Gadoxetic acid-enhanced magnetic resonance imaging in the assessment of hepatic sinusoidal obstruction syndrome in a mouse model

BACKGROUND Neoadjuvant chemotherapy can cause hepatic sinusoidal obstruction syndrome(SOS)in patients with colorectal cancer liver metastases and increases posto-perative morbidity and mortality.AIM To evaluate T1 mapping based on gadoxetic acid-enhanced magnetic resonance imaging(MRI)for diagnosis of hepatic SOS induced by monocrotaline.METHODS Twenty-four mice were divided into control(n=10)and experimental(n=14)groups.The experimental groups were injected with monocrotaline 2 or 6 days before MRI.MRI parameters were:T1 relaxation time before enhancement;T1 relaxation time 20 minutes after enhancement(T_(1post));a reduction in T1 relaxation time(△T_(1)%);and first enhancement slope percentage of the liver parenchyma(ESP).Albumin and bilirubin score was determined.Histological results served as a reference.Liver parenchyma samples from the control and experimental groups were analyzed by western blotting,and organic anion transporter polypeptide 1(OATP1)was measured.RESULTS T_(1post),△T_(1)%,and ESP of the liver parenchyma were significantly different between two groups(all P<0.001)and significantly correlated with the total histological score of hepatic SOS(r=-0.70,0.68 and 0.79;P<0.001).△T_(1)%and ESP were positively correlated with OATP1 levels(r=0.82,0.85;P<0.001),whereas T_(1post) had a negative correlation with OATP1 levels(r=-0.83;P<0.001).INTRODUCTION Hepatic sinusoidal obstruction syndrome(SOS)is also known as hepatic veno-occlusive disease of the liver[1].The main pathological feature of hepatic SOS is damage to liver terminal vessels,and the clinical symptoms of it include ascites and abdominal pain[2].It was first proposed in 1979 as an early complication of hematopoietic stem cell transplantation[3].The prevalence ranges from 5%to 60%,and hepatic SOS is a potentially severe complication and can even lead to death in severe cases[4].Recently,systemic neoadjuvant chemotherapy became widely regarded as one of the causes hepatic SOS in the patients with advanced metastatic colorectal cancer[5,6],especially those were treated with oxaliplatin[7,8].Oxaliplatin-based preoperative chemotherapy is used for patients with colorectal liver metastases as the standard regimen[8,9],because it could improve tumor resection outcome by shrinking the metastatic sites and reducing recurrence rate[10].Nevertheless,chemotherapy-induced hepatic SOS has been associated with a higher risk of postresection morbidity[11],such as intraoperative bleeding,intraoperative transfusions,and postoperative liver failure[12].Therefore,it is important to detect and diagnose of hepatic SOS timely.Currently,the gold standard is still based on liver biopsy[13],but it is an invasive procedure and has several limitations and complications,such as hemorrhage[14].A noninvasive diagnostic modality is needed for the assessment of hepatic SOS.Some noninvasive tools have been used for diagnosis of hepatic SOS.Researchers have utilized a preoperative platelet count and aspartate aminotransferase to platelet ratio index[15].In addition,some imaging methods such as shear wave ultrasonography,computed tomography,and gadoxetic acid-enhanced magnetic resonance imaging(MRI)have been promoted as useful methods for evaluation of hepatic SOS[16-18].Recent studies with monocrotaline(MCT)-treated rats were conducted to investigate diagnosis and prediction of severity of SOS.For example,intravoxel incoherent motion diffusion-weighted imaging,non-Gaussian diffusion models,and T1 rho quantification[19,20].The MCT-induced hepatic SOS animal model was reproducible,with a detailed pathological scoring criteria[21].Gadoxetic acid is a hepatocyte-specific contrast substance,which can provide parenchymal contrast in the hepato-biliary phase.It is reported that gadoxetic acid is absorbed into the liver parenchyma via organic anion transporter polypeptide 1(OATP1)on the hepatocyte membranes[22-24].Recently,several authors have described the feasibility of gadoxetic acid-enhanced MRI for the diagnosis of oxaliplatin-induced hepatic SOS[25].They mainly diagnosed hepatic SOS based on the signal intensity of the hepatobiliary specific phase.However,there were several limitations due to the inconsistency between signal intensity of the liver parenchyma and the concentration of contrast agent for evaluation of the degree of hepatic SOS[26].Therefore,we measured T1 relaxation time on parametric mapping because it is linearly related to the concentration of the contrast agent and is not affected by other factors[27].Yang et al[28]demonstrated T1 mapping on gadoxetic acid-enhanced MRI for the assessment of oxaliplatin-induced liver injury in a C57BL/6 mouse model.However,the main pathological changes in their model were hepatocyte degeneration and fibrosis.Therefore,we aimed to explore the effectiveness of T1 mapping based on gadoxetic acid-enhanced MRI for the diagnosis of hepatic SOS in a C57BL/6 mouse model,as well as a possible relation between OATP1 Levels and MRI parameters.

Evaluating pediatric ureteropelvic junction obstruction:Dynamic magnetic resonance urography vs renal scintigraphy 99mtechnetium mercaptoacetyltriglycine

BACKGROUND Ureteropelvic junction obstruction(UPJO)is a common congenital urinary tract disorder in children.It can be diagnosed as early as in utero due to the presence of hydronephrosis or later in life due to symptomatic occurrence.AIM To evaluate the discrepancy between dynamic contrast-enhanced magnetic resonance urography(dMRU)and scintigraphy 99m-technetium mercaptoacetyltriglycine(MAG-3)for the functional evaluation of UPJO.METHODS Between 2016 and 2020,126 patients with UPJO underwent surgery at Robert DebréHospital.Of these,83 received a prenatal diagnosis,and 43 were diagnosed during childhood.Four of the 126 patients underwent surgery based on the clinical situation and postnatal ultrasound findings without undergoing functional imaging evaluation.Split renal function was evaluated preoperatively using scintigraphy MAG-3(n=28),dMRU(n=53),or both(n=40).In this study,we included patients who underwent surgery for UPJO and scintigraphy MAG-3+dMRU but excluded those who underwent only scintigraphy MAG-3 or dMRU.The patients were divided into groups A(<10%discrepancy)and B(>10%discrepancy).We examined the discrepancy in split renal function between the two modalities and investigated the possible risk factors.RESULTS The split renal function between the two kidneys was compared in 40 patients(28 boys and 12 girls)using scintigraphy MAG-3 and dMRU.Differential renal function,as determined using both modalities,showed a difference of<10%in 31 children and>10%in 9 children.Calculation of the relative renal function using dMRU revealed an excellent correlation coefficient with renal scintigraphy MAG-3 for both kidneys.CONCLUSION Our findings demonstrated that dMRU is equivalent to scintigraphy MAG-3 for evaluating split renal function in patients with UPJO.

Gd-EOB-DTPA-enhanced magnetic resonance imaging for bile duct intraductal papillary mucinous neoplasms

AIM: To investigate gadolinium-ethoxybenzyldiethylenetriamine-pentaacetic acid(Gd-EOB-DTPA)-enhanced magnetic resonance imaging(MRI) of intraductal papillary mucinous neoplasms of the bile duct(IPMN-B). METHODS: The imaging findings of five cases of IPMN-B which were pathologically confirmed at our hospital between March 2012 and May 2013 were retrospectively analyzed. Three of these cases were diagnosed by duodenal endoscopy and biopsy pathology, and two cases were diagnosed by surgical pathology. All five patients underwent enhanced and non-enhanced computed tomography(CT), magnetic resonance cholangiopancreatography, and Gd-EOB-DTPA-enhanced MRI; one case underwent both Gd-EOB-DTPA-enhanced MRI and positron emission tomography-CT. The clinical data and imaging results for these cases were compared and are presented.RESULTS: Conventional imaging showed diffusedilatation of bile ducts and multiple intraductal polypoid and papillary neoplasms or serrated changes along the bile ducts. In two cases, Gd-EOB-DTPA-enhanced MRI revealed dilated biliary ducts and intraductal tumors, as well as filling defects caused by mucin in the dilated bile ducts in the hepatobiliary phase. GdEOB-DTPA-enhanced MRI in one case clearly showed a low-signal tumor in the hepatobiliary phase, similar to what was seen by positron emission tomographyCT. In two patients, routine inspection was unable to discern whether the lesions were inflammation or tumors. However, Gd-EOB-DTPA-enhanced MRI revealed a pattern of gradual enhancement during the hepatobiliary phase, and the signal intensity of the lesions was lower than the surrounding liver parenchyma, suggesting tissue inflammation in both cases, which were confirmed by surgical pathology. CONCLUSION: Gd-EOB-DTPA-enhanced MRI reveals the intraductal mucin component of IPMN-B in some cases and the extent of tumor infiltration beyond the bile ducts in invasive cases.

Common bile duct diameter in an asymptomatic population:A magnetic resonance imaging study

AIM: To measure the common bile duct(CBD) diameter by magnetic resonance cholangiopancreatography(MRCP) in a large asymptomatic population and analyze its some affecting factors.METHODS: This study included 862 asymptomatic subjects who underwent MRCP. The CBD diameter was measured at its widest visible portion on regular endexpiration MRCP for all subjects. Among these 862 subjects, 221 volunteers also underwent end-inspiration MRCP to study the effect of respiration on the CBD diameter. The age, sex, respiration, body length, body weight, body mass index(BMI), portal vein diameter(PVD), length of the extrahepatic duct and CBD, cystic junction radial orientation and location were recorded. The subjects were divided into 7 groups according to age. All of the above factors were compared with the CBD diameter on end-expiration MRCP.RESULTS: Among the 862 subjects, the CBD diameter was 4.13 ± 1.11 mm(range, 1.76-9.45 mm) and was correlated with age(r = 0.484; P < 0.05), with a dilation of 0.033 mm per year. The upper limit of the 95% reference range was 5.95 mm, resulting in a reasonable upper limit of 6 mm for the asymptomatic population. Respiration and other factors, including sex, body length, body weight, BMI, PVD, length of the extrahepatic duct and CBD, cystic junction radia orientation and location, were not related to the CBD diameter.CONCLUSION: We established a reference range for the CBD diameter on MRCP for an asymptomatic population. The CBD diameter is correlated with age. Respiration did not affect the non-dilated CBD diameter.

Multiparameter magnetic resonance imaging of liver fibrosis in a bile duct ligation mouse model

BACKGROUND Bile duct ligation(BDL)in animals is a classical method for mimicking cholestatic fibrosis.Although different surgical techniques have been described in rats and rabbits,mouse models can be more cost-effective and reproducible for investigating cholestatic fibrosis.Magnetic resonance imaging(MRI)has made great advances for noninvasive assessment of liver fibrosis.More comprehensive liver fibrotic features of BDL on MRI are important.However,the utility of multiparameter MRI to detect liver fibrosis in a BDL mouse model has not been assessed.AIM To evaluate the correlation between the pathological changes and multiparameter MRI characteristics of liver fibrosis in a BDL mouse model.METHODS Twenty-eight healthy adult male balb/c mice were randomly divided into four groups:sham,week 2 BDL,week 4 BDL,and week 6 BDL.Multiparameter MRI sequences,included magnetic resonance cholangiopancreatography,T1-weighted,T2-weighted,T2 mapping,and pre-and post-enhanced T1 mapping,were performed after sham and BDL surgery.Peripheral blood and liver tissue were collected after MRI.For statistical analysis,Student’s t-test and Pearson’s correlation coefficient were used.RESULTS Four mice died after BDL surgery;seven,six,five and six mice were included separately from the four groups.Signal intensities of liver parenchyma showed no difference on TI-and T2-weighted images.Bile duct volume,ΔT1 value,T2 value,and the rate of liver fibrosis increased steadily in week 2 BDL,week 4 BDL and week 6 BDL groups compared with those in the sham group(P<0.01).Alanine aminotransferase and aspartate transaminase levels initially surged after surgery,followed by a gradual decline over time.Strong correlations were found between bile duct volume(r=0.84),T2 value(r=0.78),ΔT1 value(r=0.62),and hepatic fibrosis rate(all P<0.01)in the BDL groups.CONCLUSION The BDL mouse model induces changes that can be observed on MRI.The MRI parameters correlate with the hepatic fibrosis rate and allow for detection of cholestatic fibrosis.

Response letter to “Acute cholangitis: Does malignant biliary obstruction vs choledocholithiasis etiology change the outcomes?” with imaging aspects

Radiological imaging findings may contribute to the differentiation of malignant biliary obstruction from choledocholithiasis in the etiology of acute cholangitis.

The performance of transrectal ultrasound in the diagnosis of seminal vesicle defects： a comparison with magnetic resonance imaging

Obstructive azoospermia （OA） is one of the most common causes of male infertility. Transrectal ultrasound （TRUS） has been used to diagnose OA for many years. From 2009 to 2013, we evaluated a prospective cohort of 1249 patients with suspected OA using TRUS. It was found that dilation of the ejaculatory duct （ED） （29.9%, 374/1249） was the most common cause of OA, followed by seminal vesicle （SV） abnormalities （28.5%, 356/1249）. A total of 237 patients were diagnosed with congenital defects （agenesis and/or hypoplasia） of the SV, constituting more than half of the cases of SV disease in OA （19.0%, 237/1249）. In contrast to ED, congenital defects of the SV could not be corrected with surgical treatment. Therefore, it is meaningful to compare TRUS and magnetic resonance imaging （MRI） for accurate diagnosis of SV defects. Among our patients, 30 with agenesis or/and hypoplasia of the SV on TRUS were further evaluated using pelvic MRI within 2 years, with the objective of verifying the TRUS results. The concordance rate for diagnosing congenital defects of the SV was 73.3% （22/30）. We concluded that TRUS is a reliable and convenient method for diagnosing agenesis or hypoplasia of the SV in OA patients with a high concordance with MRI while MRI is useful in patients with inconclusive TRUS findings.

Imaging features of malignant vs stone-induced biliary obstruction:Aspects to consider

Radiological studies play a crucial role in the evaluation of patients with biliary duct obstruction,allowing for the guidance of clinical diagnosis towards a malignant or stone-induced etiology through the recognition of relevant imaging features,which must be continuously revisited given their prognostic significance.This article aims to emphasize the importance of recognizing crucial imaging aspects of malignant and stone-induced biliary obstruction.

Performance study of aluminum shielded room for ultra-low-field magnetic resonance imaging based on SQUID： Simulations and experiments

The aluminum shielded room has been an important part of ultra-low-field magnetic resonance imaging （ULF MRI） based on the superconducting quantum interference device （SQUID）. The shielded room is effective to attenuate the external radio-frequency field and keep the extremely sensitive detector, SQUID, working properly. A high-performance shielded room can increase the signal-to-noise ratio （SNR） and improve image quality. In this study, a circular coil with a diameter of 50 cm and a square coil with a side length of 2.0 m was used to simulate the magnetic fields from the nearby electric apparatuses and the distant environmental noise sources. The shielding effectivenesses （SE） of the shielded room with different thicknesses of aluminum sheets were calculated and simulated. A room using 6-mm-thick aluminum plates with a dimension of 1.5 m x 1.5 m x 2.0 m was then constructed. The SE was experimentally measured by using three-axis SQUID magnetometers, with tranisent magnetic field induced in the aluminum plates by the strong pre-polarization pulses. The results of the measured SE agreed with that from the simulation. In addition, the introduction of a 0.5-mm gap caused the obvious reduction of SE indicating the importance of door design. The nuclear magnetic resonance （NMR） signals of water at 5.9 kHz were measured in free space and in a shielded room, and the SNR was improved from 3 to 15. The simulation and experimental results will help us design an aluminum shielded room which satisfies the requirements for future ULF human brain imaging. Finally, the cancellation technique of the transient eddy current was tried, the simulation of the cancellation technique will lead us to finding an appropriate way to suppress the eddy current fields.

Postoperative biliary adverse events following orthotopic liver transplantation: Assessment with magnetic resonance cholangiography

Biliary adverse events following orthotopic liver transplantation (OLT) are relatively common and continue to be serious causes of morbidity, mortality, and transplant dysfunction or failure. The development of these adverse events is heavily influenced by the type of anastomosis during surgery. The low specificity of clinical and biologic findings makes the diagnosis challenging. Moreover, direct cholangiographic procedures such as endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography present an inadmissible rate of adverse events to be utilized in clinically low suspected patients. Magnetic resonance (MR) maging with MR cholangiopancreatography is crucial in assessing abnormalities in the biliary system after liver surgery, including liver transplant. MR cholangiopancreatography is a safe, rapid, non-invasive, and effective diagnostic procedure for the evaluation of biliary adverse events after liver transplantation, since it plays an increasingly important role in the diagnosis and management of these events. On the basis of a recent systematic review of the literature the summary estimates of sensitivity and specificity of MR cholangiopancreatography for diagnosis of biliary adverse events following OLT were 0.95 and 0.92, respectively. It can provide a non-invasive method of imaging surgical reconstruction of the biliary anastomoses as well as adverse events including anastomotic and non-anastomotic strictures, biliary lithiasis and sphincter of Oddi dysfunction in liver transplant recipients. Nevertheless, conventional T2-weighted MR cholangiography can be implemented with T1-weighted contrast-enhanced MR cholangiography using hepatobiliary contrast agents (in particular using Gd-EOB-DTPA) in order to improve the diagnostic accuracy in the adverse events&#x02019; detection such as bile leakage and strictures, especially in selected patients with biliary-enteric anastomosis.

Magnetic resonance cholangiography in the assessment and management of biliary complications after OLT

Despite advances in patient and graft management,biliary complications(BC)still represent a challenge both in the early and delayed period after orthotopic liver transplantation(OLT).Because of unspecific clinical presentation,imaging is often mandatory in order to diagnose BC.Among imaging modalities,magnetic resonance cholangiography(MRC)has gained widespread acceptance as a tool to represent the reconstructed biliary tree noninvasively,using both the conventional technique(based on heavily T2-weighted sequences)and contrast-enhanced MRC(based on the acquisition of T1-weighted sequences after the administration of hepatobiliary contrast agents).On this basis,MRC is generally indicated to:(1)avoid unnecessary procedures of direct cholangiography in patients with a negative examination and/or identify alternative complications;and(2)provide a road map for interventional procedures or surgery.As illustrated in the review,MRC is accurate in the diagnosis of different types of biliarycomplications,including anastomotic strictures,nonanastomotic strictures,leakage and stones.

Magnetic resonance cholangiopancreatography image enhancement for automatic disease detection

AIM:To sufficiently improve magnetic resonance cholangiopancreatography(MRCP) quality to enable reliable computer-aided diagnosis(CAD).METHODS:A set of image enhancement strategies that included filters(i.e.Gaussian,median,Wiener and Perona-Malik),wavelets(i.e.contourlet,ridgelet and a non-orthogonal noise compensation implementation),graph-cut approaches using lazy-snapping and Phase Unwrapping MAxflow,and binary thresholding using a fixed threshold and dynamic thresholding via histogram analysis were implemented to overcome the adverse characteristics of MRCP images such as acquisition noise,artifacts,partial volume effect and large inter-and intra-patient image intensity variations,all of which pose problems in application development.Subjective evaluation of several popular pre-processing techniques was undertaken to improve the quality of the 2D MRCP images and enhance the detection of the significant biliary structures within them,with the purpose of biliary disease detection.RESULTS:The results varied as expected since each algorithm capitalized on different characteristics of the images.For denoising,the Perona-Malik and contourlet approaches were found to be the most suitable.In terms of extraction of the significant biliary structures and removal of background,the thresholding approaches performed well.The interactive scheme performed the best,especially by using the strengths of the graphcut algorithm enhanced by user-friendly lazy-snapping for foreground and background marker selection.CONCLUSION:Tests show promising results for some techniques,but not others,as viable image enhancement modules for automatic CAD systems for biliary and liver diseases.

Effect of the extrahepatic bile duct anatomy on choledocholithiasis and its clinical significance

BACKGROUND A comprehensive understanding of the extrahepatic bile duct anatomy is vital to guide surgical procedures and perform endoscopic retrograde cholangiography.Anatomical irregularities within the extrahepatic bile duct may increase susceptibility to bile duct stones.AIM To investigate the anatomical risk factors associated with extrahepatic bile ducts in patients diagnosed with choledocholithiasis,with a specific focus on preventing stone recurrence after surgical intervention and endoscopic lithotomy.METHODS We retrospectively analyzed the medical records of 124 patients without choledocholithiasis and 108 with confirmed choledocholithiasis who underwent magnetic resonance cholangiopancreatography examinations at our center between January 2022 and October 2022.Logistic regression analyses were conducted to identify the anatomical risk factors influencing the incidence of common bile duct stones.RESULTS Multivariate logistic regression analysis revealed that several factors independently contributed to choledocholithiasis risk.Significant independent risk factors for choledocholithiasis were diameter of the common hepatic[adjusted odds ratio(aOR)=1.43,95%confidence interval(CI):1.07-1.92,adjusted P value=0.016]and common bile(aOR=1.68,95%CI:1.27-2.23,adjusted P value<0.001)ducts,length of the common hepatic duct(aOR=0.92,95%CI:0.84-0.99,adjusted P value=0.034),and angle of the common bile duct(aOR=0.92,95%CI:0.89–0.95,adjusted P value<0.001).The anatomical features of the extrahepatic bile duct were directly associated with choledocholithiasis risk.Key risk factors include an enlarged diameter of the common hepatic and bile ducts,a shorter length of the common hepatic duct,and a reduced angle of the common bile duct.

Diagnosis of bile duct hepatocellular carcinoma thrombus without obvious intrahepatic mass

AIM:To study the diagnosis of hepatocellular carcinoma(HCC)presenting as bile duct tumor thrombus with no detectable intrahepatic mass.METHODS:Six patients with pathologically proven bile duct HCC thrombi but no intrahepatic mass demonstrated on the preoperative imaging or palpated intrahepatic mass during operative exploration,were collected.Their clinical and imaging data were retrospectively analyzed.The major findings or signs on comprehensive imaging were correlated with the surgical and pathologic findings.RESULTS:Jaundice was the major clinical symptom of the patients.The elevated serum total bilirubin,direct bilirubin and alanine aminotransferase levels were in concordance with obstructive jaundice and the underlying liver disease.Of the 6 patients showing evidence of viral hepatitis,5 were positive for serum alpha fetoprotein and carbohydrate antigen 19-9,and 1 was positive for serum carcinoembryonic antigen.No patient was correctly diagnosed by ultrasound.The main features of patients on comprehensive imaging were filling defects with cup-shaped ends of the bile duct,with large filling defects presenting as casting moulds in the expanded bile duct,hypervascular intraluminal nodules,debris or blood clots in the bile duct.No obvious circular thickening of the bile duct walls was observed.CONCLUSION:Even with no detectable intrahepatic tumor,bile duct HCC thrombus should be considered in patients predisposed to HCC,and some imaging signs are indicative of its diagnosis.

Imaging in male-factor obstructive infertility

The main purpose of imaging evaluation in male infertility is to identify and treat correctable causes of infertility, such as obstruction of the seminal tract. Various imaging modalities are available to evaluate men with obstructive infertility including scrotal ultrasonography, transrectal ultrasound (TRUS), vasography, magnetic resonance imaging, seminal vesicle aspiration, seminal tract washout, and seminal vesiculography. To date the most reliable and accurate diagnostic technique for obstructive infertility is unclear. In this review article, we report the role of these modalities in diagnosis of obstructive infertility. Scrotal sonography is the initial modality, and if patient results indicate non obstructive azoospermia as varicocele or testicular pathology they will be treated according to standard protocols for management of these pathologies. If the patient findings indicate proximal obstructive azoospermia, they can be managed by vasoepididymostomy. If the scrotal ultrasound is normal, TRUS is the second imaging modality. Accordingly, they are classified into patients with criteria of obstructive infertility without urogenital cysts where TRUS-guided aspiration and seminal vesiculography can be performed and transurethral resection of the ejaculatory ducts (TURED) will be the management of choice. In patients with urogenital cyst, TRUS-guided cyst aspiration and opacification are performed. Ifthe cyst is communicating with the seminal tract, management will be transurethral incision of the cyst. If the cyst is not in communication, the obstruction may be relieved after cyst aspiration. If the obstruction is not relieved, TURED will be the management of choice. Sperm harvested during aspiration may be stored and used in assisted reproduction techniques. If the results of TRUS are inconclusive or doubtful, endorectal magnetic resonance imaging should be performed to serve as a "detailed map" for guiding corrective operative interventions.

Is ERCP really necessary in case of suspected spontaneous passage of bile duct stones?

AIM:To investigate the usefulness of magnetic resonance cholangiopancreatography (MRCP) and the need for endoscopic retrograde cholangiopancreatography (ERCP) in cases of suspected spontaneous passage of stones into the common bile duct.METHODS:Thirty-six patients with gallbladder stones were clinically suspected of spontaneous passage of stones into the common bile duct because they presented with clinical symptoms such as abdominal pain and fever,and showed signs of inflammatory reaction and marked rise of hepatobiliary enzymes.These symptoms resolved and they showed normalized values of blood biochemical parameters after conservative treatment without evidence of stones in the common bile duct on MRCP.All these patients were subjected to ERCP within 3 d of MRCP to check for the presence of stones.RESULTS:No stones were detected by ERCP in any patient,confi rming the results of MRCP.CONCLUSION:When clinical symptoms improve,blood biochemical parameters have normalized,and MRCP shows there are no stones in the common bile duct,it can be considered the stone has spontaneously passed and thus ERCP is not necessary.

Bile duct hamartomas(von Mayenburg complexes) mimicking liver metastases from bile duct cancer:MRC findings

We present a case of a 72-year-old man with a common bile duct cancer, who was initially believed to have multiple liver metastases based on computed tomography findings, and in whom magnetic resonance cholangiography （MRC） revealed a diagnosis of bile duct hamartomas. At exploration for pancreaticoduodenectomy, liver palpation revealed disseminated nodules at the surface of the liver. These nodules showed gray-white nodular lesions of about 0.5 cm in diameter scattered on the surface of both liver lobes, which were looked like multiple liver metastases from bile duct cancer. Frozen section of the liver biopsy disclosed multiple bile ducts with slightly dilated lumens embedded in the collagenous stroma characteristics of multiple bile duct hamartomas （BDHs）. Only two reports have described the MRC features of bile duct hamartomas. Of all imaging procedures, MRC provides the most relevant features for the imaging diagnosis of bile duct hamartomas.

Iatrogenic extrahepatic bile duct injury in 182 patients: causes and management

Objective: To describe the causes and treatment ofiatrogenic bile duct injury caused by cholecystecto-my.Methods: 182 patients with iatrogenic extrahepaticbile duct injury from 4 university hospitals of Chinawere reviewed. Details of primary cholecystectomy,biliary reconstruction as well as postoperative ma-nagement were recorded. All patients were followedup for at least 6 months (6 months to 9 years, medi-an 3.5 years). The adequacy of repair was assessedby regular evaluation of the patients clinical statusand liver function variables. Hepatobiliary B-ultra-sonography was used routinely in the follow up of pa-tients, and magnetic resonance cholangiopancreatog-raphy was applied in the patients suggestive of abnor-mality.Results: In 152 patients, bile duct injury happenedduring open cholecystectomy, and in 30 patients dur-ing laparoscopic cholecystectomy. All the injuries de-veloped during anterograde cholecystectomy (at theCalot’s triangle). All the patients with these injuriesunderwent choledochocholedochostomy or Roux-en-Ycholedochojejunostomy with good results (161 pa-tients), recurrent stricture (11), and death (10).Conclusions: During cholecystectomy, the Calot’s tri-angle should be identified anatomically, but retro-grade cholecystectomy is the optimal choice. Bileduct injury should be discovered as soon as possibleand be managed timely. Different operative methodsare optional according to the degree of injury and thepostoperative period.

Multicentric recurrence of intraductal papillary neoplasm of bile duct after spontaneous detachment of primary tumor:A case report

BACKGROUND Intraductal papillary neoplasm of the bile duct(IPNB)rarely recurs in a multicentric manner.We encountered a patient with multiple recurrences of the gastric subtype of IPNB one year after spontaneous detachment of the primary tumor during peroral cholangioscopy(POCS).CASE SUMMARY A 68-year-old woman on maintenance hemodialysis because of lupus nephritis had several cardiovascular diseases and a pancreatic intraductal papillary mucinous neoplasm(IPMN).She was referred to our department for dilation of the common bile duct(CBD)and a tumor in the lumen,detected using ultrasonography.She had no complaints,and blood tests of hepatobiliary enzymes were normal.Magnetic resonance cholangiopancreatography(MRCP)showed a papillary tumor in the CBD with a filling defect detected using endoscopic retrograde cholangiography(ERC).Intraductal ultrasonography revealed a papillary tumor and stalk at the CBD.During POCS,the tumor spontaneously detached with its stalk into the CBD.Pathology showed low-intermediate nuclear atypia of the gastric subtype of IPNB.After 1 year,follow-up MRCP showed multiple tumors distributed from the left hepatic duct to the CBD.ERC and POCS showed multicentric tumors.She was alive without hepatobiliary symptoms at least two years after initial diagnosis of IPNB.CONCLUSION The patient experienced gastric subtype of IPNB without curative resection.Observation may be reasonable for patients with this subtype.

Role of endoscopic ultrasound in evaluation of patients with missed common bile duct stones

BACKGROUND Choledocholithiasis develops in up to 20%of patients with gall bladder stones.The challenge in diagnosis usually occurs with small stones that may be missed by magnetic resonance cholangiopancreatography(MRCP).Endoscopic ultrasound(EUS)is accurate in detecting common bile duct(CBD)stones missed by MRCP,especially the small ones or those impacted at the distal CBD or the papillary region.AIM To evaluate the accuracy of EUS in detecting CBD stones missed by MRCP.METHODS Patients with an intermediate likelihood of choledocholithiasis according to ESGE guidelines and those with acute pancreatitis of undetermined cause were included.The presence of choledocholithiasis was evaluated by MRCP and EUS,and then results were confirmed by endoscopic retrograde cholangiopancreatography(ERCP).The sensitivity and specificity of EUS and MRCP were compared regarding the presence of stones,the size,and the number of detected stones.RESULTS Ninety out of 100 involved patients had choledocholithiasis,while ten patients were excluded as they had pancreatic or gall bladder masses during EUS examination.In choledocholithiasis patients,the mean age was 52.37±14.64 years,and 52.2%were males.Most patients had biliary obstruction(74.4%),while only 23(25.6%)patients had unexplained pancreatitis.The overall prevalence of choledocholithiasis was 83.3%by EUS,41.1%by MRCP,and 74.4%by ERCP.Also,the number and size of CBD stones could be detected accurately in 78.2%and 75.6%by EUS and 41.1%and 70.3%by MRCP,respectively.The sensitivity of EUS was higher than that of MRCP(98.51%vs 55.22%),and their predictive value was statistically different(P<0.001).Combination of both tools raised the sensitivity to 97.22%and specificity to 100%.CONCLUSION EUS could be a useful tool in assessing patients with suspected choledocholithiasis especially if combined with MRCP.However,its usefulness depends on its availability and the experience of the local centers.