Prospective assessment of magnetic resonance cholangiopancreatography for noninvasive imaging of the biliary tree

Deep Learning Reconstruction for Enhanced Resolution and Image Quality in Breath-Hold MRCP: A Preliminary Study

OBJECTIVE

This preliminary study aims to assess the image quality of enhanced-resolution deep learning reconstruction (ER-DLR) in magnetic resonance cholangiopancreatography (MRCP) and compare it with non-ER-DLR MRCP images.

METHODS

Our retrospective study incorporated 34 patients diagnosed with biliary and pancreatic disorders. We obtained MRCP images using a single breath-hold MRCP on a 3T MRI system. We reconstructed MRCP images with ER-DLR (matrix = 768 × 960) and without ER-DLR (matrix = 256 × 320). Quantitative evaluation involved measuring the signal-to-noise ratio (SNR), contrast, contrast-to-noise ratio (CNR) between the common bile duct and periductal tissues, and slope. Two radiologists independently scored image noise, contrast, artifacts, sharpness, and overall image quality for the 2 image types using a 4-point scale. Results are expressed as median and interquartile range (IQR), and we compared quantitative and qualitative scores employing the Wilcoxon test.

RESULTS

In quantitative analyses, ER-DLR significantly improved SNR (21.08 [IQR: 14.85, 31.5] vs 15.07 [IQR: 9.57, 25.23], P  < 0.001), CNR (19.29 [IQR: 13.87, 24.98] vs 11.23 [IQR: 8.98, 15.74], P  < 0.001), contrast (0.96 [IQR: 0.94, 0.97] vs 0.9 [IQR: 0.87, 0.92], P  < 0.001), and slope of MRCP (0.62 [IQR: 0.56, 0.66] vs 0.49 [IQR: 0.45, 0.53], P  < 0.001). The qualitative evaluation demonstrated significant improvements in the perceived noise ( P  < 0.001), contrast ( P  = 0.013), sharpness ( P  < 0.001), and overall image quality ( P  < 0.001).

CONCLUSIONS

ER-DLR markedly increased the resolution, SNR, and CNR of breath-hold-MRCP compared to cases without ER-DLR.

The effect on gastrointestinal peristalsis for magnetic resonance cholangiopancreatography during breath-holding methods

The breath-hold (BH) 3D magnetic resonance cholangiopancreatography method has been reported to suppress "respiratory artifacts"; however, the influence of gastrointestinal peristalsis around the target organs has not been discussed. In contrast, the autonomic nervous system has been reported to affect gastrointestinal peristalsis and BH imaging has been reported to influence venous blood flow signal (BFS) through its involvement with the autonomic nervous system. We examined the impact of BH imaging on gastrointestinal peristalsis. Seven healthy volunteers participated. Three respiratory patterns-free breathing (FB), BH at maximum inspiration (Insp-BH), and BH at maximum expiration (Exp-BH)-were used. Gastrointestinal peristalsis was measured using cine MRI. Cine MRI data were analyzed using the normalized interframe difference method, focusing on the duodenum and gastric body. Hemodynamic changes resulting from BH methods were evaluated using 2D phase contrast, targeting the inferior vena cava (IVC). The BFS was examined for all phases of each respiratory pattern. Peristalsis variation in the duodenum showed no significant differences among FB, Exp-BH, and Insp-BH. In the gastric body, no significant differences were observed between FB and Exp-BH or between Exp-BH and Insp-BH. However, a significant difference emerged between FB and Insp-BH. Regarding BFS, in the IVC, significant differences were observed between Exp-BH and Insp-BH and between FB and Insp-BH (both, p < 0.01), with no significant difference between FB and Exp-BH. Insp-BH reduces venous blood flow and suppresses the influence of peristalsis variation.

Deep learning-based reconstruction and 3D hybrid profile order technique for MRCP at 3T: evaluation of image quality and acquisition time

OBJECTIVES

To evaluate the image quality of the 3D hybrid profile order technique and deep-learning-based reconstruction (DLR) for 3D magnetic resonance cholangiopancreatography (MRCP) within a single breath-hold (BH) at 3 T magnetic resonance imaging (MRI).

METHODS

This retrospective study included 32 patients with biliary and pancreatic disorders. BH images were reconstructed with and without DLR. The signal-to-noise ratio (SNR), contrast, contrast-to-noise ratio (CNR) between the common bile duct (CBD) and periductal tissues, and full width at half maximum (FWHM) of CBD on 3D-MRCP were evaluated quantitatively. Two radiologists scored image noise, contrast, artifacts, blur, and overall image quality of the three image types using a 4-point scale. Quantitative and qualitative scores were compared using the Friedman test and post hoc Nemenyi test.

RESULTS

The SNR and CNR were not significantly different when under respiratory gating- and BH-MRCP without DLR. However, they were significantly higher under BH with DLR than under respiratory gating (SNR, p = 0.013; CNR, p = 0.027). The contrast and FWHM of MRCP under BH with and without DLR were lower than those under respiratory gating (contrast, p < 0.001; FWHM, p = 0.015). Qualitative scores for noise, blur, and overall image quality were higher under BH with DLR than those under respiratory gating (blur, p = 0.003; overall, p = 0.008).

CONCLUSIONS

The combination of the 3D hybrid profile order technique and DLR is useful for MRCP within a single BH and does not lead to the deterioration of image quality and space resolution at 3 T MRI.

CLINICAL RELEVANCE STATEMENT

Considering its advantages, this sequence might become the standard protocol for MRCP in clinical practice, at least at 3.0 T.

KEY POINTS

• The 3D hybrid profile order can achieve MRCP within a single breath-hold without a decrease in spatial resolution. • The DLR significantly improved the CNR and SNR of BH-MRCP. • The 3D hybrid profile order technique with DLR reduces the deterioration of image quality in MRCP within a single breath-hold.

Comparison between Conventional Breath-hold and Respiratory-triggered Magnetic Resonance Cholangiopancreatography with and without Compressed Sensing: Cross-sectional Study

AIM

The application of compressed sensing (CS) has enabled breath-hold 3D-MRCP with a shorter acquisition time in clinical practice.

INTRODUCTION

To compare the image quality of breath-hold (BH) and respiratory-triggered (RT) 3D-MRCP with or without CS application in the same study population.

METHODS

In this retrospective study, from February to July 2020, a total of 98 consecutive patients underwent four different acquisition types of 3D-MRCP.; 1) BH MRCP with the generalized autocalibrating partially parallel acquisition (GRAPPA) (BH-GRAPPA), 2) RT-GRAPPA-MRCP, 3) RT-CS-MRCP and 4) BH-CS-MRCP. Relative contrast of common bile duct, 5-scale visibility score of biliary pancreatic ducts, 3-scale artifact score and 5-scale overall image quality score were evaluated by two abdominal radiologists.

RESULTS

Relative contrast value was significantly higher in BH-CS or RT-CS than in RT-GRAPPA (0.90 ± 0.057 and 0.89 ± 0.079, respectively, vs. 0.82 ± 0.071, p < 0.01) or BH-GRAPPA (vs. 0.77 ± 0.080, p < 0.01). The area affected by artifact was significantly lower in BH-CS among 4 MRCPs (p < 0.08). Overall image quality score in BH-CS was significantly higher than BH-GRAPPA (3.40 vs. 2.71, p < 0.01). There were no significant differences between RT-GRAPPA and BH-CS (vs. 3.13, p = 0.67) in overall image quality.

CONCLUSION

In this study, our results revealed BH-CS had higher relative contrast and comparable or superior image quality among four MRCP sequences.

Imaging of the biliary tract

PURPOSE OF REVIEW

Magnetic resonance cholangiopancreatography (MRCP) has become the reference examination for the exploration of the biliary tract and has replaced endoscopic cholangiography for the analysis of the biliary tract because of its equivalent performance and its noninvasive character.

RECENT FINDINGS

Based on the International Primary Sclerosing Cholangitis (PSC) Study Group recommendations for MR imaging in PSC, two protocols can be distinguished for the imaging of biliary tract: a basic protocol and a more complete protocol. It is essential to know the main pitfalls in order not to wrongly describe biliary anomalies. In addition to the excellent performance of MR imaging with MRCP in analyzing the anatomy and the anomalies of the biliary tree, complementary techniques have recently been developed. Several MR prognostic factors have been described. New hepato-specific contrast agents are now available for assessment of the general and segmental liver function. MR Elastography and Diffusion-weighted MR sequences are accurate to evaluate the degree of hepatic fibrosis. Finally, images obtained in MRCP can be postprocessed by a software that will analyze and model the biliary tree in order to quantitatively evaluate the biliary system.

SUMMARY

Magnetic resonance imaging with its recent developments becomes by now an essential tool for the evaluation of biliary diseases.

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.

Single-Breath-Hold MRI-SPACE Cholangiopancreatography with Compressed Sensing versus Conventional Respiratory-Triggered MRI-SPACE Cholangiopancreatography at 3Tesla: Comparison of Image Quality and Diagnostic Confidence

To compare two magnetic resonance cholangiopancreatography (MRCP) sequences at 3 Tesla (3T): the conventional 3D Respiratory-Triggered SPACE sequence (RT-MRCP) and a prototype 3D Compressed-Sensing Breath-Hold SPACE sequence (CS-BH-MRCP), in terms of qualitative and quantitative image quality and radiologist's diagnostic confidence for detecting common bile duct (CBD) lithiasis, biliary anastomosis stenosis in liver-transplant recipients, and communication of pancreatic cyst with the main pancreatic duct (MPD). Sixty-eight patients with suspicion of choledocholithiasis or biliary anastomosis stenosis after liver transplant, or branch-duct intraductal papillary mucinous neoplasm of the pancreas (BD-IPMN), were included. The relative CBD to peri-biliary tissues (PBT) contrast ratio (CR) was assessed. Overall image quality, presence of artefacts, background noise suppression and the visualization of 12 separated segments of the pancreatic and bile ducts were evaluated by two observers working independently on a five-point scale. Diagnostic confidence was scored on a 1-3 scale. The CS-BH-MRCP presented significantly better CRs (p < 0.0001), image quality (p = 0.004), background noise suppression (p = 0.011), fewer artefacts (p = 0.004) and better visualization of pancreatic and bile ducts segments with the exception of the proximal CBD (p = 0.054), cystic duct confluence (p = 0.459), the four secondary intrahepatic bile ducts, and central part of the MPD (p = 0.885) for which no significant differences were found. Overall, diagnostic confidence was significantly better with the CS-BH-MRCP sequence for both readers (p = 0.038 and p = 0.038, respectively). This study shows that the CS-BH-MRCP sequence presents overall better image quality and bile and pancreatic ducts visualization compared to the conventional RT-MRCP sequence at 3T.

Liver Blood Tests in the Management of Suspected Choledocholithiasis

OBJECTIVE

The likelihood of common bile duct (CBD) stones considers liver blood tests (LBTs) if they are markedly altered only. The aim of our study was to find a reliable tool based on LBTs to predict the presence of CBD stones.

METHODS

We retrospectively considered all patients who underwent magnetic resonance cholangiopancreatography (MRCP) because of suspected CBD stones from January 2014 to June 2019. Demographic, clinical data, and LBT values were collected and analyzed.

RESULTS

We selected 191 patients, 64 (33.5%) with positive MRCP and 127 (66.5%) with negative MRCP. The analysis showed that our compound LBT-based score had 83.6%, 90.7%, and 90.6% sensitivity, specificity, and negative predictive values, respectively, in determining MRCP results.

CONCLUSION

We designed a weighted score with high diagnostic power in determining MRCP results that could help in differentiating between candidates for primary cholecystectomy and patients who benefit from preoperative MRCP.

Balanced steady-state free precession MRCP is a robust alternative to respiration-navigated 3D turbo-spin-echo MRCP

Background

Despite synchronization to respiration, respiration-navigated (RN) 3D turbo-spin-echo MRCP is limited by susceptibility to motion artifacts. The aim of this study was to assess the quality of pancreaticobiliary duct visualization of a non-RN MRCP alternative based on balanced steady-state free precession imaging (BSSFP) with overlapping slices compared with RN-MRCP.

Methods

This is a retrospective study on 50 patients without pancreaticobiliary duct disease receiving MRCP at 1.5 T. We performed an intraindividual comparison of coronal RN-MRCP with combined coronal and transverse BSSFP-MRCP. Image quality was scored by 3 readers for 6 pancreaticobiliary duct segments (3 pancreatic, 3 biliary) using a 6-point scale. A segment score of 3 or lower as assessed by at least 2 of 3 readers was defined as insufficient segment visualization. Nonparametric tests and interrater reliability testing were used for statistical analysis.

Results

Overall duct visualization averaged over all readers was scored with 4.5 ± 1.1 for RN-MRCP (pancreatic, 4.1 ± 0.5; biliary, 5.0 ± 0.4) and 4.9 ± 0.9 for combined coronal and transverse BSSFP-MRCP (pancreatic, 4.6 ± 0.6; biliary, 5.1 ± 0.6), respectively (p < 0.001). The number of segments visualized insufficiently was 81/300 for RN-MRCP and 43/300 for BSSFP-MRCP (p < 0.001). Segments visualized insufficiently only in RN-MRCP had a mean score of 4.4 ± 0.8 in BSSFP-MRCP. Overall interrater agreement on superiority of BSSFP-MRCP segment scores over corresponding RN-MRCP was 0.70. Mean acquisition time was 98% longer for RN-MRCP (198.0 ± 98.7 s) than for combined coronal and transverse BSSFP-MRCP (100.2 ± 0.4 s).

Conclusions

Non-RN BSSFP-MRCP with overlapping slices is a fast alternative to RN-MRCP, frequently providing sufficient duct visualization when RN-MRCP fails.

Clinical Management of Bile Duct Diseases: Role of Endoscopic Ultrasound in a Personalized Approach

Biliary diseases are common, but clinical symptoms are often unspecific and direct access and visualization of the biliopancreatic system for diagnostic purpose is difficult. In the last decades endoscopic ultrasound (EUS) has become a primary method in the gastrointestinal tract. It significantly changed the role of endoscopy in diagnostic imaging in the gastrointestinal tract and adjacent organs. EUS has become an effective diagnostic tool in biliary stone disease as well as in the diagnosis of indeterminate biliary strictures. Furthermore, an EUS-directed transmural approach emerged as a safe and effective alternative to ERCP in patients requiring biliary drainage, in particular as a backup method if standard ERCP-approach fails. Development of new techniques, specific accessories and stents during the last decade led to an enormous step forward in terms of efficacy and safety of an EUS-directed approach. In the current article technical and clinical aspects of EUS-guided diagnostic and therapeutic approaches in different clinical indications will be discussed together with a review of the available data.

Magnetic resonance cholangiopancreatography findings in early chronic pancreatitis diagnosed according to the Japanese Diagnostic Criteria

OBJECTIVES

It is important for diagnosing early chronic pancreatitis (CP), which may be improved by therapeutic intervention. We aimed to examine the pancreatic ductal changes on magnetic resonance cholangiopancreatography (MRCP) in patients with early CP defined by the Japanese Diagnostic Criteria.

METHODS

This retrospective study included patients suspected early CP and performed both endoscopic ultrasonography (EUS) and MRCP from January 2010 to August 2018. We assessed the diameter of the main pancreatic duct (MPD) and the number of irregularly dilated duct branches using MRCP imaging in early CP.

RESULTS

We enrolled 165 patients and 25 patients (15%) fulfilled the diagnostic criteria for early CP. Irregular dilatation of ≥ 3 duct branches on MRCP was more often observed in early CP compared to non-early CP (P = 0.004), although MPD diameter was comparable (2.06 mm in early CP vs. 1.96 in non-early CP, P = 0.698). The sensitivity and specificity were 45% and 74%, respectively. The prevalence of positive MRCP findings in patients with ≥ 2 positive EUS findings was higher than that in patients with 1 positive EUS finding (P = 0.08) and in patients without an EUS finding (P < 0.001). There was no difference in the average diameter of MPD.

CONCLUSION

Patients with early CP often exhibit alteration in duct branches and not in MPD in addition to parenchymal alteration. Both pancreatic parenchyma and duct branches might need to be evaluated by EUS and MRCP.

The Role of Laparoscopic Ultrasonography in the Evaluation of Suspected Choledocholithiasis. A Single-Center Experience

Background and objectives: Opinions differ regarding the optimal diagnostic methods for patients with suspected choledocholithiasis. The aim of this study was to assess the diagnostic accuracy of laparoscopic ultrasonography (LUS) and compare it to pre-operative magnetic resonance cholangio-pancreatography (MRCP); Materials and Methods: In all patients with suspected choledocholithiasis LUS was performed during laparoscopic cholecystectomy to evaluate biliary stones. According to availability, part of the patients had pre-operative MRCP. Data for diagnostic accuracy and main outcomes were collected prospectively and analyzed retrospectively; Results: Choledocholithiasis was detected in 178 of 297 patients by LUS (59.93%) and in 39 of 87 patients by MRCP (44.8%), p = 0.041. LUS yielded a sensitivity of 99.4%, a specificity of 94.3%, a positive predictive value of 96.1% and a negative predictive value of 99.1%. However, pre-operative MRCP had a sensitivity of 61.7%, a specificity of 92.3%, a positive predictive value of 94.9% and a negative predictive value of 51.1%. Moreover, of the 47 patients with no choledocholithiasis by MRCP, in 23 cases it was later detected by LUS (a false negative MRCP finding—38.3%), p < 0.001. Median duration of hospitalization was significantly shorter in patients evaluated without pre-operative MRCP—8 days (interquartile range – IQR 11–6) vs. 11 days (IQR 14–9), p = 0.001; Conclusions: LUS may reduce the role of pre-operative MRCP and can become a rational alternative to MRCP as a primary imaging technique for the detection of choledocholithiasis.

Breath-hold compressed-sensing 3D MR cholangiopancreatography compared to free-breathing 3D MR cholangiopancreatography: prospective study of image quality and diagnostic performance in pancreatic disorders

PURPOSE

To compare image quality and diagnostic performance of three magnetic resonance cholangiopancreatography (MRCP) protocols in patients with suspected pancreatic abnormalities: free-breathing standard 3D-MRCP (STD), free-breathing compressed sensing 3D-MRCP (CS), and CS 3D-MRCP with acquisition during a single breath-hold > 20 s (BH-CS).

METHODS

Informed consent was obtained. We performed 57 MRCPs in 56 prospectively included patients (29 men, median age 59 years). The three protocols were performed in random order. Acquisition time was recorded. Two radiologists blinded to the protocols used 5-point scales to assess image quality parameters (overall image quality, amount of artifacts, background suppression, bile and pancreatic duct visualization) and diagnostic performance (anatomical variants, duct abnormalities, cystic lesions).

RESULTS

Acquisition time was 279 s with STD, 176 s with CS (-37%), and 22 s with BH-CS (-93%). STD and BH-CS were not significantly different for overall image quality, artifacts, or background suppression. The BH-CS group had fewer non-diagnostic scans (3% vs. 19% with STD and 21% with CS, p < 0.05), higher-quality scans (78% vs. 66% with STD and 58% with CS, p < 0.05), and milder artifacts (2% vs. 18% with STD and 16% with CS, p < 0.05). The main pancreatic duct was better visualized with BH-CS compared to STD (p = 0.015) and CS (p < 0.001). Diagnostic performance did not differ across the three protocols. There were fewer indeterminate scans in the BH-CS group.

CONCLUSION

3T BH-CS is reliable, saves time, and is not associated with decreases in image quality or diagnostic performance compared to STD and CS.

Comparison and evaluation of the efficacy of compressed SENSE (CS) and gradient- and spin-echo (GRASE) in breath-hold (BH) magnetic resonance cholangiopancreatography (MRCP)

CONTRACT GRANT SPONSOR

Chinese Academy of Medical Sciences (CAMS) Initiative for Innovative Medicine; Contract grant number: 2017-I2M-1-001; Contract grant sponsor: Outstanding Youth Fund of Peking Union Medical College Hospital; Contract grant number: JQ201704; Contract grant sponsor: National Natural Science Foundation of China; Contract grant number: 81871512; Contract grant sponsor: National Public Welfare Basic Scientific Research Program of Chinese Academy of Medical Sciences; Contract grant numbers: 2018PT32003 and 2017PT32004.

BACKGROUND

Both compressed-sensing (CS) and gradient- and spin-echo (GRASE) sequences can achieve 3D magnetic resonance cholangiopancreatography (MRCP) with a single breath-hold (BH). This work hypothesized that compared with conventional navigator-triggered (NT)-MRCP, the two BH-MRCP protocols, GRASE and CS, may provide better imaging quality, especially for patients with irregular breathing.

PURPOSE

To evaluate and compare the image quality and diagnostic performance of three MRCP protocols.

STUDY TYPE

Prospective.

SUBJECTS

Seventy-four patients suspected to have duct-related pathologies were enrolled.

FIELD STRENGTH

3.0T.

SEQUENCES

NT-MRCP, BH-CS-MRCP, and BH-GRASE-MRCP.

ASSESSMENT

Breath regularity was evaluated subjectively according to the respiratory waves. The acquisition time was compared. The pancreaticobiliary system was divided into 12 segments and evaluated on a 5-point scale. The diagnostic performance of the three MRCPs was evaluated and compared.

STATISTICAL TESTS

The Friedman test with a post-hoc test, receiver operating characteristic (ROC) curve analysis, McNemar test, and Kendall's W test were used.

RESULTS

The BH-MRCP decreased the scan time significantly (P < 0.05). The overall imaging scores of GRASE-MRCP and CS-MRCP were significantly higher than that of NT-MRCP for patients with irregular breathing (4.283 and 4.283 vs. 3.000, both P < 0.05). Compared with NT-MRCP, the diagnostic performance of BH-CS and BH-GRASE MRCP was significantly improved for patients with irregular breathing (AUC = 0.860 and 0.863 vs. 0.572, both P < 0.001).

DATA CONCLUSION

Compared with conventional NT-MRCP, the overall imaging quality and diagnostic performance of BH-CS and BH-GRASE MRCP were not significantly different for patients with regular breathing and significantly superior for patients with irregular breathing.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:824-832.

Acute Pancreatitis in Chronic Dialysis Patients

The annual incidence of acute pancreatitis (AP) ranges from 4.9 to 73.4 cases per 100,000 worldwide. Patients with end-stage renal disease on dialysis have an increased risk for developing AP compared with patients without renal disease. In addition to the general population risk factors, there are factors related to renal insufficiency and dialysis process that might predispose to AP in this population. Clinical features and diagnosis are the same as those in patients without renal failure; however, amylase and lipase levels should be interpreted cautiously as they might be falsely elevated in renal failure. In this article, we will describe the risk factors that are exclusive to this population. In addition, we will also focus on the laboratory indices and clinical features that are unique to this population with patients with end-stage renal disease.

Comparison of diagnostic imaging modalities for the evaluation of pancreatic duct injury in children: a multi-institutional analysis from the Pancreatic Trauma Study Group

PURPOSE

Determining the integrity of the pancreatic duct is important in high-grade pancreatic trauma to guide decision making for operative vs non-operative management. Computed tomography (CT) is generally an inadequate study for this purpose, and magnetic resonance cholangiopancreatography (MRCP) is sometimes obtained to gain additional information regarding the duct. The purpose of this multi-institutional study was to directly compare the results from CT and MRCP for evaluating pancreatic duct disruption in children with these rare injuries.

METHODS

Retrospective study of data obtained from eleven pediatric trauma centers from 2010 to 2015. Children up to age 18 with suspected blunt pancreatic duct injury who had both CT and MRCP within 1 week of injury were included. Imaging findings of both studies were directly compared and analyzed using descriptive statistics, Chi square, Wilcoxon rank-sum, and McNemar's tests.

RESULTS

Data were collected for 21 patients (mean age 7.8 years). The duct was visualized more often on MRCP than CT (48 vs 5%, p < 0.05). Duct disruption was confirmed more often on MRCP than CT (24 vs 0%), suspected based on secondary findings equally (38 vs 38%), and more often indeterminate on CT (62 vs 38%). Overall, MRCP was not superior to CT for determining duct integrity (62 vs 38%, p = 0.28).

CONCLUSIONS

In children with blunt pancreatic injury, MRCP is more useful than CT for identifying the pancreatic duct but may not be superior for confirmation of duct integrity. Endoscopic retrograde cholangiogram (ERCP) may be necessary to confirm duct disruption when considering pancreatic resection.

LEVEL OF EVIDENCE

III.

Comparison of EUS with MRCP in idiopathic acute pancreatitis: a systematic review and meta-analysis

BACKGROUND AND AIMS

Idiopathic acute pancreatitis (IAP) poses a diagnostic challenge for gastroenterologists, because confirmation of the disease etiology has important implications for the selection of the best possible treatment and the prevention of possible recurrence or the development of chronic pancreatitis (CP). ERCP, EUS, and MRCP typically are used to diagnose IAP when conventional radiologic methods fail. However, their exact role in the diagnosis of IAP has not yet been determined.

METHODS

We searched the PubMed, EMBASE, OVID, Cochrane Library (including CENTRAL), China National Knowledge Infrastructure (CNKI), and Wanfang databases from inception to April 2017. Studies involving the use of EUS and/or MRCP for the etiologic diagnosis of IAP were included. A meta-analysis was performed by using Review Manager Version 5.2 for comparative studies and R software 3.3.3 to determine diagnostic yield of the studies.

RESULTS

Among the 34 studies that met the inclusion criteria (n = 2338), 7 studies used a combination of EUS and MRCP and totaled 249 patients. The results comparing EUS with MRCP showed a diagnostic yield of 153 of the 239 patients (64%) in the EUS group, which was higher than the yield of 82 of 238 patients (34%) in the MRCP group (P < .001) in the 7 studies, and the diagnostic yield was 60% in the EUS group, 24% in the MRCP group, and 43% in the MRCP after secretin stimulation (S-MRCP) group. In our subgroup analysis of CP and biliary disease, EUS was superior to MRCP (P < .001), but when comparing the efficacy of the modalities in the diagnosis of pancreatic divisum, S-MRCP was obviously superior to MRCP and EUS (12% vs 2% vs 2%).

CONCLUSION

EUS and MRCP should both be used in the diagnostic work-up of IAP as complementary techniques. EUS had a higher diagnostic accuracy than MRCP (64% vs 34%) in the etiologic diagnosis of IAP and should be preferred for establishing a possible biliary disease and CP diagnosis, whereas S-MRCP was superior to EUS and MRCP in diagnosing a possible anatomic alteration in the biliopancreatic duct system, such as pancreatic divisum.

Accuracy of Imaging Modalities in Choledocholithiasis: A Real-Life Data

In this retrospective study of real-life data, we aimed to determine the diagnostic accuracy in patients with choledocholithiasis of some current imaging modalities, including ultrasonography (US), computerized tomography (CT), magnetic resonance cholangiopancreatography (MRCP), and endoscopic retrograde cholangiopancreatography (ERCP). This study utilized a database of imaging records from 86 consecutive patients with ERCP-proven choledocholithiasis in a single-center outpatient clinic. Features of the stones found, namely number, size, localization, choledochal dilation and cholestasis, were determined using various imaging modalities and liver function tests (LFTs). Our study focused on a total of 86 patients (43 female; 43 male) who underwent the ERCP procedure. Hepatobiliary ultrasound was performed in 71 (82.6%); MRCP in 59 (68.6%); and CT in 13 (15.1%) patients. All 86 patients had choledocholithiasis: 59 (68.6%) with multiple stones and 21 (24.4%) with stones over 10 mm in diameter. Sensitivity for the presence of choledocholithiasis was 40.8% for US, 76.9% for CT, and 86.4% for MRCP, where ERCP was taken as the reference method. Even though US, CT, and MRCP are widely used as noninvasive imaging modalities for CL, in our real-life data their sensitivity for choledocholithiasis was lower than expected. MRCP is preferred when a nontherapeutic but only diagnostic evaluation is aimed for; however, while highly competent in establishing the level of choledochal dilation, it had a low yield in differentiating the localization, size, and number of the stone(s).

Utility of MRCP in clinical decision making of suspected choledocholithiasis: An institutional analysis and literature review

BACKGROUND

The ideal treatment algorithm for suspected choledocholithiasis is not yet well defined. Imaging options include magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiopancreatography (ERCP), and intraoperative cholangiogram (IOC). MRCP is diagnostic, while the other two modalities can also be therapeutic. Each of these modalities for diagnosis and treatment carries its own set of risks, benefits, and institutional costs. We hypothesized that there would be a significant difference between the biochemical profiles and characteristics of patients who undergo ERCP vs. MRCP vs. operative intervention as the initial choice of treatment/imaging modality.

METHODS

We performed a retrospective review of the electronic medical records for all patients with a coded diagnosis of choledocholithiasis from 2011 to 2014. The initial diagnostic modality was assessed for each hospital encounter. The statistical characteristics of MRCP as compared to fluoroscopic imaging of the biliary tree (ERCP, IOC) were analyzed.

RESULTS

Overall, 527 hospital encounters were identified. Initial intervention included ERCP in 63%, MRCP in 12%, and cholecystectomy in 25% of patients. Patients undergoing cholecystectomy first, compared to MRCP or ERCP, tended to have lower values for alkaline phosphatase (P < 0.001) and AST (P = 0.002) as well as be of younger age (P < 0.0001). Of the patients that underwent MRCP as their initial procedure, 82% subsequently underwent either ERCP or laparoscopic cholecystectomy. In patients who underwent an initial MRCP followed by either ERCP or IOC, the predictive performance of MRCP was as follows: sensitivity = 0.90, specificity = 0.86, positive predictive value = 0.97, negative predictive value = 0.60, agreement (Cohen's Kappa) = 0.64.

CONCLUSIONS

There is a significant difference in the laboratory evaluation and demographics of patients undergoing ERCP, MRCP, and laparoscopic cholecystectomy. MRCP was followed with a more invasive test a majority of the time. Since MRCP did not change the management of patients with suspected choledocholithiasis, its utility in this patient population should be questioned. Further research is needed to better define the pretest characteristics which would predict which patients do not need further intervention after MRCP as well as defining the most cost-effective strategy.

The Accuracies of Diagnosing Pancreas Divisum by Magnetic Resonance Cholangiopancreatography and Endoscopic Ultrasound: A Systematic Review and Meta-analysis

Magnetic resonance cholangiopancreatography (MRCP), MRCP after secretin stimulation (S-MRCP) and endoscopic ultrasonography (EUS) are all selected to diagnose pancreas divisum. However, the accuracies of three diagnosis remain unclear. The aim is to address the diagnostic accuracies of MRCP, S-MRCP and EUS on pancreas divisum. We searched PubMed, MEDLINE and EMBASE databases from inception to January, 2015. Of the 536 citations retrieved, 16 studies were included. For MRCP diagnosis on pancreas divisum, the area under the hierarchical summary receiver-operating characteristic (HSROC) curve was 0.90 (95% confidence interval [CI] 0.87 to 0.92), and for S-MRCP and EUS, 0.99 (95% CI 0.97 to 0.99) and 0.97 (95% CI 0.96 to 0.98). Sensitivity and specificity for MRCP were 0.59 (95% CI 0.45 to 0.71) and 0.99 (95% CI 0.96 to 1.00); for S-MRCP, 0.83 (95% CI 0.66 to 0.92) and 0.99 (95% CI 0.96 to 1.00); for EUS, 0.85 (95% CI 0.67 to 0.94) and 0.97 (95% CI 0.90 to 0.99). Comprehensive comparison of three diagnostic techniques to pancreas divisum, S-MRCP was more reliable than MRCP and EUS on the effect of the diagnostic test.

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.

Clinical application of navigator-gated three-dimensional balanced turbo-field-echo magnetic resonance cholangiopancreatography at 3 T: prospective intraindividual comparison with 1.5 T

OBJECTIVE

To evaluate and compare the clinical utility of balanced turbo-field-echo (BTFE) magnetic resonance cholangiopancreatography (MRCP) sequences obtained at 3 and 1.5 T.

METHODS

We acquired three-dimensional (3D) BTFE MRCP scans with a navigator-gated technique at 3 T on a different day after 1.5 T in 39 consecutive patients. Two radiologists independently rated the image quality and visibility of anatomical structures (right and left hepatic duct, cystic duct, gallbladder, common bile duct, and main pancreatic duct) using a four-point scale. For quantitative analysis, the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and acquisition time were evaluated.

RESULTS

All visual scores tended to be higher for 1.5 T than 3 T images. There was a significant difference in the image quality and the depiction of the main pancreatic duct (p < 0.01). The image acquisition time was significantly shorter for 3 T than 1.5 T (199.3 ± 40.1 vs. 264.0 ± 86.5 s, p < 0.01). There was no significant difference in SNR and CNR.

CONCLUSIONS

3D-BTFE MRCP scans acquired at 3 T were of sufficient image quality with respect to the biliary tree. SNR and CNR were comparable on 3 and 1.5 T scans, although the acquisition time was significantly shorter with the 3 T scanner.

Safe laparoscopic clearance of the common bile duct in emergently admitted patients with choledocholithiasis and cholangitis

Backgrounds/Aims

Laparoscopic treatment of patients with choledocholithiasis and cholangitis is challenging due to mandatory recovery of the biliary drainage and clearance of the common bile duct (CBD). The aim of our study was to assess postoperative course of cholangitis and biliary sepsis after laparoscopic clearance of the CBD in emergently admitted patients with choledocholithiasis and cholangitis.

Methods

Emergently admitted patients who underwent laparoscopic clearance of the CBD were included prospectively and stratified in 2 groups i.e., cholangitis positive (CH+) or negative (CH-) group. Patient demographics, comorbidities, preoperative imaging data, inflammatory response, surgical intervention, complication rate and outcomes were compared between groups.

Results

Ninety-nine of a total 320 patients underwent laparoscopic clearance of the CBD, of which, 60 belonged to the acute cholangitis group (CH+) and 39 to the cholangitis negative group (CH-). Interventions were done on average 4 days after admission, operation duration was 95-105 min, and the conversion rate was 3-7% without differences in the groups. Preoperative inflammatory response was markedly higher in the CH+ group. Inflammation signs on intraoperative choledochoscopy were more evident in patients with cholangitis. Postoperative inflammatory response did not differ between the groups. The overall complication rate was 8.3% and 5.1%, respectively. Laparoscopic clearance of the CBD resulted in 1 lethal case (CH+ group), resulting in 1% mortality rate and a similar 12-month readmission rate.

Conclusions

Single-stage laparoscopic intraoperative US and choledochoscopy-assisted clearance of the CBD is feasible in emergently admitted patients with choledocholithiasis and cholangitis.

Usefulness of 3D hybrid profile order technique with 3T magnetic resonance cholangiography: Comparison of image quality and acquisition time

PURPOSE

To evaluate the image quality and acquisition time of magnetic resonance cholangiopancreatography (MRCP) with and without the 3D hybrid profile order technique.

MATERIALS AND METHODS

We studied 32 consecutive patients at 3T. They underwent MRCP with and without the 3D hybrid profile order imaging technique during free breathing and MRCP with the 3D hybrid profile order technique during a single breath-hold. The image acquisition time was 82% shorter with the 3D hybrid profile order technique than without it. The contrast, signal-to-noise-ratio (SNR), and contrast-noise-ratio (CNR) between the common bile duct (CBD) and periductal tissues on 3D-MRCP were evaluated quantitatively.

RESULTS

The contrast, SNR, and CNR of the CBD under free breathing was significantly higher with the 3D hybrid profile order technique than without it (P < 0.01). The contrast, SNR, and CNR of the CBD under a single breath-hold was significantly higher with the 3D hybrid profile order technique than without it (P < 0.01). There were no significant differences in the contrast, SNR, and CNR of the CBD between the 3D hybrid profile order with a single breath-hold and with free breathing (P = 0.12, 0.28, 0.28, respectively).

CONCLUSION

Using 3T MRI for MRCP with the 3D hybrid profile order sequence yielded significantly improved contrast and CNR with a shorter image acquisition time without sacrificing image quality when compared to imaging without the 3D hybrid profile order sequence. J. Magn. Reson. Imaging 2016;44:1346-1353.

Imaging of the Pancreas

The evaluation of pancreatic lesions, from solid pancreatic masses to pancreatic cysts, remains a clinical challenge. Although cross-sectional imaging remains the cornerstone of the initial evaluation of an indeterminate pancreatic lesion, advances in imaging with the advent of endoscopic ultrasound scan, elastography, contrast-enhanced endoscopic ultrasound scan, and probe-based confocal laser endomicroscopy have allowed us to visualize the pancreas in even higher resolution and diagnose premalignant and malignant lesions of the pancreas with improved accuracy. This report reviews the range of imaging tools currently available to evaluate pancreatic lesions, from solid tumors to pancreatic cysts.

Efficacy of Multidetector-Row Computed Tomography as a Practical Tool in Comparison to Invasive Procedures for Visualization of the Biliary Obstruction

Introduction:

Recently, multidetector computed tomography (MDCT) has been introduced into clinical practice. MDCT has become the noninvasive diagnostic test of choice for detailed evaluation of biliary obstruction.

Aim:

the main objective of the present study was to evaluate the diagnostic value of MDCT compared to invasive procedures for detecting biliary obstruction causes.

Material and Methods:

Since February 2009 until May 2011 fifty biliary obstruction patients based on clinical, laboratory or ultrasonographic findings, were evaluated by Multidetector-row computed tomography. The causes of biliary obstruction, which was identified using. MDCT were classified into three categories: calculus, benign stricture, and malignancy. Final diagnosis was conducted based on percutaneous transhepatic cholangiography (PTC), endoscopic retrograde cholangiopancreatography, biopsy, or surgery. The MDCT diagnosis and were compared with the final diagnosis.

Results:

A correct diagnosis of causes of biliaryobstruction was made on the basis of MDCT findings for 44 of the total 50 patients. Two patients with chronic pancreatitis were incorrectly diagnosed with a pancreatic head adenocarcinoma on the basis of MDCT findings. One patient with biliary stone was incorrectly diagnosed with a periampullary adenocarcinoma on the basis of MDCT findings. The Sensitivity, specificity and accuracy of MDCT in the diagnosis of causes of biliary obstruction were 94.12% and87.87% and94.6% respectively.

Conclusion:

Based on the findings of this study MDCT has an excellent image quality, providing valuable information about the biliary tree and other abdominal organs. The use of advanced image processing, including maximum intensity projection and multiplanar reconstruction (especially coronal or sagittal reformatted images), allows superior visualization of the biliary tree and vascular structures. Three-dimensional reconstruction images complement axial images by providing a more anatomically meaningful display of the lesion and its relationship to adjacent structures, and accurate determining the craniocaudal extent of the lesion. High accuracy, wide availability and ease of use, make the MDCT the imaging modality of choice for evaluation of biliary obstruction.

The Role of Magnetic Resonance Cholangiopancreatography in the Diagnosis of Choledocholithiasis: Do Benefits Outweigh the Costs?

Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard in evaluation of the biliary tree for choledocholithiasis. Formal indications for magnetic resonance cholangiopancreatography (MRCP) in suspected choledocholithiasis are lacking. Our objective was to determine if MRCP affects management of patients who otherwise would undergo ERCP. A review was conducted of all MRCPs and ERCPs at our institution from 2008 to 2012 with suspected choledocholithiasis. Patients who underwent MRCP and ERCP were compared with those who underwent ERCP alone. Demographic data were collected and notation of whether a post-MRCP ERCP occurred was the primary variable. MRCP was performed in 107 patients for choledocholithiasis. Eighty-eight patients were negative for choledocholithiasis (82%) and 76 were discharged without ERCP (71%). Thirty-one patients received a diagnosis of choledocholithiasis and were referred for ERCP. Of the 19 patients with MRCP-diagnosed common bile duct stones, 95 per cent were confirmed by ERCP (odds ratio 18.0, P > 0.05; agreement 77%, sensitivity 0.76, specificity 0.86, positive predictive value 0.95, negative predictive value 0.50). Length of stay was similar for all groups. A total of 131 patients underwent ERCP without a preprocedural MRCP. Choledocholithiasis was found in 116 patients (92%), whereas 12 patients (9%) had no common bile duct stones and three had an alternate diagnosis. In conclusion, MRCP significantly affected the management of patients who would have undergone ERCP. MRCP did not increase length of stay and contributed to the 95 per cent positivity rate of subsequent ERCPs. These data illustrate the utility of MRCP in suspected choledocholithiasis patients at a low cost with regard to risk and time.

Endoscopic management of post-liver transplant biliary complications

Biliary complications are being increasingly encountered in post liver transplant patients because of increased volume of transplants and longer survival of these recipients. Overall management of these complications may be challenging, but with advances in endoscopic techniques, majority of such patients are being dealt with by endoscopists rather than the surgeons. Our review article discusses the recent advances in endoscopic tools and techniques that have proved endoscopic retrograde cholangiography with various interventions, like sphincterotomy, bile duct dilatation, and stent placement, to be the mainstay for management of most of these complications. We also discuss the management dilemmas in patients with surgically altered anatomy, where accessing the bile duct is challenging, and the recent strides towards making this prospect a reality.

Diagnostic value of magnetic resonance cholangiopancreatography in choledocholithiasis

AIM: To evaluate the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) in patients with choledocholithiasis.

METHODS: We systematically searched MEDLINE, EMBASE, Web of Science, and Cochrane databases for studies reporting on the sensitivity, specificity and other accuracy measures of diagnostic effectiveness of MRCP for detection of common bile duct (CBD) stones. Pooled analysis was performed using random effects models, and receiver operating characteristic curves were generated to summarize overall test performance. Two reviewers independently assessed the methodological quality of studies using standards for reporting diagnostic accuracy and quality assessment for studies of diagnostic accuracy tools.

RESULTS: A total of 25 studies involving 2310 patients with suspected choledocholithiasis and 738 patients with CBD stones met the inclusion criteria. The average inter-rater agreement on the methodological quality checklists was 0.96. Pooled analysis of the ability of MRCP to detect CBD stones showed the following effect estimates: sensitivity, 0.90 (95%CI: 0.88-0.92, χ² = 65.80; P < 0.001); specificity, 0.95 (95%CI: 0.93-1.0, χ² = 110.51; P < 0.001); positive likelihood ratio, 13.28 (95%CI: 8.85-19.94, χ² = 78.95; P < 0.001); negative likelihood ratio, 0.13 (95%CI: 0.09-0.18, χ² = 6.27; P < 0.001); and diagnostic odds ratio, 143.82 (95%CI: 82.42-250.95, χ² = 44.19; P < 0.001). The area under the receiver operating characteristic curve was 0.97. Significant publication bias was not detected (P = 0.266).

CONCLUSION: MRCP has high diagnostic accuracy for the detection of choledocholithiasis. MRCP should be the method of choice for suspected cases of CBD stones.

Use of Magnetic Resonance Cholangiopancreatography in Clinical Practice: Not as Good as We Once Thought

BACKGROUND

Magnetic resonance cholangiopancreatography (MRCP) is believed to be a useful tool to evaluate the biliary tree and pancreas for stones, tumors, or injuries to the ductile system. The purpose of this study was to compare the accuracy of MRCP to the gold standard, endoscopic retrograde cholangiopancreatography (ERCP), in our institution.

STUDY DESIGN

We performed a retrospective review of all MRCP followed by ERCP (follow-on ERCP) at a single institution over a 6-year period. Exam findings from MRCP were compared with findings on the follow-on ERCP and compared. Studies were grouped into 2 main classifications: tests being performed for patients with suspected choledocholithiasis (stone disease) and tests being performed for concerns of malignant strictures or duct injuries (non-stone disease).

RESULTS

A total of 81 patients had MRCPs and follow-on ERCPs in this time period. Thirty-six patients had positive findings on MRCP and ERCP for stones in the common duct system, and 14 patients had positive findings on MRCP and subsequent ERCP for masses and strictures of the common duct. Three patients had positive MRCP and ERCP findings for pancreatic duct abnormalities. The specificity and positive predictive value of MRCP were 94% and 98%, respectively. However, 13 of 28 patients had lesions identified on ERCP after a normal MRCP. The sensitivity and negative predictive value were 80% and 54%, respectively.

CONCLUSIONS

Magnetic resonance cholangiopancreatography was not useful in the management algorithm of either stone or non-stone disease of the biliary tree or pancreas. It should be abandoned as a diagnostic tool for work-up of biliary duct pathology.

Endoscopic ultrasound versus magnetic resonance cholangiopancreatography for common bile duct stones

BACKGROUND

Endoscopic ultrasound (EUS) and magnetic resonance cholangiopancreatography (MRCP) are tests used in the diagnosis of common bile duct stones in patients suspected of having common bile duct stones prior to undergoing invasive treatment. There has been no systematic review of the accuracy of EUS and MRCP in the diagnosis of common bile duct stones using appropriate reference standards.

OBJECTIVES

To determine and compare the accuracy of EUS and MRCP for the diagnosis of common bile duct stones.

SEARCH METHODS

We searched MEDLINE, EMBASE, Science Citation Index Expanded, BIOSIS, and Clinicaltrials.gov until September 2012. We searched the references of included studies to identify further studies and of systematic reviews identified from various databases (Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment (HTA), Medion, and ARIF (Aggressive Research Intelligence Facility)). We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included studies that provided the number of true positives, false positives, false negatives, and true negatives for EUS or MRCP. We only accepted studies that confirmed the presence of common bile duct stones by extraction of the stones (irrespective of whether this was done by surgical or endoscopic methods) for a positive test, and absence of common bile duct stones by surgical or endoscopic negative exploration of the common bile duct or symptom free follow-up for at least six months for a negative test, as the reference standard in people suspected of having common bile duct stones. We included participants with or without prior diagnosis of cholelithiasis; with or without symptoms and complications of common bile duct stones, with or without prior treatment for common bile duct stones; and before or after cholecystectomy. At least two authors independently screened abstracts and selected studies for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently collected the data from each study. We used the bivariate model to obtain pooled estimates of sensitivity and specificity.

MAIN RESULTS

We included a total of 18 studies involving 2366 participants (976 participants with common bile duct stones and 1390 participants without common bile duct stones). Eleven studies evaluated EUS alone, and five studies evaluated MRCP alone. Two studies evaluated both tests. Most studies included patients who were suspected of having common bile duct stones based on abnormal liver function tests; abnormal transabdominal ultrasound; symptoms such as obstructive jaundice, cholangitis, or pancreatitis; or a combination of the above. The proportion of participants who had undergone cholecystectomy varied across studies. Not one of the studies was of high methodological quality. For EUS, the sensitivities ranged between 0.75 and 1.00 and the specificities ranged between 0.85 and 1.00. The summary sensitivity (95% confidence interval (CI)) and specificity (95% CI) of the 13 studies that evaluated EUS (1537 participants; 686 cases and 851 participants without common bile duct stones) were 0.95 (95% CI 0.91 to 0.97) and 0.97 (95% CI 0.94 to 0.99). For MRCP, the sensitivities ranged between 0.77 and 1.00 and the specificities ranged between 0.73 and 0.99. The summary sensitivity and specificity of the seven studies that evaluated MRCP (996 participants; 361 cases and 635 participants without common bile duct stones) were 0.93 (95% CI 0.87 to 0.96) and 0.96 (95% CI 0.90 to 0.98). There was no evidence of a difference in sensitivity or specificity between EUS and MRCP (P value = 0.5). From the included studies, at the median pre-test probability of common bile duct stones of 41% the post-test probabilities (with 95% CI) associated with positive and negative EUS test results were 0.96 (95% CI 0.92 to 0.98) and 0.03 (95% CI 0.02 to 0.06). At the same pre-test probability, the post-test probabilities associated with positive and negative MRCP test results were 0.94 (95% CI 0.87 to 0.97) and 0.05 (95% CI 0.03 to 0.09).

AUTHORS' CONCLUSIONS

Both EUS and MRCP have high diagnostic accuracy for detection of common bile duct stones. People with positive EUS or MRCP should undergo endoscopic or surgical extraction of common bile duct stones and those with negative EUS or MRCP do not need further invasive tests. However, if the symptoms persist, further investigations will be indicated. The two tests are similar in terms of diagnostic accuracy and the choice of which test to use will be informed by availability and contra-indications to each test. However, it should be noted that the results are based on studies of poor methodological quality and so the results should be interpreted with caution. Further studies that are of high methodological quality are necessary to determine the diagnostic accuracy of EUS and MRCP for the diagnosis of common bile duct stones.

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.

Giant choledochal calculosis: surgical treatment

Context:

Gallstone disease is one of the most common surgical pathologies. Choledocholithiasis may occur in some of these cases and require surgical intervention. Although there are relatively non-invasive procedures such as endoscopic retrograde cholangiopancreatography (ERCP), this technique is usually unsuccessful in patients with stones larger than 10 mm. In our case, we aimed to report a giant choledochal stone (15 cm × 4.5 cm), which is rare in surgical practice and our treatment with open surgery.

Case Report:

The patient was a 59-year-old woman. Magnetic resonance cholangiopancreatography (MRCP) had showed a hydropic gallbladder with an excessively dilated CBD and a 110 mm × 41 mm stone. In the operation, an excessively dilated CBD was seen and after choledochotomy and a very large calculus that filled CBD completely. Choledochotomy incision was carried forward and a T-tube choledochostomy with choledochoduodenostomy (CD) was performed. The patient was discharged without any complications on postoperative 8^th day.

Conclusion:

Benign gallstone disease is a multifactorial process, with risk factors such as obesity, hemolytic diseases, diabetes mellitus, and pregnancy. Risk factors for choledocholithiasis are similar to those for gallstone disease. MRCP is a non-invasive technique in detecting choledocholithiasis. The gold standard intervention for CBD stones is ERCP. Stones in CBD may reach very considerable dimensions without causing serious symptoms. The most common symptom is jaundice. During preoperative radiological examination, giant stones may be interfered with malignancies. Surgeons should obey conventional algorithms in diagnosis and open surgery must be kept in mind in earlier stages without being too insistent on endoscopic interventions.

Postoperative biliary adverse events following orthotopic liver transplantation: Assessment with magnetic resonance cholangiography

Biliary adverse events following orthotopic liver transplantation (OLT) are relatively common and continue to be serious causes of morbidity, mortality, and transplant dysfunction or failure. The development of these adverse events is heavily influenced by the type of anastomosis during surgery. The low specificity of clinical and biologic findings makes the diagnosis challenging. Moreover, direct cholangiographic procedures such as endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography present an inadmissible rate of adverse events to be utilized in clinically low suspected patients. Magnetic resonance (MR) maging with MR cholangiopancreatography is crucial in assessing abnormalities in the biliary system after liver surgery, including liver transplant. MR cholangiopancreatography is a safe, rapid, non-invasive, and effective diagnostic procedure for the evaluation of biliary adverse events after liver transplantation, since it plays an increasingly important role in the diagnosis and management of these events. On the basis of a recent systematic review of the literature the summary estimates of sensitivity and specificity of MR cholangiopancreatography for diagnosis of biliary adverse events following OLT were 0.95 and 0.92, respectively. It can provide a non-invasive method of imaging surgical reconstruction of the biliary anastomoses as well as adverse events including anastomotic and non-anastomotic strictures, biliary lithiasis and sphincter of Oddi dysfunction in liver transplant recipients. Nevertheless, conventional T2-weighted MR cholangiography can be implemented with T1-weighted contrast-enhanced MR cholangiography using hepatobiliary contrast agents (in particular using Gd-EOB-DTPA) in order to improve the diagnostic accuracy in the adverse events’ detection such as bile leakage and strictures, especially in selected patients with biliary-enteric anastomosis.

Body mass index, cholecystitis, cholelithiasis, pancreatitis and imaging of common bile duct stones

PURPOSE

Studies to date have not investigated whether body mass index (BMI) affects the sensitivity and specificity of magnetic resonance cholangiopancreatography (MRCP). The purpose of this study was to investigate the effect of BMI and also concomitant pancreatitis, cholecystitis and cholelithiasis on the sensitivity and specificity of MRCP.

MATERIALS AND METHODS

Between January 2004 and December 2011, 185 patients were included in the study and divided into 3 groups according to BMI as normal, overweight or obese. Both MRCP and endoscopic retrograde cholangiopancreatography (ERCP) were performed in all patients. ERCP was accepted as the "gold standard." The accuracy, sensitivity and specificity values of the 3 groups were calculated to determine any effects on the results of the MRCP.

RESULTS

Before separating into groups according to BMI, the statistical results for MRCP in the detection of stone disease were as follows: specificity 74.3%, sensitivity 81.7% and accuracy 79%. After dividing the patients into 3 groups according to BMI, the specificity of stone detection with MRCP in the normal-weight group was 93.8% but decreased to 65.5% in the overweight group and to 72% in the obese group. The sensitivity of stone detection with MRCP in the normal-weight group was 85.2% but decreased to 75% in the overweight group and increased to 88.9% in the obese group. The accuracy was 88.3% in the normal-weight group but decreased to 71.6% in the overweight group and to 81.9% in the obese group.

CONCLUSION

Our study showed that MRCP performance was decreased in the overweight and obese groups.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bile Duct Strictures Caused by Solid Masses: MR in Differential Diagnosis and as a Prognostic Tool to Plan the Endoscopic Treatment

The aim of the study was to assess how realiable is differential diagnosis and prognosis for endoscopic treatment with MR signal characteristics as the qualitative parameter and magnetic resonance cholangiopancreatography (MRCP) images in cases of bile duct obstructions caused by solid masses. Material and Methods. Retrospective study of MR and MRCP images in 80 patients (mean age 58 ys) was conducted. Mean signal intensity ratio (SIR) from planar MR images and MRCP linear measurements were compared between benign and malignant lesions and in groups including the size and number of stents placed during ERCP (< 10 F <) in 51 cases in which ERCP was performed. Results. Significantly higher SIR values were encountered in malignant lesions in T2W images (r = 0,0003) and STIR T2W images (r = 0,0002). Malignant lesions were characterised by longer strictures (r = 0,0071) and greater proximal biliary duct dilatation (r = 0,0024). High significance for predicting ERCP conditions was found with mean SIR in STIR T2W images and stricture length. Conclusion. Probability of malignancy of solid lesions obstructing biliary duct increased with higher SIR in T2W images and with longer strictures. Passing the stricture during ERCP treatment was easier and more probable in cases of shorter strictures caused by lesions with higher SIR in STIR T2W images.

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.

Diagnosis of common bile duct stones before ERCP: An analysis of 238 cases

AIM: To optimize the choice of the diagnostic methods for common bile duct stones before endoscopic retrograde cholangiopancreatography (ERCP).

METHODS: A retrospective analysis of clinical data for 238 patients who were suspected with common bile duct stones (CBDS) was performed. CBDS was graded using a single modality or combined modalities. In the single modality group, 16 patients were diagnosed by B ultrasound, 12 by CT, and 12 by MRCP. In the combined modality group, 100 patients were diagnosed by B ultrasound and CT, 80 by B ultrasound and MRCP, 6 by CT and MRCP, and 12 by B ultrasound, CT and MRCP. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of B ultrasound, CT, and MRCP were calculated. The accuracy of each method in diagnosis of CBDS ≥ 1.0 cm or ≤ 0.5 cm was compared.

RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of B ultrasound were 56.2%, 66.7%, 86.9%, 28.0%, and 58.3%, those of CT were 86.5%, 57.1%, 87.4%, 55.2%, 79.8%, and those of MRCP were 97.5%, 82.1%, 94.0%, 92.0%, and 93.6%, respectively. The accuracy of MRCP to diagnose CBDS was significantly higher than that of CT and B ultrasound (both P < 0.01). The accuracy of B ultrasound or CT in diagnosis of CBDS ≥ 1.0 cm was higher than that in diagnosis of CBDS ≤ 0.5 cm (both P < 0.01), while no significant difference was observed for MRCP (P > 0.05). MRCP was more accurate than CT in diagnosis of CBDS ≤ 0.5 cm (P < 0.01). Combined modalities were adopted in 83.2% of cases, mainly B ultrasound + MRCP or B ultrasound + CT, whose accuracy had no significant difference (P > 0.05).

CONCLUSION: B ultrasound is the preferred method for the dianosis of CBDS before ERCP, and MRCP is the best choice. The accuracy of B ultrasound in diagnosis of CBDS ≥ 1.0 cm is higher, and B ultrasound can be alone used under restrictions conditions or in emergency situation. In cases of stones ≤ 0.5 cm, MRCP has a higher accuracy than CT. Overall, the detection rate of CBDS was best by MRCP, followed by CT and B ultrasound. Combined modalities (B ultrasound + CT or B ultrasound + MRCP) are adopted in the vast majority of clinical cases. The choice of B ultrasound + CT + MRCP is not desirable, unless diagnosis can not be established using the first two modalities.