Anomalies and anatomic variants of the biliary tree revealed by MR cholangiopancreatography

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.

Type Va extrahepatic bile duct duplication: a case report

BACKGROUND

Extrahepatic bile duct duplication is an extremely rare congenital anomaly in which two common bile ducts exist. There are five different types of this anomaly and we present an unusual variant of duplication of an extrahepatic biliary system of type Va variety.

CASE PRESENTATION

This case report describes a 63-year-old women from rural Nepal who presented with type Va of duplicated extrahepatic bile duct, with chronic calculous cholecystitis and choledocholithiasis. She was managed with cholecystectomy with hepatic ductoplasty and hepaticojejunostomy.

CONCLUSION

A rare case of double common bile duct (type Va) complicated by choledocholithiasis, cholangitis, and chronic cholecystitis is reported here. Rare cases are sometimes overlooked by modern diagnostic techniques. Correct diagnosis helps appropriate surgical intervention.

Choledochocele with recurrent pancreatitis: Case report

Choledochal cysts are an uncommon anomaly of unknown etiology of the bilious system. This anomaly, characterized by cystic dilatations on intrahepatic or extrahepatic bile ducts, can be seen at any age from birth. Most rare congenital bile duct cysts choledochocele (type III) is usually diagnosed in adults. Since the congenital choledochal cyst has not a unique clinical finding, the basic criteria for diagnosis are based on imaging findings. This article presents a case of choledochocele accompanying recurrent pancreatitis in a 19-year-old male patient.

Giant choledochal cyst mimicking massive gallbladder hydrops in an adult patient: multi detector computed tomography and magnetic resonance imaging findings correlated to gross and histopathological findings

Choledochal cysts are uncommon congenital anomalies of the biliary tree, commonly presenting in infancy, generally in the 1(st) year of life. Presentation in adult life is less common, accounting for 20% of cases. A 19-year-old female patient presented to the Emergency Department with severe abdominal distension, a palpable abdominal mass, mild jaundice and low grade fever. Ultrasound, computed tomography (CT) and magnetic resonance imaging of the abdomen showed a massive septated cystic lesion filling the entire abdomen with a significant mass effect on surrounding structures. Origin of the lesion was unclear and diagnosis included a giant mesenteric or duplication cyst, massive gallbladder with hydrops, biliary cystadenoma and giant choledochal cyst, among others. Final diagnosis was a Type IA choledochal cyst with massive asymmetric cystic dilatation of the extra-hepatic segments of the left hepatic duct with asymmetric dilatation of the right hepatic duct. Patient had an uneventful recovery after resection of the entire extrahepatic cyst and Roux-en-Y hepaticojejunostomy at the level of the hilum. In this article, we correlate CT and MRI findings to gross and histopathological findings of this giant Todani's Type IA choledochal cyst.

Cystic duct with no visible signal on magnetic resonance cholangiography is associated with laparoscopic difficulties: an analysis of 695 cases

BACKGROUND/AIMS

We investigated the association between the magnetic resonance cholangiography (MRC) results and surgical difficulties and bile duct injuries during laparoscopic cholecystectomy (LC).

METHODS

MRC was performed on 695 consecutive patients before LC. We divided the patients into two groups (visible cystic duct group and "no signal" cystic duct on MRC group) and compared them with regard to the length of the operation, conversion rate to open cholecystectomy (OC) and rate of bile duct injury.

RESULTS

The "no signal" cystic duct on MRC group had a longer operation and higher rate of conversion to OC compared with the visible cystic duct group. However, there was no statistically significant difference in the occurrence rate of bile duct injury between the two groups.

CONCLUSIONS

The "no signal" cystic duct on MRC group was associated with laparoscopic difficulties, but not with an increased rate of biliary injury. When a visible cystic duct is not observed on MRC an early conversion to open surgery may avoid a bile duct injury during LC.

Preoperative hepatobiliary imaging: what does the radiologist need to know?

Accurate preoperative reporting is essential in guiding the surgeon in deciding when and how to operate safely and effectively. Critically, this relies on an understanding of the operative issues faced by the surgeon, which is not always appreciated by the radiologist. This paper therefore aims to address this, first focusing on relevant anatomical variants, and then issues specific to laparoscopic cholecystectomy, hepatic transplantation, and finally hepatic resection (including cholangiocarcinoma resection). Throughout the paper, there is an emphasis on associated surgical techniques to add context to the discussion.

Three-dimensional imaging for hepatobiliary and pancreatic diseases: Emphasis on clinical utility

Three-dimensional (3D) imaging allows disease processes and anatomy to be better understood, both by radiologists as well as physicians and surgeons. 3D imaging can be performed with USG, CT scan and MRI, using different modes or rendering that include surface-shaded display, volume-based rendering, multiplanar imaging, etc. All these techniques are used variably depending on the indications.

A rare case of periampullary carcinoma with ectopic ending of Vater’s ampulla

A 71-year-old woman was referred to our department complaining of painless progressive jaundice for the last 3 mo. Magnetic resonance imaging and magnetic resonance cholangiopancreatography (MRCP) showed the ectopic hepatopancreatic ampulla draining into the fourth part of the duodenum adjacent to the duodenojejunal flexure; the irregular morphology of the duodenojejunal flexure likely due to a soft tissue mass. Laparotomy confirmed the presence of the abnormal ampulla of Vater located at the fourth part of the duodenum and a soft tissue tumor about 6 cm × 5 cm × 5 cm with a peduncle adjoining the ampulla. Resection of the tumor, including some peripheral tissue, and a Roux-Y loop anastomosis choledochojejunostomy were performed. Pathological examination indicated an intestinal villous adenoma accompanied by severe dysplasia and focal canceration. Periampullary carcinoma with ectopic ending of the Vater’s ampulla into the fourth part of the duodenum is rather rare. The embryonic genetic background of this anomaly has not yet been fully explained. It is worth mentioning that MRCP is useful for demonstrating anomalies and anatomic variants of the biliary tract system and pancreatic duct.

[Anatomic variants of the biliary tree with MR Cholangiography: feasibility and surgical applications]

PURPOSE

To assess the usefulness of MR Cholangiography for evaluation of anatomic variants of the biliary tree before biliary surgery.

MATERIALS AND METHODS

Our study group consisted of 45 consecutive patients (29 males, 16 females; mean age 57 years), who were referred for MR evaluation of malignant (n=26) and benign (n=19) cholangiopancreatic diseases. MR Cholangiography studies were independently reviewed by two radiologists.

RESULTS

Anatomic variants of the biliary tree were observed in 9 patients (20%); 6 variants involved the biliary confluence and 4 the cystic duct (one patient had both). Anatomic variants involved principally the right posterior duct: 1 (2,2%) drainage of right posterior duct into left hepatic duct; 2 (4,4%) triple confluence of right posterior duct, right anterior duct, and left hepatic duct, and 3 (6,6%) aberrant drainage of right posterior duct into common hepatic duct. Observed cystic duct anomalies included: 2 (7,44%) low insertion of the cystic duct into the common hepatic duct and 3 (11,1%) medial insertion of the cystic duct into the common hepatic duct.

CONCLUSION

MR Cholangiography accurately shows anatomic variants of the biliary tree. Noninvasive preoperative evaluation of the biliary anatomy may be important for the detection of anatomic variants that may increase the complexity of hepatic surgical procedures and biliary interventions.

Duplication of the extrahepatic bile duct with anomalous union of the pancreaticobiliary ductal system revealed by MR cholangiopancreatography

MR cholangiopancreatography (MRCP) is a valuable, non-invasive tool for accurate examination of the biliary system. We report a case in which MRCP played a critical role in the diagnosis of a duplication of the extrahepatic bile duct with anomalous union of the pancreaticobiliary ductal system in a patient with hilar cholangiocarcinoma. This variant of a duplication of the extrahepatic biliary system has not been described previously in the literature.

Bile duct cyst as precursor to biliary tract cancer

BACKGROUND

Bile duct cysts (BDC) are rare, of uncertain origin, and occur most often in young females of Asian descent. Increasingly, BDCs are reported in the Western population, often with coexistent biliary tract cancer.

METHODS

The PubMed and Medline literature databases were searched for pertinent publications regarding the clinical association and molecular biological development of cancerogenesis in BDC. Reports from the last two decades were emphasized.

RESULTS

Cancer is found in 10-30% of adults with BDC. The cancer-risk is low in childhood (<1% in the first decade), and shows a clear increase with age. Cholangiocarcinoma is the most common malignancy in BDC, and represents a 20- to 30-fold risk compared to the general population. The mean age of malignancy in BDC is 32 years (about two decades earlier than in the general population). Type I and type IV cysts show a higher cancer incidence, even after cyst excision. Pathological findings strongly suggest a hyperplasia-dysplasia-carcinoma sequence in carcinogenesis of pancreatico-biliary maljunction (PBM). Reflux of pancreatic enzymes, amylase, bile stasis, and an increased intraductal concentration of bile acids contribute to proliferative activity of bile acids in BDC. While microsatellite instability, k-ras mutations, expression of COX-2 and bcl-2, and increased telomerase activity seem to occur early; involvement of cyclin D1, beta-catenin, DPC-4/Smad4 and p53 appear later in carcinogenesis.

CONCLUSION

Increased molecular knowledge substantiates the clinically related cancer-risk in BDC. Surgery remains the golden standard for treatment, relieves patients from associated complications, and interrupts the cancerous potential in BDC.

Gadobenate dimeglumine-enhanced liver MRI as the sole preoperative imaging technique: a prospective study of living liver donors

OBJECTIVE

The objective of our study was to determine whether gadobenate dimeglumine-enhanced MRI is practical as the sole preoperative imaging technique for the examination of living liver donors.

SUBJECTS AND METHODS

Forty-four consecutive living donor candidates underwent liver MRI on a 1.5-T MR unit. The MR examination included in- and opposed-phase T1-weighted gradient-echo imaging, T2-weighted MR cholangiography, MR angiography (MRA) and parenchymal phase imaging after the administration of gadobenate dimeglumine, and 60-minute delayed T1-weighted MR cholangiography. Two abdominal radiologists analyzed the images regarding the depiction of the biliary duct anatomy and the hepatic vascular anatomy and for the presence of focal or diffuse liver disease. The findings were compared with intraoperative cholangiographic and surgical findings in 24 patients who underwent partial hepatectomy.

RESULTS

In the 24 patients who underwent liver harvesting, 10 had biliary anatomic variants confirmed by intraoperative cholangiography. T2-weighted MR cholangiography allowed a correct diagnosis in 75% (n = 18/24) and T1-weighted MR cholangiography in 79% (n = 19/24) of these patients. When we evaluated the bile duct anatomy using the combined findings of T2- and T1-weighted MR cholangiographic images, the diagnostic accuracy increased to 92% (n = 22/24), but the difference was not statistically significant (p > 0.05). MRA showed a diagnostic accuracy of 79% (n = 19/24) for the hepatic arterial anatomy, 100% (n = 24/24) for the portal venous anatomy, and 96% (n = 23/24) for the hepatic venous anatomy.

CONCLUSION

Gadobenate dimeglumine-enhanced MRI allows comprehensive assessment of the biliary and hepatic vascular systems and the hepatic parenchyma and can serve as the sole preoperative imaging test for living liver donor candidates.

[Asymptomatic or paucisymptomatic CBD dilatation on US after cholecystectomy: management]

In western countries, 10-15% of the population has gallbladder stones with 46,000 cholecystectomies performed in France in 2003. So, daily ultrasonography of the abdomen performed in patients without gallbladder is a routine exam. However, identification of an enlarged common bile duct is frequent and the normal nature of this finding remains uncertain. The purpose of this article is to perform a literature review of the impact of cholecystectomy on the diameter of the common bile duct. Furthermore, it is important not to dismiss common bile duct dilatation after cholecystectomy because it may be the result of post operative complication or secondary to a congenital disease of bile duct.

Bile duct cysts in adults

BACKGROUND

Bile duct cysts are rare and of uncertain origin. Most have been reported in young females of Asian descent, but an increasing number have occurred in Western adults.

METHODS

A Medline literature search was performed to locate articles on the pathophysiological concepts, clinical behaviour and management controversies pertaining to bile duct cysts in adults. Emphasis was placed on reports from the past two decades.

RESULTS AND CONCLUSION

An increasing rate of occurrence of bile duct cyst is reported in adults. Type IV cysts are more frequent in adults than children. Presentation tends to be non-specific abdominal discomfort. Related hepatobiliary or pancreatic disease frequently precedes recognition, and may complicate the postoperative course. Surgical treatment aims to relieve complications deriving from the cysts and to reduce the significant risk of malignant change within the biliary tree. Complete cyst resection, cholecystectomy and Roux-en-Y hepaticojejunostomy reconstruction is standard. Controversy exists about the role of hepatic resection in type IV and V cysts, and the role of minimally invasive and laparoscopic treatment. In general, the outcome is good and a near-zero mortality rate has been reported in institutional series over the past decade.

Biliary cystic disease

Cystic diseases of the biliary tract encompass a complex group of congenital disorders. Some of the disorders, such as Caroli disease and the hepatobiliary cysts of autosomal-dominant polycystic kidney disease, share common embryologic origins, whereas others, such as choledochal cysts, biliary diverticula, and choledochoceles, have unclear origins. This article reviews the embryologic, clinical, pathologic, and imaging features of biliary cystic disease.