What is the upper limit of normal for the common bile duct on ultrasound: how much do you want it to be?

Ultrasound of Bile Ducts-An Update on Measurements, Reference Values, and Their Influencing Factors

Objective: To provide an overview of the technique and normal values of ultrasound studies of the bile system based on the published literature. Methods: A literature search for ultrasound studies with measurements of the bile ducts in healthy subjects was performed. Relevant data published between 1975 and end of 2024 were extracted, discussed, and complemented with the own experiences of the authors. The clinical implications are presented and discussed. Results: For the diameter of the common bile duct, reference values between 5 and 9 mm have been published. The main influencing factors are age and history of cholecystectomy, and other factors to be considered are discussed here. The cut-off for the common bile duct wall is set at 1.5 mm. The literature on measurements of intrahepatic bile ducts is scarce. A diameter of <2-3 mm can be considered normal. The method of ultrasound examination is presented here, as well as a comparison with other imaging methods and their clinical implications. Conclusions: Standardized measurement techniques and normal values in the context of influencing factors are crucial for the ultrasound examination of the bile system.

Point-of-Care Ultrasound in Clinical Care: Abdomen

Abdominal point-of-care ultrasound is an essential diagnostic tool for internal medicine physicians. It can identify intraperitoneal free fluid, evaluate the liver for size, presence of steatosis, and assessment for possible cirrhosis. Diagnosing cholelithiasis or cholecystitis can expedite care. Physical examination for mild splenomegaly may be insensitive. In such cases, sonographic measurements may provide a more definitive diagnosis. With the proper training, these organs can be evaluated at the bedside and guide clinical decision making.

Clinical significance of incidental common bile duct dilatation in children: A 10-year single medical center experience

BACKGROUND

With the widespread use of abdominal ultrasonography (US), incidental detection of common bile duct (CBD) dilatation is common in pediatric populations. This study investigated the causes and clinical significance of CBD dilatation in children without biliary symptoms, jaundice, or causative lesions in US.

METHODS

We retrospectively reviewed pediatric patients with CBD dilatation from July 2013 to June 2023. All cases were detected via abdominal US. We analyzed the patients' clinical manifestations, laboratory data, diagnosis, underlying diseases, and clinical course.

RESULTS

In a total of 687 patients enrolled, 338 met inclusion criteria (90 in hepatobiliary, 248 in CBD dilatation group). Of 128 patients with incidental CBD dilatation who underwent regular US examinations, 91 (71.1%) experienced resolution during follow-up. The proportion of patients with intrahepatic duct dilatation was significantly higher in the non-resolution group (p = 0.038). General health examination group had significant smaller CBD diameter compared to the gastrointestinal and infection groups. Correlation analysis found starting point of resolution decline at 3.24 mm (all-inclusive) and 2.51 mm (infant group) CBD diameter.

CONCLUSIONS

Most children with incidental CBD dilatation did not have abnormal hepatobiliary function or other sonographic abnormalities. They usually remained asymptomatic and experienced uneventful clinical courses.

Imaging of Benign Biliary Tract Disease

This review article discusses the most common benign biliary disorders and the various radiological findings on multiple modalities. A broad spectrum of diseases including various congenital disorders, infective and parasitic etiologies, immunological pathologies such as primary sclerosing cholangitis, and immunoglobulin G4-related sclerosing cholangitis are discussed along with obstructive diseases and ischemic cholangitis. The article emphasized the imaging differential diagnosis of the above lesions as well as clinical correlates those that are most relevant to radiologists. The article briefly touched upon management and intervention where relevant.

Biliary Duct Dilatation: AJR Expert Panel Narrative Review

Biliary duct dilatation is a common incidental finding in practice, but it is unlikely to indicate biliary obstruction in the absence of clinical symptoms or elevated levels on liver function tests (LFTs). However, the clinical presentation may be nonspecific, and LFTs may either be unavailable or difficult to interpret. The goal of this AJR Expert Panel Narrative Review is to highlight a series of topics fundamental to the management of biliary duct dilatation, providing consensus recommendations in a question-and-answer format. We start by covering a basic approach to interpreting LFT results, the strengths and weaknesses of the biliary imaging modalities, and how and where to measure the extrahepatic bile duct. Next, we define the criteria for biliary duct dilatation, including patients with prior cholecystectomy and advanced age, and discuss when and whether biliary duct dilatation can be attributed to papillary stenosis or sphincter of Oddi dysfunction. Subsequently, we discuss two conditions in which the duct is pathologically dilated but not obstructed: congenital cystic dilatation (i.e., choledochal cyst) and intraductal papillary neoplasm of the bile duct. Finally, we provide guidance regarding when to recommend obtaining additional imaging or testing, such as endoscopic ultrasound or ERCP, and include a discussion of future directions in biliary imaging.

Definition of age-dependent reference values for the diameter of the common bile duct and pancreatic duct on MRCP: a population-based, cross-sectional cohort study

OBJECTIVE

Changes of the pancreaticobiliary ducts herald disease. Magnetic resonance cholangiopancreatography (MRCP) allows accurate duct visualisation. Data on reliable upper reference ranges are missing.

DESIGN

Cross-sectional whole body MRI data from the population-based Study of Health in Pomerania were analysed. The width of the common bile duct (CBD) and the pancreatic duct (PD) was determined. We aimed to describe the distribution of physiological duct diameters on MRCP in a population of healthy subjects and to identify factors influencing duct size.

RESULTS

After excluding pre-existing pancreaticobiliary conditions, CBD and PD diameters from 938 and 774 healthy individuals, respectively, showed a significant increase with age (p<0.0001) and exceeded the conventional upper reference limit of normal in 10.9% and 18.2%, respectively. Age-dependent upper reference limits of duct diameters were delineated with non-parametric quantile regression, defined as 95th percentile: for CBD up to 8 mm in subjects <65 years and up to 11 mm in subjects ≥65 years. For the PD reference diameters were up to 3 mm in subjects <65 years and up to 4 mm in subjects ≥65 years.

CONCLUSIONS

This is the first population-based study delineating age-adjusted upper reference limits of CBD and PD on MRCP. We showed that up to 18.2% of healthy volunteers would have needed diagnostic workup, if the conventional reference values were used. The utilisation of the adapted reference levels may help to avoid unnecessary investigations and thus to reduce healthcare expenditure and test-related adverse events.

Effectiveness of ultrasound screening in right upper quadrant pain: A comparative study in a basic emergency service

Background and Aims

The use of ultrasound screening is primarily facilitated by point-of-care ultrasound (POCUS) and its integration into healthcare systems is a result of the versatility of this imaging technique. This study intends to compare the accuracy and pertinence of sonographic findings obtained by a sonographer in a Basic Emergency Service (BES) with that of radiologists at referral hospital (RH) in Portugal.

Methods

Twenty patients with right upper quadrant (RUQ) pain and suspected cholecystitis or biliary pathology underwent sonography screening using POCUS in the BES. They were then forwarded to the RH where a radiologist performed a conventional ultrasound exam on the same patients. The results of both exams were compared to determine if the findings obtained in the BES were confirmed by the radiologist in the RH.

Results

In our sample, 60% of cases were related to biliary pathology, 20% were liver-related, 10% had hepatopancreatic biliary etiology, and 10% had unknown etiology. A strong association between the sonographic findings in the BES and the RH was found in the variables "Sonographic Murphy sign" (V = 0.859; p = 0.001), "Cholelithiasis/Gallbladder sludge" (V = 0.840; p = 0.001), and "Intrahepatic biliary tract dilatation" (V = 0.717; p = 0.006). Adequate measures of agreement between the findings of the radiographer and radiologist were obtained for the "Sonographic Murphy sign" (k = 0.664; p = 0.001) and the presence of "Cholelithiasis/Gallbladder sludge" (k = 0.712; p = 0.000).

Conclusion

Major biliary abnormalities were detected in patients with RUQ pain in BES using sonography. The correlation between the sonographic findings obtained by the sonographers at BES and those obtained by radiologists at the RH in Portugal was strong, showing that POCUS screening could be extended to other similar settings; however, more studies are needed.

Computed tomographic quantitative evaluation of common bile duct size in normal dogs: A reference range study considering body weight

Introduction

Common bile duct (CBD) measurements are important for the evaluation of biliary systemic disorders. However, in veterinary medicine, reference ranges for specific body weights (BW) and correlation between CBD diameter and BW have not been studied. This study aimed to establish normal reference ranges of CBD diameter for different BW groups and to analyse correlation between CBD diameter and BW in dogs without hepatobiliary disease. Additionally, normal reference ranges of CBD to aorta ratio (CBD: Ao ratio) were established which is not affected by BW.

Methods

CBD diameter was measured at three different sites: porta hepatis (PH), duodenal papilla (DP) level and mid-portion (Mid) between these points using computed tomography (CT) in 283 dogs without hepatobiliary disease.

Results

The reference range of CBD diameter at PH level: 1.69 ± 0.29 mm (Class 1; 1 kg ≤ BW &lt; 5 kg), 1.92 ± 0.35 mm (Class 2; 5 kg ≤ BW &lt; 10 kg), 2.20 ± 0.43 mm (Class 3; 10 kg ≤ BW &lt; 15 kg), 2.79 ± 0.49 mm (Class 4; 15 kg ≤ BW &lt; 30 kg); Mid-level: 2.06 ± 0.25 mm (Class 1), 2.43 ± 0.37 mm (Class 2), 2.74 ± 0.52 mm (Class 3), 3.14 ± 0.44 mm (Class 4); DP level: 2.33 ± 0.34 mm (Class 1), 2.90 ± 0.36 mm (Class 2), 3.35 ± 0.49 mm (Class 3), and 3.83 ± 0.50 mm (Class 4). There was a significant difference in CBD diameter at each level among all BW groups. Furthermore, BW and CBD diameter showed positive linear correlation at each level. We devised CBD: Ao ratio at each level that showed no significant difference between the different BW groups; PH level: 0.34 ± 0.05; Mid-level: 0.42 ± 0.06; DP level: 0.47 ± 0.06.

Conclusion

In conclusion, since the CBD diameter for each BW is significantly different, different normal reference ranges of CBD diameter should be applied for each BW, and the CBD: Ao ratio can be used regardless of the BW.

Evaluation of the Common bile duct (CBD) Diameter After Laparoscopic Cholecystectomy (LC) and Laparoscopic Common Bile Duct Exploration (LCBDE): A Retrospective Study

BACKGROUND

Common Bile duct (CBD) measurement is a crucial aspect in the evaluation of the biliary tree. Whether the CBD undergoes any compensatory change in diameter after laparoscopic cholecystectomy or laparoscopic common bile duct exploration is still up for discussion. The aim of this study was to investigate CBD diameter changes after laparoscopic cholecystectomy (LC) and laparoscopic common bile duct exploration (LCBDE) on magnetic resonance cholangiopancreatography (MRCP).

MATERIALS AND METHODS

Our retrospective study is divided into 2 sections. The first part assessing CBD diameter changes after laparoscopic cholecystectomy due to gallstones or gallbladder polyps, involved 85 patients, who underwent MRCP procedures. These patients aged between 30 and 85 were divided into an interval LC group (group A, n=56) and a remote LC group (group B, n=29). In group A, the common CBD diameters were measured at their widest portions on MRCP obtained before and after laparoscopic cholecystectomy. Measurements of the CBD diameters were repeated on MRCP obtained twice after the surgery in group B.Section 2 consisted of 38 patients who had choledocholithiasis and were treated with laparoscopic CBD exploration and T-tube placement. These patients aged 26 to 86 formed the interval LCBDE group (group C). The CBD widest diameters were measured on MRCP before LCBDE and after T-tube cholangiography for these individuals.Patients in groups A and C were further divided into 5 and those in group B into 4 age-related subgroups to facilitate statistical analysis. The Pearson correlation test was performed to find any relationship between CBD diameters and age in groups A and B. Paired sample T test was used to compare the significant difference between the 2 sets of CBD diameters in each study group and their subgroups.

RESULTS

In the interval LC group, the post-LC mean CBD diameter was significantly wider when compared with the preoperative mean diameter ( P <0.05). There was a significant difference between the first and second post-LC means CBD diameter in the remote LC group ( P <0.05). In group C, the mean CBD diameter measured on T-tube cholangiography after LCBDE was significantly smaller than the preoperative dilated mean diameter ( P <0.05).

CONCLUSIONS

This study demonstrated significant dilation occurring in the common bile duct diameter after laparoscopic cholecystectomy. Furthermore, our remote LC group also supported that claim by showing significant dilation between the first and second post-cholecystectomy CBD diameter values. And lastly, our interval LCBDE sample's initial dilation of the CBD diameters was reduced after surgery and stone extraction.

Imaging of benign biliary pathologies

Pathologies of the biliary tree include a wide-spectrum of benign and malignant processes. The differential for benign disease includes congenital and acquired disease with variable prognosis and management pathways. Given the ability to mimic malignancy, benign processes are difficult to diagnose by imaging. Direct cholangiography techniques with tissue sampling are the gold standards for the diagnosis of benign and malignant biliary pathologies. Non-invasive imaging with ultrasound offers a first-line diagnostic tool while MRI/MRCP offers higher specificity for identifying underlying pathology and distinguishing from malignant disease. In this review, we focus on the imaging appearance of dilatation, cystic anomalies obstruction, inflammation, ischemia, strictures, pneumobilia, and hemobilia to help construct a differential for benign processes.

Early laparoscopic cholecystectomy in oldest-old patients: a propensity score matched analysis of a nationwide registry

The role of early laparoscopic cholecystectomy (ELC) in "oldest-old" patients with acute calculous cholecystitis (ACC) is still controversial. The aim of this study is to assess the safety of ELC for ACC in ≥ 85-year-old patients. Multicentric retrospective study that analysed data of patients who underwent ELC for ACC between 2013 and 2018. Patients ≥ 85-year-old (oldest-old patients) were compared with younger patients, before and after propensity score matching (PSM). The main outcomes were mortality, post-operative complications, length of stay (LOS), and readmissions. The study included 1670 patients. The unmatched comparison revealed a selection bias towards the oldest-old group, which was associated with higher Charlson Comorbidity Index (5 vs 1, p < 0.001), more ASA III/IV subjects (54.2% vs 19.3%, p < 0.001), class II/III ACC (80.1% vs 69.1%, p = 0.016) and higher Chole-Risk Score (p > 0.001). The oldest-old also required more conversion to open surgery (20% vs 10.3%, p = 0.005). Postoperatively, they had a higher 90-day mortality rate (7.6% vs 1%, p < 0.001), more total complications (40.6% vs 17.7%, p < 0.001), complications ≥ IIIa Clavien-Dindo (14.4% vs 5.8%, p = 0.002), longer LOS (6 vs 5 days, p < 0.001), and more readmissions (6.6% vs 2.6%, p < 0.001). After PSM (n = 206), the two groups were comparable in terms of baseline characteristics and intraoperative outcomes. No differences were observed in post-operative complications; bile leak; incisional, intrabdominal, urinary or respiratory tract infections; LOS or readmissions. In the oldest-old, ELC for ACC is still associated with significant morbidity and mortality. However, it seems to be safe in selected patients. Therefore, age itself should not be regarded as a contraindication to ELC for ACC.

Imaging Features of Main Posthepatectomy Complications: A Radiologist’s Challenge

In the recent years, the number of liver resections has seen an impressive growth. Usually, hepatic resections remain the treatment of various liver diseases, such as malignant tumors, benign tumors, hydatid disease, and abscesses. Despite technical advancements and tremendous experience in the field of liver resection of specialized centers, there are moderately high rates of postoperative morbidity and mortality, especially in high-risk and older patient populations. Although ultrasonography is usually the first-line imaging examination for postoperative complications, Computed Tomography (CT) is the imaging tool of choice in emergency settings due to its capability to assess the whole body in a few seconds and detect all possible complications. Magnetic resonance cholangiopancreatography (MRCP) is the imaging modality of choice for delineating early postoperative bile duct injuries and ischemic cholangitis that may arise in the late postoperative phase. Moreover, both MDCT and MRCP can precisely detect tumor recurrence. Consequently, radiologists should have knowledge of these surgical procedures for better comprehension of postoperative changes and recognition of the radiological features of various postoperative complications.

Management of Patients With Common Bile Duct Dilatation Without a Sonographic Evident Cause: Evaluating the Yield of Subsequent Magnetic Resonance Imaging and Findings Correlated With Causative Pancreaticobiliary Pathology

OBJECTIVES

The aims of the study were to evaluate the yield of magnetic resonance imaging (MRI) in patients with common bile duct (CBD) dilatation without a sonographic evident cause and to investigate sonographic and laboratory findings at presentation that might predict identification of underlying pancreaticobiliary pathology.

METHODS

Included were consecutive patients in whom MRI was performed for further evaluation of CBD dilatation detected on ultrasound (US), without a sonographic evident cause, from January 1, 2014, to December 31, 2014. Magnetic resonance imaging and clinical data were retrospectively reviewed. Patients were divided into two groups: patients with and without identified underlying causative pancreaticobiliary pathology. Ultrasound findings and laboratory results at presentation were compared between groups to identify findings suggestive of underlying pancreaticobiliary pathology.

RESULTS

Fifty-seven patients, with a mean age of 54 ± 16 years including 37 females (65%), underwent MRI. Specific pancreaticobiliary causes for CBD dilatation were identified in 38 patients (66%, 31 benign and 7 malignant). In the remaining patients, no cause was identified in 17 (30%) and MRIs were nondiagnostic in 2 patients. Magnetic resonance imaging accuracy for correctly identifying the underlying cause of CBD dilatation was 91%. Patients with associated intrahepatic bile duct dilatation on US and elevated alanine aminotransferase and alkaline phosphatase were more likely to have underlying pancreaticobiliary pathology (P < 0 .05). No patient with initial negative MRI had pancreaticobiliary malignancy.

CONCLUSIONS

Magnetic resonance imaging seems to be an accurate noninvasive method for identifying the underlying cause in most patients with CBD dilatation on US and in excluding pancreaticobiliary malignancy. Patients with associated intrahepatic bile duct dilatation and/or elevated liver enzymes are at higher risk of harboring underlying pancreaticobiliary pathology.

Evaluation of diagnostic yield of EUS among patients with asymptomatic common bile duct dilation: systematic review and meta-analysis

BACKGROUND AND AIMS

Common bile duct (CBD) dilation is a frequent indication for EUS. Among asymptomatic individuals, biliary dilation may not be clinically significant; however, EUS is often relied on for the exclusion of benign and malignant pathology that might require further intervention. The yield of EUS evaluation for this indication is not well characterized and has significant implications for health resource utilization because asymptomatic biliary dilation is prevalent. Through this systematic review, we sought to appraise the yield of EUS evaluation of asymptomatic patients with radiologic evidence of isolated CBD dilation.

METHODS

A protocolled search (PROSPERO: CRD42020193428) extracted original studies from the Cochrane Library, Ovid Embase, Google Scholar, Ovid Medline, PubMed, Scopus, and Web of Science Core Collection that described diagnostic yield of EUS among asymptomatic patients with biliary dilation. Cumulative EUS diagnostic yield was calculated through meta-analysis of proportions using inverse variance methods and a random-effects model.

RESULTS

Of 2616 studies, 8 delineated the EUS yield among 224 asymptomatic patients. The cumulative yield of EUS for any pathology was 11.2% (95% confidence interval [CI], 3.6%- 21.6%). The EUS yield for benign etiologies was 9.2% (95% CI, 1.1%-21.9%), of which choledocholithiasis comprised 3.4% (95% CI, 0%-11.2%) and malignant etiologies .5% (95% CI, 0%-3.4%) of cases.

CONCLUSIONS

EUS in patients with asymptomatic CBD dilation does yield findings of choledocholithiasis and malignancy, albeit at low rates. A cost-effectiveness analysis is warranted to further guide clinical decision-making in this area.

How to Predict Postoperative Complications After Early Laparoscopic Cholecystectomy for Acute Cholecystitis: the Chole-Risk Score

BACKGROUND

Early laparoscopic cholecystectomy (ELC) is the gold standard treatment for patients with acute calculous cholecystitis (ACC); however, it is still related to significant postoperative complications. The aim of this study is to identify factors associated with an increased risk of postoperative complications and develop a preoperative score able to predict them.

METHODS

Multicentric retrospective analysis of 1868 patients with ACC submitted to ELC. Included patients were divided into two groups according to the presentation of increased postoperative complications defined as postoperative complications ≥ Clavien-Dindo IIIa, length of stay greater than 10 days and readmissions within 30 days of discharge. Variables that were independently predictive of increased postoperative complications were combined determining the Chole-Risk Score, which was validated through a correlation analysis.

RESULTS

We included 282 (15.1%) patients with postoperative complications. The multivariate analysis predictors of increased morbidity were previous percutaneous cholecystostomy (OR 2.95, p=0.001), previous abdominal surgery (OR 1.57, p=0.031) and diabetes (OR 1.62, p=0.005); Charlson Comorbidity Index >6 (OR 2.48, p=0.003), increased total bilirubin > 2 mg/dL (OR 1.88, p=0.002), dilated bile duct (OR 1.79, p=0.027), perforated gallbladder (OR 2.62, p<0.001) and severity grade (OR 1.93, p=0.001). The Chole-Risk Score was generated by grouping these variables into four categories, with scores ranging from 0 to 4. It presented a progressive increase in postoperative complications ranging from 5.8% of patients scoring 0 to 47.8% of patients scoring 4 (p<0.001).

CONCLUSION

The Chole-Risk Score represents an intuitive tool capable of predicting postoperative complications in patients with ACC.

Patients With Unexplained Dilated Pancreatic Duct Have High Risk of Biliopancreatic Malignancy Detected by EUS

INTRODUCTION

Patients with unexplained dilated common bile duct (CBD) and/or dilated main pancreatic duct (MPD) on noninvasive abdominal imaging tests are often referred for endoscopic ultrasound (EUS) in order to rule out biliopancreatic cancer. The aim of the study was to evaluate the diagnostic yield of EUS in this patient group.

METHODS

A prospective study was conducted. Patients with unexplained dilated CBD and/or MPD on abdominal imaging, who underwent EUS, were enrolled.

RESULTS

Fifty-four patients underwent EUS (CBD dilation n=38, MPD dilation n=5 or both n=11). In 31/54 patients (57.4%), EUS revealed pathologic findings. Sixteen patients (29.6%) had EUS evidence of biliopancreatic cancer and 15 patients (27.7%) had benign pathology. Ten (62.5%) of the patients with biliopancreatic cancer had MPD dilation. MPD dilation was significantly associated with malignancy (P=0.017).

CONCLUSION

Patients with unexplained dilated MPD on noninvasive image have a high risk of biliopancreatic malignancy detected by EUS.

Recommendations for the Management of Incidental Hepatobiliary Findings in Adults: Endorsement and Adaptation of the 2017 and 2013 ACR Incidental Findings Committee White Papers by the Canadian Association of Radiologists Incidental Findings Working Group

The Canadian Association of Radiologists Incidental Findings Working Group consists of both academic subspecialty and general radiologists and is tasked with adapting and expanding upon the American College of Radiology incidental findings white papers to more closely apply to Canadian practice patterns, particularly more comprehensively dealing with the role of ultrasound and pursuing more cost-effective approaches to the workup of incidental findings without compromising patient care. Presented here are the 2020 Canadian guidelines for the management of hepatobiliary incidental findings. Topics covered include initial assessment of hepatic steatosis and cirrhosis, the workup of incidental liver masses identified on ultrasound and computed tomography (with algorithms presented), incidental gallbladder findings (wall thickening, calcification, and polyps), and management of incidental biliary dilatation.

Liver Injury and Failure in Critical Illness

The frequency of acquired liver injury and failure in critical illness has been significantly increasing over recent decades. Currently, liver injury and failure are observed in up to 20% of patients in intensive care units and are associated with significantly increased morbidity and mortality. Secondary forms of liver injury in critical illness are divided primarily into cholestatic, hypoxic, or mixed forms. Therefore, sufficient knowledge of underlying alterations (e.g., hemodynamic, inflammatory, or drug induced) is key to a better understanding of clinical manifestations, prognostic implications, as well as diagnostic and therapeutic options of acquired liver injury and failure. This review provides a structured approach for the evaluation and treatment of acquired liver injury and failure in critically ill patients.

Combining endoscopic ultrasound and tumor markers improves the diagnostic yield on the etiology of common bile duct dilation secondary to periampullary pathologies

Background

Unexplained common bile duct (CBD) dilatation may be caused by many etiologies, such as periampullary tumors, a pancreatic neoplasm, choledocholithiasis or an inflammatory stenosis. The aim of this study is to evaluate the diagnostic yield of endoscopic ultrasonography (EUS) in patients with unexplained CBD dilatation, in combination with tumor markers, liver chemistry, symptoms, surgical history and whether there is dilatation of the pancreatic duct (PD).

Methods

From January 2016 to July 2017, 115 patients were referred for EUS in our center for CBD dilatation of an unknown etiology. A treatment plan is made based on the EUS result combined with the other clinical information. The final diagnosis is determined by surgical histology or follow-up of at least 3 months.

Results

The sensitivity, specificity and accuracy of EUS for patients with choledocholithiasis were 100.0% (10/10), 100.0% (105/105) and 100.0% (115/115), respectively. The sensitivity, specificity and accuracy of EUS for patients with periampullary tumor were 86.5% (32/37), 89.7% (70/78) and 88.7% (102/115), respectively. The sensitivity, specificity and accuracy of EUS for patients with inflammatory stenosis were 88.2% (60/68), 89.4% (42/47) and 88.7% (102/115), respectively. The overall accuracy of EUS for diagnosing an undetermined etiology for CBD dilatation was 88.7% (102/115) and was higher than the accuracy of ultrasound (US) (64.1%), computed tomography (CT) (66.2%), magnetic resonance imaging (MRI) (67.0%) or PET-CT (66.0%). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EUS combined with tumor markers for patients with malignant dilatation of CBD were 91.9% (34/37), 97.4% (76/78), 94.4% (34/36), 96.2% (76/79) and 95.7% (110/115), respectively. PD dilation (P=0.026) and weight loss (P=0.035) had significant predictive values of malignancy.

Conclusions

EUS is an effective diagnostic tool for determining the etiology of a CBD dilatation, and offers meaningful information for guiding a treatment plan. EUS used in conjunction with tumor markers has high yield in differentiating benign and malignant CBD dilatation. More attention should be paid to patients with PD dilation or weight loss to prevent misdiagnosis of malignant CBD dilation.

Standardization of common bile duct size using ultrasound in pediatric patients

BACKGROUND/PURPOSE

The incidence of choledocholithiasis is increasing. The diagnosis of common bile duct (CBD) obstruction is based on abnormal CBD size. Establishing norms for CBD size in children would improve diagnostic accuracy. We analyzed ultrasounds (US) to determine normal pediatric CBD size based on age and then validated this against patients with choledocholithiasis.

METHODS

A retrospective review was conducted for children less than 21 years of age with US defined CBD size. Patients were stratified into age groups by ANOVA statistical analysis. Secondary analysis included patients with confirmed choledocholithiasis in comparison to the normal cohort.

RESULTS

A total of 778 patients had US without pathology. Group 1 (<1 year) had a mean CBD of 1.24±0.54 mm, group 2 (1-10 years) 1.97±0.71 mm, and group 3 (>10 years) 2.98±1.17 mm, p<0.05. Fourteen additional patients were found to have choledocholithiasis with a mean CBD size of 8.1 mm. All patients with choledocholithiasis had CBD sizes outside of our normal range, but only 50% of patients had enlarged CBD size based on adult normal range of values.

CONCLUSION

Normal CBD size in children is less than a normal adult patient. More accurate normal values will aid in determining if a child needs further evaluation for possible obstruction of the CBD.

TYPE OF STUDY

diagnostic Level of evidence: III.

The Use of Endoscopic Ultrasound in the Evaluation of Unexplained Biliary Dilation

Isolated biliary dilation, as an incidental diagnosis, is increasing owing to an increase in the use of noninvasive abdominal imaging and poses a diagnostic challenge to physicians especially when further noninvasive diagnostic testing fails to reveal an etiology. This article reviews available data describing the natural history of this clinical scenario and the impact of endoscopic ultrasound examination in the evaluation of unexplained dilation of the common bile duct.

Asymptomatic Bile Duct Dilatation in Children: Is It a Disease?

PURPOSE

Bile duct dilatation is a relatively common sonographic finding; nevertheless, its clinical significance in children is controversial because little research has been done in the area. Therefore, we investigated the natural course and clinical significance of biliary duct dilatation in children.

METHODS

We performed a retrospective study of 181 children (range, 1-day-old to 17-year-old) in whom dilatation of the intrahepatic duct and/or common hepatic duct and/or common bile duct was detected by abdominal ultrasonography at the Severance Children's Hospital between November 2005 and March 2014. We reviewed and analyzed laboratory test results, clinical manifestations, and clinical course in these patients.

RESULTS

Pediatric patients (n=181) were enrolled in the study and divided into two groups. The first group included 59 subjects, without definitive cause of bile duct dilatation, who did not require treatment; the second group included 122 subjects, with definitive cause of bile duct dilatation or underlying biliary disease, who did require treatment. In the first group, 24 patients (40.7%) showed spontaneous resolution of bile duct dilatation, 20 patients (33.9%) showed no change, and 15 patients (25.4%) were lost to follow-up. In the second group, 31 patients were diagnosed with choledochal cysts, and 91 patients presented with biliary tract dilatations due to secondary causes, such as gallbladder or liver disease, post-operative complications, or malignancy.

CONCLUSION

Biliary dilatation in pediatric patients without symptoms, and without laboratory and other sonographic abnormalities, showed a benign clinical course. No pathologic conditions were noted on follow-up ultrasonography.

Endoscopic ultrasound in common bile duct dilatation with normal liver enzymes

In recent years, the description of isolated bile duct dilatation has been increasingly observed in subjects with normal liver function tests and nonspecific abdominal symptoms, probably due to the widespread use of high-resolution imaging techniques. However, there is scant literature about the evolution of this condition and the impact of endoscopic ultrasound (EUS) in the diagnostic work up. When noninvasive imaging tests (transabdominal ultrasound, computed tomography or magnetic resonance cholangiopancreatography) fail to identify the cause of dilatation and clinical or biochemical alarm signs are absent, the probability of having biliary disease is considered low. In this setting, using EUS, the presence of pathologic findings (choledocholithiasis, strictures, chronic pancreatitis, ampullary or pancreatic tumors, cholangiocarcinoma), not always with a benign course, has been observed. The aim of this review has been to evaluate the prevalence of disease among non-jaundiced patients without signs of cytolysis and/or cholestasis and the assessment of EUS yield. Data point out to a promising role of EUS in the identification of a potential biliary pathology. EUS is a low invasive technique, with high accuracy, that could play a double cost-effective role: identifying pathologic conditions with dismal prognosis, in asymptomatic patients with negative prior imaging tests, and excluding pathologic conditions and further follow-up in healthy subjects.

Clinical presentations of patients from different age cohorts with biliary tract stone diseases

BACKGROUND AND AIM

The role of clinical symptoms, transabdominal ultrasound scan (USS), and liver function tests (LFTs) in evaluating common bile duct (CBD) stones in patients suspected to have pancreatobiliary disease has been studied. However, it is unclear whether these predictive models are useful in different age cohorts. The aim of this study is to investigate the clinical presentations from different age cohorts with and without CBD stones.

METHODS

Four hundred and forty-three patients with pancreatobiliary diseases were divided into cohorts according to decades as follows: young (Y, 18-64 years old, n = 143), young-old (YO, 65-74 years old, n = 168), old-old (OO, 75-84 years old, n = 97), and very old (VO, ≥ 85 years old, n = 35). The clinical symptoms, LFTs, and USS findings were demonstrated and compared among patients.

RESULTS

Y- and YO-group patients were more likely to develop symptoms such as biliary colic in the presence of CBD stones. The proportion of abnormal serum aspartate aminotransferase and alanine aminotransferase were significantly greater in Y-, YO-, and OO-group patients with than in those without CBD stones. Sensitivity of USS for CBD stones in Y: 0.15; YO: 0.45; OO: 0.57; and VO: 0.68. Accuracy of USS for detected CBD stone in Y: 48%; YO: 62.5%; OO: 70.1%; and VO: 71.4%.

CONCLUSION

Combined evaluation of clinical symptoms, biochemical and USS findings may help predict the presence of CBD stones. In Y, YO, and OO patients with CBD stones, the incidences of abnormal LFTs were higher. The sensitivity and accuracy of USS in detecting CBD stones were increased according to age.

Managing incidental findings on abdominal and pelvic CT and MRI, Part 4: white paper of the ACR Incidental Findings Committee II on gallbladder and biliary findings

This white paper describes gallbladder and biliary incidental findings found on CT and MRI. Recommendations for management are included. This represents the fourth of 4 such papers from the ACR Incidental Findings Committee II, which used a consensus method based on repeated reviews and revisions and a collective review and interpretation of relevant literature. Topics include the management of a variety of gallbladder abnormalities and biliary dilation. A table is provided for reference.

Prospective evaluation of early endoscopic ultrasonography for triage in suspected choledocholithiasis: results from a large single centre series

BACKGROUND

Endoscopic ultrasonography is accurate, safe, and cost-effective in diagnosing common bile duct stones, thus suggesting the possibility to avoid invasive endoscopic retrograde cholangiopancreatography.

AIM

To prospectively evaluate the diagnostic and therapeutic performance of early endoscopic ultrasonography in suspected choledocholithiasis.

PATIENTS AND METHODS

All consecutive patients presenting to the Emergency Department with suspicion of choledocholithiasis between January 2010 and January 2012 were evaluated and categorized as low, moderate, or high probability of choledocholithiasis, according to accepted criteria. Endoscopic endosonography was carried out within 48 h from the admission and endoscopic retrograde cholangiopancreatography was performed soon in case of confirmed choledocholithiasis.

RESULTS

Overall 179 patients were included: 48 (26.8%) were classified as low, 65 (36.3%) as moderate, and 66 (36.9%) as high probability of choledocholithiasis. Of the 86 patients with common bile duct stones at endoscopic endosonography, endoscopic retrograde cholangiopancreatography confirmed the finding in 79 (92%). By multivariate analysis only the common bile duct diameter proved an independent predictor of common bile duct stones.

CONCLUSIONS

Early endoscopic endosonography is accurate in identifying choledocholithiasis allowing immediate endoscopic treatment and significant spare of unnecessary endoscopic retrograde cholangiopancreatography. This approach can be useful as a triage test to select patients not needing endoscopic retrograde cholangiopancreatography, allowing, in selected cases, their early discharge.

Initial large diameter of common bile duct is associated with long-term dilatation of bile duct after endoscopic extraction of stones

OBJECTIVE

To investigate the time and extent of recovery of dilated common bile duct (CBD) after the extraction of CBD stones and to identify the factors related to the long-term dilatation of the CBD after stone removal.

METHODS

Data of 329 consecutive patients undergoing endoscopic extraction of CBD stones from January 2008 to December 2012 were retrospectively reviewed. Finally, 44 patients were enrolled in the study.

RESULTS

The CBD diameter significantly decreased after stone extraction (P < 0.001). However, the CBD diameter in patients who were followed up for 1 week and longer and <1 week did not differ significantly. The diameter decreased more in patients with an initial CBD diameter ≥ 15 mm than in those with an initial CBD diameter <15 mm before stone extraction (P = 0.007), but the normalization of dilated CBD was less frequent in patients with a large initial CBD diameter. The factors related to the long-term dilatation of CBD (>10 mm for >6 months) were initial CBD diameter, the largest diameter of CBD stone and endoscopic papillary large balloon dilatation. Initial CBD diameter was an independent factor with multivariate analysis (OR 1.754, P = 0.017).

CONCLUSIONS

The CBD diameter recovers rapidly after the extraction of CBD stones. An initial large CBD diameter before stone extraction is associated with the long-term dilatation of CBD.

Clinical significance and long-term outcome of incidentally found bile duct dilatation

BACKGROUND AND AIM

The significance of incidentally detected bile duct dilatation has not yet been elucidated and there are only a few studies on asymptomatic patients with a dilated bile duct. This study aimed to investigate the causes and natural course of bile duct dilatation in asymptomatic patients.

METHODS

A retrospective review of medical records was conducted for individuals in whom bile duct dilatation was detected by routine screening abdominal ultrasound at a health promotion center in Samsung Medical Center from January 2005 to April 2008.

RESULTS

A total of 514 patients were included; the mean age was 60.1 ± 9.9 and the median follow-up period was 72 (interquartile range 56-85) months. Thirty-eight individuals who had a definite cause or biliary disease requiring treatment at the time of detection of bile duct dilatation were compared with 476 individuals who did not have a definitive cause or who did not need treatment. Both common bile duct (CBD) dilatation and intrahepatic bile duct (IHBD) dilatation were significantly related to the presence of a definitive causative lesion (OR 3.95; 95 % CI 1.77-8.82; p = 0.001). In the IHBD dilatation group, the severity of dilatation was also associated with the presence of a definitive causative lesion (OR 5.77; 95 % CI 1.32-25.26; p = 0.020).

CONCLUSION

Incidentally found biliary dilatation could be a prodrome of significant biliary tree disease. Therefore, further evaluation and regular follow up should be considered especially for marked IHBD dilatation or concomitant dilatation of CBD and IHBD detected on ultrasound.

Which patients with dilated common bile and/or pancreatic ducts have positive findings on EUS?

BACKGROUND

Patients with dilated common bile duct (CBD) (>7mm) and/or pancreatic duct (PD) on abdominal imaging are often referred for endoscopic ultrasound (EUS). In many cases, the EUS shows no obvious etiology for the dilated ducts.

OBJECTIVE

Find clinical factors that may predict which patients are more likely to have positive findings on EUS to explain the etiologies for the dilated ducts.

DESIGN

Retrospective database analysis.

SETTING

Tertiary-care university hospital.

PATIENTS

Patients referred for EUS for dilated CBD and/or PD from January 2004 to February 2010 were included in this study. Only patients without an obvious etiology for the dilated ducts on abdominal imaging were included.

INTERVENTIONS

An EUS was performed by using either a radial echoendoscope or a linear endoscope to evaluate the common bile duct and/or the pancreatic duct. When appropriate fine needle aspiration of the mass or cyst was performed.

MAIN OUTCOME MEASUREMENTS

The characteristics of patients who had positive findings on EUS to explain the etiology of their dilated PD and/or CBD.

RESULTS

A total of 140 patients were included in the study with a mean age of 64 years, 51 (36%) male and 115 (82%) white. The majority of our patients had a presenting symptom of abdominal pain 105 (75%). 49 (36%) had elevated AST or ALT, 25 (8%) had an elevated bilirubin and 13 (23%) had an elevated lipase. EUS findings explained the dilated ducts in 54 (39%) of our patients, most common diagnoses included: CBD stone in 11 (8%), non-calcific chronic pancreatitis in 9 (6%), pancreatic mass in 8 (6%), IPMN in 7 (5%). On bivarate analysis patients who were older (p = 0.006), male (p = 0.001), had elevated LFTs (p = <0.001), had elevated lipase (p = 0.021) or had dilated CBD and PD (p = 0.007) were more likely to have an etiology for their dilated duct(s) discovered on EUS.

LIMITATIONS

A retrospective study with a small number of patients.

CONCLUSION

Older patients, males and those patients presenting with concurrent elevations in the AST/ALT and/or lipase were more likely to have an underlying etiology discovered on EUS. Furthermore, EUS may detect an undiagnosed pancreatic malignancy in patients presenting with unexplained duct dilation.

Is Opioid Addiction a Sufficient Predicting Factor for Common Bile Duct Dilatation? A Sonographic Study

In the absence of hepatobiliary symptoms, opioid consumption has been shown to cause dilatation of the common bile duct (CBD). The main objective of this study was to measure with sonography CBD diameters in opioid addicts as compared with nonaddicts. The research was done on 208 individuals; 104 were opioid addicts using various routes of administration (inhalation, oral, or intravenous), and 104 had no history of addiction (control group). All patients underwent abdominopelvic sonography, and the internal diameters of the proximal part of the CBD were recorded. The average CBD diameter in the control group was 4.13 ± 1.14 mm, which significantly increased to 8.16 ± 2.54 mm in the case group. A significant increase in the average diameter of CBD in the case group with the oral route was 10.7 ± 2.26 mm, compared with 7.5 ± 1.64 mm and 7.6 ± 3.05 mm, respectively, for those using inhalation and intravenous routes. The diameter of CBD was age dependent. The dilatation of the CBD detected by sonography occurring in opioid addicts in all age groups was attributed principally to the effect of opioids. Oral administration of opioid caused the highest dilatation effect on CBD.

The diameter of common bile duct does not predict the cause of extrahepatic cholestasis

BACKGROUND

Extrahepatic cholestasis is usually caused by either a bile duct stone or a stricture. In early phase in primary care, when novel imaging studies such as magnetic resonance cholangiopancreatography or endoscopic retrograde cholangiopancreatography (ERCP) are seldom available, the differential diagnosis between benign and malignant causes is clinically challenging. The aim of the present study was to analyze the value of the degree of common bile duct dilatation in differential diagnosis of extrahepatic cholestasis.

METHODS

In all, 212 consecutive patients in whom a bile duct stricture (n=103) or a stone (n=109) had been found in ERCP were included in the study population. The maximum diameter of the common bile duct was measured from ERCP images. Plasma bilirubin concentration was measured before ERCP.

RESULTS

The median (range) values for the common bile duct diameter for the patients with a stricture and those with a stone were 16 (5 to 33 mm) and 15 mm (6 to 29 mm), respectively (P=0.0038). In receiver operating characteristic analysis, the difference was barely significant when compared with random value (P=0.0399). Area under curve for bile duct diameter was 0.615.

CONCLUSIONS

In conclusion, the degree of bile duct dilatation does not aid in differential diagnosis between benign and malignant causes of extrahepatic cholestasis.

Endoscopic ultrasound in the evaluation of radiologic abnormalities of the liver and biliary tree

Gastroenterologists increasingly find themselves in the un-enviable position of having to choose the optimal radiographic test to visualize the biliary tree and the liver. This dilemma is compounded by the rapid evolution of the available technologies and their ever-increasing resolution capabilities. Endoscopic ultrasound (EUS) has shown itself to be equally capable of providing detailed imaging of the biliary tree and of surrounding structures; its potential for evaluating liver lesions is just now being realized. EUS-fine needle aspiration (FNA) may supplant some of the existing technologies as it offers a way to sample masses, strictures, lymph nodes, and now certain segments of the liver and periportal regions. This review takes an in-depth look at the role of EUS in evaluating bile duct dilatation, suspected choledocholithiasis, biliary strictures, and polyps and masses of the gallbladder. It also reviews the literature on the exciting and rapidly evolving role of EUS-FNA evaluation of occult, metastatic, and primary hepato-cellular malignancies, as well as periportal lesions. Technologies such as EUS elastography may completely obviate FNA of liver lesions.

The investigation of unexplained biliary dilatation

The investigation of biliary dilatation forms a routine part of gastroenterology practice. In developed countries, biliary dilatation is usually the result of obstruction of bile flow by either stones or mitotic lesions of the pancreas or biliary tree, and standard radiologic and endoscopic techniques are used to identify and relieve the obstruction. In the absence of an obvious cause, however, the investigation and management of biliary dilatation can prove challenging, particularly while trying to minimize invasive studies. This review examines factors thought to influence bile duct size in the absence of obvious obstructing pathology and looks at some causes of biliary dilatation that are unusual and potentially difficult to diagnose.

The role of sonography in imaging of the biliary tract

Sonography is the recommended initial imaging test in the evaluation of patients presenting with right upper quadrant pain or jaundice. Dependent upon clinical circumstances, the differential diagnosis includes choledocholithiasis, biliary stricture, or tumor. Sonography is very sensitive in detection of mechanical biliary obstruction and stone disease, although less sensitive for detection of obstructing tumors, including pancreatic carcinoma and cholangiocarcinoma. In patients with sonographically documented cholelithiasis and choledocholithiasis, laparoscopic cholecystectomy with operative clearance of the biliary stone disease is usually performed. In patients with clinically suspected biliary stone disease, without initial sonographic documentation of choledocholithiasis, endoscopic ultrasound or magnetic resonance cholangiopancreatography is the next logical imaging step. Endoscopic ultrasound documentation of choledocholithiasis in a postcholecystectomy patient should lead to retrograde cholangiography, sphincterotomy, and clearance of the ductal calculi by endoscopic catheter techniques. In patients with clinical and sonographic findings suggestive of malignant biliary obstruction, a multipass contrast-enhanced computed tomography (CT) examination to detect and stage possible pancreatic carcinoma, cholangiocarcinoma, or periductal neoplasm is usually recommended. Assessment of tumor resectability and staging can be performed by CT or a combination of CT and endoscopic ultrasound, the latter often combined with fine needle aspiration biopsy of suspected periductal tumor. In patients whose CT scan suggests hepatic hilar or central intrahepatic biliary tumor, percutaneous cholangiography and transhepatic biliary stent placement is usually followed by brushing or fluoroscopically directed fine needle aspiration biopsy for tissue diagnosis. Sonography is the imaging procedure of choice for biliary tract intervention, including cholecystostomy, guidance for percutaneous transhepatic cholangiography, and drainage of peribiliary abscesses.

EUS yield in evaluating biliary dilatation in patients with normal serum liver enzymes

The finding of common bile duct (CBD) dilatation on abdominal imaging frequently results in additional testing. It has been our impression that endoscopic ultrasound (EUS) evaluation of a dilated CBD is a low-yield examination in the setting of normal serum liver enzymes. We therefore sought to evaluate the EUS yield in evaluating CBD dilatation in patients with normal as compared to elevated serum liver enzymes. A retrospective review was performed to identify patients referred for EUS evaluation of a dilated CBD in the absence of obvious pathology on prior imaging. Charts were reviewed for patient symptoms, presence of elevated serum liver enzymes, imaging studies before EUS, and EUS findings. Exclusion criteria included clinical jaundice, known biliary stricture, mass lesion or stone, and previously sphincterotomy and/or stent placement. Forty-seven patients were identified: 32 with normal and 15 with elevated serum liver enzymes. There was no difference in mean CBD diameter between these two groups (8.51 vs. 8.79 mm, p=0.854). Of the entire group, 15 patients had undergone prior magnetic resonance cholangiopancreatography (MRCP); an additional 7 patients had undergone prior endoscopic retrograde cholangiopancreatography (ERCP). EUS findings to explain CBD dilatation were found more commonly in patients with elevated compared with normal serum liver enzymes (53% vs. 6%, p=0.001). Periampullary diverticula and choledocholithiasis were the most common findings; of 32 patients with normal serum liver enzymes, one periampullary diverticulum and one CBD stone were found, respectively. The CBD stone had been missed by prior MRCP examination. Of 15 patients with elevated serum liver enzymes, there were 3 cases of choledocholithiasis, 4 periampullary diverticula, and 1 ampullary tumor. EUS should be the test of choice for further evaluation of CBD dilatation when index imaging is normal. Although the EUS yield is low in cases of biliary dilatation in the setting of normal serum liver enzymes, its preferential use would potentially avoid unnecessary MRCP and ERCP.

Normal and pathologic features of the postoperative biliary tract at 3D MR cholangiopancreatography and MR imaging

Magnetic resonance (MR) imaging with cholangiopancreatographic sequences plays a critical role in evaluating alterations in the biliary tract after surgical procedures such as cholecystectomy, liver transplantation, hepatic resection, and the creation of a biliary-enteric anastomosis. MR cholangiopancreatography, a rapid, noninvasive, and accurate imaging technique for the assessment of early and late complications of hepatobiliary surgery, usually enables the identification of normal and abnormal postoperative changes. In cases of complete obstruction of the bile duct, MR cholangiopancreatography allows analysis of the biliary tract above and below the level of the obstruction, a capability essential for treatment planning and one that is not provided by either endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography. MR cholangiopancreatography is particularly useful for the evaluation of biliary-enteric anastomoses, for which an endoscopic approach is generally precluded. It also can help detect and localize bile duct strictures and stones and can help accurately classify bile duct injuries. It is useful for detecting bile leaks, although it generally does not directly depict the extravasation of bile. In addition to MR cholangiopancreatography, T1- and T2-weighted MR imaging may be performed to depict extrabiliary soft-tissue structures and abnormalities such as an abscess, tumor recurrence or metastasis, hematoma, or hemobilia. Mangafodipir trisodium-enhanced MR cholangiopancreatography, a recently developed technique that provides a combination of anatomic and functional information, is particularly helpful for documenting bile leaks because it allows a functional evaluation of biliary excretion and may directly depict bile leakage from injured ducts.

Effect of aging on the adult extrahepatic bile duct: a sonographic study

OBJECTIVE

To determine whether the size of the extrahepatic bile duct increases with age in adults.

METHODS

We prospectively collected data on 251 patients aged 20 years or older who underwent abdominal sonography. None of the patients had a history of liver, gallbladder, biliary, or pancreatic disease or surgery. The extrahepatic bile duct was measured at 3 locations: in the porta hepatis, in the most distal aspect of the head of the pancreas, and midway between these points. Least squares linear regression was used to correlate patient age and the size of the extrahepatic bile duct.

RESULTS

There were 126 men and 125 women aged 20 to 94 years (mean +/- SD, 52.5 +/- 17.63 years). Twelve percent of the study population were younger than 30 years, and 12% were older than 80 years. The mean diameters of the common bile duct in the 3 locations were as follows: proximal, 3.39 +/- 1.14 mm; middle, 3.72 +/- 1.28 mm; and distal, 4.28 +/- 1.18 mm. The overall mean for all measures was 3.66 +/- 1.15 mm. The width of the common bile duct ranged from 1.0 to 8.6 mm. There was a significant correlation between common bile duct size and age (r = 0.535; P < .001). Mean common bile duct sizes were 3.128 +/- 0.862 mm in the patients younger than 50 years and 4.19 +/- 1.15 mm in the patients older than 50 years (P < .001 by independent t test for equality of means). We have found that the duct gradually dilated 0.04 mm/y.

CONCLUSIONS

This study revealed an age-dependent change in the diameter of the extrahepatic bile duct. We suggest that the upper normal limit of the duct in elderly persons be set at 8.5 mm.

Transabdominal sonography of bile ducts

Ultrasound is considered to be the initial imaging modality of choice for evaluation of bile ducts. In this article, sonographic anatomy of the bile ducts and ultrasound findings in congenital, inflammatory, neoplastic, and other abnormalities of bile ducts are described. Roles of color Doppler ultrasound and newer applications, such as harmonic imaging and three-dimensional ultrasound, in evaluation of bile ducts are discussed.