Extrahepatic biliary diseases: 3D MR cholangiopancreatography compared with endoscopic retrograde cholangiopancreatography

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.

Imaging of benign biliary pathologies

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

Efficacy of an artificial neural network algorithm based on thick-slab magnetic resonance cholangiopancreatography images for the automated diagnosis of common bile duct stones

BACKGROUND AND AIM

Magnetic resonance cholangiopancreatography (MRCP) can accurately diagnose common bile duct (CBD) stones but is laborious to interpret. We developed an artificial neural network (ANN) capable of automatically assisting physicians with the diagnosis of CBD stones. This study aimed to evaluate the ANN's diagnostic performance for detecting CBD stones in thick-slab MRCP images and identify clinical factors predictive of accurate diagnosis.

METHODS

The presence of CBD stones was confirmed via direct visualization through endoscopic retrograde cholangiopancreatography (ERCP). The absence of CBD stones was confirmed by either a negative endoscopic ultrasound accompanied by clinical improvements or negative findings on ERCP. Our base networks were constructed using state-of-the-art EfficientNet-B5 neural network models, which are widely used for image classification.

RESULTS

In total, 3156 images were collected from 789 patients. Of these, 2628 images from 657 patients were used for training. An additional 1924 images from 481 patients were prospectively collected for validation. Across the entire prospective validation cohort, the ANN achieved a sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of 93.03%, 97.05%, 97.01%, 93.12%, and 95.01%, respectively. Similarly, a radiologist achieved a sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy 91.16%, 93.25%, 93.22%, 90.20%, and 91.68%, respectively. In multivariate analysis, only bile duct diameter > 10 mm (odds ratio = 2.45, 95% confidence interval [1.08-6.07], P = 0.040) was related to ANN diagnostic accuracy.

CONCLUSION

Our ANN algorithm automatically and quickly diagnoses CBD stones in thick-slab MRCP images, therein aiding physicians with optimizing clinical practice, such as whether to perform ERCP.

Quantitative MRCP Imaging: Accuracy, Repeatability, Reproducibility, and Cohort-Derived Normative Ranges

BACKGROUND

Magnetic resonance cholangiopancreatography (MRCP) is an important tool for noninvasive imaging of biliary disease, however, its assessment is currently subjective, resulting in the need for objective biomarkers.

PURPOSE

To investigate the accuracy, scan/rescan repeatability, and cross-scanner reproducibility of a novel quantitative MRCP tool on phantoms and in vivo. Additionally, to report normative ranges derived from the healthy cohort for duct measurements and tree-level summary metrics.

STUDY TYPE

Prospective.

PHANTOMS/SUBJECTS

Phantoms: two bespoke designs, one with varying tube-width, curvature, and orientation, and one exhibiting a complex structure based on a real biliary tree. Subjects Twenty healthy volunteers, 10 patients with biliary disease, and 10 with nonbiliary liver disease.

SEQUENCE/FIELD STRENGTH

MRCP data were acquired using heavily T2 -weighted 3D multishot fast/turbo spin echo acquisitions at 1.5T and 3T.

ASSESSMENT

Digital instances of the phantoms were synthesized with varying resolution and signal-to-noise ratio. Physical 3D-printed phantoms were scanned across six scanners (two field strengths for each of three manufacturers). Human subjects were imaged on four scanners (two fieldstrengths for each of two manufacturers).

STATISTICAL TESTS

Bland-Altman analysis and repeatability coefficient (RC).

RESULTS

Accuracy of the diameter measurement approximated the scanning resolution, with 95% limits of agreement (LoA) from -1.1 to 1.0 mm. Excellent phantom repeatability was observed, with LoA from -0.4 to 0.4 mm. Good reproducibility was observed across the six scanners for both phantoms, with a range of LoA from -1.1 to 0.5 mm. Inter- and intraobserver agreement was high. Quantitative MRCP detected strictures and dilatations in the phantom with 76.6% and 85.9% sensitivity and 100% specificity in both. Patients and healthy volunteers exhibited significant differences in metrics including common bile duct (CBD) maximum diameter (7.6 mm vs. 5.2 mm P = 0.002), and overall biliary tree volume 12.36 mL vs. 4.61 mL, P = 0.0026).

DATA CONCLUSION

The results indicate that quantitative MRCP provides accurate, repeatable, and reproducible measurements capable of objectively assessing cholangiopathic change. Evidence Level: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;52:807-820.

Bimodal ERCP, a new way of seeing things

Background and study aims  Conventional endoscopic retrograde cholangiopancreatography (ERCP) is hampered by two-dimensional visualization, post-procedural adverse events (AEs), and exposure to ionizing radiation. Bimodal ERCP might mitigate these challenges, but no reports of its use are available to date. The aim of this study was to explore the feasibility of bimodal ERCP, while investigating its potential clinical yield. Patients and methods  This was a retrospective observational study of patients that underwent bimodal ERCP in a single tertiary academic referral center. Thirteen patients undergoing conventional ERCP had a previously T2-weighted isotropic 3 D TSE MRCP sequence aligned and fused with the two-dimensional image generated from the fluoroscopy c-arm unit in real time. Results  Over a 2-month period, 13 patients with a mean age of 54 underwent bimodal ERCP for bile duct stricture (61.5 %), complex cholelithiasis (7.7 %) and ductal leakage (30.1 %). Bimodal ERCP was feasible in all 13 cases, and image quality was assessed as "good" in 11 patients (84.6 %). Bimodal ERCP aided in visualizing the lesion of interest (76.9 %), assisted in understanding the 3 D anatomy of the biliopancreatic ductal system (61.5 %), and aided in finding a favorable position for the c-arm (38.4 %) for subsequent therapeutic intervention. Conclusions  This first report on bimodal ERCP proves its feasibility and suggests that it may assist in increasing both the diagnostic and therapeutic yield of ERCP, while at the same time decreasing AEs during and after ERCP. Its main application might lie in treatment of complex intrahepatic disease.

[Passive and active magnetic resonance cholangiopancreatography : Technique, indications, and typical anatomy]

CLINICAL/METHODICAL ISSUE

In daily routine, every radiologist is confronted with a variety of questions concerning the biliary tract and pancreatic system.

STANDARD RADIOLOGICAL METHODS

Today, besides sonography, magnetic resonance cholangiopancreatography (MRCP) is considered the method of choice in the investigation of many disorders of the hepatobiliary and pancreatic system and is commonly preferred over invasive ERCP in a mere diagnostic setting.

METHODICAL INNOVATIONS

Since its introduction in 1991, MRCP has constantly evolved. Major innovations have been the reduction of acquisition time by using fast spin echo (FSE) sequences, the use of respiratory gating and contrast-enhanced imaging of the bile ducts with hepatobiliary-specific MRI contrast agents.

PERFORMANCE

Many diagnoses may already be made with noncontrast enhanced images. By supplemental administration of a hepatobiliary-specific contrast agent, it is also possible to evaluate the flow dynamics of the bile. This is of additional value especially in patients who underwent surgery of the biliodigestive system or endoscopic interventions.

ACHIEVEMENTS

Aside from robustness and reproducibility, a major advantage of this technique is the modular design of imaging protocols, which can easily be adapted to the clinical question.

PRACTICAL RECOMMENDATIONS

MRCP is a reliable and low-risk imaging method for primary diagnosis and follow-up of biliary and pancreatic pathologies.

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.

Usefulness of three-dimensional magnetic resonance cholangiopancreatography with partial maximum intensity projection for diagnosing autoimmune pancreatitis

PURPOSE

To compare three-dimensional magnetic resonance cholangiopancreatography (MRCP) with/without partial maximum intensity projection (MIP) and endoscopic retrograde cholangiopancreatography (ERCP) in patients with autoimmune pancreatitis (AIP).

MATERIALS AND METHODS

Three-dimensional MRCP and ERCP images were retrospectively analyzed in 24 patients with AIP. We evaluated the narrowing length of the main pancreatic duct (NR-MPD), multiple skipped MPD narrowing (SK-MPD), and side branches arising from the narrowed portion of the MPD (SB-MPD) using four MRCP datasets: 5 original images (MIP₅), 10 original images (MIP₁₀), all original images (full-MIP), and a combination of these three datasets (a-MIP). The images were scored using a 3- or 5-point scale. The scores of the four MRCP datasets were statistically analyzed, and the positive rate of each finding was compared between MRCP and ERCP.

RESULTS

The median scores for SB-MPD on MIP₅ and a-MIP were significantly higher than those on MIP₁₀ and full-MIP. In other words, partial MIP is superior to full-MIP for visualization of detailed structures. The positive rate for SB-MPD on full-MIP was significantly lower than that on ERCP, whereas the positive rate on MIP₅, MIP₁₀, and a-MIP was not significantly different from that on ERCP. Moreover, the positive rate for NR-MPD and SK-MPD on the MRCP images was significantly higher than that on the ERCP images.

CONCLUSION

Partial MIP is useful for evaluating the MPD and is comparable with ERCP for diagnosing AIP.

Benign Biliary Strictures

Differentiating benign and malignant biliary strictures is a challenging and important clinical scenario. The typical presentation is indolent and involves elevation of liver enzymes, constitutional symptoms, and obstructive jaundice with or without superimposed or recurrent cholangitis. While overall the most common causes of biliary strictures are malignant, including cholangiocarcinoma and pancreatic adenocarcinoma, benign strictures encompass a wide spectrum of etiologies including iatrogenic, autoimmune, infectious, inflammatory, and congenital. Imaging plays a crucial role in evaluating strictures, characterizing their extent, and providing clues to the ultimate source of biliary obstruction. While ultrasound is a good screening tool for biliary ductal dilatation, it is limited by a poor negative predictive value. Magnetic resonance cholangiopancreatography is more than 95% sensitive and specific for detecting biliary strictures with the benefit of precise anatomic localization. Other commonly employed imaging modalities include endoscopic retrograde cholangiopancreatography with endoscopic ultrasound, contrast-enhanced CT, and cholangiography. First-line treatment of benign biliary strictures is endoscopic dilation and stenting. In patients with anatomy that precludes endoscopic cannulation, percutaneous biliary drain insertion and balloon dilation is preferred.

Yield of magnetic resonance cholangiopancreatography for the investigation of bile duct dilatation in asymptomatic patients

BACKGROUND

Biliary dilatation in the asymptomatic patient is a frequent incidental finding in the work-up for which there are no current guidelines.

OBJECTIVES

The purpose of this study was to determine the yield of magnetic resonance cholangiopancreatography (MRCP) in asymptomatic patients with an incidental finding of biliary duct dilatation.

METHODS

The study included 68 consecutive patients for evaluation of biliary duct dilatation found incidentally on computed tomography (CT) or ultrasound (US). MRCP scans were reviewed, and data were retrospectively collected on demographics and laboratory work-up. Patients were divided by the presence of a significant or non-significant MRCP findings explaining the biliary duct dilatation and compared for normal or abnormal liver function.

RESULTS

Liver function was normal in 47 patients and abnormal in 21 patients. MRCP identified the cause of the bile duct dilatation in 41 patients (60.3%). Rates of insignificant causes were 51% in the normal-liver-function group and 7% in the abnormal-function group. Corresponding rates of significant causes were 27.7% and 61.9% (p = 0.007).

CONCLUSIONS

MRCP is a valuable tool in the work-up of biliary duct dilatation. Although significantly more significant causes of bile dilatation are identified in patients with abnormal liver function, almost one-third of patients with normal liver function need further work-up. This has important implications for establishing criteria for the use of MRCP in asymptomatic patients with biliary dilatation.

Balanced MR cholangiopancreatography with motion-sensitised driven-equilibrium (MSDE) preparation: feasibility of Gd-EOB-DTPA-enhanced biliary examination

AIM

To evaluate the effectiveness of motion-sensitised driven-equilibrium (MSDE)-prepared balanced magnetic resonance cholangiopancreatography (MRCP) in a gadolinium ethoxybenzyl diethylene triamine pentaacetic acid (Gd-EOB-DTPA)-enhanced study compared to conventional T2-weighted MRCP.

MATERIALS AND METHODS

Fifteen patients (seven male and eight female patients) prospectively underwent conventional three-dimensional turbo spin-echo T2-weighted MRCP and MSDE-balanced MRCP using a 1.5 T MRI system after hepatobiliary phase image acquisition. For quantitative evaluation, the contrast-to-noise ratio (CNR) of the common hepatic duct to liver tissue was calculated. For qualitative analysis, two radiologists evaluated the depiction of the biliary system and main pancreatic duct (MPD) using a scoring system. Signal suppression of the portal vein (PV) and hepatic vein (HV) on MSDE-balanced MRCP was also scored.

RESULTS

MSDE-balanced MRCP showed significantly higher CNR than T2-weighted MRCP. For all biliary structures, the mean depiction scores of MSDE-balanced MRCP were significantly higher than those of T2-weighted MRCP, whereas the mean depiction score of MPD with MSDE-balanced MRCP was significantly lower than that of T2-weighted MRCP. Signal suppression of the PV and HV was thought to be clinically sufficient.

CONCLUSIONS

MSDE-balanced MRCP more clearly depicted biliary structures compared with T2-weighted MRCP in a Gd-EOB-DTPA-enhanced study. This sequence may be utilised for routine MRCP on Gd-EOB-DTPA-enhanced MRI.

Endoscopic ultrasound versus magnetic resonance cholangiopancreatography in suspected choledocholithiasis: A systematic review

BACKGROUND AND OBJECTIVES

There is a lack of consensus about the optimal noninvasive strategy for patients with suspected choledocholithiasis. Two previous systematic reviews used different methodologies not based on pretest probabilities that demonstrated no statistically significant difference between Endoscopic ultrasound (EUS) and magnetic resonance cholangiopancreatography (MRCP) for the detection of choledocholithiasis. In this article, we made a comparison of the diagnostic ability of EUS and MRCP to detect choledocholithiasis in suspected patients.

METHODS

We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations with all published randomized prospective trials. We performed the systemic review using MedLine, EMBASE, Cochrane, LILACS, and Scopus reviews through May 2015. We identified eight randomized, prospective, blinded trials comparing EUS and MRCP. All the patients were submitted to a gold standard method. We calculated the study-specific variables and performed analyses using aggregated variables such as sensitivity, specificity, prevalence, positive predictive value (PPV) and negative predictive value (NPV), and accuracy.

RESULTS

Five hundred and thirty eight patients were included in the analysis. The pretest probability for choledocholithiasis was 38.7. The mean sensitivity of EUS and MRCP for detection of choledocholithiasis was 93.7 and 83.5, respectively; the specificity was 88.5 and 91.5, respectively. Regarding EUS and MRCP, PPV was 89 and 87.8, respectively, and NPV was 96.9 and 87.8, respectively. The accuracy of EUS and MRCP was 93.3 and 89.7, respectively.

CONCLUSIONS

For the same pretest probability of choledocholithiasis, EUS has higher posttest probability when the result is positive and a lower posttest probability when the result is negative compared with MRCP.

Role of MRCP in Differentiation of Benign and Malignant Causes of Biliary Obstruction

BACKGROUND

Differentiation of the benign and malignant etiology of biliary obstruction is difficult. We studied the diagnostic accuracy of MRCP (Magnetic Resonance Cholangio-pancreatography) in differentiating between benign and malignant causes of biliary obstruction.

AIM

To evaluate the role of Magnetic Resonance Cholangio-Pancreatography in differentiating benign from malignant causes of biliary obstruction using surgical, ERCP or histopathological findings as gold standard.

MATERIALS AND METHODS

Seventy five patients with clinical and laboratory finding suggestive of biliary obstruction underwent MRI/MRCP. The final diagnosis was based on either surgical findings, histopathology of resected specimen or ERCP findings. Diagnostic effectivity of MRCP was calculated which included sensitivity, specificity and accuracy. Statistical analysis was done by using chi-square test and p value was calculated.

RESULTS

Out of 75 cases, there were 54 benign and 21 malignant cases. Mean age of patients with malignant obstruction was more than benign with slight male preponderance. The diagnostic accuracy of MRCP in differentiating benign from malignant biliary obstructive diseases in correlation with surgical, ERCP and histopathological outcome was 93.3%, sensitivity 85.7%, specificity 96.3%. It was found that irregular, asymmetric and long segment narrowing was more common in malignant stricture.

CONCLUSIONS

MRCP is the investigation of choice for suspected choledocholithiasis, choledochal cyst and primary sclerosing cholangitis. A benign stricture can be differentiated from a malignant one if it shows regular, symmetric and short segment narrowing. Irregular, asymmetric and long segment narrowing was more commonly found in malignant stricture.

Imaging and interventions in hilar cholangiocarcinoma: A review

Hilar cholangiocarcinoma is a common malignant tumor of the biliary tree. It has poor prognosis with very low 5-year survival rates. Various imaging modalities are available for detection and staging of the hilar cholangiocarcinoma. Although ultrasonography is the initial investigation of choice, imaging with contrast enhanced computed tomography scan or magnetic resonance imaging is needed prior to management. Surgery is curative wherever possible. Radiological interventions play a role in operable patients in the form of biliary drainage and/or portal vein embolization. In inoperable cases, palliative interventions include biliary drainage, biliary stenting and intra-biliary palliative treatment techniques. Complete knowledge of application of various imaging modalities available and about the possible radiological interventions is important for a radiologist to play a critical role in appropriate management of such patients.We review the various imaging techniques and appearances of hilar cholangiocarcinoma and the possible radiological interventions.

Comparative study of pineapple juice as a negative oral contrast agent in magnetic resonance cholangiopancreatography

OBJECTIVES

The aim of this study was to compare the image quality of magnetic resonance Cholangiopancreatography (MRCP) using Pineapple Juice (PJ) or ranitidine as negative oral contrast agents and no agent.

MATERIALS AND METHODS

MRCP images of patients administered PJ (n = 117) or Ranitidine (n = 110) at random, and patients without an agent (n = 50) were evaluated. The subjective image quality of the overall, extra hepatic bile duct and pancreatic duct and the degree of elimination of gastrointestinal fluid were scored by two blinded radiologists. RESULTS were compared using Mann-Whitney's U-test.

RESULTS

The degrees of elimination of gastro duodenal fluid of PJ and ranitidine were significantly better than those without an agent (p < 0.01 and p < 0.01, respectively). The subjective image quality of PJ of the overall and extra hepatic bile duct were significantly better, although no significant differences for ranitidine were observed compared with those without an agent (p < 0.01 and p =0.23, p = 0.025 and p = 0.18). There were no significant differences for the pancreatic duct (p = 0.13 and p = 0.20), nor were there any significant differences in the evaluations between PJ and ranitidine (p = 0.21 and p = 0.96).

CONCLUSION

PJ showed better performance compared to that of conventional ranitidine in terms of pancreatic and biliary depiction and safety.

Magnetic resonance (MR) imaging and MR cholangiopancreatography findings in cats with cholangitis and pancreatitis

Cholangiohepatitis/cholangitis is second only to hepatic lipidosis as the most common liver disease in cats and is often associated with concurrent pancreatitis. Magnetic resonance imaging (MRI) and MR cholangiopancreatography (MRCP) have developed into an accurate, highly sensitive and specific imaging tool for the diagnosis of biliary and pancreatic duct disorders in humans. In this prospective case series, 10 cats with suspected cholangitis and/or pancreatitis were enrolled based on clinical history, physical examination and appropriate diagnostic test results. MRI and MRCP sequences with secretin stimulation of the cranial abdomen were performed, and sonography and laparoscopic biopsies for histologic diagnosis were obtained for comparison. MRI detected pancreatic abnormalities in cats suspected of pancreatitis, including T1 pre-contrast hypointense and T2 hyperintense pancreatic parenchyma and a dilated pancreatic duct. The MRI findings of the liver were non-specific. Nine of 10 cats had biliary abnormalities, including gall bladder wall thickening, gall bladder wall moderate contrast enhancement and/or gall bladder debris. Eight of 10 cats had histologic evidence of pancreatitis, as well as hepatitis or cholangitis, with one cat diagnosed with hepatic lymphoma. The advantages of MRI/MRCP over sonography of these cats included the striking pancreatic signal changes associated with pancreatitis and the ability to comprehensibly assess and measure the pancreas and hepatobiliary structures without operator dependence or interference from bowel gas. MRI/MRCP imaging of the feline abdomen may be beneficial in cases with equivocal ultrasound imaging findings.

Ischemic-type biliary lesions after ortothopic liver transplantation: diagnosis with magnetic resonance cholangiography

PURPOSE

To determine the accuracy of magnetic resonance (MR) cholangiography for detection of ischemic-type biliary lesions (ITBL) following orthotropic liver transplantation (OLT).

MATERIALS AND METHODS

MR cholangiography was performed in 16 patients with established diagnosis of ITBL following OLT. Two blinded observers reviewed all images in consensus and recorded diagnostic features including presence of intrahepatic and extrahepatic biliary strictures, dilatations, beading, pruning, and filling defects. Sensitivity, specificity, positive predictive value, and accuracy of MR cholangiography were calculated. Final diagnosis was established at endoscopic retrograde cholangiography.

RESULTS

MR cholangiography proved to be a valuable tool for the detection of stenoses and dilatations in patients with ITBL following OLT. Sensitivity of the different diagnostic features ranged between 71% and 100%, specificity between 50% and 100%, accuracy between 81% and 100%, and positive predictive value between 87% and 100%.

CONCLUSION

MR cholangiography proved to be an accurate imaging technique to noninvasively detect biliary complications in patients with ITBL after OLT.

Magnetic resonance cholangiopancreatography: the ABC of MRCP

Magnetic resonance cholangiopancreatography (MRCP) is a technique that has evolved over the past two decades. It continues to have a fundamental role in the non-invasive investigation of many pancreatico-biliary disorders. The purpose of this review is to summarise the key concepts behind MRCP, the different techniques that are currently employed (including functional and secretin-stimulated MRCP), the pitfalls the reader should be aware of, and the main clinical indications for its use.

Benign biliary strictures: a current comprehensive clinical and imaging review. AJR Am J Roentgenol. 2011;197:W295-W306. [PMID: 21785056 DOI: 10.2214/ajr.10.6002]

OBJECTIVE

There is a wide spectrum of nonneoplastic causes of biliary stricture that can pose a significant challenge to clinicians and radiologists. Imaging plays a key role in differentiating benign from malignant strictures, defining the extent, and directing the biopsy. We describe the salient clinical and imaging manifestations of benign biliary strictures that will help radiologists to accurately diagnose these entities.

CONCLUSION

Accurate diagnosis and management are based on correlating imaging findings with epidemiologic, clinical, and laboratory data. Cross-sectional imaging modalities permit precise localization of the site and length of the segment involved, thereby serving as a road map to surgery, and permit exclusion of underlying malignancy.

Diagnostic accuracy of endoscopic ultrasonography in patients with inconclusive magnetic resonance imaging diagnosis of biliopancreatic abnormalities

AIM

To determine the sensitivity and specificity of endoscopic ultrasonography (EUS) in patients with inconclusive magnetic resonance imaging/magnetic resonance cholangiopancreatography (MRI/MRCP) in pancreatobiliary abnormalities.

METHODS

During 10 months, patients with pancreatobiliary diseases referred to endoscopic retrograde cholangiopancreatography (ERCP) because of inconclusive MRI/MRCP diagnosis were scheduled to undergo endoscopic ultrasonography. Patients were divided into four major groups: patients with (i) resectable periampullary neoplasms who were referred to a surgeon, (ii) unresectable periampullary cancer who underwent ERCP for biliary stenting, (iii) bile duct stone who were referred to ERCP for stone extraction, and (iv) normal pancreatobiliary tract. Reference standards for comparison were ERCP, surgery, a biopsy confirming malignancy, or the clinical course during follow up (at least 12 months) in cases without evidences of malignancy.

RESULTS

One hundred and seven patients (51 men; mean [SD] age 60.0 [15.5]) were included in the study. Final diagnoses were common bile duct (CBD) stone (n = 24), periampullary neoplasms (n = 46), others (n = 23) and no pathologic findings (n = 14). EUS determined the staging for clinical decision-making in 47 patients with neoplasms which showed that tumors in 34 patients (79.1%) were unresectable (advanced stage). After EUS, 47 patients (43.9%) did not require ERCP. The accuracy of EUS for the diagnosis of CBD stone and periampullary neoplasms were 96.3% and 99.1%, respectively.

CONCLUSIONS

EUS is a useful modality in cases of inconclusive MRI/MRCP indicating pancreatobiliary disorders.

Hilar cholangiocarcinoma: MR correlation with surgical and histological findings

AIM

To evaluate magnetic resonance cholangiography (MRC) with high-resolution dynamic gadolinium-enhanced magnetic resonance imaging (MRI) in determining the imaging features of hilar cholangiocarcinoma that relate to tumour extent and influence resectability.

MATERIALS AND METHODS

Twenty-six patients that underwent resection were reviewed. Tumour location and extent, lobar atrophy, the degree of portal vein and hepatic artery involvement were recorded. The findings were correlated with surgical and histopathological findings.

RESULTS

Biliary assessment was concordant in 14 and discordant in eight of 14 stented and four of 12 non-stented patients. In 63/82 veins and 43/74 arteries results were fully concordant. The mean sensitivity, specificity, positive and negative predictive values (PPV, NPV) in predicting involvement of the main portal vein (MPV) at surgery were 83.3, 100, 100, and 92.5%; of the left main branch of the portal vein (LPV) were 100, 91.6, 93.3, and 100%; and of the right branch of the portal vein (RPV) were 87.5, 100, 100, and 87.5%. The sensitivity, specificity, PPV and NPV of MRI in determining histological involvement of the MPV was 75, 90.9, 60, and 92.5%; 100, 73.3, 73, and 100% for the LPV, and 100, 66.6, 42.8, and 100% for the RPV, respectively.

CONCLUSION

MRC with high-resolution dynamic gadolinium-enhanced MRI is effective in determining tumour extent and vascular involvement, but prior stenting may lead to overestimation.

Magnetic resonance cholangiopancreatography and contrast-enhanced magnetic resonance cholangiopancreatography versus endoscopic ultrasonography in the diagnosis of extrahepatic biliary pathology

PURPOSE

This study compared the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasonography (EUS) in evaluating the cause of extrahepatic bile duct dilatation.

MATERIALS AND METHODS

Forty-five patients (26 men, mean age 57 years) with extrahepatic biliary dilatation, as shown by transabdominal ultrasound, with or without elevated biliary and pancreatic serum indices, were prospectively studied with MRCP and EUS between September 2007 and October 2008. EUS and MRCP were performed within no more than 24 h of each other to reduce the possibility of changes due to stone migration. Image analysis was carried out in a double-blind fashion.

RESULTS

MRCP had 88.9% diagnostic accuracy, 91.9% sensitivity and 75% specificity, with 94.4% positive predictive value and 66.7% negative predictive value. EUS had 93.3% diagnostic accuracy, 97.3% sensitivity and 75% specificity; the positive and negative predictive values were 94.7% and 85.7%, respectively.

CONCLUSIONS

MRCP and EUS do not show significant statistical differences in diagnostic accuracy. MRCP is an accurate, noninvasive modality in the study of extrahepatic biliary pathology. EUS is especially reliable in patients with extrahepatic biliary obstruction caused by endoluminal sludge.

Evaluation of the biliary and pancreatic system with 2D SSFSE, breathhold 3D FRFSE and respiratory-triggered 3D FRFSE sequences

PURPOSE

The authors compared biliary and pancreatic imaging obtained through 2D single-shot fast spin-echo (SSFSE), breath-hold 3D fast recovery fast spin-echo (FRFSE) and respiratory-triggered 3D FRFSE sequences.

MATERIALS AND METHODS

A total of 106 magnetic resonance cholangiopancreatography (MRCP) examinations performed between December 2007 and September 2008 were evaluated with a comparison of 2D SSFSE (thin section and thick slab), breath-hold 3D FRFSE and respiratory-triggered 3D FRFSE sequences. The biliary tract was divided into seven segments: right hepatic duct, left hepatic duct, common hepatic duct, cystic duct, common bile duct, cystic duct junction and biliary-pancreatic confluence. The main pancreatic duct was divided into three segments (head, body and tail). Visualisation of biliary variants was also compared. Two blinded radiologists evaluated segment visibility using a quantitative scale. The Student's t test for paired samples was used for statistical analysis.

RESULTS

Compared with 2D SSFSE, respiratory-triggered 3D FRFSE sequences showed better visibility of the right hepatic duct (p=0.0277), the cystic duct (p=0.0081), the cystic duct junction (p=0.0010), the biliary-pancreatic confluence (p=0.0334) and biliary variants (p=0.0198). In the comparison between breath-hold 3D FRFSE and 2D SSFSE, a significant statistical difference was found in visualisation of the cystic duct (p=0.027), the cystic duct junction (p=0.020), the biliary-pancreatic confluence (p=0.0338) and biliary variants (p=0.0311).

CONCLUSIONS

Three-dimensional FRFSE offers a significant benefit over conventional 2D imaging.

Administrative codes combined with medical records based criteria accurately identified bacterial infections among rheumatoid arthritis patients

OBJECTIVE

To evaluate diagnostic properties of International Classification of Diseases, Version 9 (ICD-9) diagnosis codes and infection criteria to identify bacterial infections among rheumatoid arthritis (RA) patients.

STUDY DESIGN AND SETTING

We performed a cross-sectional study of RA patients with and without ICD-9 codes for bacterial infections. Sixteen bacterial infection criteria were developed. Diagnostic properties of comprehensive and restrictive sets of ICD-9 codes and the infection criteria were tested against an adjudicated review of medical records.

RESULTS

Records on 162 RA patients with and 50 without purported bacterial infections were reviewed. Positive and negative predictive values of ICD-9 codes ranged from 54%-85% and 84%-100%, respectively. Positive predictive values of the medical records based criteria were 84% and 89% for "definite" and "definite or empirically treated" infections, respectively. Positive predictive value of infection criteria increased by 50% as disease prevalence increased using ICD-9 codes to enhance infection likelihood.

CONCLUSION

ICD-9 codes alone may misclassify bacterial infections in hospitalized RA patients. Misclassification varies with the specificity of the codes used and strength of evidence required to confirm infections. Combining ICD-9 codes with infection criteria identified infections with greatest accuracy. Novel infection criteria may limit the requirement to review medical records.

Postprocedural interpretation of endoscopic retrograde cholangiopancreatography by radiology

BACKGROUND

With the increase in the use of endoscopic retrograde cholangiopancreatography (ERCP) (necessitating real-time interpretation), it is unknown whether post-ERCP radiologist reporting is still necessary or helpful.

OBJECTIVES

To determine the rate of discrepancy of results, and the rate of clinically relevant misses and additions, by the radiology report in a blinded setting.

METHODS

A retrospective analysis of the procedure and blinded postprocedure radiology reports of 100 consecutive ERCP cases was performed. A list of clinically relevant pathology and subgroups was made a priori. Discrepancies are described as proportions, with 95% CIs. The radiology yield regarding pathology that was clearly demonstrated at ERCP (bile leaks and stones removed) was calculated. Clinical follow-up was used to clarify additional abnormalities reported by radiology.

RESULTS

Clinically relevant discrepancies in report pairs occurred in 29.0% of cases (95% CI 20% to 39%), or 40.0% if discrepancies regarding bile duct dilation are considered (95% CI 30% to 50%). In 15 of 30 cases (50.0% [95% CI 31% to 69%]) in which bile duct stones were removed, the radiologist did not report a stone. The radiologist did not report five of eight bile leaks (62.5% [95% CI 24% to 91%]). In seven cases (7.0% [95% CI 2.9% to 13.9%]), an additional abnormality was noted by radiology, including a biliary stricture, bile duct and pancreatic duct stones, as well as sclerosing cholangitis. However, during a mean follow-up period of 5.6 months, it appeared that these radiology interpretations were likely incorrect. Discrepancy rates did not vary among the ERCP attendings or by radiology volume.

CONCLUSIONS

Discrepancies between endoscopists' and radiologists' ERCP reports are common. Blinded radiology interpretation frequently misses important pathology, and falsely positive additional diagnoses may be made.

Evaluation of the longitudinal tumor extent of bile duct cancer: value of adding gadolinium-enhanced dynamic imaging to unenhanced images and magnetic resonance cholangiography

OBJECTIVE

To determine the added value of gadolinium-enhanced dynamic magnetic resonance (MR) images compared with unenhanced and MR cholangiography (MRC) images, to evaluate the longitudinal extension of bile duct cancer.

MATERIALS AND METHOD

Thirty-three patients with hilar cholangiocarcinoma or common duct cancer who had undergone MRC, unenhanced, and gadolinium-enhanced dynamic MR images and surgery were included in this study. Two experienced radiologists independently reviewed 2 image sets in 2 steps, that is, the MRC set (unenhanced and MRC) and the combined image set (MRC set with dynamic images). At each step, the readers determined the tumor status according to the Bismuth-Corlette classification. The readers assigned their confidence levels on a 5-point scale regarding whether the tumor involved the secondary confluence of the bile duct and the intrapancreatic common bile duct. The radiologists' diagnostic confidence of the 2 image sets was analyzed using receiver operating characteristic analysis.

RESULTS

Receiver operating characteristic analysis showed higher areas under the curve values when the combined image set was interpreted (0.990 +/- 0.017 for reader 1 and 0.951 +/- 0.027 for reader 2) than when the MRC set was interpreted (0.982 +/- 0.017 for reader 1 and 0.902 +/- 0.038 for reader 2); however, the difference was not statistically significant for either reader (P > 0.05). In addition, regarding evaluation of the tumor status according to the Bismuth-Corlette classification, the overall accuracy was higher for the combined image set than for the MRC set alone, but the difference was not significant (P > 0.05). When dynamic images were added to the MRC images, interobserver agreement improved from 0.72 to 0.84.

CONCLUSIONS

The addition of contrast-enhanced dynamic images to unenhanced and MRC images did not significantly improve the diagnostic accuracy for assessment of the longitudinal extent of bile duct cancer.

Magnetic resonance cholangiopancreatography: A useful tool in the evaluation of pancreatic and biliary disorders

Magnetic resonance cholangiopancreatography (MRCP) is being used with increasing frequency as a noninvasive alternative to diagnostic retrograde cholangiopancreatography (ERCP). The aim of this pictorial review is to demonstrate the usefulness of MRCP in the evaluation of pancreatic and biliary system disorders. Because the recently developed techniques allows improved spatial resolution and permits imaging of the entire pancreaticobiliary tract during a single breath hold, MRCP is of proven utility in a variety of pancreatic and biliary disorders. It uses MR imaging to visualize fluid in the biliary and pancreatic ducts as high signal intensity on T2 weighted sequences and is the newest modality for pancreatic and biliary duct imaging. Herein, we present the clinical applications of MRCP in a variety of pancreaticobiliary system disorders and conclude that it is an important diagnostic tool in terms of imaging of the pancreaticobiliary ductal system.

Assessment of the main pancreatic duct using computed tomography with multiplanar reconstructions

The aim of this study was to assess the morphology of the main pancreatic duct (MPD) using multiplanar reconstructions and to compare this with the morphology of the MPD of anatomic subjects.

MATERIALS AND METHODS

The morphology of the MPD was studied by means of multiplanar reconstructions obtained on the one hand from thin tomodensitometric slices and on the other hand from the dissection of anatomic subjects. This study involved 15 subjects in each group.

RESULTS

Full multiplanar reconstruction was obtained in 13 cases. In 2 cases, the isthmus did not appear in the reconstructions. The morphology of the MPD was similar in both groups. The length of the MPD was identical at the head and isthmus of the pancreas in both groups but was greater in the dissection group than in the reconstruction group in the body and tail areas of the pancreas. The diameter of the MPD was greater at the head of the pancreas in the dissection group and was identical in both groups for the other segments of the MPD.

CONCLUSIONS

Multiplanar tomodensitometric reconstruction of the main pancreatic duct is feasible. This new technique, currently under evaluation, could allow the study of canalar pathologies of the pancreas through tomodensitometry.

Differentiation between benign and malignant hilar obstructions using laboratory and radiological investigations: a prospective study

BACKGROUND

Preoperative determination of the aetiology of bile duct strictures at the hilum is difficult. We evaluated the diagnostic accuracy of laboratory parameters and imaging modalities in differentiating between benign and malignant causes of hilar biliary obstruction.

PATIENTS AND METHODS

Fifty-eight patients (26 men) with a history of obstructive jaundice and liver function tests (LFTs) and ultrasound suggestive of biliary obstruction at the hilum were studied. They were evaluated by tumour marker assay (CA19-9), CT and MRI/MRCP. A single experienced radiologist, blinded to the results of other tests, evaluated the imaging. The final diagnosis was made either from histology of the resected specimen, operative findings or image-guided biopsy in inoperable patients. A receiver operator characteristic (ROC) curve was constructed for each laboratory parameter to determine optimal diagnostic cut-off to predict malignant biliary stricture (MBS).

RESULTS

In all, 34 patients had a benign and 24 had malignant aetiology. The mean age of benign patients was 38 years compared with 54 years for MBS. Forty-seven patients were treated with surgery while 11 had ERCP/PTC and stenting. The ROC curve showed that preoperative bilirubin level >8.4 mg/dl (sensitivity 83.3%, specificity 70%), alkaline phosphatase level >478 IU (sensitivity 63%, specificity 49%) and CA19-9 levels >100 U/L (sensitivity 45.8%, specificity 88.2%) for predicting MBS. The sensitivity, specificity and diagnostic accuracy of MRI/MRCP (87.5%, 85.3%, 82.7%, respectively) was marginally superior to CT (79.2%, 79.4%, 79.3%, respectively).

CONCLUSIONS

Patients with a bilirubin level of >8.4 mg% and CA19-9 level >100 U/L were more likely to have malignant aetiology. MRI/MRCP was a better imaging modality than CT.

MRCP compared to diagnostic ERCP for diagnosis when biliary obstruction is suspected: a systematic review

BACKGROUND

Magnetic resonance cholangiopancreatography (MRCP) is an alternative to diagnostic endoscopic retrograde cholangiopancreatography (ERCP) for investigating biliary obstruction. The use of MRCP, a non-invasive procedure, may prevent the use of unnecessary invasive procedures. The aim of the study was to compare the findings of MRCP with those of ERCP by the computation of accuracy statistics.

METHODS

Thirteen electronic bibliographic databases, covering biomedical, science, health economics and grey literature were searched. A systematic review of studies comparing MRCP to diagnostic ERCP in patients with suspected biliary obstruction was conducted. Sensitivity, specificity, likelihood ratios, acceptability and adverse events were reported.

RESULTS

25 studies were identified reporting several conditions including choledocholithiasis (18 studies), malignancy (four studies), obstruction (three studies), stricture (two studies) and dilatation (five studies). Three of the 18 studies reporting choledocholithiasis were excluded from the analysis due to lack of data, or differences in study design. The sensitivity for the 15 studies of choledocholithiasis ranged from 0.50 to 1.00 while specificity ranged from 0.83 to 1.00. The positive likelihood ratio ranged: from 5.44-47.72 and the negative likelihood ratio for the 15 studies ranged from 0.00-0.51. Significant heterogeneity was found across the 15 studies so the sensitivities and specificities were summarised by a Receiver Operating Characteristic (ROC) curve. For malignancy, sensitivity ranged from 0.81 to 0.94 and specificity from 0.92 to 1.00. Positive likelihood ratios ranged from 10.12 to 43 and negative likelihood ratios ranged from 0.15 to 0.21, although these estimates were less reliable.

CONCLUSION

MRCP is a comparable diagnostic investigation in comparison to ERCP for diagnosing biliary obstruction.

EUS vs MRCP for detection of choledocholithiasis

BACKGROUND

Numerous published studies have shown the high diagnostic performance of both EUS and MRCP compared with ERCP for the detection of choledocholithiasis.

DESIGN

We undertook a systematic review of all published randomized, prospective trials that compared EUS with MRCP with the primary aim being to compare the overall diagnostic accuracy for the detection of choledocholithiasis in patients with suspected biliary disease.

METHODS

A MEDLINE review was performed. We identified 5 randomized, prospective, blinded trials comparing MRCP and EUS for the detection of choledocholithiasis, with subsequent ERCP or intraoperative cholangiography as a criterion standard. The study-specific variables for EUS and MRCP for choledocholithiasis were calculated from the data, and analyses were performed by using aggregated variables (sensitivity, specificity, positive and negative predictive values, and likelihood ratios).

RESULTS

The pooled data set consisted of 301 patients. The aggregated sensitivities of EUS and MRCP for the detection of choledocholithiasis were 0.93 and 0.85, respectively, whereas their specificities were 0.96 and 0.93, respectively. The aggregated positive predictive values for EUS and MRCP were 0.93 and 0.87, respectively, with the corresponding negative predictive values of 0.96 and 0.92, respectively. Positive likelihood ratios were >10 for both tests, and corresponding negative likelihood ratios approached 0.10 for both tests. No statistically significant differences between EUS and MRCP were found in our analysis.

CONCLUSIONS

EUS and MRCP have high diagnostic performance overall. Our analysis showed no statistically significant difference between the modalities. We recommend taking into consideration other factors, such as resource availability, experience, and cost considerations in deciding between these 2 tests.

EUS diagnosis and simultaneous endoscopic retrograde cholangiography treatment of common bile duct stones by using an oblique-viewing echoendoscope

BACKGROUND

MRCP and EUS have replaced ERCP in the diagnosis of biliary diseases, but the latter is needed for treatment. This study evaluates a new approach in the management of common bile duct stones, by using an oblique-viewing echoendoscope.

METHODS

Nineteen patients with acute abdominal pain associated with increased liver tests entered the study. Evaluation of the biliary tree was performed by using an oblique-viewing echoendoscope (JF-UM20; Olympus Europe GmbH, Hamburg, Germany). When biliary stones or sludge were found, bile duct cannulation and sphincterotomy were performed in the same session.

RESULTS

Bile duct stones were diagnosed by EUS in 4 patients and biliary sludge in 12; the subsequent cholangiography and sphincterotomy with stone extraction confirmed the diagnosis in all patients. Bile duct cannulation failed in 1 patient. EUS showed features of chronic pancreatitis in 3 cases. The mean time for the whole procedure (EUS plus endoscopic retrograde cholangiography with biliary treatment) was 27 minutes. No procedure-related complications were observed.

CONCLUSION

This new approach appears to be feasible and safe, providing an accurate diagnosis and, at the same time, an appropriate treatment of common bile duct stones when needed. With technical improvements, this extended EUS technique could be used as the first-line procedure in patients with biliopancreatic diseases.

MRI combined with MR cholangiopancreatography versus helical CT in the evaluation of patients with suspected periampullary tumors: a prospective comparative study

PURPOSE

To establish the diagnostic accuracy of MRI including MR cholangiopancreatography (MRCP) compared with helical CT in the differentiation of malignant and benign lesions in the periampullary region.

MATERIAL AND METHODS

Fifty-one patients (27 M, 24 F, mean age 66 years, range 39-86 years) with obstructive jaundice and sonographic evidence of intra- and extrahepatic bile duct dilatation (n=31) or suspicion of periampullary tumor, based on previously performed ultrasound and/or CT examination (n=20), were studied. MRI with MRCP and helical CT were reviewed blindly under standardized conditions. Lesion status (differentiation of malignant versus benign) was rated on a 5-point diagnostic confidence scale. Reference standards for comparison were findings at surgery or laparoscopy and/ or the clinical outcome. The predictive value of imaging findings was determined with multivariate logistic regression analysis.

RESULTS

The areas under the receiver operating characteristic curve were 0.96 for MRI with MRCP and 0.81 for CT (P <0.05). Multivariate analysis of eight imaging variables at MRI indicated that a stricture with malignant characteristics at MRCP was the best predictor of malignancy.

CONCLUSION

MRI with MRCP was significantly more accurate than CT in differentiating between malignant and benign lesions in patients with suspected periampullary tumors, mainly due to the information obtained on the MRCP images of the biliary and pancreatic duct anatomy.

Pineapple juice as a negative oral contrast agent in magnetic resonance cholangiopancreatography: a preliminary evaluation

The quality of magnetic resonance cholangiopancreatography (MRCP) images is frequently degraded by high signal from the gastrointestinal tract. The aim of this study is to evaluate pineapple juice (PJ) as an oral negative contrast agent in MRCP. Preliminary in vitro evaluation demonstrated that PJ shortened T(2) relaxation time and hence decreased T(2) signal intensity on a standard MRCP sequence to a similar degree to a commercially available negative contrast agent (ferumoxsil). Electrothermal atomic absorption spectrometry assay demonstrated a high manganese concentration in PJ of 2.76 mg dl(-1), which is likely to be responsible for its T(2) imaging properties. MRCP was subsequently performed in 10 healthy volunteers, before and at 15 min and 30 min following ingestion of 400 ml of PJ. Images were assessed blindly by two Consultant Radiologists using a standard grading technique based on contrast effect (degree of suppression of bowel signal), and image effect (diagnostic quality). There were statistically significant improvements in contrast and image effect between pre and post PJ images. There was particularly significant improvement in visualization of the pancreatic duct, but no significant difference between 15 min and 30 min post PJ images. Visualization of the ampulla, common bile duct, common hepatic and central intrahepatic ducts were also significantly improved at 15 min following PJ. Our results demonstrate that PJ, may be used as an alternative to commercially available negative oral contrast agent in MRCP.

Malignant biliary obstruction: value of imaging findings

This review focuses on the clinical impact of different modalities to image primary and secondary malignant biliary obstruction. The detection and staging of cancers of the pancreatic and biliary tract are best accomplished with endoscopic ultrasound, contrast-enhanced computed tomography, and magnetic resonance cholangiopancreatography. Three-dimensional ultrasound is a new noninvasive method that may be used increasingly as an initial test to select patients who require further diagnostic evaluation by magnetic resonance cholangiopancreatography or therapeutic endoscopic retrograde cholangiopancreatography. All-in-one computed tomography including three-dimensional reconstructions of the biliary tree may be competitive against all-in-one magnetic resonance imaging for diagnosis and staging of pancreatic tumors. Magnetic resonance cholangiopancreatography is excellent for identifying the presence and the level of biliary obstruction. With newer diagnostic imaging technologies emerging, endoscopic retrograde cholangiopancreatography is evolving into a predominantly therapeutic procedure.

Magnetic resonance imaging of the common bile duct to exclude choledocholithiasis

BACKGROUND

Prior to cholecystectomy it is important to assess the common duct for choledocholithiasis. Given that a proportion of common duct stones will pass without incident and that methods of removal of these stones are potentially morbid, it would be very useful to have a test that identified only those stones that need intervention. The present study was designed to assess whether a negative magnetic resonance cholangiopancreaticogram (MRCP) is able to reliably exclude clinically relevant common duct stones.

METHODS

A retrospective analysis on all patients with cholelithiasis, who underwent MRCP, between November 2001 and May 2003, for suspected choledocholithiasis, was performed. Patients were considered to have no clinically relevant choledocholithiasis if they had a negative MRCP for choledocholithiasis, and were not readmitted to the hospital with complications of choledocholithiasis within a minimum of 3 months after treatment for their cholelithiasis.

RESULTS

The MRCP was negative for choledocholithiasis in 74% of patients (60/81). The MRCP missed clinically relevant choledocholithiasis in only two patients, and had a positive predictive value of 0.95 and a negative predictive value of 0.97 for choledocholithiasis.

CONCLUSION

In patients with strong indications for choledocholithiasis MRCP is able to reliably exclude clinically relevant choledocholithiasis and is therefore recommended as the preoperative diagnostic imaging tool of choice.

Differentiation of extrahepatic bile duct cholangiocarcinoma from benign stricture: findings at MRCP versus ERCP

PURPOSE

To retrospectively evaluate criteria for differentiating extrahepatic bile duct cholangiocarcinoma from benign cause of stricture at magnetic resonance cholangiopancreatography (MRCP) and to compare diagnostic accuracy with this modality versus endoscopic retrograde cholangiopancreatography (ERCP).

MATERIALS AND METHODS

MRCP and ERCP images in 50 patients (27 with cholangiocarcinoma [18 men, nine women; mean age, 58 years] and 23 with benign cause of stricture [13 men, 10 women; mean age, 60 years]) were retrospectively reviewed to assess the appearance of bile duct strictures. Final diagnosis was based on surgical or biopsy findings. Strictures were described according to their imaging appearance (irregular or smooth margins, asymmetric or symmetric narrowing, abrupt narrowing or gradual tapering, and presence or absence of double-duct sign). Sensitivity, specificity, and accuracy of MRCP and ERCP were calculated by using ratings of confidence in image-based diagnosis. Lengths of stricture were electronically measured and compared by using the Student t test.

RESULTS

Among cholangiographic criteria for malignant biliary stricture, irregular margins and asymmetric narrowing were more common in cholangiocarcinomas (24 [89%] of 27 patients) than in benign strictures (six [26%] and eight [35%] of 23 patients, respectively). Sensitivity, specificity, and accuracy of the two methods for differentiation of malignant from benign causes of biliary stricture were 81% (22 of 27), 70% (16 of 23), and 76% (38 of 50), respectively, for MRCP and 74% (20 of 27), 70% (16 of 23), and 72% (36 of 50), respectively, for ERCP. Mean length (+/- standard deviation) of cholangiocarcinomas was 30.0 mm +/- 8.5, and that of benign strictures was 13.6 mm +/- 9.1 (P <.001).

CONCLUSION

Accuracy of MRCP is comparable with that of ERCP. Regardless of modality, a lengthy segment of extrahepatic bile duct stricture with irregular margin and asymmetric narrowing suggests cholangiocarcinoma, and a short segment with regular margin and symmetric narrowing suggests benign cause.

Histologic assessment of biliary obstruction with different percutaneous endoluminal techniques

Background

Despite the sophisticated cross sectional image techniques currently available, a number of biliary stenosis or obstructions remain of an uncertain nature. In these pathological conditions, an "intrinsic" parietal alteration is the cause of biliary obstruction and it is very difficult to differentiate benign from malignant lesions using cross-sectional imaging procedures alone. We evaluated the efficacy of different endoluminal techniques to achieve a definitive pathological diagnosis in these situations.

Methods

Eighty patients underwent brushing, and or biopsy of the biliary tree through an existing transhepatic biliary drainage route. A subcoort of 12 patients needed balloon-dilatation of the bile duct and the material covering the balloon surface was also sent for pathological examination (balloon surface sampling). Pathological results were compared with surgical findings or with long-term clinical and instrumental follow-ups. Success rates, sensitivity, specificity, accuracy, confidential intervals, positive predictive value and negative predictive value of the three percutaneous techniques in differentiating benign from malignant disease were assessed.

The agreement coefficient of biopsy and brushing with final diagnosis was calculated using the Cohen's "K" value.

Results

Fifty-six patients had malignant strictures confirmed by surgery, histology, and by clinical follow-ups. Success rates of brushing, balloon surface sampling, and biopsy were 90.7, 100, and 100%, respectively. The comparative efficacy of brushing, balloon-surface sampling, and biopsy resulted as follows: sensitivity of 47.8, 87.5, and 92.1%, respectively; specificity of 100% for all the techniques; accuracy of 69.2, 91.7 and 93.6%, Positive Predictive Value of 100% for all the procedures and Negative Predictive Value of 55, 80, and 75%, respectively.

Conclusions

Percutaneous endoluminal biopsy is more accurate and sensitive than percutaneous bile duct brushing in the detection of malignant diseases (p < 0.01).

Diagnosing and treating Sphincter of Oddi dysfunction: a critical literature review and reevaluation

Sphincter of Oddi dysfunction is a pathologic syndrome, without considering etiology, physiopathology, or anatomic aspects of the condition. The clinical manifestations of the syndrome may be a consequence of an "organic stenosis" of the tract or a consequence of "abnormal motility" of the sphincter. Until some years ago, the gold standard technique for studying and treating this pathologic condition was endoscopic retrograde cholangiopancreatography. Two criteria for defining patients in the Milwaukee classification are related to this procedure. The Milwaukee classification was introduced to use clinical and radiologic criteria to define patients with Sphincter of Oddi dysfunction to choose the best treatment. Subsequently, great emphasis has been placed on manometry of the sphincter performed by endoscopic cannulation. The enormous increase of cholecystectomies by means of laparoscopic technique has increased the number of patients who return to their reference-surgeon with a post-cholecystectomy pain and possible Sphincter of Oddi dysfunction. The aim of this paper is to review the literature and to evaluate an up-to-date flow chart for diagnosing and treating the syndrome by using alternative diagnostic procedures that are less invasive than endoscopic retrograde cholangiopancreatography.

Contribution of magnetic resonance cholangiopancreatography to the management of patients with suspected common bile duct stones

OBJECTIVES

To evaluate the value of magnetic resonance cholangiography (MRC) as a systematic first-line investigation in the management of patients with suspected common bile duct stones.

METHODS

Ninety-nine consecutive patients with clinical suspicion of choledocolithiasis were prospectively explored by MRC. All MRCs were interpreted by two radiologists with knowledge of the patient's clinical condition and laboratory results. In case of discrepancy, a third opinion was obtained to reach consensus. The definitive diagnosis was established on the basis of endoscopic exploration of the common bile duct (n=40), clinical and biological follow-up at 6 Months (n=55) or other investigations (n=4). The clinician's level of confidence, management options implemented, and impact of management decisions were used to assess the contribution of MRC. The diagnostic accuracy of MRC for common bile duct stones was also determined.

RESULTS

At the observed level of confidence (85.9%), MRC identified a differential diagnosis in 7.1% of patients avoiding unnecessary endoscopic exploration in 59.6%. Systematic first-line MRC enabled appropriate management in 83.8% of patients. The sensitivity, specificity, and positive and negative predictive values of MRC for the diagnosis of common bile duct stones were 95.7%, 98.7%, 95.7% and 98.7%, respectively, with excellent inter-observer agreement (kappa=0.915).

CONCLUSION

Magnetic resonance cholangiography can be used to efficiently screen patients who may need further invasive exploration of the common bile duct. It specifically identifies patients requiring therapeutic ERCP.

Imaging diagnosis of pancreato-biliary diseases: A control study

AIM: To evaluate the clinical value of various imageological methods in diagnosing the pancreato-biliary diseases and to seek the optimal procedure.

METHODS: Eighty-two cases of pancreato-biliary diseases confirmed by surgery and pathology were analyzed. There were 38 cases of cholelithiasis, 34 cases of pancreato-biliary tumors and 10 other cases. The imageological methods included B-US, CT, ERCP, PTC, cross-sectional MRI and MR cholangiopancreatography (MRCP).

RESULTS: The accuracy rate of MRCP in detecting the location of pancreato-biliary obstruction was 100%. In differentiating malignant from benign obstruction, the sensitivity of the combination of MRCP and cross-sectional MRI was 82.3%, the specificity was 93.8%, and the accuracy rate was 89.0%. The accuracy rate for determining the nature of obstruction was 87.8%, which was superior to that of B-US (P = 0.0000) and CT (P = 0.0330), but there was no significant difference between direct cholangiopancreatography and the combination of MRCP and conventional MRI (P = 0.6666).

CONCLUSION: In most cases, MRCP can substitute direct cholangiopancreatography for diagnosis. The combination of MRCP and cross-sectional MRI should be considered as an important means in diagnosing the pancreato-biliary diseases, pre-operative assessment and post-operative follow-ups.

Prospective evaluation of magnetic resonance cholangiopancreatography in patients with biliary disease: comparative study with conventional ultrasonography and endoscopic retrograde cholangiopancreatography diagnostic algorithm

BACKGROUND

Magnetic resonance cholangiopancreatography is an accurate technique that can replace invasive diagnostic methods of the biliary and pancreatic duct.

AIMS

Our aim was to assess sensitivity and specificity of magnetic resonance cholangiopancreatography and ultrasonography using the results of endoscopic retrograde cholangiopancreatography as reference, and to establish a diagnostic algorithm under which circumstances magnetic resonance cholangiopancreatography can replace endoscopic retrograde cholangiopancreatography.

PATIENTS

Eighty-three patients with suspicion of biliary disease based on clinical, biochemical and ultrasonography findings were studied.

METHODS

Ultrasonography, magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography were performed, comparing the results of the techniques for the determination of their sensitivity and specificity.

RESULTS

Sensitivity and specificity results obtained by magnetic resonance cholangiopancreatography were: 100 and 92.8% when dilated ducts were detected (n=61); 97.4 and 97.2% in the diagnosis of choledocholithiasis (n=38); 100 and 96.7% in malignant lesions (n=14) and 81.8 and 98.4% when biliary ducts were normal. The percentage of images of diagnostic quality was 97.6%. Sensitivity and specificity achieved by ultrasonography was: 100 and 57.1% in detection of dilatation, 71 and 97.2% in choledocholithiasis, 92.8 and 96.7% in malignancy and 66.6 and 96.8% in normal ducts.

CONCLUSIONS

Magnetic resonance cholangiopancreatography is a technique with high sensitivity and specificity in the evaluation of biliary ducts. Thus, magnetic resonance cholangiopancreatography may replace diagnostic endoscopic retrograde cholangiopancreatography for purely diagnostic purposes, following an initial clinical and ultrasonographic exam.

MR cholangiography versus cholangioscopy for evaluation of longitudinal extension of hilar cholangiocarcinoma

BACKGROUND

The utility of magnetic resonance cholangiography for assessment of longitudinal tumor extension of hilar cholangiocarcinoma was investigated with reference to findings by percutaneous transhepatic cholangioscopy.

METHODS

Ninety-nine patients with hilar cholangiocarcinoma underwent both magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy. Longitudinal tumor extension was described with the Bismuth-Corlette classification. Hilar cholangiocarcinoma was classified morphologically into stenotic, diffuse sclerosing, and polypoid types based on selective cholangiographic findings obtained during percutaneous transhepatic cholangioscopy. Agreement between percutaneous transhepatic cholangioscopy and magnetic resonance cholangiography according to the Bismuth-Corlette classification was compared. The degree of agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy according to each morphologic type was also compared in each subgroup without reference to Bismuth-Corlette type.

RESULTS

The overall agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy with regard to Bismuth-Corlette types was 87.9% (kappa = 0.832, p < 0.01). The agreement of magnetic resonance cholangiography for each Bismuth-Corlette type with reference to percutaneous transhepatic cholangioscopy was as follows: type I (n = 18), 16/18 (88.9%); type II (n = 16), 14/16 (87.5%); type IIIa (n = 23), 19/23 (82.6%); type IIIb (n = 14), 14/14 (100%); and type IV (n = 28), 24/28 (85.7%). The overall agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy for Bismuth-Corlette type according to selective cholangiographic findings was as follows: stenotic type, 58/61 (95.1%, kappa = 0.929, p < 0.01); diffuse sclerosing type, 12/16 (75%, kappa = 0.619, p < 0.01); and polypoid type, 17/22 (77.3%, kappa = 0.696, p < 0.01).

CONCLUSION

There is good overall agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy on longitudinal extension of hilar cholangiocarcinoma. Especially for the stenotic type of hilar cholangiocarcinoma (based on selective cholangiographic findings), magnetic resonance cholangiography may replace percutaneous transhepatic cholangioscopy in the determination of longitudinal tumor extension. For polypoid or diffuse sclerosing types, however, percutaneous transhepatic cholangioscopy is required for accurate evaluation of longitudinal tumor extension.

A prospective comparison of the diagnostic accuracy of ERCP, MRCP, CT, and EUS in biliary strictures

BACKGROUND

The differential diagnosis of biliary strictures remains a challenge. This study evaluated magnetic resonance cholangiopancreatography (MRCP) as a new procedure in comparison with the established methods of diagnosis including ERCP or percutaneous transhepatic cholangiography (PTC), CT, and EUS.

METHODS

Fifty patients (21 men, 29 women, mean age 65.7 years) with jaundice but no pain suspected to have biliary strictures were enrolled in this prospective study. MRCP, ERCP/PTC, CT, and EUS were performed prospectively; images and videotapes (EUS) of these tests were reviewed blindly under standardized conditions. Reference standards for comparison were surgery, a biopsy confirming malignancy, or the clinical course during follow-up (at least 12 months) in cases without histopathologic proof of malignancy.

RESULTS

Seven patients ultimately proved to have jaundice caused by parenchymal liver disease and 43 had a biliary stricture (17 benign, 26 malignant). Forty patients underwent all 4 imaging tests. There were 10 patients in whom patient-specific problems precluded some procedures but who were included in an intention-to-diagnose analysis. The sensitivity and specificity for diagnosis of malignancy in the 50 patients were as follows: 85% / 75% for ERCP/PTC, 85% / 71% for MRCP, 77% / 63% for CT, and 79% / 62% for EUS, with similar values in the 40 patients who underwent all 4 imaging methods. The combination of MRCP and EUS improved specificity.

CONCLUSIONS

Although MRCP provides the same imaging information as direct cholangiography, it has limited specificity for the diagnosis of malignant strictures. In the differential diagnosis of biliary strictures, several tests including ERCP-guided tissue diagnosis are still required, and MRCP has only a limited clinical role.