MR cholangiopancreatography in children: feasibility, safety, and initial experience

Diagnostic and therapeutic roles of iron oxide nanoparticles in biomedicine

Nanotechnology changed our understanding of physics and chemics and influenced the biomedical field. Iron oxide nanoparticles (IONs) are one of the first emerging biomedical applications of nanotechnology. The IONs are composed of iron oxide core exhibiting magnetism and coated with biocompatible molecules. The small size, strong magnetism, and biocompatibility of IONs facilitate the application of IONs in the medical imaging field. We listed several clinical available IONs including Resovist (Bayer Schering Pharma, Berlin, Germany) and Feridex intravenous (I.V.)/Endorem as magnetic resonance (MR) contrast agents for liver tumor detection. We also illustrated GastroMARK as a gastrointestinal contrast agent for MR imaging. Recently, IONs named Feraheme for treating iron-deficiency anemia have been approved by the Food and Drug Administration. Moreover, tumor ablation by IONs named NanoTherm has also been discussed. In addition to the clinical application, several potential biomedical applications of IONs including cancer-targeting capability by conjugating IONs with cancer-specific ligands, cell trafficking tools, or tumor ablation agents have also been discussed. With the growing awareness of nanotechnology, further application of IONs is still on the horizon that would shed light on biomedicine.

Patient- and Examination-Related Predictors of 3D MRCP Image Quality in Children

Background: MRCP provides noninvasive imaging of the biliary tree and pancreatic duct. In our experience, MRCP image quality is commonly suboptimal in children. Objective: To characterize the frequency of nondiagnostic 3D fast spin echo (FSE) MRCP acquisitions and determine predictors of nondiagnostic MRCP image quality in children. Methods: This retrospective study included 200 randomly selected pediatric patients (mean age, 11.7 years; 101 female, 99 male) who underwent MRCP between January 1, 2019 and December 31, 2020. Patient and examination-related variables were recorded. Three fellowship-trained pediatric radiologists independently reviewed 3D FSE MRCP acquisitions for diagnostic quality (diagnostic vs nondiagnostic) and overall image quality score (1-5 scale; 1=worst image quality imaginable, 5=best image quality imaginable). After computing interreader agreement, analyses used readers' most common diagnostic quality assessment and mean image quality score. Multivariable logistic regression and linear regression analyses were used to identify predictor variables of a diagnostic examination and higher image quality score. Results: Interreader agreement for an MRCP acquisition being diagnostic, expressed as kappa, was 0.53-0.71; interreader agreement for image quality score, expressed as intraclass correlation coefficient, was 0.37-0.57. A total of 36/200 (18%) MRCP acquisitions were nondiagnostic; mean image quality score was 3.5 ± 1.1. Multivariable predictors of a diagnostic MRCP acquisition included greater body mass index (OR=1.11 [95% CI: 1.02-1.21], p=.02), scanner field strength of 1.5 T (OR=2.87 [95% CI: 1.23-6.68], p=.01), and presence of acute pancreatitis (OR=4.91 [95% CI: 1.53-15.77], p=.008). Multivariable predictors of a higher image quality score (β=0.05-0.94) included older age (p=.01), imaging under sedation/general anesthesia (p<.001), presence of biliary dilation (p=.004), and inpatient status (p=.02). A lower image quality score was predicted by a scanner field strength of 3 T (β=-0.61, p<.001). A greater amount of time between the start of the MRI examination and the MRCP acquisition exhibited a nonsignificant association with a decrease in image quality score (p=.06). Conclusion: Pediatric MRCP acquisitions are commonly nondiagnostic. Patient-specific and technical factors systematically impact MRCP image quality in children. Clinical Impact: Recognition of image quality predictors that are potentially modifiable and amendable to proactive intervention can guide efforts to optimize MRCP image quality in children.

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.

Advances in MR Imaging of the Biliary Tract

Imaging of the biliary system has improved and has allowed MR to become a key noninvasive tool for evaluation of the biliary system. A variety of magnetic resonance cholangiopancreatography techniques have been developed, with improved visualization of the biliary system and biliary pathology. Key avenues of advancement include increasing the speed of acquisition, improving spatial resolution, and reducing artifacts. T1-weighted imaging using gadolinium-based hepatobiliary contrast agents allows for evaluation in additional indications, such as liver donor evaluation, biliary leak identification, and choledochal cyst confirmation. There is potential for further increased utility of MR in the evaluation of the biliary system.

Intrahepatic bile duct variation: MR cholangiography and implication in hepatobiliary surgery

Background

The aim of this study was to assess the prevalence of biliary anatomical variants using 3-T MR cholangiography (MRC) with its impact in reduction of the complication of hepatobiliary surgical techniques.

Results

MRC was applied to 120 subjects (24 potential liver donors and 96 volunteers) and the right posterior hepatic duct insertion was documented, and accordingly, the biliary variants were classified based on Huang classification (Huang et al, Transplant Proc 28: 1669–1670, 1996).

Biliary anatomic variants were divided based on Huang classification: Huang A1, 65.83% (n = 79); Huang A2, 11.67% (n = 14); Huang A3, 13.3% (n = 16); Huang A4, 7.5% (n = 9); and Huang A5, 1.67% (n = 2). The total frequency for A2, A3, A4, and A5 was 34.17% (n = 41). The distance between RPHD insertion and the junction of right and left hepatic ducts (L) was measured, and Huang A1 cases were then subtyped into S1 subtype (L > 1 cm) and S2 subtype (L ≤ 1 cm). We had 52 subjects with subtype S1 (43.33%) and 27 subjects with subtype S2 (22.5%).

Twenty-three subjects had bile duct exploration or intraoperative cholangiograms and showed Huang type A1 in 14 (60.87%), type A2 in 3 (13.05%), and type A3 in 6 (26.08%). Twenty-two (95.65%) had the same classification in MRC and intraoperative while only one case (4.35%) was considered as A2 at MRC but the intraoperative classification was Huang A3, which was attributed to the insertion of the RPHD insertion at the distal end of the left hepatic duct.

Conclusion

MRC is an accurate tool for biliary tract mapping before hepatobiliary surgery to provide excellent identification of biliary variants which can reduce the incidence of biliary complications.

Diagnostic performance of magnetic resonance cholangiopancreatography (MRCP) versus endoscopic retrograde cholangiopancreatography (ERCP) in the pediatric population: a clinical effectiveness study

PURPOSE

To determine the diagnostic performance of magnetic resonance cholangiopancreatography (MRCP) for detecting biliary and pancreatic abnormalities in a pediatric population, using endoscopic retrograde cholangiopancreatography (ERCP) as the reference standard.

MATERIALS AND METHODS

Institutional review board approval with a waiver of informed consent was obtained for this retrospective investigation. Records from the Cincinnati Children's Hospital Medical Center, Division of Gastroenterology and Department of Radiology were used to identify patients aged ≤ 18 years who had undergone both ERCP and MRCP within a 4-week interval between January 2013 and May 2017. Biliary and pancreatic duct findings were documented for each modality to determine the diagnostic performance of MRCP (with 95% confidence intervals), using ERCP as the reference standard.

RESULTS

54 patients met inclusion criteria. Mean patient age at time of ERCP was 10.4 ± 4.9 years, and 25 (46%) were male. Mean interval between ERCP and MRCP was 11.2 ± 9.7 days. For detection of any abnormality (n = 99 ERCP findings), MRCP had a sensitivity of 76.8% (67.5-84.0%) and a positive predictive value (PPV) of 81.7% (72.7-88.3%). MRCP was 75.7% (59.9-86.6%) sensitive, with a PPV of 84.9% (69.1-93.4%) for biliary findings (n = 37) and 73.5% (59.7-83.8%) sensitive, with a PPV of 78.3% (64.4-87.7%) for pancreatic findings (n = 49). For pancreatobiliary abnormalities (n = 13), MRCP had a sensitivity of 92.3% (66.7-99.6%) and a PPV of 85.7% (60.1-97.5%).

CONCLUSION

In clinical practice, MRCP is moderately sensitive for biliary and pancreatic abnormalities, with false-negative and false-positive examinations being relatively common.

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.

Pancreatic Insufficiency: What Is the Gold Standard?

Endoscopic pancreatic function testing assesses exocrine insufficiency and chronic pancreatitis. Indirect pancreatic function tests have limited sensitivity and specificity in early disease stages. Magnetic resonance cholangiopancreatography shows promise in detecting early changes as a direct measure of pancreatic function. This article summarizes the evolution of pancreatic function testing and highlights areas for future research, such as development of diagnostic biomarkers to stratify disease severity and targeted therapies to retard disease progression.

Performance survey on a new standardized formula for oral signal suppression in MRCP

•

Recently, a new biological standardized product for MRCP became available.

•

The product is considered effective as oral signal suppressor in T2-w images.

•

Obtained MRCP imagery show a good image quality.

•

Patients’ feedback on taste and palatability is very high.

Background

Orally administered substances, which reduce image contamination by overlying gastrointestinal fluid signals, can be used to enhance the quality of MRCP images. Recently, a new standardized formula consisting of biological substances has become available. The objective of this study is to provide a first assessment of achievable MRCP image quality, taste and palatability of this new dedicated agent.

Methods

In January 2015 to May 2015 practicing radiologists in Germany, Austria and Switzerland were asked to evaluate image quality as well as taste and palatability when using the new agent (LumiVision^®; b.e. imaging; Baden-Baden; Germany) in MRCP questionnaire. Both criteria were rated with a 6-point Likert scale ranging from “1” (best) to “6” (worst).

Results

A total 185 of 475 radiologic institutions (39%) submitted feedback on image quality, 187 (39%) on the taste/palatability. Assessments of image quality regarding presence of disturbing gastrointestinal fluid signal resulted in a median of 2. The majority of patients rated the subjective taste as very good (median of 1). No side effects of relevance were recorded.

Conclusion

This large survey shows that the tested product is considered effective by radiologists regarding MRCP image quality. Patients’ feedback on taste and palatability was very positive.

Efficacy of oral contrast agents for upper gastrointestinal signal suppression in MRCP: A systematic review of the literature

Background

Orally administered substances which suppress signals from gastrointestinal fluid can be used to enhance image quality in magnetic resonance cholangiopancreatography (MRCP). In daily practice, the available substances range from commercial products to regular viands such as fruit juices.

Purpose

To provide an overview on the significance of and the substances used as gastrointestinal fluid signal suppressors in MRCP.

Material and Methods

A systematic review of the existing literature was performed to evaluate the efficacy and efficiency of oral T2-signal suppressors in MRCP.

Results

Twenty-five publications on 16 different oral contrast media were identified. The most commonly used substances were ferumoxsil, ferric ammonium citrate, and pineapple juice. Twenty-three out of 25 publications supported the use of oral signal suppressors in MRCP. Advantages of oral signal suppressors include improved visualization of the pancreatobiliary ductal system, increased help with differential diagnoses, and higher detection rates of relevant diagnoses due to a reduction of overlaying signals.

Conclusion

The application of oral substances for gastrointestinal signal suppression in MRCP is recommendable. A variety of substances are used in daily routine with good but varying effectivity and patient tolerance.

Paediatric Gastrointestinal Endoscopy: European Society for Paediatric Gastroenterology Hepatology and Nutrition and European Society of Gastrointestinal Endoscopy Guidelines

This guideline refers to infants, children, and adolescents ages 0 to 18 years. The areas covered include indications for diagnostic and therapeutic esophagogastroduodenoscopy and ileocolonoscopy; endoscopy for foreign body ingestion; corrosive ingestion and stricture/stenosis endoscopic management; upper and lower gastrointestinal bleeding; endoscopic retrograde cholangiopancreatography; and endoscopic ultrasonography. Percutaneous endoscopic gastrostomy and endoscopy specific to inflammatory bowel disease has been dealt with in other guidelines and are therefore not mentioned in this guideline. Training and ongoing skill maintenance are to be dealt with in an imminent sister publication to this.

MRCP Versus ERCP in the Evaluation of Chronic Pancreatitis in Children: Which Is the Better Choice?

OBJECTIVES

To evaluate the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) in the detection of chronic pancreatitis (CP)-specific changes in the pediatric population.

METHODS

The study included 48 children with pancreatic disorders subjected to both endoscopic retrograde cholangiopancreatography (ERCP) and MRCP within a 1- to 4-month interval. The sensitivity, specificity, positive predictive value, and negative predictive value of MRCP in the detection of CP-specific changes were determined using ERCP as a diagnostic standard.

RESULTS

Diagnostic ERCP pancreatograms were obtained in 41 (85.4%) of 48 patients and diagnostic MRCP images in all 48 children. The sensitivity and positive predictive value of MRCP were 77.1% and 90%, respectively, and its specificity and negative predictive value amounted to 50% and 27.3%, respectively. The patients with consistent results of MRCP and ERCP (ie, true-positive and true-negative cases) and individuals with incompatible results of the tests (ie, false-positive and false-negative cases) differed in terms of their median age at MRCP (14.17 vs 10.33 years) and median CP stage according to the Cambridge Scale (4 vs 2).

CONCLUSIONS

Magnetic resonance cholangiopancreatography provides diagnostic information equivalent to ERCP in a large percentage of pediatric patients with CP and should be used as the imaging method of choice, especially if the likelihood of therapeutic intervention is low.

Secretin-Stimulated Magnetic Resonance Imaging Assessment of the Benign Pancreatic Disorders: Systematic Review and Proposal for a Standardized Protocol

This systemic review summarizes the current literature and general consensus on secretin-stimulated magnetic resonance imaging (s-MRI) of the benign pancreatic disorders and discusses important aspects on how s-MRI is optimally performed. The aim is to provide an overview, for clinicians and radiologist, of the s-MRI protocols and the range of clinical applications. Furthermore, the review will summarize the criteria for evaluation of pancreatic morphology and function based on s-MRI.The literature search indentified 69 original articles and 15 reviews. Chronic pancreatitis was the disease that was most frequently assessed by s-MRI (33%), followed by acute pancreatitis (9%). Dynamic thick-slab 2-dimensional magnetic resonance cholangiopancreatography was the most used imaging sequence (86%). The diameter of the main pancreatic duct (75%) and pancreatic exocrine function based on visual grading of duodenal filling (67%) were the most evaluated pancreatic features. Sufficient similarities between studies were identified to propose the most agreeable standardized s-MRI protocol for morphological and functional assessment of the pancreas. In the future, more research and increased collaboration between centers is necessary to achieve more consensus and optimization of s-MRI protocols.

Acute Pancreatitis in Pediatric Patients: Demographics, Etiology, and Diagnostic Imaging

OBJECTIVE

The objective of this article is to provide updates on acute pancreatitis in children regarding the imaging findings, causes, and complications based on a review of the current studies in the pediatrics literature. We discuss the epidemiology of acute pancreatitis, the role of imaging and imaging findings in the diagnosis of acute pancreatitis, and the causes and complications of acute pancreatitis.

CONCLUSION

The incidence of acute pancreatitis is increasing in children. Imaging plays an important role in the diagnosis of acute pancreatitis because imaging findings can be used to establish the cause of acute pancreatitis, evaluate for complications of acute pancreatitis, and possibly predict the course of the disease.

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

BACKGROUND

Magnetic resonance imaging/cholangiopancreatography (MRI/MRCP) is now an essential imaging modality for the evaluation of biliary and pancreatic pathology in children, but there are no data depicting the normal diameters of the common bile duct (CBD) and pancreatic duct. Recognition of abnormal duct size is important and the increasing use of MRCP necessitates normal MRI measurements.

OBJECTIVE

To present normal MRI measurements for the common bile duct and pancreatic duct in children.

MATERIALS AND METHODS

In this retrospective study we searched all children ages birth to 10 years in our MR urography (MRU) database from 2006 until 2013. We excluded children with a history of hepatobiliary or pancreatic surgery. We stratified 204 children into five age groups and retrospectively measured the CBD and the pancreatic duct on 2-D axial and 3-D coronal T2-weighted sequences. We performed statistical analysis, using logistic and linear regressions to detect the age association of the visibility and size of the duct measurements. We used non-parametric tests to detect gender and imaging plane differences.

RESULTS

Our study included 204 children, 106 (52%) boys and 98 (48%) girls, with a median age of 33 months (range 0-119 months). The children were distributed into five age groups. The common bile duct was visible in all children in all age groups. The pancreatic duct was significantly less visible in the youngest children, group 1 (54/67, 80.5%; P = 0.003) than in the oldest children, group 5 (22/22, 100%). In group 2 the pancreatic duct was seen in 19/21 (90.4%), in group 3 52/55 (94.5%), and in group 4 39/39 (100%). All duct measurements increased with age (P < 0.001; r-value > 0.423), and the incremental differences between ages were significant. The measurement variations between the axial and coronal planes were statistically significant (P < 0.001); however these differences were fractions of millimeters. For example, in group 1 the mean coronal measurement of the CBD was 2.1 mm and the axial measurement was 2.0 mm; the mean coronal measurement of the pancreatic duct was 0.9 mm and the axial measurement was 0.8 mm.

CONCLUSION

Our study provides normative measurements for the common bile duct and pancreatic duct for children up to age 10 years. The upper limits of the CBD and pancreatic duct increase with age, and the values range 1.1-4.0 mm for the CBD and 0.6-1.9 mm for the pancreatic duct.

Characteristics of Pediatric Pancreatitis on Magnetic Resonance Cholangiopancreatography

Pediatric pancreatitis is not uncommon and results in considerable morbidity and mortality in the affected children. Unlike adults, pediatric pancreatitis is more frequently associated with underlying structural abnormalities, trauma, and drugs rather than an idiopathic etiology. Magnetic resonance cholangiopancreatography (MRCP) is a good imaging modality for evaluating pancreatitis and determining etiology without exposure to radiation. This article focuses on MRCP findings associated with various causes of pancreatitis in children, particularly structural abnormalities of the pancreaticobiliary system, as well as describing the feasibility, limitations, and solutions associated with pediatric MRCP.

Diagnosis and management of choledochal cyst: 20 years of single center experience

We report the first case series from Africa and the Middle East on choledochal cyst, a disease which shows significant geographical distribution with high incidence in the Asian population. In this study, the epidemiological data of the patients are presented and analyzed. Attention was paid to diagnostic imaging and its accuracy in the diagnosis and classification of choledochal cyst. Most cases of choledochal cyst disease have type I and IV-A cysts according to the Todani classification system, which support the etiological theories of choledochal cyst, especially Babbitt’s theory of the anomalous pancreaticobiliary duct junction, which are clearly stated. The difficulties and hazards of surgical management and methods used to avoid operative complications are clarified. Early and late postoperative complications are also included. This study should be followed by multicenter studies throughout Egypt to help assess the incidence of choledochal cysts in one of the largest populations in Africa and the Middle East.

Pediatric hepatobiliary magnetic resonance imaging

Magnetic resonance (MR) imaging is an effective and noninvasive modality for evaluating hepatobiliary pathologic conditions. This article provides an up-to-date review of anatomy, indications, and imaging goals and protocols, including patient preparation, pulse sequences, and contrast agents used in pediatric MR hepatobiliary imaging. This article also highlights some of the common MR features of pediatric liver pathologic conditions, including tumors, congenital biliary ductal plate malformations, trauma, fibrosis, and infection.

Comparison of respiratory-triggered 3-D fast spin-echo and single-shot fast spin-echo radial slab MR cholangiopancreatography images in children

BACKGROUND

The two most commonly performed magnetic resonance cholangiopancreatography (MRCP) sequences, 3-D fast spin-echo (3-D FSE) and single-shot fast spin-echo radial slabs (radial slabs), have not been compared in children.

OBJECTIVE

The purpose of this study was to compare 3-D FSE and radial slabs MRCP sequences on a 3-T scanner to determine their ability to show various segments of pancreaticobiliary tree and presence of artifacts in children.

MATERIALS AND METHODS

We reviewed 79 consecutive MRCPs performed in 74 children on a 3-T scanner. We noted visibility of major ducts on 3-D FSE and radial slabs. We noted the order of branching of ducts in the right and left hepatic ducts and the degree of visibility of the pancreatic duct. Statistical analysis was performed using McNemar and signed rank tests.

RESULTS

There was no significant difference in the visibility of major bile ducts and the order of branching in the right hepatic lobe between sequences. A higher order of branching in the left lobe was seen on radial slabs than 3-D FSE (mean order of branching 2.82 versus 2.27; P-value = 0.0002). The visibility of pancreatic duct was better on radial slabs as compared to 3-D FSE (mean value of 1.53 vs. 0.90; P-value < 0.0001). 3-D FSE sequence was artifact-free in 25/79 (31.6%) MRCP exams as compared to radial slabs, which were artifact-free in 18/79 (22.8%) MRCP exams (P-value = 0.0001).

CONCLUSION

There is no significant difference in the visibility of major bile ducts between 3-D FSE and radial slab MRCP sequences at 3-T in children. However, radial slab MRCP shows a higher order of branching in the left hepatic lobe and superior visibility of the pancreatic duct than 3-D FSE.

Magnetic resonance imaging of the pediatric pancreaticobiliary system

Magnetic resonance cholangiopancreatography (MRCP) is an extremely useful tool for evaluating a wide variety of disorders affecting the pancreaticobiliary system in neonates/infants, children, and adolescents. This imaging technique has numerous distinct advantages over alternative diagnostic modalities, such as endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography, including its noninvasive nature and lack of ionizing radiation. Such advantages make MRCP the preferred first-line method for advanced imaging the pediatric pancreaticobiliary tree, after ultrasonography. This article presents a contemporary review of the use of MRCP in the pediatric population, including techniques, indications, and the imaging appearances of common and uncommon pediatric disorders.

Does secretin add value in pediatric magnetic resonance cholangiopancreatography?

BACKGROUND

Secretin--a hormone that stimulates pancreatic exocrine secretion--is described to improve visualization of the pancreatic duct by magnetic resonance cholangiopancreatography (MRCP). In our pediatric practice, however, we have not observed substantial benefit with the use of secretin.

OBJECTIVE

To determine whether secretin dilates and improves visualization of the pancreatic duct in pediatric MRCP.

MATERIALS AND METHODS

Retrospective evaluation of secretin-enhanced MRCPs performed over a 15-month period. One reviewer measured the pancreatic duct pre- and post-secretin and two reviewers, blinded to the administration of secretin, assessed image quality and subjective duct visibility. Similar assessments of the biliary tree served as internal controls.

RESULTS

We reviewed 20 MRCPs in 17 children. Following secretin administration, there was a small (0.3 mm) but statistically significant increase in pancreatic duct diameter (P = 0.002) and small (<0.2 mm) but significant increase in intrahepatic bile duct diameter (P = 0.0104). On subjective review, there was no significant difference in image quality or duct visibility based on the administration of secretin.

CONCLUSION

Secretin induces dilatation of the pancreatic duct but the value of that effect in pediatric MRCP is suspect given the small change in duct diameter and the lack of improvement in image quality and duct visibility.

MR cholangiopancreatography at 3.0 T in children: diagnostic quality and ability in assessment of common paediatric pancreatobiliary pathology

OBJECTIVE

To assess the diagnostic quality of MR cholangiopancreatography (MRCP) at 3.0 T in children and to assess its diagnostic ability in answering the clinical query. Also, to determine the frequency of artefacts and anatomic variations in ductal anatomy.

METHODS

Consecutive MRCPs performed in children using a 3-T scanner were retrospectively reviewed to note indications, findings, imaging diagnosis, normal variants, quality and artefacts. Analysis was performed based on the final diagnosis assigned by pathology or the combination of clinical, laboratory, imaging features and follow-up to determine whether it was possible to answer the clinical query by MRCP findings.

RESULTS

There were 82 MRCPs performed at 3.0 T on 77 children. 42/82 (51%) MRCPs were of good quality, 35/82 (43%) MRCPs were suboptimal but diagnostic and the remaining 5/82 (6%) MRCPs were non-diagnostic. MRCP answered the clinical query in 61/82 (74%) cases; however, it did not answer the clinical query in 11/82 (14%) cases and was equivocal in 10/82 (12%) cases. There was significant association between the quality of MRCP and the ability of MRCP to answer the clinical query (p<0.0001). 64/82 (78%) MRCP examinations had at least 1 artefact. Variation in the bile duct anatomy was seen in 27/77 (35%) children.

CONCLUSION

MRCP performed at 3.0 T is of diagnostic quality in most cases and is able to provide an answer to the clinical query in the majority of cases.

ADVANCES IN KNOWLEDGE

3-T MRCP is feasible and useful in the assessment of pancreatobiliary abnormalities in children.

Targeted MRI contrast agents for pediatric hepatobiliary disease

New options are available for the magnetic resonance imaging (MRI) assessment of pediatric hepatobiliary disease. This article describes the potential utility for MRI with contrast agents tailored for hepatobiliary imaging. MRI contrast agents that preferentially target the liver may be helpful in characterizing liver masses and bile duct abnormalities in select children. The imaging approach is noninvasive and relatively rapid to perform. It also provides anatomic and functional information and is a radiation-free alternative to other imaging strategies. This relatively new imaging procedure is placed in the context of more established imaging modalities. The pharmacokinetics, technical considerations, and potential applications of these hepatobiliary-specific contrast agents also are discussed.

Usefulness of magnetic resonance cholangiopancreatography in pancreatobiliary abnormalities in pediatric patients

BACKGROUND

Magnetic resonance cholangiopancreatography (MRCP) is an innovative and noninvasive technique for evaluating the biliary tree and pancreatic duct in children. The aim of this study was to assess the usefulness of MRCP as a noninvasive method to evaluate the biliary system in children.

METHODS

We retrospectively reviewed the records of patients undergoing MRCP between October 2002 and May 2007 for suspected biliary system abnormalities. MRCP findings were compared with other imaging modalities, operative findings, and clinical endpoints.

RESULTS

Complete data were available for 60 patients (35 girls, 25 boys; mean age 2 years, 33 children less than 1 year old). Ultrasound was performed in all 60 patients. Twenty-two patients had choledochal cyst, and 19 had a thin or invisible gall bladder. Endoscopic retrograde cholangiopancreatography was done in two patients. The sensitivities and specificities of MRCP for diagnosing choledochal cyst and biliary atresia were 100.0% and 100.0% and 86.7% and 100.0%, respectively. Surgery was performed in 37 patients, including 21 with a choledochal cyst, 14 with biliary atresia, and 1 with a pancreatic duct stone.

CONCLUSION

MRCP is useful method for evaluation of the pancreaticobiliary system in pediatric patients. It yields a high degree of accuracy in the diagnosis of biliary atresia and choledochal cyst.

MR imaging of the abdomen and pelvis in infants, children, and adolescents

Recent developments in magnetic resonance (MR) imaging have profoundly changed the investigation of abdominal and pelvic disease in pediatrics. Motion reduction techniques, such periodically rotated overlapping parallel lines with enhanced reconstruction, or PROPELLER, have resulted in reliable imaging with quiet breathing. Faster imaging sequences minimize artifact and allow for more efficient studies. Diffusion-weighted imaging has become increasingly important in the evaluation of neoplastic disease, depicting disease with increased cellularity and helping to differentiate benign from malignant masses. MR enterography helps visualize intra- and extraluminal bowel pathologic conditions. MR cholangiopancreatography can depict congenital and acquired causes of pancreatic and biliary abnormalities. MR urography is an effective technique for a one-stop-shop evaluation of structural urinary tract abnormality and renal function. Three-dimensional acquisitions allow volumetric display of structures from multiple angles. Specialized techniques allow quantification of iron and fat in the viscera in children with hemolytic anemia and obesity, respectively. This article covers current techniques and strategies to perform and optimize MR imaging of the abdomen and pelvis in infants, children, and adolescents and describes important practical applications.

Choledochal cysts in infants and children: experiences over a 20-year period at a single institution

This analysis was undertaken to compare the clinicopathological features of infants with choledochal cysts to those of older children with these entities and to evaluate the surgical outcomes for both subject groups. The medical records of all children admitted to the Cathay General Hospital with choledochal cysts over a 20-year period were retrospectively reviewed. Twenty-five subjects were included and divided into the infant (<1 year at presentation; 8 subjects) and classical pediatric (1-18 years at presentation; 17 subjects) groups. Anatomical subtypes were: IA (16), IC (6), and IVA (3). The median biliary amylase value was markedly elevated for the pediatric group but not for the infant group. Most (82.4%) patients in the pediatric group, but none in the infant group, presented with abdominal pain. Jaundice and clay-colored stool were present in all patients in the infant group but only 35% of those in the pediatric group. All patients underwent choledochocystectomy and Roux-en-Y hepaticojejunostomy with good outcomes. Neonates/infants with choledochal cysts present differently from older children with these entities. Amylase measurements may serve to distinguish biliary atresia with cystic dilatation from choledochal cyst in neonates/infants. Prognosis following radical cyst excision and reconstruction with Roux-en-Y hepaticojejunostomy is excellent.

Pediatrics: ERCP in children

Although endoscopic retrograde cholangiopancreatography (ERCP) is a well-established technique for both the diagnosis and treatment of biliary and pancreatic disorders in adults, indications for some pediatric applications, such as idiopathic and recurrent pancreatitis, remain contentious. This News & Views article discusses a recent study that evaluated the technical outcomes and safety of 231 ERCPs in children.

Acute pancreatitis in children

AIM

To identify clinical, laboratory, and imaging characteristics associated with severe acute pancreatitis in children.

METHODS

This was a retrospective study of children under 18 years of age with acute pancreatitis between September 1993 and August 2008. Severity of pancreatitis was graded according to established criteria. Clinical, laboratory and radiological data for mild and severe pancreatitis were collected for analysis.

RESULTS

There were 180 cases of pancreatitis; 51 (28.3%) met criteria for severe disease. Severe pancreatitis was most commonly associated with systemic disease (22 of 51; 43.1%) and trauma (13 of 51; 25.4%). Patients with severe pancreatitis had significantly higher body weight, higher frequency of dyspnoea and pleural effusion, and lower serum calcium and albumin levels. Ten patients with systemic disease died; four of them had systemic lupus erythematosus (SLE). Computed tomography (CT) was more accurate than ultrasound in evaluation of the severity of pancreatitis.

CONCLUSIONS

Acute pancreatitis in children is associated with significant morbidity and mortality. The severity of paediatric pancreatitis may be influenced by aetiology. CT is recommended for evaluation of severity of pancreatitis.

Hepatobiliary and pancreatic imaging in children-techniques and an overview of non-neoplastic disease entities

Imaging plays a major role in the diagnostic work-up of children with hepatobiliary or pancreatic diseases. It consists mainly of US, CT and MRI, with US and MRI being the preferred imaging modalities because of the lack of ionizing radiation. In this review the technique of US, CT and MRI in children will be addressed, followed by a comprehensive overview of the imaging characteristics of several hepatobiliary and pancreatic disease entities most common in the paediatric age group.

MRI of the liver--how to do it

This article details indications, patient preparation, pulse sequences/protocols, and contrast agents for pediatric hepatobiliary MRI. When performed well, MRI provides superior diagnostic information relative to CT for evaluation of hepatic tumors, liver transplants, and biliary disease.

Pancreatitis and the role of US, MRCP and ERCP

Imaging plays a crucial role in the diagnosis of acute and chronic pancreatitis in children. Ultrasound (US) is the primary imaging modality. The US study can be improved by incorporating high resolution imaging, color Doppler, harmonic imaging and panorama view. Computer tomography (CT) is widely used for further evaluation. MR imaging in combination with MR cholangiopancreaticography (MRCP) is emerging as the modality of choice. It is non-invasive and radiation-free. It has high potential to replace endoscopic retrograde cholangiopancreaticography (ERCP), too. The latter is becoming more of an interventional tool. This review discusses the current status and comparative diagnostic potential of US, MRCP and ERCP.

Pediatric MR cholangiopancreatography: principles, technique, and clinical applications

High-quality magnetic resonance (MR) cholangiopancreatographic images are difficult to obtain in children due to the small caliber of the pediatric bile ducts and to motion artifacts. However, there has been ongoing improvement in image quality, thanks to better coil technology, increased speed of acquisition, refinement in respiratory compensation techniques, and newer sequences. Heavily T2-weighted fast spin-echo (FSE) and single-shot FSE MR imaging sequences with long echo times are used to image the biliary and pancreatic ducts. Secretin has been shown to improve the visualization of the pancreatic duct and pancreaticobiliary junction. Factors that affect image quality in pediatric MR cholangiopancreatography include sedation, negative oral contrast material, radiofrequency coil selection, respiratory compensation techniques, echo time, echo train length, section-slab thickness, planes of scanning, field of view, and number of signals acquired. However, giving proper attention to these factors and tailoring the study to the body size of the patient (which varies considerably) can lead to high-quality diagnostic MR cholangiopancreatographic images. Use of MR cholangiopancreatography in children is limited by the need for sedation or anesthesia, high cost, limited availability, and long scanning times. Nonetheless, this modality can be a viable alternative to endoscopic retrograde cholangiopancreatography (ERCP) in the evaluation of various entities such as choledochal cyst, recurrent pancreatitis, primary sclerosing cholangitis, and a transplanted liver, and may obviate ERCP.

Potential of MR-imaging in the paediatric abdomen

OBJECTIVE

To describe the potential and relevant applications of MR-imaging (MRI) in typical paediatric abdominal conditions and diseases.

METHOD

The commonly used indications, applications, and sequences as well as typical imaging findings of paediatric abdominal MRI are presented and discussed, with emphasis on specific paediatric needs and queries. Only applications as used in routine clinical work are listed, other more sophisticated and advanced techniques will only briefly be mentioned. Furthermore, some aspects of paediatric MR Urography are presented and discussed.

CONCLUSION

Though conventional imaging methods (ultrasound and plain film) are valuable and - particularly in the paediatric abdomen - form the mainstay of routine imaging in paediatric abdominal radiology, some conditions require sectional imaging. MRI is increasingly applied to these queries in neonates, infants and children as an alternative method to CT without any radiation burden, and - when performed adequately and skilfully - can answer most treatment relevant questions. MR will increasingly be applied with new applications and broader availability also with functional information deriving from new equipment and research offering an ideal one stop imaging approach to many conditions also in children.

Primary sclerosing cholangitis in children: utility of magnetic resonance cholangiopancreatography

BACKGROUND

Even when histologic findings are highly suggestive of primary sclerosing cholangitis (PSC), cholangiographic correlation is required for the diagnosis. The present gold standard, endoscopic retrograde cholangiopancreatography (ERCP), is invasive and associated with complications.

OBJECTIVE

To evaluate the usefulness of magnetic resonance cholangiopancreatography (MRCP) in diagnosing PSC in children.

MATERIALS AND METHODS

MRCP studies were retrospectively reviewed in 20 children with clinical suspicion of PSC and who had undergone liver biopsy. MRCP studies were considered positive or negative for PSC depending on the presence or absence of dilatation, irregularity, multifocal strictures and beading of the bile ducts.

RESULTS

Twenty children (14 boys, 6 girls) with an average age of 13 years qualified for the study. Of 19 diagnostic MRCP studies, 16 were called positive and 3 were called negative. An overall diagnosis of PSC-positive was assigned to all 19 patients based on clinical and laboratory findings, biopsy results and cholangiographic data. Based on this overall diagnosis, MRCP was 84% sensitive and accurate to diagnose PSC in children.

CONCLUSION

MRCP can be a valuable tool in diagnosing pediatric PSC that can demonstrate major intra- and extrahepatic ducts in most cases. An unequivocally positive MRCP study should not be followed by ERCP for diagnosing PSC in children.