A Study Of Application On 64 Silce Spiral CT Negative Cholangiopancrea Tography To Biliary Atresia In Infant

BackgroundBiliary atresia (BA) is a rare abnormality in new born babies or infants, but is the most common cause for infant obstructive jaundice, and the major hepatic disease that causes infant death. The treatment of BA is mainly early operation, with biliary reconstruction to reintegrate biliary passage,to challenge better prognosis. The best operative time is 40～60 days after birth. Survival rate can reach 75% by operation within 60 days after birth, however only 10% after 90 days after birth. If haven't operation, patient can't surpass one year of life time.Prompt diagnosis and treatment will largely affect the infants'survival qualities, which may have great significance.How to make accurate diagnosis of BA is paid widespread attention by most pediatric doctors on the long way. Although there are many diagnostic methods for BA evaluation, there exist many shortcomings, as like as:(1)Type-B ultrasonography, with good specificity but short of sensitivity. (2) Percutaneous transhepatic cholangiography and endoscopic retrograde cholangiopancreatography require strict manipulation, with low achievement ratio, which are already rarely used clinically.(3) Peritoneoscope can provide accurate diagnosis, but have invasive drawbacks.(4) Needle biopsy of liver also an invasive method, which can help early differential diagnosis.(5)Persistent duodenal secretion examination is impeded by drainage technique.(6)SPECT examination has low specificity and high false positive rate.(7)MRCP, the ability of displaying biliary system is still unsatisfactory, and infants can't cooperate well, which limit its practicing.(8)multi-slice CT cholangiopancreatography includes positive CT cholangiopancreatography with biliary contrast agent and negative CT cholangiopancreatography(N-CTCP) without biliary contrast agent. With widely used of multi-slice CT and 64-slice CT, N-CTCP have great ability of displaying the total biliary system, and its image quality reaches or even surpasses that of MRCP.Up till now, there are no literatures on diagnosis of biliary atresia by using N-CTCP from domestic and abroad.We exam the suspected biliary atresia patients by using N-CTCP by Toshiba 64-slice spiral CT, and take advantage of its rapid scanning speed, large coverage with high resolution, isotropic imaging and great reconstruction abilities. By biliary system volumn rendering(VR), multiplanar reconstruction(MPR),minimum intension projection (MinIP)and other post-reconstruction methods, summarize the N-CTCP characteristics of biliary atresia, and evaluate its sensitivity, specificity and accuracy, to explore its practicing value in diagnosis of biliary atresia.PART ONE A Study on 64-slice Negative CT Cholangiopancreatography Scanning ConditionObjectivesOptimize reasonable scanning conditions of N-CTCP with good image quality under the conception of ALARA(as low as reasonably achievable)by using Toshiba Aquilion 64-slice spiral CT. Material and Methods1.Subjects:All subjects were from out-patients or in-patients of Guangzhou Women and Children's Hospital during November 2008 to March 2009, including healthy human beings or chidren suspected abdominal diseases, excluding suspected biliary atresia.40 peoples were recruited in this study, randomly allocated into two groups. The first group was the high quality group, among them there were 13 male patients and 7 female patients, averaging 63.84±36.053 birth days;the second group was the standard group,among them there were 9 male patients and 11 female patients, averaging 63.34±29.18 birth days.2.Equitment:All studies were done using Toshiba Aquilion 64-slice spiral CT, and post-reconstruction work were done on the vitrea2.0 workstation provided by Toshiba.3.Scan methods and Conditions:All patients should hold empty stomach for 3～4 hours before scanning, drink 250ml water 15～30min before scanning, and given oral chloral hydrate(0.5ml/kg) for sedation.By using the technique of 3-D automatic tube current modulation (ATCM), the first group were scanned by "High Quality"exposure condition in Sure Exp 3D,and the second group were scanned by "Standard Quality" exposure condition in Sure Exp 3D.The sanning parameters were unified in these two groups, with the scanning scope from the upper limit of the liver to the spina iliaca anterior superior. All the patients had the abdomen CT plain scan, arterial phase, portal vein phase and equilibrium phase after injection of contrast agent.4.Post-reconstruction and Analysis All volume data of CT plain scan and contrast scan of all different phases were transferred to vitrea workstation to perform multi-planar reconstruction (MPR).There sophisticated radiologists double-blindly evaluated the MPR images quality from plain scan and contrast scan of all different phases. Pictures showing smooth biliary wall,with little false defect or stenosis, and with clear first scale branch were classified as good images, while showing coarse biliary wall,with much false defect or stenosis, and with unclear first scale branch were classified as bad images.5.Statistic analysis:Statistic analyses were performed with SPSS 13.0 software.All measurement data were recorded as standard±deviation. And statistic significance is defined as P<0.05.Sex and distribution of diseases between the high quality group and the standard group were compared by Chi-square test. Image quality of plain scan and contrast scan from every phase between the two groups were compared by Mann-Whitney test and Chi-square test. And radiation doses were compared by Chi-square test and by least significance difference(LSD)-t test(Not Paired t test)Result1.No sex deviation was found between the high quality group and the standard group(P>0.05).No difference of distribution of diseases was found between the two groups(Z=-0.848,P>0.05).2.No diifference of image quality was found between the high quality group and the standard group(P=0.146>0.05).Diifference of image quality was found in different phases of scanning in the two respective groups(P=0.000<0.05),which can be concluded that image quality from the portal phase was much better than other phases.3.With homogeneity of variance, difference of radiation doses between the high quality group and the standard group were found by least significance difference(LSD)-t test(P=0.000<0.05)Conclusion1.No difference was found in the image quality between of the high quality group and the standard group classified based on the Sure Exp 3D exposure technique.2.In all phases from the high quality group and the standard group,image quality from the portal phase was much better than other phases.3.Radiation doses of the high quality group were much higher than that of the standard group.Difference was significant by statistical analysis.4.Satisfactory images could be obtained in portal phase with standard scanning condition by using the technique of 3-D automatic tube current modulation (ATCM) in infants.PART TWO A Study on 64-slice Negative CT Cholangiopancreatography in Normal InfantObjectivesBy using reasonable conditions of N-CTCP, evaluate the presentation of N-CTCP and its biliary system showing abilities in the normal infant group.Material and Methods1.Subjects:All subjects were from out-patients or in-patients of Guangzhou Women and Children's Hospital during April 2009 to December 2009, who had abdominal contrast scan.We chose from them excluding obstructive jaundice, biliary obstruction or other biliary diseases.30 subjects were recruided in this study.2.Equitment:All studies were done using Toshiba Aquilion 64-slice spiral CT, and post-reconstruction work were done on the vitrea2.0 workstation provided by Toshiba.3.Scan methods and Conditions:Preparation, scanning method and scanning condition are the same as that in Study Part One.4.Post-reconstruction and AnalysisAll volume data of CT plain scan and contrast scan of all different phases were transferred to vitrea workstation to perform multi-planar reconstruction (MPR) and the features of N-CTCP in normal infants.5.Statistic analysis:Statistic analyses were performed with SPSS 13.0 software. All measurement data were recorded as standard±deviation. And statistic significance is defined as P<0.05.Result30 cases of normal infants all showed normal hepatic size, with filling gallbladder and clear configuration of porta hepatic, exceptionally with abnormal densities and widened interspace of portal vein. Part of them displayed extrahepatic bile ducts and left or right hepatic ducts, with smooth main stems. No one could show the second scale branches of hepatic ducts.Conclusion1.Normal infants can either display extrahepatic bile ducts or not, when they do, they would display continuous bile stem and smooth margin.2.The second scale branches wouldn't be displayed in normal infants using different reconstruction methods.3.There is no difference between in the display rate of common bile duct and that of bilateral hepatic duct in normal infants. 4. There is no statistical significance in the inner diameter of common bile duct, right and left hepatic duct.PART THREE A Study on 64-slice Negative CT Cholangiopancreatography in Biliary atresia InfantObjectivesEvaluate the imaging presentation of N-CTCP in biliary atresia infant group, and investigate its diagnositic value.Material and Methods1.Subjects:All subjects were from out-patients or in-patients of Guangzhou Women and Children's Hospital during April 2009 to December 2009, who had abdominal contrast scan and suspected biliary atresia.52 subjects were recruided in this study. Among them,32 cases were proven as biliary atresia by post-surgery pathology, and 20 cases were proven as infantile hepatitis.2.Equitment:The same as Study Part two.3.Scan methods and Conditions:Preparation, scanning method and scanning condition are the same as that in Study Part Two.4.Post-reconstruction and AnalysisAll volume data of CT plain scan and contrast scan of all different phases were transferred to vitrea workstation to perform MinlP.There sophisticated radiologists double-blindly evaluated the MinIP images quality from plain scan and contrast scan of all different phases. Evaluating standard were the same as that of Study Part One. 5.Statistic analysis:Statistic analyses were performed with SPSS 13.0 software. All measurement data were recorded as standard±deviation.Evaluate gallbladder sizes and displaying ratio of and biliary structures (including intrahepatic bile ducts and left or right hepatic ducts) in N-CTCP from all cases.And compare the sensitivity, specificity, and accuracy of different biliary atresia signs.Compare image quality from the three different reconstruction methods including MPR, MinIP and VR by Mann-Whitney test.Result1.No difference between dignostic evaluation and post-surgery pathology were found in 32 biliary atresia patients, by McNemar test P=1.000>0.05.2.Imaging feature of biliary atresia include:1)No gallbladder or small gallbladder;2)Appearing triangular low density around the porta hepatic area;3)Widened interspace of portal vein, appearing as"double-track sign"or"target sign";4)No common bile duct were recognizable in all biliary atresia patients;5) Hepatosplenomegaly. Difference of small gallbladder, triangular sign and widened interspace of portal vein were found between BA and HIS patients by statistical analysis, while no difference of any recognizable extrahepatic bile ducts or hepatosplenomegaly were found between them.3.Specificity of triangular sign in biliary atresia patients was as high as 100%, but with low sensitivity. Sensitivity, specificity, and accuracy of small gallbladder sign (including no gallbladder sign) were comparatively high. Specificity of double-track sign was also high, but sensitivity and accuracy were relatively low. Therefore, signs of hepatosplenomegaly and no recognizable extrahepatic bile ducts are not so valuable for diagnosis of biliary atresia. Signs of triangular low density, small gallbladder, double-track and no recognizable extrahepatic bile ducts are helpful for conforming diagnosis, particularly triangular sign.Conclusion1.By comparing N-CTCP diagnostic and post-surgery pathology results, goodness of fit of the two diagnostic methods is significant and is rather strong.2.Triangular low density around the porta hepatic area, small gallbladder, widened interspace of portal vein, appearing as"double-track sign"or"target sign" are the key signs of diagnosis of BA, while which could be excluded if the common bile duct is recognizable.3.Among the MPR, MinIP and VR reconstruction methods, MinIP showed best in infants of BA.