The Study Of Clinical Application With Three-dimensional Technology In Precise Diagnosis And Treatment Of Hepatolithus

BackgroundHepatolithiasis, also called calculosis, is the presence of gallstones in the common hepatic duct, the region of hepatic biliary confluence as well as all levels of intrahepatic bile ducts with accompanied complications such as inflammation or stenosis of bile ducts, hepatic fibrosis, hepatatrophia, liver dysfunction, and so on. Hepatolithiasis is a worldwide disease and is prevalent in Asian countries, especially in South China, Southwest China, the Yangtze valley and southeast coastal areas. Due to the complicated pathological changes, relative high recurrence rate and severe accompanied complications, hepatolithiasis is the main cause of death from benign hepatobiliary diseases. As the main therapy, surgical treatment, especially hepatectomy is widely accepted with the aid of bile-duct anaplasty and choledochojejunostomy. However, due to extensive distribution of intrahepatic duct calculus with accompanied different degrees of devastated liver lesion and stenosis of hepatic ducts, stenosis of bile duct and inadequate drainage-caused recurrence of calculosis after surgical operation, surgical treatment could not always lead to satisfactory results.The diagnosis of hepatolithiasis is mainly relied on non-invasive imaging examination, such as type-B Ultrasound, computed tomography (CT) and magnetic resonance imaging (MR), etc. The classification diagnosis is based on the detection of the location, size, number and distribution of calculi and the location and degree of stenosis of bile ducts. To make a surgery plan, diverse and combinatory factors should be considered, such as the function of liver and Oddi sphincter, emergence of hepatocholangeitis, obstructive jaundice, hepatic portal bile duct stricture, portal hypertension or splenomegaly and so on. Due to the extensive distribution of calculi, different degrees of stenosis of intrahepatic ducts and devastated liver lesions, each of the above-mentioned imaging examinations has its advantages and disadvantages. Such situation requires the combinatory application of several imaging examinations to get final comprehensive diagnosis. Currently, there is no single perfect method can reach a final systematic and comprehensive diagnosis conclusion on the number and distribution of calculi, the degree and length of stenosis of bile ducts, the liver pathomorphism, the relationship between bile duct and blood vessel.Currently, there isn't a worldwide-recognized classification criterion of hepatolithiasis. There are only three classification methods have been commonly used for the classification of hepatolithiasis, including the Japanese Nakayama classification, the Tsunoda classification and the Chinese classification which was proposed by the biliary-tract surgery group of Chinese Medical Association (CMA) in 2007. The above classification methods are all based on the distribution of Calculi and the location and degree of cholangiectasis and stenosis of bile ducts. However, these methods are lack of precise stereotaxis of the distribution of Calculi and the location and degree of cholangiectasis due to the limitation of imaging examinations, which also can not give detailed anatomical relationship among bile ducts, portal vein and hepatic vein. Thus it's hard to design a suitable surgery plan to achieve the precise operation for hepatolithiasis.In recent years, with the development of computerized techniques for three-dimensional (3D) reconstruction and visualization technology,3D visualization technique have been successfully applied to the studies of human body anatomy structure and organ functions, and also to the clinical applications of disease diagnosis and intra-operative navigation. Since 2003, our group used the hepatic CT scan data set from digitalized virtual Chinese Female No. one and specimens liver with perfusion of hepatic ducts to perform the studies of the 3D reconstruction and virtual surgery. After then, using the data of Live humans liver, gall, spleen, pancreas, other visceral organs and vessels scaned by the 64 multi-detector helical CT, we performed the study of 3D reconstruction and virtual surgery.Because the study of 3D reconstruction and virtual surgery is based on the individual characteristics of patients, it satisfied the individual requirement. Currently, our group has completed the individual 3D reconstruction and virtual simulation of many hepatobiliary diseases, including liver cancer, hepatic hemangioma and pancreatic carcinoma and so on, which shows important value of clinical application. In this work, we apply the 3D visualization technique to study the digital dissection of biliary tract, clinical pathological classification and of individualized surgical therapy for hepatolithiasis, which shall improve diagnostic accuracy and precision of surgical treatment for hepatolithiasis, and finally will contribute to the clinical efficacy of hepatolithiasis.Objects1. Establishment of digitalized 3D reconstruction of biliary system. We perform 3D reconstruction of liver and it's internal ducts, especially calculus and bile duct, to establish digitized anatomy of hepatobiliary system by using the CT image-postprocessing Mxview (Philips) workstation and abdomen medical image-3D visualization system (MI-3DVS) respectively.2. We apply 3D reconstruction and simulation techniques to the clinical diagnosis, classification and surgical treatment of hepatolithiasis, then to explore the clinical value of this techniques for reasonable selection of surgical operation and controlled hepatectomy of hepatolithiasis.Methods1. The study of digitalized anatomy of biliary system based on 64 multi-detector helical CT scanning data1.1 Equipments64 multi-detector helical CT machine (Holland PHILIPS); The Mxview workstation accompanied with 64 multi-detector helical CT machine; FreeForm Modeling System (USA, SensAble Technologies); Force feedback system PHANToM (PHANToM Desktop); ACDSee9 Message Center (ACD System Ltd.); medical image-3D visualization system (MI-3DVS) developed and set up by ourselves [Host machine containing memory (2G), microprocessor (2.0G×2Xeon 5130)].1.2 The set of CT scanning parameters and data storage of biliary system from clinical hepatolithiasis casesWhen performing routine plain CT scan, the patient was lying down in supine position and scanned from diaphragmatic dome to lower margin of pancreas. The scanning parameter was set as following:120 KV and 250 mAs with 0.625 mm×64 multi-detector combination,5 mm-thick reconstruction layer,5 mm layer intervals, thread pitch 0.984 and 0.5s for one rotation of the tube. The patients were fasted at least 6 to 8 hours before examination. As negative gastrointestinal contrast reagent,500-ml clean water was taken orally by patients. Plain scan was performed from the bifurcation of bronchi to the upper margin of pubic symphysis ahead of contrast enhanced scan which was performed through the antecubital vein and forearm vein using automatic high pressure injector to do bolus injection of nonionic diodone ultravist with the dosage of 1.5ml/kg at a rate of 5ml/s. Hepatic arterial phase scan, late arterial scan and portal phase scanning was performed 21-25s,30-35s and 50-55s respectively after injection of contrast reagent and each of the scan lasted about 6-8s. After the scan, the image data was transmitted to Mxview workstation and all the three phase (plain scan phase, arterial phase and portal phase) data was burned into disc for storage. The data format is in DICOM (Digital Imaging and Communications in Medicine) 3.0 which can be transformed to BMP format through DICOM viewer. 1.3 3D reconstruction of biliary system on the Mxview workstation accompanied with PHILIPS Brilliance 64 multi-detector helical CTThe scanning data of 5-mm-thick layer in the original database were 3D reconstructed using thin slice width reconstruction (0.67-mm thickness and 0.33-mm layer interval). The reconstructed CT images were transmitted to Maxview workstation. In Maxview workstation,3D reconstruction of coronal, sagittal, arbitrary plane surface or curved surface of pancreaticobiliary duct and celiac blood vessels were performed using those thin-thick image data. The main reconstruction methods include maximum intensity projection (MIP), minimum intensity projection (MinIP), curve reconstruction (CR), Volume rendering (VR) and multiplanar reformation (MPR). Thus we can observe the anatomic structure of bile duct through multi-angle and multi-dimension.1.4 3D reconstruction of hepatobiliary system using MI-3DVSIn this work, the segmentation method combined the algorithms of threshold segmentation and region growing,3D segmentation and two-dimensional segmentation. The scanning data from 64 multi-detector helical CT were read by MxliteView DICOM Viewer, adjusted with suitable window width and level, and exported as JPEG format files. Then the JPEG files were imported into ACDSee 9 Message Center, transformed into BMP files and imported into MI-3DVS after re-sizing the images. In MI-3DVS, the sequential segmentation of biliary tract system and around blood vessel system were performed using self-adaptive region growing algorithm to get the data with Stereo Lithography (STL) format of hepatobiliary system, abdominal aorta, celiac artery and its branches, portal vein and its branches, and hepatic veins, et al. Finally, the reconstructed STL models were imported into FreeForm Modeling System for smoothing and retouching to get the smooth and lifelike 3D images of hepatobiliary system. The video and the multi-angle video recordings were recorded for 3D observation of the anatomic structure of biliary system.2. Classification of hepatolithiasis using 3D visualization technique of hepatobiliary system2.1 Equipment same as 1.12.2 Methods for 3D reconstruction of biliary tract system:same as 1.1,1.2,1.42.3 Individual liver segmentation of hepatolithiasis based on the anatomy of hepatic vein and portal veinBased on the 3D reconstruction of liver, portal vein, hepatic vein and bile duct, the segmentation of liver is indicated by portal veins as indicative marks, hepatic veins as boundary marks, gall bladder and ligament as auxiliary segmentation marks. Each segment of liver is supported by an independent branch of portal vein. For the segmentation of liver and location diagnosis of lesion, the anatomy of portal veins and the relationship between lesion and portal veins is more important. Normally, the branches stem from main trunk of portal vein was defined as the first level branch, and the part of liver supported by a third-level branches of portal veins is defined as one hepatic segment. Thus we can divide the liver into 1 to 10 hepatic segments named with Roman numerals fromⅠtoⅩ. Because the Gelisson system contains the portal veins and bile duct, we can do accurate location diagnosis of hepatolithiasis and cholangiectasis or stenosis of bile duct.2.4 Anatomic classification of hepatolithiasis based on the individualized liver segmentationBased on the Japanese Nakayama classification, the Tsunoda classification and the Chinese classification which was proposed by the biliary-tract surgery group of Chinese Medical Association (CMA) in 2007, we used the results of hepatic segmentation from 3D visualization and classified the anatomy of hepatolithiasis through the following criteria.2.4.1 Location:using roman-numers-labeled hepatic segmentation to localize the calculi and cholangiectasis or stenosis of bile duct.2.4.2 Stenosis:Because the diameter of normal bile duct is 2 to 3 mm,2mm was selected as the criterion of absolute stenosis. The criterion of relative stenosis is defined as the diameter ratio of proximal terminal to distal terminal. Thus the stenosis is classified as SO (no stenosis), S1 (mild stenosis is defined as the diameter ratio above 1/2), SO (severe stenosis, also called absolute stenosis, is defined as the diameter ration below 1/2).2.4.3 Distention:To evaluate the distention degree of bile duct,10 mm was used as the criterion to discriminate the mild and sever distention of the internal diameter of intrahepatic duct. Thus the distention the internal diameter is classified as DO (no distention), D1 (mild distention,>2mm and <10mm), D2 (moderate distention,>10mm), D3 (severe distention,> 15mm).2.4.4 Atrophy:We observed the volume variation of the pathological hepatic segments through 3D reconstruction to confirm whether there is atrophy of the pathological liver or the compensatory hypertrophy of neighboring hepatic segments. The surgical removal is unique choice for the hepatic segments showing atrophy. So using the hepatic segment with atrophy as a pathological typing index can help to select the surgical operation with surgical excision of hepatic segment or incision removal of intrahepatic calculus.2.4.5 Portal hypertension (PHT) or Cirrhosis. One of the important factors affecting the prognosis of hepatolithiasis is the portal vein hypertension and splenomegaly caused by biliary cirrhosis, which commonly influence the selection of surgical operation of hepatolithiasis. For the existence of multiple calculi of intrahepatic duct combined with biliary cirrhosis, the surgical operation shall choose incision removal of calculus in different kind of ways and internal and external drainage and be cautious for hepatectomy. The 3D visualization technique can clearly observe the pathological changes of splenomegaly, the distention of around blood vessels, atrophy and hypertrophy of liver. Thus we use portal hypertension as a pathological typing index.Other factors, such as Oddi's sphincter functional disturbance, hepatocholangeitis, obstructive jaundice, hepatic abscesses, hemobilia and accompanied cholangiocarcinoma, etc, which are helpful to choose the type and timing of surgical operation, but are hard to made a correct diagnosis from imaging analysis.3. The application of 3D reconstruction technique in the diagnosis and treatment of hepatolithiasis3.1 Research objects. The data of 64 multi-detector helical CT of total 60 patients with hepatolithiasis were collected from Oct.2008 to Oct.2010. All the patients'data were analyzed with 3D reconstruction and pathological classification, and subjected to surgery simulation to determine the surgical procedure and resection sites. After then the real surgical operations were performed and compare the real situation with the results from previous 3D reconstruction and surgery simulation.3.2 Instruments and equipment:same as 1.13.3 Methods for 3D reconstruction of biliary tract system:same as 1.1,1.2,1.4.3.4 Post-processing after imagingThe reconstructed STL models were imported into FreeForm Modeling System for smoothing and denoising to get the smooth, lifelike 3D models. For the convenience of 3D observation, we use MIPS to render the liver, hepatic veins, hepatic artery, portal veins, biliary tract, calculus, abdominal vessels and around visceral organs with different colors. At the same time, the 3D anatomic relationships were observed.3.5 virtual operation of hepatolithiasisThe 3D model was magnified, minified, rotated, and transparentized to observe every parts of organs and lesions in all directions with the FreeForm Modeling System, so that the distribution of calculi, the states of intra- and extra-hepatic bile ducts and liver would be explicit, based on which a proper operation plan can be made. Additionally, virtual reality surgery could be applied to hepatolithiasis to choose an optimal operation method based on PHANTOM, an instrument with force feedback, and self-developed surgical instruments.3.6 Actual operation of hepatolithiasisBased on the observation of the video of 3D models and printscreens in any directions, the size, the amount and position of hepatolithiasis will be explicit; the stenosis and distention of hepatic duct, the length of the narrow bile ducts, and hepatatrophia and megalohepatia could be observed simultaneously; so as to make preoperative prognosis, pathological classification and operation plans. When brought to operating room, the video of 3D models and printscreens compared to the actual operation, can offer the real-time direction of operations. The common surgical methods are listed as follows:bile duct exploration (BDE), hepatectomy (HT), left lateral lobectomy (LLL), right posterior lobectomy (RPL), left hepatectomy(LH), hepaticojejunstomy(HJS), intrahepatic bile duct support tube placement (IBDSTP), and so on. The actual operation is the combination of different surgical methods mentioned above. After actual operation, on the basement of the comparison between 3D models and the true structure of organs in operation, and that between the virtual reality operation and the process of the real one,then the clinical value of 3D technique in the accurate treatment of hepatolithiasis is evaluated.Results1. Digitized biliary tract anatomy study based on 64 multi-detector helical CT scanning data1.13D reconstruction of biliary tract by 64 multi-detector helical CTThe 3D reconstruction of biliary tract was successfully performed in 54 out of 60 patients with cholelithes. The 3D reconstruction of intrahepatic ducts was unsatisfactory in 6 patients due to unobvious distention of biliary tract system. Diverse shapes of calculi in intrahepatic ducts were observed in the cross section of plain CT scanning and appeared as mottled, quasi-circular, striped or beadlike high density images. The position of calculi and nearby bile ducts showed various degrees of stenosis and distention, combination with atrophy of Liver lesion or compensatory hypertrophy of surrounding liver tissue. Extrahepatic cholelithes were marked by rounded or annular high-density shadow surrounded by low density gall images and appeared as "target sign" or "meniscus sign".Through 3D reconstruction of biliary tract, single, multiple calculi or disseminated distribution of high density intrahepatic calculi in different subsections of liver could be observed, complicating with various distention of intrahepatic ducts. The bile ducts at the calculus region were narrowed,and the distal bile ducts branches dilated like "biliary tree". Sometimes the dilated bile ducts became a "Gall Lake" or regional hepatapostema with different density. MinIP could show not only high density calculi and dilated intra- and extra-hepatic bile ducts, but also present radioparent calculus with soft tissue density in the choledoch. The dilated bile ducts could branch up to three to four levels and mostly appeared as a "dry stick". Commonly, the distension of bile ducts near porta was more serious than that of bile ducts far from porta, while distension or stenosis of intrahepatic duct was regional and the branch was sparse and slim. Besides the shape and volume of high density calculi in the intrahepatic ducts, the lesion liver prenchyma atrophied and hyperplastic complex was also observed. As far as complicated choledocholithiasis was concerned, single or multiple beadlike high density calculi images with various shapes and volume could be seen in the choledoch. The distension of bile ducts at upside obstruction was obvious, while distal bile ducts did not show or suddenly obstructed. Oledocholithiasis was marked by distension of all bile ducts above calculus as well as cholecyst; intrahepatic ducts dilated to different extent and appeared as a "dry stick". The choledoch under calculus was gradually narrowed, while dilated in full range in complicated pyogenic cholangitis.1.23D reconstruction of biliary tracts by MI-3DVS1.2.1 3D reconstruction of live, intra- and extra-hepatic vascular systemThe liver model can truly reflect the actual volume and anatomy marker of liver, and simultaneously present liver and branches of intrahepatic artery, vein and portal vein through adjusting the transparency of liver. The model presented vivid shapes and stereoscopic identification of various structures, including abdominal aorta, celiac arteries and branches, such as gastroduodenal artery, right and left renal artery, right and left gastric artery, splenic artery, part of mesenteric artery, proper hepatic artery, right and left hepatic artery as well as intrahepatic branches, and so on. The model of the portal system presented portal trunk, splenic vein and superior mesenteric vein out of liver, and the intrahepatic portal system could clearly present right and left main portal vein as well as branches in various hepatic lobes and subsections in the liver. The model of the hepatic vein system could clearly present the intrahepatic distribution of three hepatic veins and their branches, the confluence of three hepatic veins, suprahepatic and inferior vena cava as well as the spatial anatomy relationship of all hepatic veins.1.2.2 3D reconstruction of biliary tract system and calculusAided by plain CT scanning images and portal phase scanning images, MI-3DVS medical images segmentation with adaptive region growing algorithm usually could segment biliary tract system completely in single-time. For some fine structures such as the region where cystic duct and choledoch converge, and the hilar bile duct without expansion, scanning data of different blood vessel phases including plain scanning phase, arterial phase, venous phase and portal phase could be used for image segmentation of biliary tract system of various phases. The specific anatomy information in various phases could be integrated into an complete 3D image of biliary tract by system automatic registration function. The reconstructed biliary tract system mode could truly reflect the spatial ubiety relationship among calculi, biliary tract system and intra- and extra-hepatic blood vessels. After the 3D biliary tract system model was completed with celiac viscera and blood vessel model, the stereoscopic relationship of the whole epigastric viscera, the hepatic vascular system and the biliary tract system was completely presented.After segmentation and reconstruction by MI-3DVS and through accurate segmentation of biliary tract system and calculus, the 3D reconstruction images of livers as well as intrahepatic duct system of 54 patients in this study were presented with vivid shapes and stereoscopic effects. These images clearly presented the 3D shape of patient liver and indicated the existence of megalohepatia or hepatatrophia, the 3D shape of three levels of intrahepatic bile duct tree, as well as the length and diameter of stenotic or dilated bile ducts. In part of patients with hepatolithiasis combined with extensive intrahepatic duct distension, the forth level of bile ducts, e.g., bile ducts in hepatic subsegments, could also be shown. Besides, the volume, number, in intra- and extra-hepatic 3D distribution of calculi as well as the spatial structure of bile ducts and intrahepatic vascular system could be clearly presented too.2. Study on pathology classification of hepatolithiasis by 3D visualization techniqueTyping diagnosis of hepatolithiasis was carried out by combining multiple factors including the location of calculi orlesion bile ducts (location, L), the degree of biliary stenosis (stenosis, S), the degree of biliary distention (distention, D), the atrophy of lesion liver subsection (atrophy, A), the portal hypertension (PHT), and so on. For example:Hepatolithiasis (LⅡ,Ⅲ, SⅢ1, DⅢ2, AⅡ,Ⅲ):indicating lithiasis in theⅡandⅢsubsection of liver, combined with slight stenosis and distention of intrahepatic duct in theⅢsubsection as well as the atrophy of theⅡandⅢsubsections of liver.Hepatolithiasis (LⅥ,Ⅶ,SⅥ1, DⅥ0, AⅥ):indicating lithiasis in theⅥandⅦsubsection of liver, complicating with slight stenosis ofⅥsubsection of bile duct without distention of remote bile duct, as well as atrophy of theⅥsubsections of liver.The liver subsections of patients with hepatolithiasis based on the technique of 3D visualization complicating wit the individual characters of liver anatomy. It brings out accurate position diagnosis for the distribution of calculi and lesion regions of bile ducts which combined with the degree and range of biliary stenosis or distention and having or not biliary cirrhosis, hepatatrophia as well as megalohepatia, could draw out relatively reasonable clinicopathologic analysis could be drawn out. This new analysis method considering multi-factors including distribution of calculi, regions of biliary stenosis or distention, liver volume variation and cirrhosis and so on, thus could make out more accurate position diagnosis for hepatolithiasis and the lesion region of bile duct, and is more practically significant in clinic guidance for determining the excision range and the surgical processing modes such as bile tract drainage.3. Application of 3D reconstruction technique in diagnosis and therapy of hepatolithiasis3.1 Definite 3D shape of intrahepatic "biliary tree" and "blood vessel tree" by 3D reconstructionThe 3D shape of liver model of patients in this study has vivid shape and correct anatomy structure marker. After Transparency processing on liver, through single or various combination of video mode, it will be clearly observed the existence of hepatatrophia,3D distribution and shape of intrahepatic ducts and blood vessels, volume and distribution range of calculi in intrahepatic ducts, the degree of biliary stenosis and distention, having or not combination with extrahepatic cholangiolithiasis. By virtue of the 3D model, not only the distribution of intrahepatic calculi, the pathological change of biliary system and liver parenchyma as well as the relationship between disease focus and surrounding tissues could be observed, but also the blood supply patterns of liver and variation types of hepatic arteries could be determined, thus the typing diagnosis and virtual operation of hepatolithiasis could be precisely carried out.3.2 Simulated operation of hepatolithiasisIn the simulated environment of operation, the tissues and organs could be observed in any angle through magnifying, minifying, rotating and hyalinizing the 3D model. The distribution of calculi, the pathologic lesion of biliary tract system and liver as well as changes in intrahepatic blood vessel tree could be determined. Based on these observations, clinic classification of hepatolithiasis and choice of optimal operation mode were carried out. The operation process mentioned above was simulated in turn to observe the surgical outcome. In this study, simulated operations were carried out on 30 cases of complex hepatolithiasis, while other 30 patients with positively diagnostic type I hepatolithiasis or hepatolithiasis without stenosis of bile duct did not performed simulated operations. After observing the dissection relationship of important blood vessels and bile ducts in the excision plane of 30 patients by simulated operation, the optimal operation plan were formulated to direct the actual operation process. 3.3 Clinic application of 3D visualization technique of biliary tractBased on the observation and analysis of 3D video and sectional drawing as well as drilling by simulated operation on 30 patients with complex hepatolithiasis, operation plans were made on all patients. The actual plan included 30 cases of BDE+LLL+HJS,8 cases of BDE+LLL+IBDSTP,3 cases of LLL+RPL+HJS,3 cases of LH+HJS, and 10 cases of LLL+ HJS+1BDSTP. The reconstruction model of liver complied with the actual operation condition in 54 patients well. The accordance rate between simulated operation plans and actual operation was 90% (27/30. The radical surgery was difficult to be carried out on 3 emergency patients). No serious complications were observed post-operation, and no case of death. Postoperative radiography of bile duct on 51 patients presents no residual of calculus. Lithiasis relapsed in 3 patients after half a year, and the recurrence rate in half a year was 5.58%(3/51).Conclusion1. Technique of 3D reconstruction can realize the digitized anatomy of biliary tract.Both the CT 3D reconstruction by 64 multi-detector helical CT MxliteView workstation or by MI-3DVS, the 3D reconstruction can achieve the digitized anatomy of biliary tracts. Compared with 2D CT imaging, the digitized dissection can show the form of the bile duct tree of the biliary tract system and the distribution of calculi in three-dimension. However, the 3D images reconstructed by the CT MxliteView workstation were only the biliary tract images in a certain blood vessel phase. which only showed the 2D sagittal or coronal plain films of the 3D images in vision to surgeons,but not the 3D images in the true sense. It is difficult for these 2D plain films to present the 3D spatial relationship among blood vessels, including hepatic artery, portal vein, hepatic vein, and the biliary tree simultaneously.Thus it is difficult to observe the spatial dissection of bile ducts, calculi and the intrahepatic vascular system in various angles or directions. However, MI-3DVS could render the liver surrounding viscus, celiac blood vessels, and various intrahepatic duct systems with different colors. Then through the visualization technique the complete 3D images of the whole epigastric viscus are obtained. In these 3D images, the liver, hepatic artery, hepatic vein, portal vein, celiac blood vessels as well as surrounding viscus could be presented independently, or simultaneously, or in various combinations. The pattern of intrahepatic duct tree, distribution of calculi, as well as the location and degree of biliary stricture could be clearly presented through partially magnifying or rotating this 3D image. Compared with the traditional black-and-white 2D image, the 3D image presents the critical dissection structures including the region of lesion as well as surrounding blood vessels and viscus with higher definition and visualization, and realizes the 3D presentation in the true sense and thus will contribute to accurate preoperative diagnosis for hepatolithiasis.2.3D visualization can realize precise classification diagnosis of hepatolithiasis.The liver subsection of patients with hepatolithiasis based on the technique of 3D visualization complies with the individual characters of liver anatomy. It brings out accurate position diagnosis for the distribution of calculi and lesion regions of bile duct. Combining the degree and range of biliary stenosis or distention and having or not biliary cirrhosis, hepatatrophia as well as megalohepatia, relatively reasonable clinicopathologic analysis could be drawn out. This new analysis method considers multi-factors including distribution of calculi, regions of biliary stenosis or distention, liver volume variation and cirrhosis and so on, thus could make out more accurate position diagnosis for hepatolithiasis and the lesion region of bile duct, and is more practically significant in clinic guidance for determining the excision range and the surgical process such as bile tract drainage.3.3D visualization technique plays an important guide in the treatment of hepatolithiasis.3D visualization of biliary tract and virtual operation could realize accurate preoperative diagnosis of hepatolithiasis and simulated operation; formulate the optimum operation plan through comparing various plans and surgical pathways or methods of critical steps, thus implementing accurate surgical operation. For these reasons, the 3D visualization technique has an important reference value in reasonable choice of operation mode for complex hepatolithiasis.