Reference values of MRI measurements of the common bile duct and pancreatic duct in children

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.

Utility of common bile duct measurement in the diagnosis of cholecystitis and choledocholithiasis in children

BACKGROUND

Ultrasound is an integral part of evaluating for acute cholecystitis and choledocholithiasis in pediatric patients. Finding the common bile duct (CBD), a structure which is normally <4 mm in children, can be very challenging.

OBJECTIVE

The primary objective of this study was to determine the prevalence of isolated sonographic CBD dilation in pediatric patients with acute cholecystitis and/or choledocholithiasis without laboratory abnormalities or pathologic findings on radiology based biliary ultrasound, apart from cholelithiasis.

METHODS

We conducted a retrospective chart review of patients ≤21-years-old, at a single free-standing tertiary care children's hospital, who received a biliary ultrasound in the radiology department (RADUS) from September 2005 to February 2020. We identified patients who had a diagnosis of acute cholecystitis and/or choledocholithiasis on RADUS. Based on prior studies, a positive ultrasound was defined as having gallbladder wall thickening (GWT), pericholecystic fluid (PCF), or sonographic Murphy's sign (SMS). The final diagnosis was confirmed using the gold standard, cholecystectomy pathology diagnosis for patients with cholecystitis and endoscopic retrograde cholangiopancreatography (ERCP) diagnosis for patients with choledocholithiasis. Ultrasound data and contemporaneous laboratory values were collected.

RESULTS

180 patients met inclusion criteria. For the study population, 97 (53.9%) had a positive ultrasound, 127 patients (70.6%) had a dilated CBD, and 170 (94.4%) had at least one abnormal laboratory finding. Within the study population there were 76 patients (42.3%) with acute cholecystitis, 55 patients (30.5%) with choledocholithiasis, and 49 patients (27.2%) with acute cholecystitis and choledocholithiasis. Of the 127 patients with a dilated CBD, 80 (62.9%) had a normal ultrasound, apart from cholelithiasis. In this group of 80, 78 patients (97.5%) had at least one abnormal laboratory finding. Thus, for the entire study population, isolated CBD dilation without a positive ultrasound or laboratory abnormalities occurred in 2 patients (1.1%). Of note, these 2 patients had an ultrasound diagnosis of choledocholithiasis.

CONCLUSION

The prevalence of isolated sonographic CBD dilation in pediatric patients with cholecystitis and/or choledocholithiasis was 1.1%. Thus, biliary ultrasound without CBD measurement is unlikely to result in missed cholecystitis and/or choledocholithiasis if the biliary ultrasound does not demonstrate GWT, PCF, SMS, or choledocholithiasis, and the patient has normal laboratory values.

Cholangiopancreatography in cats: a post-mortem comparison of MRI with fluoroscopy, corrosion casting and histopathology

In human medicine, magnetic resonance cholangiopancreatography (MRCP) is a valuable diagnostic tool for hepatobiliary and pancreatic diseases. In veterinary medicine, however, data evaluating the diagnostic value of MRCP are limited. The primary objectives of this prospective, observational, analytical investigation were to assess whether MRCP reliably visualizes the biliary tract and pancreatic ducts in cats without and with related disorders, and whether MRCP images and measurements of the ducts agree with those of fluoroscopic retrograde cholangiopancreatography (FRCP), corrosion casting and histopathology. A secondary objective was to provide MRCP reference diameters for bile ducts, GB, and pancreatic ducts. Donated bodies of 12 euthanized adult cats underwent MRCP, FRCP, and autopsy with corrosion casting of the biliary tract and pancreatic ducts using vinyl polysiloxane. Diameters of the biliary ducts, gallbladder (GB), and pancreatic ducts were measured using MRCP, FRCP, corrosion casts and histopathologic slides. There was an agreement between MRCP and FRCP in measuring diameters of the GB body, GB neck, cystic duct, and common bile duct (CBD) at papilla. Strong positive correlations existed between MRCP and corrosion casting for measuring GB body and neck, cystic duct, and CBD at the extrahepatic ducts' junction. In contrast to the reference methods, post-mortem MRCP did not visualize right and left extrahepatic ducts, and pancreatic ducts in most cats. Based on this study, MRCP with 1.5 Tesla can be regarded as a contributory method to improve the assessment of feline biliary tract and pancreatic ducts when their diameter is >1 mm.

Magnetic resonance imaging following the demonstration of a normal common bile duct on ultrasound in children with suspected choledocholithiasis: what is the benefit?

BACKGROUND

The role of MRI in evaluating children with an in situ gallbladder and suspected choledocholithiasis following a negative or inconclusive US is unclear.

OBJECTIVE

To determine whether MRI benefits children with suspected choledocholithiasis and a normal common bile duct (CBD) without stones on US.

MATERIALS AND METHODS

We conducted a retrospective 10-year review of paired US and MRI (within 10 days) in children 18 years or younger with suspected choledocholithiasis. With MRI as a reference standard, two reviewers independently evaluated the images for CBD diameter, choledocholithiasis, cholelithiasis and pancreatic edema. Serum lipase was recorded. We calculated exact binomial confidence limits for test positive predictive values (PPVs) and negative predictive values (NPVs) using R library epiR.

RESULTS

Of 87 patients (46 female, 41 male; mean age 14 years, standard deviation [SD] 4.6 years; mean interval between US and MRI 1.6 days, SD 1.8 days), 55% (48/87) had true-negative US, without CBD dilation/stones confirmed on MRI; 5% (4/87) had false-positive US showing CBD dilatation without stones, not confirmed on MRI; 33% (29/87) had true-positive US, with MRI confirming CBD dilatation; and 7% (6/87) had false-negative US, where MRI revealed CBD stones without dilatation (2 patients) and CBD dilatation with or without stones (4 patients). Patients with false-negative US had persistent or worsening symptoms, pancreatitis or SCD. The overall US false-negative rate was 17% (6/35). Normal-caliber CBD on US without stones had an NPV of 89% (48/54, 95% confidence interval: 0.77-0.96).

CONCLUSION

MRI adds little information in children with a sonographically normal CBD except in the setting of pancreatitis or worsening clinical symptoms. Further evaluation is warranted in children with elevated risk of stone disease.

Magnetic resonance imaging glossary of findings of pediatric pancreatitis and the revised Atlanta classification

While still uncommon, the incidence of acute pancreatitis in children has been increasing over the last two decades. The Atlanta classification for acute pancreatitis, developed for adults, stratifies cases of acute pancreatitis based on imaging and clinical criteria. This classification scheme allows for standardized use of terminology to facilitate treatment and prognostication. Although US and CT should be used in critical or unstable patients, MRI is an ideal imaging modality in pediatric patients with acute pancreatitis because of its ability to characterize tissue without ionizing radiation. We review MRI examples specific to Atlanta classification terminology in pediatric patients. Chronic pancreatitis has also been increasingly diagnosed in children, and imaging plays a key role in the diagnosis and management of this insidious disease. MRI with magnetic resonance cholangiopancreatography is the optimal modality for assessing the pancreas in a child with known or suspected chronic pancreatitis because it provides tissue characterization and high-contrast imaging of the pancreatic duct without the use of invasive instrumentation or ionizing radiation. We also review and demonstrate accepted MRI findings of chronic pancreatitis.

Creation of a Pediatric Choledocholithiasis Prediction Model

BACKGROUND

Definitive non-invasive detection of pediatric choledocholithiasis could allow more efficient identification of those patients who are most likely to benefit from therapeutic endoscopic retrograde cholangiopancreatography (ERCP) for stone extraction.

OBJECTIVE

To craft a pediatric choledocholithiasis prediction model using a combination of commonly available serum laboratory values and ultrasound results.

METHODS

A retrospective review of laboratory and imaging results from 316 pediatric patients who underwent intraoperative cholangiogram or ERCP due to suspicion of choledocholithiasis were collected and compared to presence of common bile duct stones on cholangiography. Multivariate logistic regression with supervised machine learning was used to create a predictive scoring model. Monte-Carlo cross-validation was used to validate the scoring model and a score threshold that would provide at least 90% specificity for choledocholithiasis was determined in an effort to minimize non-therapeutic ERCP.

RESULTS

Alanine aminotransferase (ALT), total bilirubin, alkaline phosphatase, and common bile duct diameter via ultrasound were found to be the key clinical variables to determine the likelihood of choledocholithiasis. The dictated specificity threshold of 90.3% yielded a sensitivity of 40.8% and overall accuracy of 71.5% in detecting choledocholithiasis. Positive predictive value was 71.4% and negative predictive value was 72.1%.

CONCLUSION

Our novel pediatric choledocholithiasis predictive model is a highly specific tool to suggest ERCP in the setting of likely choledocholithiasis.

Acute pancreatitis in children: a review with clinical perspectives to enhance imaging interpretation

Pediatric acute pancreatitis has distinct etiologic, clinical and prognostic characteristics in contrast to the adult form of the disease. This review offers a comprehensive imaging update that emphasizes the importance of recognizing specific findings that are relevant from the clinical standpoint. Knowledge of these features facilitates communication among multidisciplinary team members and ultimately could lead to the improved care of pediatric acute pancreatitis patients.

Current State of Imaging of Pediatric Pancreatitis: AJR Expert Panel Narrative Review

Pancreatitis is as common in children as it is in adults, though causes and accepted imaging strategies differ in children. In this narrative review we discuss the epidemiology of childhood pancreatitis and key imaging features for pediatric acute, acute recurrent, and chronic pancreatitis. We rely heavily on our collective experience in discussing advantages and disadvantages of different imaging modalities; practical tips for optimization of ultrasound, CT, and MRI with MRCP in children; and image interpretation pearls. Challenges and considerations unique to imaging pediatric pancreatitis are discussed, including timing of imaging, role of secretin-enhanced MRCP, utility of urgent MRI, severity prediction, autoimmune pancreatitis, and best methods for serial imaging. We suggest a methodical approach to pancreatic MRI interpretation in children and have included a sample structured report, and we provide consensus statements according to our experience imaging children with pancreatitis.

Pediatric biliary disorders: Multimodality imaging evaluation with clinicopathologic correlation

The spectrum of pathologies affecting the biliary tree in the pediatric population varies depending on the age of presentation. While in utero insults can result in an array of anatomic variants and congenital anomalies in newborns, diverse acquired biliary pathologies are observed in older children. These acquired pathologies display different presentations and consequences than adults. Multimodality imaging assessment of the pediatric biliary system is requisite to establishing an appropriate management plan. Awareness of the imaging features of the various biliary pathologies and conveying clinically actionable information is essential to facilitate appropriate patient management. In this paper, we will illustrate the anatomy and embryology of the pediatric biliary system. Then, we will provide an overview of the imaging modalities used to assess the biliary system. Finally, we will review the unique features of the pediatric biliary pathologies, complemented by histopathologic correlation and discussions of clinical management.

North American Society for Pediatric Gastroenterology, Hepatology and Nutrition and the Society for Pediatric Radiology Joint Position Paper on Noninvasive Imaging of Pediatric Pancreatitis: Literature Summary and Recommendations

ABSTRACT

The reported incidence of pediatric pancreatitis is increasing. Noninvasive imaging, including ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), play important roles in the diagnosis, staging, follow-up, and management of pancreatitis in children. In this position paper, generated by members of the Pancreas Committee of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) and the Abdominal Imaging Committee of The Society for Pediatric Radiology (SPR), we review the roles of noninvasive imaging in pediatric acute, acute recurrent, and chronic pancreatitis. We discuss available evidence related to noninvasive imaging, highlighting evidence specific to pediatric populations, and we make joint recommendations for use of noninvasive imaging. Further, we highlight the need for research to define the performance and role of noninvasive imaging in pediatric pancreatitis.

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.

A quantitative image analysis using MRI for diagnosis of biliary atresia

PURPOSE

Biliary atresia is a life-threatening disease that needs early diagnosis and management. Recently, MRI images have been used for the diagnosis of biliary atresia with improved accuracy of diagnosis when other imaging modalities such as ultrasonography are equivocal. This study aimed to evaluate the juxta-hilar extrahepatic biliary tree using MRI images to determine a quantitative value for diagnosing biliary atresia.

MATERIALS AND METHODS

This retrospective study was approved by the Ethical Committee at Mackey Memorial Hospital (IRB Number: 15MMHIS149e). Between January 2010 and December 2015, twenty-five patients with surgically confirmed biliary atresia were enrolled (age 18-65 days). Another 25 patients with clinically or surgically diagnosed idiopathic neonatal hepatitis (age 6-64 days) and 20 patients with non-hepatobiliary disease (age 6-65 days) were considered control group and normal subjects, respectively. The diameter of the enlarged, T2-hyperintense structure was measured using MRI images by two radiologists both blinded. The cut-off value for a biliary atresia diagnosis was obtained by area under the curve analysis.

RESULTS

The diameter of the T2-hyperintense structure at porta hepatis in biliary atresia (4.79 ± 1.14 mm) is larger than in idiopathic neonatal hepatitis (1.72 ± 0.42 mm) or in non-hepatobiliary disease (1.72 ± 0.35 mm) (p < 0.05). The optimum cut-off value for diagnosing biliary atresia was 3.1 mm with 98% sensitivity and 98% specificity.

CONCLUSION

The value of the enlarged, T2-hyperintense structure measured on MRI images was significantly increased in biliary atresia and may be useful in diagnosing biliary atresia.

Pediatric cholangiopathies: diseases of the gallbladder and biliary tract

Pediatric gallbladder and bile duct disease encompasses a broad spectrum of processes, from congenital to developmental to neoplastic. We describe normal pediatric biliary anatomy and summarize the most common pathologic entities, with a focus on non-invasive imaging techniques and findings. Ultrasound is the first-line imaging modality in children with suspected biliary pathology based on its widespread availability, cost effectiveness, and lack of ionizing radiation. MRI and MRCP are often used for further evaluation in cases of diagnostic uncertainty and for surgical planning.

Magnetic resonance imaging of pancreaticobiliary diseases in children: from technique to practice

Magnetic resonance imaging is useful for evaluating pancreaticobiliary diseases in children after initial sonography, obviating the use of ionizing radiation or invasive procedures such as endoscopic retrograde cholangiopancreatography (ERCP) or transhepatic biliary procedures. Advanced MRI applications have improved depiction of pediatric pancreaticobiliary anatomy and have greatly impacted management of biliary and pancreatic diseases in children. In this article, we review current MRI and magnetic resonance cholangiopancreatography (MRCP) techniques and discuss their role in the assessment of common pancreatic and biliary disorders in children.

Factors Interfering with Delineation on MRCP of Pancreaticobiliary Maljunction in Paediatric Patients

Background

The aim of this study was to assess factors for delineating the pancreaticobiliary junction in the presence of pediatric congenital choledochal cysts (CCC) using Magnetic resonance cholangiopancreatography (MRCP).

Methods

Retrospective review of medical records for 48 patients with CCC was conducted, including demographics, biliary amylase and MRCP findings if available. With univariate and multivariate logistic regression, we measured significant factors affecting pancreaticobiliary maljunction(PBM) diagnoses by MRCP.

Results

Of the subjects enrolled with CCC. Twenty-eight cases had PBM according to MRCP. Univariate analysis confirmed that age, cyst diameter > 30 mm and cysts that descended to the introitus pelvis affected junctional delineation and detection of PBM (P<0.05). Stepwise logistic regression analysis confirmed large cysts in the introitus pelvis predicted pancreaticobiliary junctional delineation in MRCP and these data agreed with the literature. A correlation between cyst diameter and the length of the common channel was found as was cyst diameter and biliary amylase although there were no significant differences between them.

Conclusions

Age, cyst diameter >30 mm and descending cysts into the introitus pelvis affected junctional delineation of the pancreatic and bile duct in PBM with MRCP. Large cyst descension into the introitus pelvis was an independent factors affecting PBM detection.