Is age associated with size of adult extrahepatic bile duct: sonographic study

Utility of Common Bile Duct Identification on Biliary Ultrasound in Emergency Department Patients

Background

Biliary ultrasound is often utilized in the evaluation of abdominal pain in the Emergency Department (ED). Common bile duct (CBD) identification is traditionally a standard component of the biliary ultrasound examination but can be challenging to perform for the novice sonographer. Previous work has demonstrated that CBD dilatation is rare in cases of cholecystitis with normal liver function tests (LFTs). We sought to assess the frequency of CBD dilatation in the subset of ED patients undergoing hepatobiliary ultrasound who have normal LFTs and an absence of gallstones or biliary sludge on ultrasound. We also performed an assessment of changes in CBD diameter by age and cholecystectomy status.

Methods

This was a retrospective chart review at a single academic ED. Patients were enrolled in the study if they underwent a radiology performed (RP) hepatobiliary ultrasound within the 2 year study period. Records were reviewed for the presence of gallstones or sludge, CBD diameter, age, clinical indication for the ultrasound, and LFTs. Descriptive analyses were performed, and interobserver agreement among data abstractors was assessed by K analysis for the presence of CBD dilatation. The Mann-Whitney test was utilized to assess statistical significance in the comparison of differences between CBD diameters amongst age groups.

Results

Of 1929 RP hepatobiliary ultrasounds performed in the study period, 312 were excluded and 1617 met inclusion criteria. Amongst these, there were 506 patients who had normal LFTs and an ultrasound with no stones or sludge. Ten patients within this group had a dilated CBD > 7 mm (1.98%, 95% CI of 1.08% to 3.6%). We also noted a statistically significant increase in CBD size in the older age cohort and in those individuals with a history of cholecystectomy.

Conclusion

CBD dilation in ED patients who present with normal LFTs and an absence of gallstones and biliary sludge is rare. Physicians should be reassured that the routine identification of the CBD on ultrasound in this setting is of low yield and need not be pursued.

Normal morphometry of the biliary tree in pediatric and adult populations: A systematic review and meta-analysis

PURPOSE

This study aimed to characterise the normal morphometry of the biliary tree in pediatric and adult populations, through a systematic review and meta-analysis.

METHODS

This study, conducted using the PRISMA guidelines and registered with PROSPERO, searched MEDLINE, EMBASE, SCOPUS and Web of Science databases up to October 2022, and updated to August 2023. Studies that reported extractable data on diameter and length of the right, left and common hepatic ducts (LHD, RHD and CHD), and common bile duct (CBD) were included. Quality of the included studies were assessed using the Anatomical Quality Assessment (AQUA) tool. Statistical analysis included subgroup analyses according to sex, age, geographical location, and imaging modality.

RESULTS

In total, 60 studies were included, of which 44 studies reported adequate data for meta-analysis on 23,796 subjects. Overall, the pooled mean diameter of the CBD was 4.69 mm (95 % CI: 4.28-5.11). Significant differences were found between pediatric (1.32 mm, 95 % CI: 1.03-1.61) and adult (4.97 mm, 95 % CI: 4.67-5.27) subjects, as well as US (3.82 mm, 95 % CI: 3.15-4.49) and other imaging modalities, including MRI (6.21 mm, 95 % CI: 4.85-7.57) and ERCP (7.24 mm, 95 % CI: 6.08-8.40). The CBD diameter measured significantly larger distally (5.20 mm, 95 % CI: 4.60-5.80) than proximally (4.01 mm, 95 % CI: 3.51-4.51).

CONCLUSIONS

The results obtained from this evidence-based study may guide the establishment of standardised reference values and ranges of the normal biliary tree in pediatric and adult populations and aid clinical understanding.

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.

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.

Incidental biliary dilation in the era of the opiate epidemic: High prevalence of biliary dilation in opiate users evaluated in the Emergency Department

BACKGROUND

Biliary dilation is frequently related to obstruction; however, non-obstructive factors such as age and previous cholecystectomy have also been reported. In the past two decades there has been a dramatic increase in opiate use/dependence and utilization of cross-sectional abdominal imaging, with increased detection of biliary dilation, particularly in patients who use opiates.

AIM

To evaluate associations between opiate use, age, cholecystectomy status, ethnicity, gender, and body mass index utilizing our institution’s integrated informatics platform.

METHODS

One thousand six hundred and eighty-five patients (20% sample) presenting to our Emergency Department for all causes over a 5-year period (2011-2016) who had undergone cross-sectional abdominal imaging and had normal total bilirubin were included and analyzed.

RESULTS

Common bile duct (CBD) diameter was significantly higher in opiate users compared to non-opiate users (8.67 mm vs 7.24 mm, P < 0.001) and in patients with a history of cholecystectomy compared to those with an intact gallbladder (8.98 vs 6.72, P < 0.001). For patients with an intact gallbladder who did not use opiates (n = 432), increasing age did not predict CBD diameter (r² = 0.159, P = 0.873). Height weakly predicted CBD diameter (r² = 0.561, P = 0.018), but weight, body mass index, ethnicity and gender did not.

CONCLUSION

Opiate use and a history of cholecystectomy are associated with CBD dilation in the absence of an obstructive process. Age alone is not associated with increased CBD diameter. These findings suggest that factors such as opiate use and history of cholecystectomy may underlie the previously-reported association of advancing age with increased CBD diameter. Further prospective study is warranted.

Does measurement of the hepatic artery velocity improve the sonographic diagnosis of cholangitis?

OBJECTIVE

To determine the frequency of elevated peak systolic proper hepatic artery velocity (HAV) in patients with acute cholangitis and to determine the diagnostic performance of this metric relative to existing criteria.

METHODS

Between 9/2016 and 11/2017, 107 patients clinically suspected to have cholangitis were referred for an abdominal ultrasound. Of these, 56 patients had HAV measurements and were included in the final analysis. Clinical and imaging features, including HAV, HAV resistive index (RI), portal vein velocity (PVV), biliary dilation, and presence of an obstructive etiology were extracted. The diagnostic performance of HAV was compared to the existing available clinical criteria (Charcot's triad and 2018 Tokyo Guidelines). Elevated HAV was defined as HAV > 100 cm/s. Presence of cholangitis was determined by the discharge summary following medical workup and admission or observation.

RESULTS

32% had cholangitis while 68% did not. Average HAV for patients with cholangitis was 152 ± 54 cm/s versus 91 ± 44 cm/s for those without (p < 0.0001; t test). The HAV was elevated in 83% of patients with cholangitis. When considered in isolation, an elevated HAV had a high negative predictive value (90%), was more accurate (77%; 95% confidence interval 64-87%) than Charcot's triad (73%; 60-83%), and had similar accuracy compared to 2018 Tokyo Guidelines (79%; 66-88%). Substitution of conventional imaging criteria with elevated HAV in the 2018 Tokyo Guidelines yielded the highest overall accuracy of 84% (72-92%).

CONCLUSION

HAV is elevated in the majority of patients with cholangitis. Substitution of an elevated HAV for conventional sonographic criteria is more accurate than existing clinical criteria in identifying patients with cholangitis.

Transabdominal Ultrasonography in Symptomatic Choledocholithiasis - Usefulness in Settings with Limited Resources

Objective:

Ultrasonography remains the initial imaging modality in the management of biliary disease. This study is designed to evaluate the accuracy of transabdominal ultrasonography in diagnosing biliary pathology in patients with choledocholithiasis.

Methods:

This was a retrospective study of a continuous sample of patients over a period of 3 years ending in January 2016; these patients were referred for endoscopic management of choledocholithiasis to a tertiary care hospital in Colombo, Sri Lanka. Ultrasound reporting was carried out by different consultant radiologists at both the index and the referring hospitals. The findings of endoscopic retrograde cholangiograms were compared with the ultrasound scan (USS) results.

Results:

A total of 247 patients were included in the study. USS was 97.4% accurate in detecting intrahepatic duct dilatation (IHDD). Stone counts and the location of stone(s) in the USSs correlated strongly with the number of stones delivered during endoscopic removal and their location in cholangiograms (P < 0.001). The difference in mean diameter of the common bile duct (CBD) of patients with choledochal cysts (CCs) (18.57 mm) and of patients without them (12.39 mm) is statistically significant (P < 0.001). At 14.5 mm, the negative predictive value for a CC is 99.02%.

Conclusion:

Ultrasonography is a reliable tool in predicting IHDD, stone count, and the location of stones in the biliary tree, particularly in a resource-poor setting. A CBD diameter of 14.5 mm in transabdominal ultrasound scan can be used as a cutoff for predicting extrahepatic CC.

Association between common bile duct diameter and abdominal aorta calcium score

BACKGROUND AND OBJECTIVE

There is evidence of association between aging and increase in the normal upper limit of the common bile duct (CBD) diameter. As aging is a documented risk factor for atherosclerosis, and the possible effect that atherosclerosis can have on the CBD diameter via affecting its smooth muscle contractility and blood flow, we decided to determine the association between CBD diameter and atherosclerosis in the abdominal aorta (AA).

METHODS

A total of 99 asymptomatic patients (53 males and 46 females; age range of 18-88 years) without history of cholecystectomy who underwent abdominal contrast-enhanced CT scan were included. The CBD diameter was measured. The atherosclerosis of AA was quantified by Agatston score.

RESULTS

Mean (± SD) CBD diameter was 6.14 (± 1.95) mm; range = 2.4-12.7 mm. Agatston score was 0 in 59 patients. In the remaining 40 patients, median (interquartile range, IQR) Agatston score was 497.5 (2026.3). Mean (± SD) CBD diameter in patients with Agatston score > 0 was 7.39 (± 2.07) mm compared to 5.29 (± 1.32) mm in patients without calcification plaque (P < 0.001). A moderate correlation was seen between CBD diameter and Agatston score (ρ = 0.43; P = 0.005).

CONCLUSION

Although the exact cause of increased CBD diameter with advancing age is not understood, a general atherosclerotic process which occurs with aging may affect smooth muscle of the CBD. Whether an upper limit for normal CBD should be defined or not when evaluating dilated CBD for patients with subclinical or clinical atherosclerosis needs further studies.

Normograms for the Extrahepatic Bile Duct Diameter in Children

OBJECTIVE

The normal diameter of the extrahepatic bile duct (EHD) in children has been poorly studied. Prior studies have enrolled small subject numbers, have studied only specific pediatric age groups, or have potential bias due to loosely defined exclusion criteria. We sought to establish parameters for the normal diameter of the EHD in children from birth to late adolescence, including premature infants.

METHODS

A 12½-month institutional review board-approved, Health Insurance Portability and Accountability Act-compliant, retrospective chart review of all transabdominal ultrasounds performed on children (younger than 18 years) was conducted at a single pediatric tertiary referral center. Exclusion criteria included a past medical history of any pancreaticobiliary or hepatology disorder. New abnormal findings related to the liver, biliary system, or pancreas were also excluded. Recorded EHD measurements from review of the radiology reports were compiled. Estimated mean and 95% prediction intervals of EHD were calculated and reported for 6 nonoverlapping pediatric age groups.

RESULTS

A total of 1016 ultrasounds on unique patients were included within the study. Estimated mean values and calculated 95% prediction intervals (in parentheses) for the diameter of the EHD were prematurity, 0.7 (0.3-1.7) mm; 0 to 2 months, 1.0 (0.4-2.3) mm; 3 to 11 months, 1.2 (0.5-2.9) mm; 1 to 4 years, 1.4 (0.6-3.3) mm; 5 to 12 years, 1.9 (0.8-4.3) mm; 13 to 17 years, 2.3 (1.0-5.2) mm.

CONCLUSIONS

Our derived data of normal predicted parameters of the EHD diameter in children of all age groups will help guide clinicians in identifying those patients outside the norm that may benefit from additional testing.

CT evaluation of common duct dilation after cholecystectomy and with advancing age

PURPOSE

To evaluate common duct (CD) dilation by computed tomography (CT) in patients with intact gallbladders and diameter change over time in remote and interval cholecystectomy patients, frequency of visualization of the CD, and its relationship to age.

METHODS

This IRB-approved retrospective study evaluated baseline CD diameter, intrahepatic biliary dilation, and interval duct diameter change in patients with CTs ≥ 2 years apart (n = 324), in block-randomized order by two blinded board-certified radiologists. 272 patients were divided into three groups: (1) prior cholecystectomy before the first CT, (2) cholecystectomy between the first and last CTs, and (3) no cholecystectomy. A subset of 191 nonoperated patients was evaluated for age-related dilation.

RESULTS

Group 1 ducts were significantly larger than the other groups at both baseline and follow-up CTs (p < 0.001). Group 2 showed a greater increase in duct size than the other groups at follow-up (p < 0.001). The CD was measurable in 89% of the CT studies. In nonoperated patients, there was a statistically significant correlation between CD size and increasing age (p < 0.001), although the CD size remained within normal size limits.

CONCLUSION

Remote cholecystectomy patients have larger CD diameters than the nonoperated and interval cholecystectomy groups. Greater increase in ductal diameter occurred between studies in the interval cholecystectomy patients, suggesting that dilation occurs after cholecystectomy. Also, the CD dilates slightly with age in nonoperated patients.

Ultrasound measurements of the bile ducts and gallbladder: normal ranges and effects of age, sex, cholecystectomy, and pathologic states

OBJECTIVE

The objectives of this study were to determine the normal values and ranges for bile duct and gallbladder measurements, adjusted for demographic data, and to assess the effects of a variety of pathologic states on these values.

METHODS

Four thousand one hundred nineteen abdominal ultrasounds were retrospectively analyzed. The values for the extrahepatic bile duct (EHD), left (LIHD) and right (RIHD) intrahepatic ducts, gallbladder wall thickness, and gallbladder volume in "normal" patients were evaluated with respect to age, sex, ethnicity, and cholecystectomy status. These values were compared using multivariate analysis to those in a variety of diseased states, including cirrhosis, fatty liver, gallstones, sludge, cholecystitis, and biliary obstruction.

RESULTS

One thousand four hundred eighty-four of the 4119 examinations were classified as normal. The mean EHD, RIHD, LIHD, and gallbladder wall thickness and volume measurements in normal patients were 3.8 ± 1.6 mm, 1.9 ± 1.9 mm, 1.9 ± 1.1 mm, 2.6 ± 1.6 mm, and 242 ± 234 mL, respectively.There were small increases in EHD diameter with age (+0.02 ± 0.11 mm/y, P < 0.001), female sex (+0.3 ± 1.6 mm, P < 0.0001), and cholecystectomy (+1.0 ± 1.6 mm, P < 0.0001) and a small decrease with fatty liver (-0.4 ± 1.6 mm, P = 0.0003). The gallbladder wall was thicker in patients with gallstones (+0.4 ± 1.4 mm, P = 0.0049), sludge (+0.5 ± 1.4 mm, P = 0.0019), and acute cholecystitis (+3.1 ± 1.6 mm, P < 0.0001). With biliary obstruction, the mean EHD, RIHD, LIHD, and gallbladder volume measurements were 6.0 ± 2.1 mm, 4.2 ± 1.4 mm, 4.1 ± 1.4 mm, and 171 ± 207 mL, respectively (P < 0.0001 for all values).

CONCLUSIONS

This study clarifies normal values and ranges for bile duct and gallbladder measurements, adjusted for demographic data, and evaluates these measurements in a variety of common pathologic states.

The role of ultrasonography in the evaluation of diffuse liver disease

The use of ultrasonography (US) to detect and characterize diffuse liver disease can be challenging, but remains a useful tool for the diagnosis and management of many diffuse parenchymal liver diseases such as cirrhosis, steatosis, and malignancies. Newer techniques, such as elastography, are proving useful for earlier detection of hepatic parenchymal changes. The role of US in the assessment of possible biliary ductal obstruction is well established, and Doppler US may provide additional physiologic information regarding hepatic blood flow. US plays a central role in target selection and guidance of percutaneous liver biopsies.

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.

Effects of age and cholecystectomy on common bile duct diameter as measured by endoscopic ultrasonography

BACKGROUND AND AIM

Increased common bile duct (CBD) diameter has been attributed to aging and previous cholecystectomy. These relationships are, however, controversial and based mainly on old studies and methodologies. Our objective is to evaluate the relationship between age, cholecystectomy, and other clinical factors and CBD diameter, as measured by endoscopic ultrasound (EUS).

METHODS

We carried out a retrospective cohort study including patients who underwent EUS in our institution. Patients with an obstructing lesion of the bile ducts, previous sphincter manipulation, or insufficient data were excluded. CBD diameter was measured as a routine part of the examination, in the most distal extrapancreatic portion, between its two exterior margins. The patients were divided into five age groups. The mean CBD diameter in each group was calculated and compared with the other groups. Effects of cholecystectomy, gender, time from operation, and elevated liver enzymes were also evaluated.

RESULTS

Six hundred forty-seven patients were included in the study (66% women). Twenty-three percent were postcholecystectomy. There was no difference between the first three groups regarding CBD diameter, but it was significantly wider in groups 4 and 5 (p < 0.001). In all age groups, the postcholecystectomy patients had significantly wider CBD than those with an intact gallbladder (in all groups, p < 0.01).

CONCLUSIONS

This EUS study confirms that the CBD dilates significantly after the age of 70 years, but even in the most elderly patients, with an intact gallbladder, the normal CBD does not exceed 7.6 mm, thus a wider CBD warrants further investigation. The single additional factor contributing to dilatation of the CBD was cholecystectomy. A linear regression equation is proposed for the prediction of CBD diameter.

Appropriate donor size for porcine liver xenotransplant

OBJECTIVES

Owing to an imbalance between demand and supply, which is more prominent in pediatric transplant, every year more patients lose their lives on waiting lists. In addition to the use of deceased-donor split and living-donor organs, xenotransplant could provide a solution if associated problems, such as immunologic and physiologic ones, are solved. This study sought to analyze the surgical aspects for liver xenotransplant in a porcine model.

MATERIALS AND METHODS

Landrace pigs (n=22, 23 to 37 kg) underwent a laparotomy under general anesthesia. The hepatic hilum was prepared and the common bile ducts, common hepatic artery, portal vein, supra- and infrahepatic inferior vena cava were identified. The length and diameter of each vessel and bile duct and the weight of the liver were measured.

RESULTS

Pearson tests showed a clear correlation between the increase of the pigs' weight and the livers' weight, and the length of the vessels and the bile ducts. We did not find a clear correlation between the increase of the pigs' liver weight and the diameters of the vessels and the bile duct.

CONCLUSIONS

As the first reporting, this study on xenotransplants from the surgical point of view, we postulate that it could be possible to estimate the size of the liver and the proper length of its vessels and bile duct by weighing only the pigs. It was not feasible to match the diameter of mentioned structures by the livers' weight. However, the weight of pig's liver as well as vascular anatomy of pigs appeared to be suitable alternative for the human liver.

Respiratory variation of the extrahepatic bile duct: evaluation with deep inspiratory and expiratory MRCP

PURPOSE

The purpose of the study was to evaluate the respiratory variation of the extrahepatic bile duct in morphology including shape, length and duct diameter on the breath-hold magnetic resonance cholangiopancreatography (MRCP) obtained during deep inspiration and deep expiration in patients with or without biliary diseases.

MATERIALS AND METHODS

This study included 102 patients with or without biliary diseases. Breath-hold MRCP was obtained twice during the end-inspiration and the end-expiration. MRCP images were evaluated for the length, maximal diameter and "bowing" of the extrahepatic bile duct.

RESULTS

In the normal group, the mean maximal diameter of the extrahepatic bile duct was significantly larger on the end-inspiratory MRCP (8.0 ± 2.0 mm) than on the end-expiratory MRCP (7.3 ± 1.8 mm) (P<.0001), while it was not significantly different in the dilated group. In the normal group, 25 (39%) of 65 patients had an increase in the mean maximal diameter of more than 1 mm at the end-inspiration, whereas 4 (11%) of 37 patients in the dilated group had it. The bowing of the extrahepatic bile duct on the end-inspiratory MRCP was observed in 60 (92%) of 65 normal patients, while it was seen in 22 (60%) of 37 patients with biliary dilatation (P<.0001).

CONCLUSION

Deep inspiratory and expiratory MRCP demonstrated the respiratory variations of the extrahepatic bile duct in the shape (bowing), length and maximal duct diameter in patients with nondilated bile ducts. Awareness of this normal phenomenon will be important for the correct interpretation of MRCP in patients with or without biliary diseases.

Ultrasound of the extrahepatic bile duct: issues of size

Ultrasound is a pivotal study for evaluation of the biliary tree. In particular, the size of the extrahepatic bile duct is a critical measurement and has been a contentious issue since the early days of diagnostic ultrasound. This article reviews the history and ongoing issues regarding sonography of the normal-size duct and a variety of factors that may affect its size, including age, prior surgery, congenital abnormalities, anatomical variations, and medications. Other related sonographic issues are discussed including abnormal nondilated ducts and abnormal intraluminal contents such as sludge or air that make evaluation of the duct more difficult, particularly in patients with primary sclerosing cholangitis and prior liver transplantation. Ultimately, the luminal size of the extrahepatic duct should be considered as a single part of the entire assessment of the biliary tree that must also include the intrahepatic and pancreatic ducts, the pattern of dilatation (variable vs progressively dilated to a single point of obstruction), any wall thickening, intraluminal sludge, calculi or mass, and extraluminal compression. Clinical symptoms and abnormal laboratory values should prompt further evaluation despite a normal appearance of the bile duct, whereas pursuit of an isolated finding of an enlarged duct without supporting clinical data may not be warranted.

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.

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.