Evaluation Of Liver Fluke Disease Bymultimodal Imaging Techniques: Application Values And Correlational Study In FibroScan, CT And IVIM DW-MRI

BackgroundLiver fluke disease is a chronic infectious disease in biliary parasites. Liver fluke infection is due to eating raw freshwater fish or shrimp infected by liver fluke. Liver fluke wwas most known to the human were Clonorchis sinensis, Opisthorchis viverrini and cat of Clonorchis sinensis. Approximately 35 million people worldwide are infected with clonorchiasis, and it has a population of 15 million China infection of Clonorchis sinensis in Guangdong province and Guangxi Province, which has a population of 8 million and 500 thousand infection. The life history of liver fluke is divided into adult, egg, miracidium, sporocyst, Lei You, cercaria, metacercaria and metacercarial stages. The final host for human and carnivorous mammals such as cats, dogs, etc.. The first intermediate host for freshwater snails, the second intermediate hosts for freshwater fish, shrimp. That is because the human infection of liver fluke disease caused by the second intermediate host of raw food. Adult liver fluke parasites mainly in intrahepatic bile ducts in the liver, especially Ⅲ bile duct, the parasitic long time up to 20-30 years. Long term parasitic in intrahepatic bile ducts of the liver fluke adults can be long-term mechanical and chemical stimulation of bile duct, bile duct epithelial hyperplasia, bile duct fibrosis around and intrahepatic bile duct dilatation caused and ultimately progress to bile duct cancer cells, liver fibrosis or cirrhosis and hepatocellular carcinoma. At present, liver fluke disease patients is often due to the emergence of abdominal pain, jaundice, fatigue or nausea and vomiting gastrointestinal symptoms, stool examination or ultrasound and CT/MR prompt intrahepatic III bile duct dilatation and were discovered by accident, this part of the patients can be under the guidance of doctors for treatment of liver fluke infection and prevent further liver damage. Most liver fluke infection had no obvious clinical symptoms, however, chronic inflammation of the long-term survival of intrahepatic bile duct in liver fluke can cause bile duct, bile duct and cause the surrounding liver parenchyma injury. The liver fluke infection screening and early assessment of chronic liver injury patients is particularly important. The measurement of liver stiffness can reflect the degree of liver fibrosis. Liver biopsy has been in clinical use for a long time, and the liver biopsy is still the gold standard for the assessment of diffuse liver injury (especially liver fibrosis). American Association for the disease of the liver, the European Association for the study of the liver, Asia Pacific Association for the study of the liver, the National Institutes of health and the liver other researchers recommend most chronic hepatitis or chronic hepatitis B before treatment should be liver biopsy was performed in. However, liver biopsy is an invasive procedure that is accompanied by some unavoidable risks and complications. Reported that the death rate caused by liver puncture complications ranging from 1:1000 to 1:10000. The most common complications were pain and discomfort at the puncture site, and the incidence was about 20%. At the same time, because the sample size is too small, so that the accuracy of the diagnosis of the disease is affected, and different puncture people usually have different diagnostic results. The above reasons are restricted in the application of liver.In recent years, transient elastography as a non-invasive examination canevaluate hepatic fibrosis grading, screening the general population may be the underlying liver disease by measure liver stiffness, with a high degree of accuracy and repeatability. The measurement results with lower the observer and the observed error, even in the assessment of the severity of liver fibrosis, the classification can replace liver biopsy. By transient elastography in early and reliable for hepatic fibrosis was quantified, and 95% of the patients are feasible.Computer tomographyas a kind of effective and non traumatic method, with good temporal resolution and spatial resolution. CT examination can be on the liver volume, liver morphology and essence, the situation of bile duct was evaluated. Liver fluke disease can cause a series of liver and biliary system diseases, such as intrahepatic bile duct dilatation, intrahepatic bile duct calculus, cholangitis, liver abscess, cholecystitis, gallstones and other. The liver fluke disease complications can be accurately diagnosed and evaluated by CT examination. However, liver fluke disease liver volume changes were ignored by clinical, liver volume changes reflect the pathological changes of liver parenchyma. At present, the domestic and foreign research about the volume of liver and spleen by measuring CT there are two main methods, namely volume index and specific volume calculation software. The volume index is obtained by the maximum length measurement of liver or spleen diameter, width and thickness, three numerical multiplication gain. The volume index of hand is more convenient, but the final value of the volume is exaggerated, and there is a difference between the measurement. The software calculates the volume by manually outlining the outline of the liver or spleen, and then the size of the volume of the software automatically generated. Many studies have confirmed that related to the prognosis and the severity of the liver and spleen volume changes and hepatic fibrosis, liver cirrhosis, splenomegaly and child Pugh score correlated, splenomegaly in hepatocirrhosis plays an important role. This study attempted to assess the liver fluke disease using CT volume index.IVIM DW-MRI (intravoxel incoherent motion, diffusion Weighted-Magnetic Resolunce imaging) with multiple b values of magnetic resonance diffusion imaging, not only reflect the spread of water molecules in the living tissues, but also can reflect the microcirculation perfusion. Liver fluke disease intrahepatic bile ducts of the liver fluke adults of bile duct wall long-term mechanical and chemical stimuli, leading to chronic cholangitis, liver fibrosis, resulting in the increase of liver stiffness. Liver fibrosis of liver cell and fiber components increase, reduce the space between the liver cells and extracellular water molecular diffusion limited; hyperplasia of liver extracellular fiber extrusion liver cells leads to a reduction in the volume of liver cells, so the intracellular space is reduced and inner cell molecular diffusion limited; at the same time, liver cell gap fiber composition hyperplasia in average blood flow in the liver and reduce blood flow velocity slowed down, liver perfusion reduced. Based on the pathological changes of liver fluke disease, IVIM related diffusion and perfusion parameters should be affected in theory. This study attempts to evaluate liver stiffness, liver volume,liver perfusion and diffusion in liver fluke by FibroScan, CT and IVIM DW-MRI, and to explore the correlationsamong the three kinds of technologies, aims toprovideeffective and non-invasive assessment methodsto make early diagnosis for liver damage in liver fluke disease.Part I Assessment of Liver stiffness by transient elastography (FibroScan(?)) in Liver fluke diseaseAim:Assess liver stiffness of asymptomatic liver fluke disease patientsby FibroScan and evaluate the influence factors of liver stiffness.MethodsStudy population and study designThis study prospectively enrolled 96 patients with liver fluke infection, all patients were diagnosed by stool ova test.All patients were residentsin endemic areas (Foshan City, Guangdong Province) with high prevalence of liver fuke infection,their durations of ingested freshwater raw fish or shrimp were more than 10 years,all patients had no symptoms of abdominal pain, jaundice, fatigue, vomiting or other symptoms of digestive system, and their liver function tests were normal.Excluded patients should meet the following criterias:1.Chronic HBV/HCV infection or acute viral hepatitis (n=6); 2.Acute intrahepatic cholangitis (n=2); 3.Had or had received treatment of chronic liver, kidney, lung disease (n=3).these diseases were defined International Classification of Disease,10th Revision; 4. Diabetes, hypertension, renal impairment, heart disease, or BMI≥28 kg/m2 (n=5), this cut-off value of BMI was developed as a reference standard by the National Health and Family Planning Commission of the people’s Republic of China; 5.Imaging examination revealed liver abnormalities or ascites (n=7); 6.Drink more than 40 grams per day,lasted more than 5 years (n=3); 7.LSM failed (n=5).According to above exclusion criteria, this study collected 65 patients.The study was approved by Institutional Review Board of The First People’s Hospital of Foshan, Guangdong. Written informed consent was obtained from all patients.Liver stiffness measrementAssessment of liver stiffness using Fibroscan (EchoSens, Paris, France).Two experienced operators, who were blinded to clinical and biochemical data,were responsible for obtaining Fibroscan values.The operating pocedure was according to a previously described method.LSM values were detected in all patients be fasting or after 2 hours of postprandial.The patients taked supine position, right hand raised behind the head,10 effective measurements, the success rate of at least 60%,interquartile range (IQR) of less than 30% of the median liver stiffness value were included.All the liver stiffness values using kPa as the unit.Cut-off value ofLSMAlthough previous studies have proposed their own cutoff values of LSM,but the normal reference values of LSM in Europe and Asia are different, and even the values of South Korea, South Asia, and China in the Asian countries are different. We adopted the cutoff value of LSM which was proposed by theLiver Stiffness Evaluation Groupof China, LSM>7.4kPa were defined as abnormal.Statistical analysisThe data were presented as means±standard deviation (SD).To analyze the correlation between various covariates and LSM values, we used partial correlation analysis; to compare the differences between the covariates, we used independent sample t test.A value of p<0.05 was considered as statistically significant. Data analysis was performed using SPSS 19.0 statistical software(SPSS, Chicago, IL, USA).Abbreviated wordsnLSM and aLSM represented normal LSM value and abnormal LSM value repectively. nGender represented gender of patients with normal LSM value,aGender represented gender of patients with abnormal LSM value.nAge representedage of patients with normal LSM value.aAge representedage of patients with abnormal LSM value.nDuration representedduration of ingested freshwater raw fish or shrimp of patients with normal LSM value,aDuration representedduration of ingested freshwater raw fish or shrimp of patients with abnormal LSM value.nBMI representedBMI of patients with normal LSM value,aDuration representedBMI of patients with abnormal LSM value.ResultsThe prevalence of aLSM values65 cases (40male,25female, average age was 47.3±11.4 years old) with liver fluke disease,27 cases had aLSM vaules, the prevalence was 41.5%, the maximumLSM value was 11.6kPa, the minimum value was 7.5kPa.38 cases had nLSM values, the proportion was 58.5%, the maximum LSM value was 7.3kPa, the minimum value was 3.3kPa.The correlation between various covariates and nLSM valuesOn partial correlation analysis,nAge, nGender, nDuration and nBMI were showed no significant correlation to nLSM values,respectivelyr=0.106,p=0.546; r=0.256,p=0.137;r=0.204,p=0.239; r=0.092,p=0.597.The correlation between various covariates and aLSM valuesOn partial correlation analysis,aDuration was the independent factor which showed a positive correlation to aLSM values (r=0.502,p=0.012).aAge, aGender and aBMI were showed no significant correlation to aLSM values,respectivelyr=0.043,p=0.840; r=0.132,p=0.540; r=-0.083,p=0.699.Comparisons of the covariates between patients with nLSM and aLSM valuesaDuration was significantly longer than nDuration (p<0.001).Although there were not statistical significant,aLSM patientshad higher proportion of male gender,older average age.The difference between nBMI and aBMI was small.(Table 1)Conclusion:High proportion of asymptomatic liver fluke disease patients had abnormal LSM values.The durations of patients withabnormal LSM values were significantly longer than the durations of patients with normal LSM values,and the durations of patients withabnormal LSM values was the independent factor which showed a positive correlation to abnormal LSM values.Part II Quantitative evaluation of the correlation between liver-spleen volume and liver stiffness in liver fluke diseaseAimTO measure the liver and spleen volume by CT, and quantitative evaluation of the correlation between liver-spleen volume and liver stiffness in liver fluke disease.Methods1.Study population:theinclusion and exclusion criteriaes of cases were same to part I.The 65 cases were performed abdominal CT scan.2.Cases grouping:(1) normal liver stiffness group; (2)abnormal liver stiffnessgroup.3.The analysis objects:volume of right liver lobe(RV), volume of caudate lobe(SlV); left lateral lobe (S2+3V), spleen volume (SPV); volume of right lobe/spleen volume(RV/SPV); normal liver stiffness values (nLSM); abnormalliver stiffness values (aLSM).4.CT scanning methods and parametersPhilips Brilliance iCT(philips medical systems, cleveland),location scan, determine the scope of the upper abdomen (scanning the diaphragm to the lower edge of the spleen, liver and spleen); scan thickness:1-2mm,0.27s/r。Contrast agent is iopromide injection (Ultravist, Bayer healthcare Pharmaceuticals Inc), with high pressure injector by median antebrachial vein injection.Injection rate:4-5 mL/s.Total dose:90-100mL.In 25,55-65,120s after injection of the arterial phase, portal venous phase and parenchymal phase three phase scan. Scanning parameters: detector:128x0.625mm, Pitch0.915,80 Kv,100 mAs,360°/0.4s.5.CT image postprocessing and data acquisitioniCT Philips Brilliance Workspace machine with Portal software, the volume determination was analyzed by the software of EBW automatic liver tissue. The proposed Couinaud’s liver the intrahepatic Glssion system distribution 8 segment method based on, depicted in the right lobe of the liver volume, liver left external lobe volume and the caudate lobe of liver volume and splenic volume in, the software automatically calculated volume of the area described.6.Transient elastography detectionThe instantaneous elastic imaging detector, before the examination preparation, detection method and definition of abnormal liver stiffness values were the same with the first part.7. Statistical analysisUsing SPSS 13.0 (Ⅱ of Chicago, USA) statistical software for data analysis: (1)Linear regression analysis was used to analysis the correlation between aLSM and aRV, aS1V, aS2+3V, aSPV,aRV/aSPV; nLSM and nRV, nS1V, nS2+3V,nSPV,nRV/nSPV; (2)Two independent samples t test was used to compare the differences between abnormal liver stifffness values group and normal liver stiffness values group in RV, SI V, S2+3V, SPV and RV/SPV;(1) and (2) which had a correlation ora significant difference was analysis by ROC curve. P< 0.05 as there was a significant difference between the test standard.Results4. The correlation between normal liver stiffness values and liver-spleen volume parameters.There were no correlation between nLSM and nRV, nS1V, nS2+3V, nSPV,nRV/nSPV (r=0.155, p=0.176>0.05; r=-0.042, p=0.400>0.05; r=-0.137, p=0.206>0.05; r=0.113, p=0.250>0.05; r=-0.046, p=0.393>0.05;).5. The correlation between abnormal liver stiffness values and liver-spleen volume parametersThere were no correlation between aLSM and aRV, aS1V, aS2+3V,aSPV (r=-0.216, p=O.139>0.05; r=0.054, p=0.394>0.05; r=0.141, p=0.241>0.05; r=0.242, p=0.112> 0.05); There was significant negative correlation between aLSM and aRV/aSPV (r=-0.681, p=0.000<0.05)。6. The comparisonbetween normal liver stiffness group and abnormal liver stiffness values group in volume parameters.There were no significant differences between nRV and aRV (768.41±50.53,759.71 ±34.11, p=0.136>0.05),nS1V and aS1V (58.50±5.92,60.53±5.07, p=0.147 >0.05),nS2+3V and aS2+3V (281.26±23.36,282.06±22.20, p=0.719>0.05), nSPV and aSPV (204.32±36.13,226.92±34.80, p=0.122>0.05).There were significant differences between nRV/nSPV and aRV/aSPV(3.86±0.67,3.57±0.96, p=0.023<0.05)。4.ROC curveArea under the ROC curve was 0.625±0.076, p=0.088> 0.05, indicating that RV/SPV value can not diagnosisliver stiffness.Area of the 95% confidence interval for 0.477 and 0.773, including 0.5, reached the same conclusion.Conclusion1 liver fluke disease with normal liver stiffness, the liver and spleen volume did not change significantly.2.1 Liver fluke disease withabnormaliver stiffness,the higher the hardness of the liver, the lower volume of right liver lobe/spleen volume ratio is.3.In abnormal liver stiffness group,volume of right liver lobe/spleen volume ratio was significantly lower than that of normal liver stiffness group.4. Volume of right liver lobe/spleen volume ratio can not distinguish liver fluke disease with normal or abnormal liver stiffness.Part Ⅲ Based on low b values IVIM DW-MRIto evaluate the correlation between liver microcirculationperfusion and liver stiffness in liver fluke diseaseAimTo reflect the microcirculation of liver parenchyma in liver fluke disease by IVIM DW-MRI,and reveals the correlation between perfusion parameters and liver stiffness.Methods1.Study population:theinclusion criteriae of cases was same to part I.Add the following exclusion criteria:Poor quality of DWI image(n=23). The other 42 patients were performed liver IVIM DW-MRI examination.2.Cases grouping:(1) normal liver stiffness group; (2)abnormal liver stiffnessgroup.3.The analysis objects:D (ture diffusion coefficient); D* (pseudo-diffusion coefficient); f (perfusion fraction); ADC (apparent diffusion coefficient); nLSM, aLSM.4.DW-MRI scanning methods and parametersPhilips 1.5TMRI (Intera; Philips Medical Systems,Best, The Netherlands),upper abdomen special 4US coil; MRI scanning includs axialSS-FSE T2WI.Dradient echo T1WI; DWI:free-breathing,EPIsingle-shot,11个b值 (0、10、20、40、70、100、 150、200、400、600、800 mm2/s); TR/TE=1800 ms/66 ms, FOV:320mm; Thickness: 4mm.5. DW-MRI image postprocessing and data acquisitionThe Philips 1.5T comes with MRI DWI tool and Imaging J postprocessing software. Region of interest (ROI) respectively placed in the right lobe of the liver middle hepatic (liver S5 and S8), liver S8 (not at the top of the liver) and liver S7 (near the liver S8), avoid the blood vessels and bile ducts. Each copy of region of interest (ROI) ensure the area all the time, each region of interest (ROI) averaging three measurements. All the b values of the same level and same position measurement. Replication region of interest to the DWI parameter map, obtained the average value. IVIM perfusion parameters of nD, nD* and NF recorded as normal liver hardness, hardness of IVIM group of abnormal liver perfusion of microcirculation related parameters aD, aD* and AF for the record.6. Transient elastography detectionThe instantaneous elastic imaging detector, before the examination preparation, detection method and definition of abnormal liver stiffness values were the same with the first part.7. Statistical analysisUsing SPSS 13.0 (II of Chicago, USA) statistical software for data analysis: (1)Linear regression analysis was used to analysis the correlation between aLSM and aD, aD*, af, aADC; the correlation between nLSM and nD,nD*,nf,nADC; (2) Two independent samples t test was used to compare the differences between abnormal liver stiffness values group and normal liver stiffness values group in D,D*,f and ADC; P< 0.05 as there was a significant difference between the test standard.Results4. The correlation between normal liver stiffness values and D,D*,f and ADC There were no correlation between nLSM and nD,nD*,nf,nADC (r=0.240,p=0.135> 0.05; r=-0.008,p=0.486>0.05; r=-0.245,p=0.121>0.05; r=-0.191,p=0.192>0.05)。 5. The correlation between abnormal liver stiffness values and D,D*,f and ADC There was significant negative correlation between aLSM and aD,aD* and aADC, respectively r=-0.718,p=0.000< 0.05; r=-0.834,p=0.000< 0.05; r=-0.752,p=0.000 <0.05。There were no correlation between aLSM and f,r=-0.340,p=0.077>0.05.6. The comparisonbetween normal liver stiffness group and abnormal liver stiffness values group in IVIM relative parameters.There were no significant differences between aD and nD (1.08±0.17,1.04±0.15, p=0.632>0.05)、aD* and nD* (42.96±9.88,48.52±8.42, p=0.479>0.05)、af and nf (29.07±3.57,29.98±4.95, p=0.193>0.05)、aADC and nADC (1.15±0.19,1.14 ±0.19, p=0.715>0.05)。Conclusion1 liver fluke disease with normal liver stiffness, there was no significant correlation betweenliver perfusion, diffusion and liver stiffness.2 liver fluke disease with abnormal liver stiffness, the higher hardness,, the smaller D, D* and ADC values, the liver microcirculation reduced and water diffusion restricted.3.The research reveals the liver stiffness of liver fluke disease was not increased significantly in this study.