

Objective To provide objective parameters for differentiating pancreatic cystic tumors via using computed tomography texture analysis (CTTA) to quantify the special imaging features of pancreatic cystadenomas.Methods Enhanced CT images of pancreas from patients who were admitted in Department of Radiology in First Hospital affiliated with Zhejiang University and First People's Hospital of Hangzhou City and pathologically diagnosed as pancreatic serous cystadenomas (n =48) and mucinous cystadenomas (n =34) from January 2009 to December 2016 were retrospectively analyzed.Regions of interest were drawn on the parenchymal phase CT images in 5 slices according to the border of the tumors.Mean grey level intensity (M),variance (V),entropy (E),skewness (Ske) and kurtosis (Kur) were obtained from fine texture (σ =1.0) to coarse texture (σ =2.5).Receiver operating characteristic (ROC) curve for texture parameters with statistically difference was drawn,and the area under curve (AUC),diagnostic sensitivity and specificity were calculated.The diagnostic accuracy of senior and junior doctors was compared with the traditional CT analysis method.Results Reliability coefficient of the two radiologists was 0.809 ～ 0.997 with high consistency.Compared with mucinous cystic tumors,serous cystadenomas had a significantly different V (5.93 ± 9.02 vs 1.29±0.62),E (2.39±0.61 vs2.02±0.39) and Kur(30.18 ±42.55 vs 8.80-±4.34) in Ske0 of 2.5 (P ＜0.05),and there were no statistically significant differences on other parameters.The AUC of differential parameters for diagnosing two kinds of cystic tumors ranged from 0.56 to 0.84.The diagnostic accuracy of the traditional CT analysis method by junior doctor and senior radiologist was 60％ and 71％,respectively.Conclusions CTTA can not only effectively quantify the heterogeneity of pancreatic cystadenomas,but also is effective in the differentiation.

Objective To prospectively investigate the radiation dose and image quality of pediatric chest CT using Sn100 kV on a third-generation dual-source CT (DSCT)in comparison to standard 100 kV chest CT. Methods From December 12,2015 to June 30,2016,45 consecutive pediatric patients referred for non-contrast chest CT scan in Peking Union Medical College Hospital were prospectively enrolled as study group. They were examined at 100 kV with a dedicated tin filter on a third-generation DSCT. These patients were retrospectively matched with 45 patients who were examined on a second-generation DSCT at 100 kV without tin filter. The radiation dose as well as the lung and mediastinal window image quality(IQ)of the two groups were compared and analyzed statistically. IQ was evaluated using a five-point scale (1=unevaluable,5=excellent). Differences of radiation dose and noise between the two groups were determined with variance analysis and t test,IQ with Mann-Whitney U test,and the consistency of diagnosis with Kappa test. Results The average CT dose index volume of the study group was (0.24±0.11)mGy,which was decreased by 92% compared with the control group [(3.10+1.18)mGy] (t=16.287,P=0.000). Mean dose-length product and mean effective dose for study group were significantly lower than those of control group [(7.13±4.72)mGy·cm vs. (84.78±46.78)mGy·cm,t=11.077,P=0.000;(0.11±0.06)mSv vs.(1.23±0.61)mSv,t=12.334,P=0.000]. There was no significant difference between the two groups in terms of image noise (t=-0.003,P=0.397)and contrast to noise ratio (t=0.545,P=0.488). There was no significant difference between the two groups in lung window IQ (doctor 1:U=796.000,P=0.055;doctor 2:U=889.500,P=0.277),while significant difference was seen concerning of the mediastinal window IQ (doctor 1:U=305.000,P=0.000;doctor 2:U=276.500,P=0.000). Referring to the lung window,the median IQ for the study group and control group was 4 (3-5)and 4 (3-5),respectively. All imaging findings had acceptable IQ. The breath motion artifacts (χ=13.846,P=0.001)and heart beat artifacts (χ=53.519,P=0.000)of the study group were significantly lower than those of the control group. Conclusion Compared with standard 100 kV chest CT,the use of tin-filtered Sn100 kV on a third-generation DSCT provided 92% dose reduction in pediatric chest CT examinations while maintaining diagnostically acceptable lung window images.
Artifacts ; Child ; Feasibility Studies ; Humans ; Lung ; diagnostic imaging ; Radiation Dosage ; Radiographic Image Interpretation, Computer-Assisted ; Retrospective Studies ; Thorax ; diagnostic imaging ; Tomography, X-Ray Computed ; methods