CT and MR cholangiography: advantages and pitfalls in perioperative evaluation of biliary tree

Usefulness of pancreatic volume quantitative analysis as a predictor of development and severity of post-endoscopic retrograde cholangiopancreatography pancreatitis

BACKGROUND

Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) is one of the most common and serious adverse events associated with ERCP. Thus, we aimed to investigate the usefulness of pre-ERCP pancreatic volume, which is deeply involved in exocrine pancreatic function, as a predictor of PEP development and severity.

METHODS

In total, 1107 patients who underwent their first ERCP were recruited from January 2012 to December 2022 for this retrospective study. Pancreatic volume was measured by cross-sectional analysis using pre-ERCP computed tomography images. The potential risk factors for PEP were analyzed using multivariate logistic regression.

RESULTS

Of the 745 patients included in the study, 34 (4.6 %) developed PEP: severe, moderate, or mild PEP in 1, 7, and 26 cases, respectively. Multivariate analysis revealed that only a large pancreatic volume (>70 cm3) was an independent risk factor for the development of PEP (odds ratio, 7.98; 95 % confidence interval, 11.80-67.50; P < 0.001). Additionally, the incidence of PEP was significantly higher in patients with a pancreatic volume >70 cm3 than in those with a pancreatic volume ≤70 cm3 (18.5 % [31/168] vs. 0.5 % [3/577]; P < 0.001). Also, the association between the pre-ERCP pancreatic volume and PEP severity was positively correlated (r = 0.625, P < 0.005), with a larger pancreatic volume corresponding to increased PEP severity.

CONCLUSIONS

A large pancreatic volume before ERCP may be a novel risk factor for PEP incidence and severity. This finding suggests that quantitative analysis of the pre-ERCP pancreatic volume could be a useful predictor of PEP.

Utility of Contrast-Enhanced Harmonic Endoscopic Ultrasonography to Diagnose Pancreaticobiliary Maljunction

BACKGROUND

Detection of a common channel outside the duodenal wall is important in diagnosing pancreaticobiliary maljunction (PBM). The present study evaluated the utility of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) in diagnosing PBM.

METHODS

This single-center retrospective study enrolled 45 patients who were diagnosed with PBM or high confluence of pancreatobiliary ducts (HCPBD) between January 2007 and December 2021. The diagnostic sensitivities of contrast-enhanced computed tomography (CE-CT), magnetic resonance imaging (MRI), and CH-EUS for diagnosing PBM were analyzed. Imaging findings were evaluated by two reviewers blinded to the clinicopathological results.

RESULTS

Based on diagnostic criteria, 33 patients were diagnosed with PBM and 12 with HCPBD. Compared with the patients with HCPBD, those with PBM had significantly longer common channel (12.5 mm vs. 8.1 mm, P = 0.018) and common bile duct (13.0 mm vs. 8.6 mm, P = 0.049) lengths. The κ-coefficients for differentiating PBM and HCPBD were 0.871 between CE-CT and MRI, 0.330 between CE-CT and CH-EUS, and 0.611 between MRI and CH-EUS. The diagnostic sensitivity of CH-EUS (95.2%) was higher than that of CE-CT (83.3%) and MRI (82.8%), although the differences were not statistically significant.

CONCLUSION

CH-EUS may be useful for the diagnosis of PBM.

The Frequency of Anatomical Variants of the Bile Ducts: A Review Based on a Single Classification as Support for Cholangiographic Examinations

Complications arising from hepatobiliary surgery can have adverse effects on both the quality of life and the survival of patients. Magnetic resonance cholangiography (MRC) techniques are highly effective at revealing anatomical variants of the bile ducts and thus play a vital role in minimizing the occurrence of complications. The aims of this review are threefold: to ascertain the classifications utilized for categorizing anatomical variants of the bile ducts, to present the reported results on the prevalence of these anatomical variants, and to explore the diagnostic modalities employed to visualize these anatomical variants and associated complications during surgical procedures. A review of the literature was carried out using the Cochrane Library database and the PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), and Google Scholar platforms. We conducted a comprehensive review of relevant studies to categorize the different anatomical variants according to the Huang classification. According to the Huang classification, our study showed type A1, 60.44%; type A2, 11.76%; type A3, 11.73%; type A4, 5.47%; type A5, 0.26%; and type B, which was identified in insignificant numbers (0.16%) or does not appear; additionally, variants that do not fit into the Huang classification have also been identified (10.18%). The Huang classification serves as an invaluable presurgical guide, aiding in the strategic planning of biliary interventions and effectively reducing the risk of iatrogenic complications, morbidity, mortality, and postoperative length of stay. MRC is still considered the noninvasive gold standard method for evaluating the bile ducts and their anatomical variations.

A rare case of bile leak due to type 2 duct of Luschka injury post open cholecystectomy: a case report

Bile leak is an uncommon complication post cholecystectomy. The bile may originate from the cystic duct stump and less commonly from the aberrant ducts of Luschka. Such complications may occur when anatomical variations in the biliary tree go unnoticed. This case report presents a 24-year-old otherwise healthy female who presented with abdominal pain and distension that began 3 days after she underwent open cholecystectomy for symptomatic cholelithiasis. Imaging revealed choledocholelithiasis in the distal common bile duct, and free intrabdominal fluid collection. Endoscopic retrograde cholangiopancreatography done showed contrast leak from the duct of Luschka to the gall bladder bed. The biliary tree has many anatomic variations. These variations have clinical significance for surgical treatment of patients with biliary pathology. Surgeons should be aware of such variations to decrease the risk of bile leak post cholecystectomy.

Variations in the cystic duct: frequency and the relationship among insertion sides and heights on the bile duct

BACKGROUND

Evaluation of the cystic duct anatomy prior to bile duct or gallbladder surgery is important, to decrease the risk of bile duct injury. This study aimed to clarify the frequency of cystic duct variations and the relationship between them.

METHODS

Data of 205 patients who underwent cholecystectomy after imaging at Sada Hospital, Japan, were analyzed. The Chi-square test was used to analyze the relationships among variations.

RESULTS

The lateral and posterior sides of the bile duct were the two most common insertion points (92 patients, 44.9%), and the middle height was the most common insertion height (135 patients, 65.9%). Clinically important variations (spiral courses, parallel courses, low insertions, and right hepatic duct draining) relating to the risk of bile duct injury were observed in 24 patients (11.7%). Regarding the relationship between the insertion sides and heights, we noticed that the posterior insertion frequently existed in low insertions (75.0%, P < 0.001) and did not exist in high insertions. In contrast, the anterior insertion coexisted with high and never low insertions. Spiral courses have two courses: anterior and posterior, and anterior ones were only found in high insertion cases.

CONCLUSIONS

The insertion point of the cystic duct and the spiral courses tended to be anterior or lateral superiorly and posterior inferiorly. Clinically significant variations in cystic duct insertions are common and surgeons should be cautious about these variations to avoid complications.

Identification and verification of communicating accessory bile duct associated with a biliary circuit by modified and dynamic intraoperative cholangiography during laparoscopic cholecystectomy

Communicating accessory bile duct (CABD) is a rare anatomical anomaly of the bile duct and forms a biliary circuit. It is difficult to identify during laparoscopic cholecystectomy (LC) without the use of intraoperative cholangiography (IOC). A modified IOC, in which tube insertion was performed through the infundibulum of the gallbladder, was evaluated dynamically. This procedure allowed us to accurately identify and verify the presence of CABD, a biliary circuit, and the short cystic duct. The short cystic duct could be separated safely without damaging the biliary circuit. Modified and dynamic IOC is recommended for identifying and verifying the presence of CABD during LC.

Precision Mapping of Intrahepatic Biliary Anatomy and Its Anatomical Variants Having a Normal Liver Using 2D and 3D MRCP

Despite significant advances in hepatobiliary surgery, biliary injury and leakage remain typical postoperative complications. Thus, a precise depiction of the intrahepatic biliary anatomy and anatomical variant is crucial in preoperative evaluation. This study aimed to evaluate the precision of 2D and 3D magnetic resonance cholangiopancreatography (MRCP) in exact mapping of intrahepatic biliary anatomy and its variants anatomically in subjects with normal liver using intraoperative cholangiography (IOC) as a reference standard. Thirty-five subjects with normal liver activity were imaged via IOC and 3D MRCP. The findings were compared and statistically analyzed. Type I was observed in 23 subjects using IOC and 22 using MRCP. Type II was evident in 4 subjects via IOC and 6 via MRCP. Type III was observed equally by both modalities (4 subjects). Both modalities observed type IV in 3 subjects. The unclassified type was observed in a single subject via IOC and was missed in 3D MRCP. Accurate detection by MRCP of intrahepatic biliary anatomy and its anatomical variants was made in 33 subjects out of 35, with an accuracy of 94.3% and a sensitivity of 100%. In the remaining two subjects, MRCP results provided a false-positive pattern of trifurcation. MRCP competently maps the standard biliary anatomy.

Common bile duct perforation due to choledocholithiasis in a cat with gallbladder agenesis

Case summary

An 8-year-old neutered male domestic shorthair cat was presented for further investigation of anorexia, vomiting and lethargy. Abdominal ultrasonography and contrast-enhanced CT revealed choledocholithiasis with suspected bacterial peritonitis and non-visualisation of the gallbladder. During surgery, the common bile duct was noted to be perforated, and a cholelith was found in the abdominal cavity. No gallbladder was confirmed during surgery. Three months postoperatively, the cat underwent CT cholangiography and absence of the gallbladder with a vestigial duplicated gallbladder was diagnosed.

Relevance and novel information

Gallbladder agenesis is extremely rare in cats, with only one previous report, but several dogs have been diagnosed based on CT cholangiography and laparoscopy. This report describes gallbladder agenesis concurrent with choledocholithiasis in an adult cat and represents the first report of CT cholangiography in a cat with gallbladder agenesis.

Lateral dorsal infundibular approach: an alternative option for the safe completion of difficult laparoscopic cholecystectomy

BACKGROUND

Difficult laparoscopic cholecystectomy (LC) due to acute cholecystitis (AC) increases the risk of bile duct injuries and postoperative complications. Here, we added the lateral dorsal infundibular approach as an initial surgical maneuver during LC to improve outcomes.

METHODS

We describe the detailed technical procedure of the lateral dorsal infundibular approach in patients with AC resulting in difficult LC. This technique was developed after nearly 10 years of experience in laparoscopic surgery, and has been routinely used in the past 5 years. We also retrospectively analyzed the perioperative data for 469 patients with difficult LC.

RESULTS

A total of 469 patients with AC received difficult LC between July 2016 and June 2021, of which 438 (93.4%) performed a lateral dorsal infundibular approach. Sixty-four patients (13.6%) had variations of the hepatic bile duct and cystic duct according to preoperative magnetic resonance cholangiopancreatography, 438 patients (93.4%) received elective surgery, 31 (6.6%) received emergency surgery, and 10 (2.1%) underwent conversion. There was no postoperative bile leaks and no bile duct injuries in the described technique.

CONCLUSION

During difficult LC, the critical view of safety can be gradually achieved by changing the surgical approach to achieve cholecystectomy.

Novel Mathematical Diagnostic Analysis of Malignant Biliary Stenosis Using Magnetic Resonance Cholangiography in Patients Undergoing Pancreaticoduodenectomy

BACKGROUND/AIM

A novel mathematical diagnostic analysis using Fourier transform (FT) algorithm of the extrahepatic bile duct (BD) using magnetic resonance-cholangiography (MRC) was performed to evaluate irregularities of the bile duct lumen indicating BD cancer (BDC) extension compared to pancreatic head malignancies controls.

PATIENTS AND METHODS

BD lumen was automatically traced, and a 2D-diagram cross-section was measured and a FT-based integrated-power-spectral-density-function value (FTV) of both diameter and area (mm ²  and mm ⁴ /Hz) was calculated for cancerous and non-cancerous parts utilizing a computer workstation.

RESULTS

FT analysis that was achieved in 59 patients consisted of BDC in 31, pancreatic cancer with biliary stenosis (PC) in 10 and pancreatic neoplasm without stenosis (PN) in 18. FTV-diameter and -area of non-tumorous proximal BD were larger compared to tumor involving BD (p<0.01), and those of the entire BD in BDCs were significantly larger than those in PN (p<0.01). FTV-diameter and -area in proximal BDC-positive were smaller than those in BDC-negative (p<0.05). BDC part was significantly discriminated by the cutoff value (286 mm ² Hz ^-1  in diameter and 10,311 mm ⁴ Hz ^-1 in area) compared to PC and diagnostic accuracy was over 70% (p<0.01).

CONCLUSION

Novel mathematical MRC FT-analysis is promising for differentiating between BDC and PC with biliary stenosis and can be utilized as an objective diagnostic tool in the future.

Bile Leak Due to Luschka Duct Injury After Laparoscopic Cholecystectomy: A Case Report

Bile leak is a common complication after laparoscopic cholecystectomy. Anatomical variations in the biliary tree can go unnoticed by the surgical team and cause complications such as this. This case report presents a patient admitted to the emergency department a week after a laparoscopic cholecystectomy due to abdominal pain and nausea. After a computed tomography, the patient was brought to the operating room for an exploratory laparoscopy, where an injured Luschka duct was found. The biliary tree has many variations that the surgeon should be aware of to minimize the risk of complications of this nature after laparoscopic cholecystectomy. There are imagining techniques with various grades of effectiveness, but in the end, the surgeon’s expertise and experience are the main factors in avoiding these complications.

Application of three-dimensional visualization technology in the anatomical variations of hilar bile ducts in Chinese population

This study aimed to establish three-dimensional models of the biliary tract of Chinese people using the Hisense computer-aided surgery (CAS) system and to explore the branching patterns and variation types of the biliary system under the study of 3D reconstruction of the biliary tract. Three-dimensional models of the biliary tract were reconstructed in 50 patients using the Hisense CAS system. The branching patterns of intrahepatic bile ducts were observed. The biliary tract was classified according to the confluence of the right posterior sectoral duct (RPSD), right anterior sectoral duct (RASD) and left hepatic duct (LHD), and the presence or absence of accessory hepatic ducts. The 3D models of the bile ducts were successfully reconstructed in 50 Chinese patients. The branching patterns of the bile ducts were classified into seven types. The anatomy of the bile ducts was typical in 54% of cases (n = 27), showed triple confluence in 10% (n = 5), and crossover anomaly in 14% (n = 7), which means anomalous drainage of the RPSD into the LHD, anomalous drainage of the RPSD into the common hepatic duct (CHD) in 10% (n = 5), anomalous drainage of the RPSD into the cystic duct (CD) in 2% (n = 1), absence of left main hepatic duct in 1% (n = 1), presence of accessory duct in 8% (n = 4). Among them, there were three cases of accessory hepatic ducts coexisting with other variation types. By using the Hisense CAS system to establish 3D models of the biliary tract of the Chinese people, we established the branching model of the second-order bile ducts, which has important value for the classification of the biliary system and its variation types.

Presence of cystic duct stone is a risk for postoperative retained stones in patients with acute cholecystitis

PURPOSE

Retained stones (RS) in the common bile duct (CBD) are one of the major problems after laparoscopic cholecystectomy and usually require endoscopic treatment. However, few reports have investigated risk factors for the development of RS in the CBD.

METHODS

A total of 325 patients with acute cholecystitis underwent laparoscopic cholecystectomy at our hospital between January 2013 and Jury 2021. Patient characteristics, including radiographic factors and perioperative outcomes, were reviewed, and perioperative factors predicting RS in the CBD were investigated.

RESULTS

RS in the CBD were developed in 34 patients. All 34 patients were treated endoscopically. ASA-PS class 3 or more (p = 0.029, odds ratio = 2.601), subtotal cholecystectomy performance (p = 0.004, odds ratio = 3.783) and the presence of cystic duct stones (p < 0.001, odds ratio = 11.759) were found by logistic regression analysis to be independent risk factors for developing RS in the CBD. Cystic duct stones were preoperatively detected in 60 patients. Of these, 21 cases were not detected on magnetic resonance cholangiopancreatography (MRCP) but on CT, while 15 cases were not detected on CT but on MRCP.

CONCLUSIONS

The presence of cystic duct stones on preoperative CT or MRCP is a crucial risk factor for developing RS in the CBD. Both CT and MRCP are useful to avoid overlooking cystic duct stones.

Modified and dynamic intraoperativecholangiography during laparoscopic cholecystectomy in two patients with aberrant right posterior hepatic duct

Aberrant right posterior hepatic duct (ARPHD) is one of the anatomical anomalies of the bile duct. It is a risk factor for bile duct injury during laparoscopic cholecystectomy (LC). ARPHD can be diagnosed before surgery by magnetic resonance cholangiopancreatography or drip infusion cholangiographic-computed tomography. However, it is not easy to identify ARPHD during LC. Classic intraoperative cholangiography (IOC) procedure that does not lead to bile duct injury avoidance needs to be modified. In modified IOC, cannulation is performed from the infundibulum or neck of the gallbladder. We reported a modified and dynamic IOC procedure that can identify ARPHD safely and precisely during LC. The modified IOC provided direct evidence of no injury to ARPHD in 2 cases.

Noninvasive imaging of hepatic dysfunction: A state-of-the-art review

Hepatic dysfunction represents a wide spectrum of pathological changes, which can be frequently found in hepatitis, cholestasis, metabolic diseases, and focal liver lesions. As hepatic dysfunction is often clinically silent until advanced stages, there remains an unmet need to identify affected patients at early stages to enable individualized intervention which can improve prognosis. Passive liver function tests include biochemical parameters and clinical grading systems (e.g., the Child-Pugh score and Model for End-Stage Liver Disease score). Despite widely used and readily available, these approaches provide indirect and limited information regarding hepatic function. Dynamic quantitative tests of liver function are based on clearance capacity tests such as the indocyanine green (ICG) clearance test. However, controversial results have been reported for the ICG clearance test in relation with clinical outcome and the accuracy is easily affected by various factors. Imaging techniques, including ultrasound, computed tomography, and magnetic resonance imaging, allow morphological and functional assessment of the entire hepatobiliary system, hence demonstrating great potential in evaluating hepatic dysfunction noninvasively. In this article, we provide a state-of-the-art summary of noninvasive imaging modalities for hepatic dysfunction assessment along the pathophysiological track, with special emphasis on the imaging modality comparison and selection for each clinical scenario.

Utility of Dynamic Hepatobiliary Scintigraphy in Identifying a Duct of Luschka Bile Leak

ABSTRACT

Hepatobiliary scintigraphy is a sensitive tool for the detection of a suspected bile leak following cholecystectomy. Traditionally, it has been used to identify, but not localize the source of the leak. Herein we present a case of a bile leak related to a duct of Luschka injury that was identified on dynamic hepatobiliary scintigraphy, but was less evident on a concurrently acquired MRI. This case highlights the scintigraphic features of a bile leak from an accessory duct and underscores the importance of reviewing early dynamic images to potentially identify the source of a leak.

Validity of MDCT cholangiography in differentiating benign and malignant biliary obstruction

Background

MDCT cholangiography can be utilized to identify variant biliary anatomy to guide preoperative planning of biliary surgery, and determine the cause and level of biliary obstruction. Early tumor detection and staging of biliary cancer are key factors for a possible cure by surgical resection. Between December 2019 and October 2020, 69 patients with clinically suspected biliary obstruction were enrolled in the study, subjected to clinical assessment (full history taking and clinical examination) and imaging assessment by MDCT cholangiography. Our findings were correlated to standard reference examinations including operative/ERCP/biopsy and histopathology findings.

Results

The most affected age was between 60 and 70 years old, and males were more affected. The commonest clinical presentation was yellowish discoloration of the skin and sclera followed by biliary colic. Right hypochondrial tenderness was the main clinical finding on clinical examination. Our patients were categorized according to the etiology of biliary obstruction into 7 groups: malignant stricture 52.2% (36 patients), calcular 24.6% (17 patients), iatrogenic 5.8% (4 patients), portahepatis lesions 5.8% (4 patients), benign stricture 4.3% (3 patients), inflammatory 4.3% (3 patients), and congenital 1.4% (1 patient). The malignant group shows dominant mass, moderate biliary obstruction, and arterial and venous enhancement. The overall sensitivity was 94% for malignancy.

Conclusion

MDCT cholangiography is non-invasive, fast, and highly sensitive and specific in the diagnosis of different causes and levels of biliary obstruction and is useful in the characterization of the lesion in cases of malignant obstruction and differentiating it from benign stricture. It can be used as an effective alternative to ERCP or PTC.

Imaging Evaluation of Living Liver Donor Candidates: Techniques, Protocols, and Anatomy

The need for liver transplants is increasing because the prevalence of liver diseases and the indications for transplants are growing. In response to the shortage of grafts from deceased donors, more transplants are being performed worldwide with grafts from living donors. Radiologic evaluation is an integral component in the assessment of donor candidates to ensure their eligibility and to choose the most appropriate surgical approach. MRI is the preferred modality for evaluation of the liver parenchyma and biliary tree. In most centers, a combination of MRI and CT is used to take advantage of the higher spatial resolution of CT for evaluation of arteries. However, MRI-only assessment is feasible. In addition to assessment of the liver parenchyma for abnormalities such as steatosis, a detailed evaluation of the hepatic vascular and biliary system for pertinent anatomic variants is crucial, because these variants can affect surgical techniques and outcomes in both recipients and donors. In this pictorial article, after a brief review of the most common surgical techniques and postsurgical liver anatomy, the biliary and vascular anatomy are discussed, with specific attention paid to the variants that are pertinent to this surgical procedure. The roles of liver segmentation and volumetric assessment and current imaging techniques and protocols are also discussed. Online supplemental material is available for this article. ©RSNA, 2021.

In vitro and in vivo comparative study of a novel 68Ga-labeled PSMA-targeted inhibitor and 68Ga-PSMA-11

⁶⁸Ga-radiolabeled small molecules that specifically target prostate-specific membrane antigen (PSMA) have been extensively investigated, and some of these tracers have been used in the diagnosis of prostate cancer via ⁶⁸Ga-positron emission tomography (⁶⁸Ga-PET). Nevertheless, current ⁶⁸Ga-labeled radiotracers show only fair detection rates for metastatic prostate cancer lesions, especially those with lower levels of prostate specific antigen (PSA), which often occurs in the biochemical recurrence of prostate cancer. The goal of this study was to design and synthesize a new PSMA-targeted radiotracer, ⁶⁸Ga-SC691, with high affinity for prostate cancer cells and excellent pharmacokinetics. To this end, structural optimization was carried out on the bifunctional group, target motif, and linker while the high affinity targeting scaffold remained. To explore its potential in the clinic, a comparative study was further performed in vitro and in vivo between ⁶⁸Ga-SC691 and ⁶⁸Ga-PSMA-11, a clinically approved tracer for PSMA-positive prostate cancer. SC691 was radiolabeled to provide ⁶⁸Ga-SC691 in 99% radiolabeling yield under mild conditions. High uptake and a high internalization ratio into LNCaP cells were observed in in vitro studies. In vivo studies showed that ⁶⁸Ga-SC691 had favorable biodistribution properties and could specifically accumulate on PSMA-positive LNCaP xenografts visualized by micro-PET/CT. This radiotracer showed excellent PET imaging quality and comparable, if not higher, uptake in LNCaP xenografts than ⁶⁸Ga-PSMA-11.

Preoperative prediction of difficult laparoscopic cholecystectomy based on diffusion-weighted magnetic resonance imaging

INTRODUCTION

Laparoscopic cholecystectomy is a common surgery with a varying difficulty level. Difficult laparoscopic cholecystectomy may be experienced by many surgeons. If difficult procedures are predicted preoperatively, surgeons may be able to plan the surgical approach and treatment accordingly. Studies have reported using blood and clinical imaging data to predict difficult cholecystectomy. However, to our knowledge, no studies have reported using MRI. The purpose of this study was to evaluate the usefulness of MRI as a predictor of difficult laparoscopic cholecystectomy.

METHODS

We retrospectively evaluated 25 patients with cholecystitis or biliary colic who had undergone diffusion-weighted whole-body imaging before laparoscopic cholecystectomy. The apparent diffusion coefficient value of the cystic duct was measured and its relationship with operative time and blood loss was examined to assess the capacity of diffuse-weighted whole-body imaging to predict difficult cholecystectomy. Further, we collected blood data and compared its usefulness as a predictor.

RESULTS

The apparent diffusion coefficient value of the cystic duct was significantly lower in patients with difficult laparoscopic cholecystectomy than in those with non-difficult procedures (P = .00007). White blood cell count and serum C-reactive protein level were significantly higher in patients with difficult cholecystectomy than in those with non-difficult procedures (P = .035, .030). In the receiver operating characteristic analysis, the apparent diffusion coefficient value was the best predictor.

CONCLUSION

Our results suggest that the apparent diffusion coefficient value of the cystic duct is a predictor of difficult laparoscopic cholecystectomy. In the future, it may be useful to study changes in coefficient values over time to determine optimal surgical timing.

Anatomic variations of the intra-hepatic biliary tree in the Caribbean: A systematic review

BACKGROUND

In the classic descriptions of the human liver, the common hepatic duct forms at the confluence of left and right hepatic ducts. Many authors have documented variations in the intra-hepatic ductal system, but to the best of our knowledge there has been no report on bile duct variations in Caribbean populations.

AIM

To evaluate the variations in bile duct anatomy using magnetic resonance cholangiography (MRC) in unselected patients at a major hepatobiliary referral centre in the Eastern Caribbean. Knowledge of the intra-hepatic biliary anatomy is important to optimize service delivery for any physician treating liver and biliary disorders.

METHODS

This study was carried out at a tertiary referral hospital for hepatobiliary diseases in the Eastern Caribbean. We retrospectively evaluated magnetic resonance cholangiograms in 152 consecutive patients at this facility over a two-year period from April 1, 2017 to March 31, 2019. Two consultant radiologists experienced in MRC interpretation reviewed all scans and described biliary anatomy according to the Huang’s classification. A systematic review of published studies was performed and relevant data were extracted in order to calculate the global prevalence of each biliary variant. The variants in our population were compared to the global population.

RESULTS

There were 152 MRCs evaluated in this study in 86 males and 66 females. There were 109 (71.7%) persons with “classic” biliary anatomy (type A1) and variants were present in 43 (28.3%) persons. There was no statistical relationship between the presence of anatomic variants and gender or ethnicity. We encountered the following variants: 29 (19.1%) type A2, 7 (4.6%) type A3, 6 (3.95%) type A4, 0 type A5 and a single variant (quadrification) that did not fit the classification system. Compared to the global prevalence, our population had a significantly greater occurrence of A1 anatomy (71.7% vs 62.6%; P = 0.0227) and A2 trifurcations (19.1% vs 11.5%; P = 0.0069), but a significantly lower incidence of A3 variants (4.61% vs 11.5%; P = 0.0047).

CONCLUSION

There are significant differences in intra-hepatic biliary anatomy in this unselected Eastern Caribbean population compared to global statistics. Specifically, persons of Caribbean descent have a greater incidence of Huang A2 trifurcations and a lower incidence of Huang A3 variants.

Correlation Among 3-Dimensional Magnetic Resonance Cholangiography, Intraoperative Cholangiography, and Intraoperative Findings in Right Liver Donors

OBJECTIVES

A correct preoperative definition of the hepatic duct confluence anatomy of right liver living donors is pivotal in determining their candidacy for donation and planning surgery during liver transplant. Here, we evaluated the accuracy of 3-dimensional magnetic resonance cholangiography compared with intraoperative cholangiography in assessing biliary anatomy and aimed to identify imaging characteristics that may help to predict the yield of hepatic duct orifices in the right liver graft.

MATERIALS AND METHODS

All consecutive living hepa-tectomy donors for adult liver transplant included in this study (N = 110) were evaluated with preoperative 3-dimensional magnetic resonance cholangiography, which was performed before and after intravenous administration of gadolinium (20-40 cm³). For intraoperative cholangiography, a 4F catheter was advanced through the cystic duct, and contrast matter (5-10 mL) was injected into the biliary tree via the catheter. The number of right hepatic ducts in explanted graft was determined on the back table.

RESULTS

Of 110 donors, 71 had type 1 (normal) biliary anatomy based on both 3-dimensional magnetic resonance and intraoperative cholangiography and 39 had abnormal biliary anatomy, with 2 having type 3 (abnormal) biliary anatomy. Normal biliary anatomy was found in back-table examination, and abnormal biliary anatomy (type 2) was found with intraoperative cholangiography. Sensitivity, specificity, and predic-tive values of 3-dimensional magnetic resonance cholangiography in revealing the biliary anatomy and anomalies were compared with intraoperative cholangiography findings. Observed final hepatic duct outcomes were also assessed. Use of 3-dimensional magnetic resonance cholangiography accurately predicted the biliary anatomy in 97 of 110 cases. Sensitivity was 80.4%, positive predictive value was 94.4%, specificity was 96.9%, and negative predictive value was 87.3%.

CONCLUSIONS

Three-dimensional magnetic resonance cholangiography reliably represented normal biliary anatomy; the presence of anatomic variations decreased its sensitivity, making intraoperative cholangiography or duct probing necessary tools to accurately perform right hepatic duct transection.

3D-printed anatomical models of the cystic duct and its variants, a low-cost solution for an in-house built simulator for laparoscopic surgery training

OBJECTIVES

To explore a method to create affordable anatomical models of the biliary tree that are adequate for training laparoscopic cholecystectomy with an in-house built simulator.

METHODS

We used a fused deposition modeling 3D printer to create molds of Acrylonitrile Butadiene Styrene (ABS) from Digital Imaging and Communication on Medicine (DICOM) images, and the molds were filled with silicone rubber. Thirteen surgeons with 4-5-year experience in the procedure evaluated the molds using a low-cost in-house built simulator utilizing a 5-point Likert-type scale.

RESULTS

Molds produced through this method had a consistent anatomical appearance and overall realism that evaluators agreed or definitely agreed (4.5/5). Evaluators agreed on recommending the mold for resident surgical training.

CONCLUSIONS

3D-printed molds created through this method can be applied to create affordable high-quality educational anatomical models of the biliary tree for training laparoscopic cholecystectomy.

Use of diffusion-weighted imaging in the noninvasive diagnostic of obstructed biliary ducts

OBJECTIVE

This study sought to evaluate the role of diffusion-weighted imaging (DWI) in differentiation between obstructed and unobstructed bile ducts in patients undergoing magnetic resonance imaging (MRI).

METHODS

Eighty-four patients, 40 males and 44 females (mean age: 56.4 ± 15.1 years), undergoing MRI with DWI (0-50-500-700) were evaluated and divided into two groups: 58 with abnormal laboratory tests (obstructed group) and 26 with normal laboratory values (unobstructed group). Laboratory tests were total bilirubin, alkaline phosphatase, and gamma-glutamyltransferase. Median ADC values were calculated and correlated with laboratory tests and degree of bile-duct dilatation (absent, moderate, or severe). The persistence of signal on DWI (b500 and b700) in the biliary tract was evaluated. Bilirubin values were tested for correlation with bile-duct ADC values and persistence of b700 signal. For statistical analysis, Student t test, chi-square test and Wilcoxon-Mann-Whitney test were used. ADC maps were plotted for three levels of the biliary tree, and a receiver operating characteristic (ROC) curve was calculated.

RESULTS

In the obstructed group, 15 patients had severe dilatation, 24 had moderate dilatation, and 19 had no appreciable dilatation; 38 patients had persistent signal on b700 images. In the unobstructed group, 23 patients had no dilatation and 3 had moderate dilatation; 4 patients had persistent signal on b700 images. Correlation was found between degree of bile-duct dilatation, bilirubin levels, persistence of b700 signal, and ADC map values. The calculated ADC map cutoff value (353 10^-6 mm²/s) was able to differentiate the obstructed and unobstructed groups with 92.3% sensitivity, 81% specificity, and 91.9% accuracy.

CONCLUSIONS

DWI is able to distinguish patients with obstructed versus unobstructed bile ducts, regardless of the degree of dilatation, correlating with clinical and laboratory findings.

Prevalence of Different Hepatobiliary Tree Variants on Magnetic Resonance Cholangiopancreatography in Patients Visiting a Tertiary Care Teaching Hospital in Karachi

Introduction

Hepatobiliary tree variant anatomy is crucial to understand the preoperative planning of hepatobiliary surgeries. Although the presence of variant anatomy is not an absolute contraindication for liver transplantation, inadvertent mapping can lead to postoperative biliary complications. These variants are also important to be recognized in various hepatobiliary surgeries and interventional procedures. Magnetic resonance cholangiopancreatography (MRCP) is an excellent non-invasive imaging tool that can identify biliary anatomy. The purpose of the current study is focused on determining anatomical variants of the biliary tree on MRCP in our population visiting a teaching hospital in Karachi.

Methods

This cross-sectional study was conducted on patients referred to Dr. Ziauddin Hospital for MRCP. MRCP was performed on MAGNETOM Avanto, SIEMENS, Belgium, Germany. Images were analyzed on a workstation by two radiologists and a postgraduate trainee. A senior radiologist reviewed equivocal cases. SPSS 22.0 (SPSS Inc., Chicago, IL) was used for statistical analysis. Chi-square test was used to see the link between anatomical variants of biliary tree and gender. P-value of ≤0.05 was considered as statistically significant.

Results

We recruited 369 patients undergoing MRCP consecutively for our study. Out of 369, 342 patients were eligible for analysis (139 males and 203 females). Standard anatomy was found to be prevalent in 65.8%. Type 3 was the leading variant. A statistically significant difference was recorded for the type 2 anatomic variant which was more frequent in males than females (p-value <0.001), while types 1, 3, and 4 anatomic variants were found to be more in females than males but this difference was not statistically significant. Few other variants were also recorded.

Conclusion

This study is robust evidence regarding biliary variants in Pakistan. It is important to consider these variants in our region, owing to an increased trend of liver transplants and other hepatobiliary procedures.

Intraductal Papillary Neoplasm of Bile Duct: Updated Clinicopathological Characteristics and Molecular and Genetic Alterations

Intraductal papillary neoplasm of the bile duct (IPNB), a pre-invasive neoplasm of the bile duct, is being established pathologically as a precursor lesion of invasive cholangiocarcinoma (CCA), and at the time of surgical resection, approximately half of IPNBs show stromal invasion (IPNB associated with invasive carcinoma). IPNB can involve any part of the biliary tree. IPNB shows grossly visible, exophytic growth in a dilated bile duct lumen, with histologically villous/papillary neoplastic epithelia with tubular components covering fine fibrovascular stalks. Interestingly, IPNB can be classified into four subtypes (intestinal, gastric, pancreatobiliary and oncocytic), similar to intraductal papillary mucinous neoplasm of the pancreas (IPMN). IPNBs are classified into low-grade and high-grade based on lining epithelial features. The new subclassification of IPNB into types 1 (low-grade dysplasia and high-grade dysplasia with regular architecture) and 2 (high-grade dysplasia with irregular architecture) proposed by the Japan–Korea pathologist group may be useful in the clinical field. The outcome of post-operative IPNBs is more favorable in type 1 than type 2. Recent genetic studies using next-generation sequencing have demonstrated the existence of several groups of mutations of genes: (i) IPNB showing mutations in KRAS, GNAS and RNF43 belonged to type 1, particularly the intestinal subtype, similar to the mutation patterns of IPMN; (ii) IPNB showing mutations in CTNNB1 and lacking mutations in KRAS, GNAS and RNF43 belonged to the pancreatobiliary subtype but differed from IPMN. IPNB showing mutation of TP53, SMAD4 and PIK3CA might reflect complicated and other features characterizing type 2. The recent recognition of IPNBs may facilitate further clinical and basic studies of CCA with respect to the pre-invasive and early invasive stages.

Does preoperative MRCP imaging predict risk for conversion to subtotal cholecystectomy in patients with acute cholecystitis?

BACKGROUND

Subtotal cholecystectomy (SC) is a useful procedure for avoiding bile duct injury in patients with difficult gallbladder. However, risk factors for conversion to SC, especially preoperative magnetic resonance cholangiopancreatography (MRCP) findings that predict conversion to SC, have not been investigated in detail.

METHODS

A total of 290 patients with acute cholecystitis who underwent laparoscopic cholecystectomy at our hospital between November 2011 and March 2020 were included. Patient characteristics and perioperative outcomes were reviewed, and preoperative clinical factors predicting conversion to SC were investigated.

RESULTS

Forty-three patients underwent SC, whereas the remaining 247 patients underwent total cholecystectomy. An American Society of Anesthesiologists (ASA) score of 3 or greater (p = 0.011), surgery on or after 9 days from symptom onset (p < 0.001), obscuration of the gallbladder wall around the neck on MRCP images (p = 0.010) and disruption of the common hepatic duct on MRCP images (p < 0.001) were significantly associated with conversion to SC. Logistic regression analyses revealed that an ASA score of 3 or greater (odds ratio = 2.667, p = 0.020), surgery on or after 9 days from symptom onset (odds ratio = 4.229, p < 0.001) and disruption of the common hepatic duct on MRCP images (odds ratio = 4.478, p = 0.002) were independent predictors for conversion to SC.

CONCLUSIONS

Early surgery yielded a lower risk for conversion to SC. Disruption of the common hepatic duct on preoperative MRCP images is associated with a risk for conversion to SC.

Surgical anatomy of caudate bile ducts: Silicon-injected cadaveric-livers dissected under magnification

Backgrounds/Aims

Caudate bile ducts are routinely presented using negative images as X-ray-cholangiograms. Such information does not provide for instant surgical orientation of the relationships between caudate ducts and the liver itself−a paramount skill for successfully performing hilar cholangiocarcinoma resection and living donor/split transplantation. This study presents a 4-step procedure to prepare, dissect and present, high-quality, 2D/3D anatomical images of biliary caudate ducts in a surgically meaningful way.

Methods

Fresh cadavers had arteries and veins injected with colored-silicone and ducts bile-stained to facilitate recognition. Dissections were performed under magnification with microsurgical instruments. Stepwise 2D and 3D images were acquired.

Results

Dissection of silicone-injected specimens under magnification allows identification of caudate structures, its portions and processes while preserving tridimensional arrangement of caudate vessels, biliary ducts and collectors. Such dissections can help enhance cholangiogram interpretation and favor its direct correlation to intraoperative findings.

Conclusions

A procedure including: a) preparation of high-quality cadaveric livers, b) with silicone-injected vessels, c) dissected under surgical microscope and d) documented using 2&3D images aimed at enhancing the clinical understanding of the anatomy of caudate ducts is presented. It has potential to enhance morphological and clinical understanding of caudate ducts, being useful to anatomists and surgeons alike.

Successful diagnosis and treatment of double common bile duct with cholelithiasis by laparoscopic cholecystectomy

Double common bile duct (DCBD) is an extremely rare congenital anomaly of the biliary system associated with serious complications. An association between DCBD and inadvertent bile duct injury during surgery has been reported. However, DCBD is difficult to diagnose preoperatively. We report a rare case of DCBD (type 3b), combined with cholelithiasis and cholecystitis, diagnosed preoperatively, and treated safely by laparoscopic cholecystectomy. A 79-year-old woman was admitted with a 1-week history of chest pain. Abdominal computed tomography revealed gallbladder distension with obvious wall thickening. Laparoscopic cholecystectomy was planned to determine the presence of stones in the common bile duct and an anomalous biliary tract. Magnetic resonance cholangiopancreatography (MRCP) was performed, and anomalous anatomy of the biliary tract was suspected. Drip infusion cholangiography with computed tomography (DIC-CT) showed type 3b DCBD. On hospital day 7, laparoscopic cholecystectomy was performed without accessory common bile duct resection. The postoperative course was uneventful, and the patient was discharged on postoperative day 5. To our knowledge, this is the first report of the successful diagnosis of DCBD using DIC-CT. MRCP and DIC-CT can be useful for the pre-operative diagnosis of DCBD to decrease the risk of bile duct injury during surgery.

Laparoscopic cholecystectomy for a cholelithiasis patient with an aberrant biliary duct of B5: a case report

BACKGROUND

An aberrant biliary duct of segment 5 (B5) is a rare anomaly of the biliary tract. All anatomical anomalies of the biliary tract are risk factors for bile duct injury during surgery. We report a case of cholelithiasis with an aberrant B5 that was detected during a detailed preoperative imaging examination and treated with laparoscopic cholecystectomy.

CASE PRESENTATION

A 69-year-old woman was admitted to the emergency room of our hospital with abdominal pain. She was diagnosed with cholelithiasis, and an aberrant B5 branching off the hepatic duct was suggested during preoperative imaging. Laparoscopic cholecystectomy was performed at our surgical department. There were no intra- or postoperative complications, and the patient was discharged on the fourth day after surgery.

CONCLUSIONS

Laparoscopic cholecystectomy can be safely performed without intra- or postoperative complications in patients with cholelithiasis and an aberrant B5 if it is accurately diagnosed preoperatively.

Deep learning reconstruction of drip-infusion cholangiography acquired with ultra-high-resolution computed tomography

PURPOSE

Deep learning reconstruction (DLR) introduces deep convolutional neural networks into the reconstruction flow. We examined the clinical applicability of drip-infusion cholangiography (DIC) acquired on an ultra-high-resolution CT (U-HRCT) scanner reconstructed with DLR in comparison to hybrid and model-based iterative reconstruction (hybrid-IR, MBIR).

METHODS

This retrospective, single-institution study included 30 patients seen between January 2018 and November 2019. A radiologist recorded the standard deviation of attenuation in the paraspinal muscle as the image noise and calculated the contrast-to-noise ratio (CNR) in the common bile duct. The overall visual image quality of the bile duct on thick-slab maximum intensity projections was assessed by two other radiologists and graded on a 5-point confidence scale ranging from 1 (not delineated) to 5 (clearly delineated). The difference among hybrid-IR, MBIR, and DLR images was compared.

RESULTS

The image noise was significantly lower on DLR than hybrid-IR and MBIR images and the CNR and the overall visual image quality of the bile duct were significantly higher on DLR than on hybrid-IR and MBIR images (all: p < 0.001).

CONCLUSION

DLR resulted in significant quantitative and qualitative improvement of DIC acquired with U-HRCT.

Biliary anatomy and pancreatic duct variations: A cross-sectional study

BACKGROUND/AIM

Biliary tree and pancreatic duct can appear in different variations whose proper understanding is obligatory for surgeons. Magnetic resonance cholangiopancreatography (MRCP) is considered a safe and accurate tool for evaluating biliary tree and pancreatic duct. Typical anatomy for right hepatic duct (RHD) and left hepatic duct (LHD) is reported as 57% and 63%, respectively. The most common (4-10%) pancreatic anomaly is divisum. In the present study, we evaluated and determined the prevalence of biliary tree and pancreatic duct variations among patients at a university hospital.

MATERIALS AND METHODS

The MRCP records of 370 patients from 2015 to 2017 were obtained for cross-sectional study. Images were retrospectively reviewed for variations by two independent senior radiologists. Demographic data were obtained for all the patients. Huang et al. classification was used for RHD and LHD variations. The cystic duct was reported based on its course and insertion pattern. The pancreatic duct was observed for the presence of divisum, its course, and configuration.

RESULTS

Three hundred and twenty-five patients were included in the final study. Most commonly observed variant for RHD were A1 (34.2%) and A2 (32.2%). For LHD, B1 (71.4%) was the most common variant. Cystic duct insertion was commonly seen as right lateral insertion (27.7%). Pancreatic divisum was observed in 0.6% of cases. Nationality, origin, and gender-specific variations were obtained.

CONCLUSION

Variations in biliary anatomy and pancreatic duct are very diverse and extend from the intrahepatic biliary system down to the pancreas. Performing a similar study on a larger population is mandatory to illustrate the range of variations present within the community.

Improved visualization of a fine intrahepatic biliary duct on drip infusion cholangiography-computed tomography: Impact of knowledge-based iterative model reconstruction

AIM

The purpose of this study was to investigate the visualization of fine biliary ducts with knowledge-based iterative model reconstruction (IMR) in low-dose drip infusion computed tomography (CT) cholangiography (DIC-CT) as compared with filtered back projection (FBP) and hybrid iterative reconstruction (iDose⁴ ).

METHODS

A total of 38 patients underwent DIC-CT for living donor liver transplantation. CT was performed approximately 20 min after the end of the infusion of meglumine iotroxate (100 mL). Images were reconstructed using FBP, iDose⁴ , and IMR, and 1-mm slice images at fixed window level and width were prepared for assessment. Two reviewers independently evaluated the quality of visualization of the fine biliary ducts of the caudate lobe (B1) using a 5-point scale. The visualization scores of three reconstructed images were compared using the Kruskal-Wallis test and Mann-Whitney U-test.

RESULTS

For reviewer 1, the visualization score of IMR was significantly higher than that of FBP (P = 0.012), and tended to be higher than that of iDose⁴ (P = 0.078). For reviewer 2, the visualization score of IMR was significantly higher than those of both FBP and iDose⁴ (P < 0.01).

CONCLUSIONS

IMR showed better visualization of B1 on DIC-CT than FBP or iDose⁴ . DIC-CT reconstructed with IMR may be useful to the anatomical grasp of biliary tracts in cases of hepatectomy.

Assessment of biliary anatomy in potential living liver donors: Added value of gadoxetic acid-enhanced T1 MR Cholangiography (MRC) including utilization of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique in comparison to T2W-MRC

OBJECTIVES

To assess the added value of gadoxetic-acid-enhanced T1-weighted magnetic resonance Cholangiography (T1W-MRC) including controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA)-Volumetric Interpolated Breathhold (VIBE) technique compared to T2-weighted MR Cholangiography (T2W-MRC) in depicting biliary anatomy in potential living liver donors.

METHODS

Eighty-five potential donors including 34 men with a mean age of 35.6 years (range, 18-55 years) and 51 women with a mean age of 36.7 years (range, 23-57 years), were enrolled in this ethics-approved retrospective study. Image quality for depiction of bile ducts was evaluated by two readers in consensus in 3 separate reading sessions: 1) T2W-MRC alone, 2) T1W-MRC alone (including CAIPI-VIBE and generalized autocalibrating partially parallel acquisitions (GRAPPA)-VIBE techniques, and 3) combined T1W/T2W-MRC. Accuracy of T2W-MRC, T1W-MRC, and combined T1W/T2W-MRC for the identification/classification of the biliary variants was calculated using intraoperative cholangiogram (IOC) as the reference standard. Image quality and reader diagnostic confidence provided by CAIPI-VIBE technique was compared with GRAPPA-VIBE technique. Datasets were compared using the Wilcoxon signed-rank test.

RESULTS

Image quality for depiction of the bile ducts was significantly superior in the combined T1W/T2W-MRC group, when compared to each of T2W-MRC and T1W-MRC groups independently (P value = 0.001-0.034). The combination of CAIPI-VIBE and GRAPPA-VIBE was superior compared to each of the sequences individually. The accuracy of T2W-MRC and T1W-MRC was 93% and 91%, respectively. T1W-MRC depicted four biliary variants better than T2W-MRC. Two variants not well seen in T2W-MRC were clearly shown on T1W-MRC.

CONCLUSION

Gadoxetic-acid-enhanced T1W-MRC and conventional T2W-MRC techniques are complementary for depiction of biliary variants in potential liver donors and the combination of the two improves the results. The combination of CAIPI-VIBE and GRAPPA-VIBE techniques appear to be complementary for optimal diagnostic yield of T1W-MRC.

Usefulness of preoperative drip infusion cholangiography with computed tomography for predicting surgical difficulty during laparoscopic cholecystectomy

BACKGROUND

Drip infusion cholangiography with computed tomography (DIC-CT) is a major preoperative modality used for patients undergoing laparoscopic cholecystectomy (LC).

METHODS

This study included 218 patients for whom preoperative DIC-CT images were obtained prior to undergoing LC. The association between gallbladder (GB) opacification in DIC-CT and the operative time was assessed.

RESULTS

The GB opacification on the DIC-CT images was classified as follows: Grade 0, homogeneous opacification; Grade 1, heterogeneous opacification; Grade 2, only cystic duct can be identified; and Grade 3, no opacification. Images obtained for the 218 patients showed 41 (18.8%) with Grade 0, 91 (41.7%) with Grade 1, 54 (24.8%) with Grade 2, and 32 (14.7%) with Grade 3. The operative time and intraoperative blood loss were significantly longer and larger, respectively, in cases classified as Grade 2 or 3 (GB negative) compared with cases classified as Grade 0 or 1 (GB positive). We created an LC difficulty score based on the following variables that were significant independent predictors of increased operative time: GB negativity in DIC-CT (P = .002, 2 points), GB wall thickness (P = .002, 2 points), body mass index (P = .015, 1 point), preoperative alkaline phosphatase value (P = .018, 1 point), and preoperative C-reactive protein value (P = .04, 1 point). The LC difficulty score (Grade A, score 0-2; Grade B, score 3-5; and Grade C, score 6-7) was significantly associated with a prolonged operative time.

CONCLUSION

Drip infusion cholangiography with computed tomography is useful for predicting the surgical difficulty of LC.

Ducts of Luschka as a rare cause of postoperative biloma. MRCP findings

Laparoscopic cholecystectomy can be complicated by a post- operative biloma. Bile leak from the duct of Luschka is reported to be the second most frequent cause, reported in 0.15%-2% of the patients. This case report aims to underline the significance of this anatomic variation and how the management of the aforementioned complication can be facilitated by MRI- MRCP. A 78 year old male patient underwent an elective laparoscopic cholecystectomy and was found to have a post-operative biloma. An MRCP was carried out to visualize the bile tree and bile leak was identified to be originated from a duct of Luschka. The patient was referred for an ERCP, sphingterotomy and placement of biliary stent to release the pressure in the bile ducts. In the next few days the bile leak was controlled and eventually ceased. The patient was discharged free of symptoms and no sign of bile leak was to be found on his follow up imaging. In comparison with other imaging modalities picturing the bile tree, MRCP fits the ideal profile to be used as a first line choice for clinicians, as it offers detailed anatomical images with high contrast between bile and adjacent tissues, without using any contrast agent or radiation.

[Differential diagnoses of biliary tract diseases : Computed tomography and magnetic resonance imaging]

CLINICAL/METHODICAL ISSUE

Bile duct diseases can be found in all age groups and show an increased prevalence in northern Europe. Pathologies range from benign diseases to malignant tumors with very poor survival.

STANDARD RADIOLOGICAL METHODS

Magnetic resonance imaging (MRI) and computed tomography (CT) are the radiological methods of choice for a detailed evaluation of the bile duct system in addition to sonography. By assessing the lumen and the wall of the bile ducts as well as the surrounding structures, both obstructive and nonobstructive pathologies can be diagnosed and differentiated with high sensitivity and specificity.

METHODICAL INNOVATIONS

Technical developments with postprocessing modalities as well as the use of biliary-excreted liver-specific MR contrast agents improve the diagnosis of bile duct diseases and enable morphological and functional assessment.

PERFORMANCE

Due to high patient tolerance, minimal procedural risk in contrast to invasive endoscopic methods and the possibility of three-dimensional post-processing, beside CT, MRI with magnetic resonance cholangiography (MRC) represents the method of choice in patients with sonographically or clinically suspected bile duct disease and has significantly reduced the indications of diagnostic endoscopic retrograde cholangiopancreatography (ERCP). A complementary multimodality and multiparametric imaging approach is particularly helpful for preoperative assessment.

PRACTICAL RECOMMENDATIONS

Rapidly evolving technology for both MRI and CT represent opportunities and challenges. By understanding the advantages and limitations of modern MR and CT techniques and by knowing the spectrum of bile duct pathologies, improved diagnosis and narrowing of possible differential diagnosis can be achieved.

The Morphometry Extrahepatic Bile Ducts

The extrahepatic bile duct morphometry was determined by the analysis of the colangiographies performed at Medimar Imaging Services SRL of the “St. Andrei “in Constanta on a General Electric Brightspeed Select CT scanner 16 slides. For the left liver duct found a caliber of 3.5-6.6 mm, its length ranging from 4.2-24.9 mm, and the right hepatic duct had a caliber ranging from 4.2-7.2 mm, the length being between 3.0-25.0 mm. At the confluence of the two hepatic ducts an angle of 35.0-124.1° was formed. In the common hepatic duct we found a caliber of 3.9-9.7 mm, in length between 20.2-52.9 mm. Cystic duct having a size of 2.4 to 5.5 mm, finding a length ranging from 24.6 to 66.4 mm. The angle formed at the end of the cystic duct in the hepatic duct had a value between 6.2-55.8°, and between the cystic and biliary ducts an angle of between 88.5-170.4° was formed. The coledoc duct had a caliber of 3.1-14.7 mm and a length of 19.8-57.3 mm.

Evaluation of biliary anatomy in the caudate lobe using drip infusion cholangiography-computed tomography

PURPOSE

This study aimed to retrospectively evaluate the caudate branches (CBs), which are bile ducts originating from the caudate lobe (CL), using drip infusion cholangiography with computed tomography (DIC-CT).

METHODS

The confluence patterns of CBs were evaluated in 185 adult patients undergoing DIC-CT. The following bile duct features were evaluated: (a) number of depicted CBs; (b) identification of the caudate portion from which the CBs were derived; (c) identification of the confluence site of a CB; and (d) whether there was a difference in the confluence site of the CBs depending on the position of the right posterior hepatic duct (RPHD) and the portal vein (PV).

RESULTS

DIC-CT enabled detection of a total of 640 bile ducts from the CL in 185 patients, and the total number of CBs from the Spiegel lobe (SP), the paracaval portion, and the caudate process (CP) were 347 (54.2%), 112 (17.5%), and 181 (28.2%), respectively. In the SP, over 60% of CBs joined the left hepatic duct system (LHDS). The positional relationship between the RPHD and the PV was divided into a supra-portal course (n = 168) and an infra-portal course (n = 17). The number of CBs joining the LHDS was significantly different between a supra-portal course and an infra-portal course (p = 0.0484).

CONCLUSION

CBs were depicted by DIC-CT in 98.9% of the subjects, and a detailed evaluation was possible. The number of CBs joining the LHDS was associated with the position of the RPHD and the PV.

Status and future directions in the management of pancreatic cancer: potential impact of nanotechnology

Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed at a late stage, has limited treatments, and patients have poor survival rates. It currently ranks as the seventh leading cause of cancer deaths globally and has increasing rates of diagnosis. Improved PDAC treatment requires the development of innovative, effective, and economical therapeutic drugs. The late stage diagnosis limits options for surgical resection, and traditional PDAC chemotherapeutics correlate with increased organ and hematologic toxicity. In addition, PDAC tumor tissue is dense and highly resistant to many traditional chemotherapeutic applications, making the disease difficult to treat and impeding options for palliative care. New developments in nanotechnology may offer innovative options for targeted PDAC therapeutic drug delivery. Nanotechnology can be implemented using multimodality methods that offer increased opportunities for earlier diagnosis, precision enhanced imaging, targeted long-term tumor surveillance, and controlled drug delivery, as well as improved palliative care and patient comfort. Nanoscale delivery methods have demonstrated the capacity to infiltrate the dense, fibrous tumor tissue associated with PDAC, increasing delivery and effectiveness of chemotherapeutic agents and reducing toxicity through the loading of multiple drug therapies on a single nano delivery vehicle. This review presents an overview of nanoscale drug delivery systems and multimodality carriers at the forefront of new PDAC treatments.

Complicated peribiliary cysts in patient without any prior liver disease

Peribiliary cysts involve cystic dilation of the extramural peribiliary glands in the liver hilum and portal tracts. Most peribiliary cysts are asymptomatic. We present the case of a patient without any prior liver disease who developed obstructive jaundice and a liver abscess due to peribiliary cysts. Peribiliary cysts usually appear in patients with severe chronic liver disease and are asymptomatic, although they sometimes appear in patients without prior liver disease and cause serious complications.

Hepatocyte-specific contrast agent-enhanced magnetic resonance cholangiography: perioperative evaluation of the biliary tree

A large number of gadolinium chelates have recently been tested in clinical trials. Some of those have already been approved for clinical use in the United States and Europe. Thus, new diagnostic perspectives have been incorporated into magnetic resonance imaging studies. Among such gadolinium chelates are hepatobiliary-specific contrast agents (HSCAs), which, due to their property of being selectively taken up by hepatocytes and excreted by the biliary ducts, have been widely used for the detection and characterization of focal hepatic lesions. In comparison with conventional magnetic resonance cholangiography (MRC), HSCA-enhanced MRC provides additional information, with higher spatial resolution and better anatomic evaluation of a non-dilated biliary tree. A thorough anatomic assessment of the biliary tree is crucial in various hepatic surgical procedures, such as complex resection in patients with colorectal cancer and living-donor liver transplantation. However, the use of HSCA-enhanced MRC is still limited, because of a lack of data in the literature and the poor familiarity of radiologists regarding its main indications. This pictorial essay aims to demonstrate the use of HSCA-enhanced MRC, with particular emphasis on anatomical analysis of the biliary tree, clinical applications, and the most important imaging findings.