Detection of common bile duct stones before laparoscopic cholecystectomy. Evaluation with MR cholangiography

Purpose:
To assess the diagnostic value of MR cholangiography (MRC) for detecting common bile duct (CBD) stones in candidates for laparoscopic cholecystectomy (LC). Material and Methods:
A series of 95 selected patients with gallstones and suspected CBD lithiasis (abnormal serum liver tests and/or CBD size ≥6.5 mm at US) were referred to our institution for MRC, before LC. MRC was performed on a 0.5 T magnet through a non-breath-hold, respiratory-triggered, fat-suppressed, thin-slab, heavily T2-weighted fast spin-echo sequence and through a breath-hold, thick-slab, single-shot T2-weighted sequence in the coronal plane. Axial T1- and T2-weighted sequences were first obtained. Two observers in conference reviewed source images and maximum intensity projections to determine the presence or absence of choledocholithiasis. MR findings were compared with endoscopic retrograde cholangiography and intraoperative cholangiography (IOC); IOC was always performed during LC. Results:
CBD calculi (single or multiple) were identified in 41 out of 95 patients (43%). Two false-positive and 4 false-negative cases were found on MRC. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of MRC for choledocholithiasis were 90%, 96%, 94%, 95%, and 93%, respectively. Conclusion:
MRC is a highly effective diagnostic modality for evaluation of patients with risk factors for CBD stones prior to LC.     

Diagnosing bile duct stones: comparison of unenhanced helical CT, oral contrast-enhanced CT cholangiography, and MR cholangiography

OBJECTIVE. In this investigation we compared the diagnostic performance of unenhanced helical CT, oral contrast-enhanced CT cholangiography, and MR cholangiography for the diagnosis of choledocholithiasis. SUBJECTS AND METHODS. Fifty-one patients referred for endoscopic retrograde cholangiography of suspected biliary stones were studied with unenhanced helical CT, MR cholangiography, and helical CT performed after oral administration of a cholangiographic contrast agent (iopodic acid). The studies were randomized for interpretation. Two radiologists evaluated the images by consensus and determined the presence and location of stones. We used retrograde cholangiography findings as the standard of reference. Sensitivity and specificity (with 95% confidence intervals [CIs]) of the three examinations were calculated and compared using the exact form of the McNemar test. RESULTS. Bile duct stones were revealed with retrograde cholangiography in 26 patients (51%). Sensitivity was 65% (95% CI, 44.4-82%) for unenhanced helical CT, 92% (95% CI, 73-99%) for CT cholangiography, and 96% (95% CI, 78-99%) for MR cholangiography. Specificity was 84% (95% CI, 63-95%) for unenhanced helical CT, 92% (95% CI, 73-99%) for CT cholangiography, and 100% (95% CI, 83-100%) for MR cholangiography. The sensitivity of CT cholangiography and MR cholangiography was significantly higher than that of unenhanced helical CT (p<0.01). Differences in specificity were not significant. CONCLUSION. Our results indicate that oral contrast-enhanced CT cholangiography and MR cholangiography are significantly more sensitive than unenhanced helical CT for the detection of bile duct calculi.     

Role of preoperative helical CT before laparoscopic cholecystectomy: evaluation of gallbladder and peritoneal adhesion

OBJECTIVE: The purpose of this study was to assess the value of preoperative helical CT for the detection of adhesion of the gallbladder or surrounding peritoneum. SUBJECTS AND METHODS: Dynamic-enhanced helical CT of the abdomen was obtained before laparoscopic cholecystectomy in 47 patients. Images were reconstructed with a 5-mm interval. Appearances on CT images were correlated with operative findings, and useful findings for predicting gallbladder or peritoneal adhesion were determined by univariate and multivariate analysis. RESULTS: Patients with gallbladder or peritoneal adhesion often have gallbladder wall thickening, gallbladder wall enhancement, and increased density of the pericholecystic fat more frequently than patients without adhesion on both precontrast and postcontrast CT. Each of these findings was significant on univariate analysis. On multivariate analysis, increased density of the pericholecystic fat and focal attenuation increase in the liver were significant factors for predicting gallbladder or peritoneal adhesion. CONCLUSION: Increased density or stranding of pericholecystic fat and transient focal hepatic attenuation increase at dynamic arterial-phase CT indicates gallbladder and peritoneal adhesion.     

Three-dimensional volume-rendered helical CT before laparoscopic adrenalectomy

Use of three-dimensional (3D) volume-rendered helical computed tomography (CT) in surgical planning before laparoscopic adrenalectomy was evaluated in a retrospective study. In 35 consecutive patients before laparoscopic adrenalectomy, 3D volume-rendered CT scans were created from helical CT scans. Videotapes that showed anterior, lateral, posterior, and posterocephalic approaches were assessed retrospectively. The relationship (not contacting, abutting, displacing, or invading) of adrenal masses to adjacent organs (diaphragm, liver, spleen, kidneys, stomach, pancreas, and vessels) was recorded and compared with findings in surgery reports. When such findings were available, they corresponded to those in the videotape. Three-dimensional volume-rendered CT successfully displayed the relationship of adrenal masses to adjacent anatomic structures and organs before laparoscopic adrenalectomy.     

Usefulness of three-dimensional CT cholangiography for patients prior to laparoscopic cholecystectomy

PURPOSE: The aim of this study was to demonstrate three-dimensional biliary anatomy by using spiral CT scanning for patients prior to laparoscopic cholecystectomy. MATERIALS AND METHODS: We studied 22 patients (11 men, 11 women; mean age, 60 years) with preoperative imaging. All patients had normal serum bilirubin levels. Either 50 ml (in 10 cases) or 100 ml (in 12 cases) of meglumine iotroxate was infused intravenously over 30 minutes. Spiral CT scanning was started immediately after the infusion was finished. Volumetric data through the entire biliary tracts were obtained during one breath-hold. The data were reconstructed by using a maximum intensity projection algorithm and three-dimensional shaded surface rendering. RESULTS: In all patients, the anatomical relationship between the cystic duct and the common bile duct was clearly depicted, including one with junctional anomaly. The intrahepatic biliary ducts and the confluence of the hepatic ducts were displayed from all angles. The third or higher intrahepatic branches were delineated in 11 of the 12 (92%) patients with the use of 100 ml of the cholangiographic agent and in seven of the 10 (70%) with 50 ml. CONCLUSION: Three-dimensional CT cholangiography was able to provide adequate information about precise biliary anatomy.     

Value of MR cholangiography in patients with iatrogenic bile duct injury after cholecystectomy

OBJECTIVE: Our aim was to determine the diagnostic role of MR cholangiography in the evaluation of iatrogenic bile duct injuries after cholecystectomy. SUBJECTS AND METHODS: Nineteen patients (14 women and five men; mean age, 47 years; age range, 24-75 years) with suspected bile duct injury as a result of laparoscopic cholecystectomy (17 patients) and open cholecystectomy (two patients) underwent MR cholangiography. MR images were evaluated for bile duct discontinuity, presence or absence of biliary dilation, stricture, excision injury, free fluid, and collections. Bile duct excision and stricture were classified according to the Bismuth classification. Final diagnosis was made on the basis of findings at surgery in 15 patients, on percutaneous transhepatic cholangiography (PTC) in one patient, and on endoscopic retrograde cholangiography (ERC) and at clinical follow-up until hospital discharge in the remaining three patients. RESULTS: In 16 patients, injury of the bile duct was observed. Two patients had Bismuth type I injury; one patient, type II injury; 11 patients, type III injury; and one patient each, type IV and V injuries. Three patients showed findings suggestive of leakage from the cystic duct remnant, which were confirmed on ERC. CONCLUSION: MR cholangiography is an accurate diagnostic technique in the identification of postoperative bile duct injuries. This technique allows exploration above and below the level of obstruction, a resource provided by neither ERC nor PTC, and allows the accurate classification of these injuries, which is essential for treatment planning.     

Injury to aberrant bile ducts during cholecystectomy: a common cause of diagnostic error and treatment delay

OBJECTIVE: Bronchiolitis obliterans syndrome is the major cause of long-term graft failure in lung transplant recipients and may be partially reversible if diagnosed early and treated. Diagnosis is difficult because findings of transbronchial biopsy are often negative in patients with early disease. We are investigating a novel MR ventilation agent, hyperpolarized 3He, for evaluating ventilatory abnormalities in lung transplant recipients with suspected bronchiolitis obliterans syndrome. CONCLUSION: In this preliminary study, the extent of ventilatory defects revealed on 3He-enhanced MR images correlated with severity of bronchiolitis obliterans syndrome using an established clinical grading system. This new technique may hold potential for diagnosing bronchiolitis obliterans syndrome in lung transplant recipients.     

Complementary role of helical CT cholangiography to MR cholangiography in the evaluation of biliary function and kinetics

To explore the potential role of computed tomographic cholangiography (CTC) in relation to magnetic resonance cholangiography (MRC) in cases in which knowledge of biliary kinetics and functional information are important for therapeutic decisions, 31 patients (14 men and 17 women) underwent MRC followed by CTC. We examined nine post-cholecystectomy cases with right upper quadrant abdominal pain, six cases with a previous biliary-enteric anastomosis and clinical evidence of cholangitis, eight biliary strictures with pain or symptoms of cholangitis, four cases with strong clinical evidence of sclerosing cholangitis, three cases with suspected post-laparoscopic cholecystectomy bile leakage, and one case with chronic pancreatitis and a common bile duct stent associated with cholangitis. In relation to MRC, CTC provided additional biliary functional information as follows: abnormal biliary drainage through the ampulla in 7/9 cholecystectomy cases, impaired drainage in 3/6 biliary-enteric anastomoses, and complete obstruction in 2/8 biliary strictures. CTC diagnosed early sclerosing cholangitis in 4/4 cases and confirmed suspected bile leakage in 1/3 post-laparoscopic cholecystectomy patients, and the patency of the biliary stent in the patient with chronic pancreatitis. Thus, CTC provides clinically important information about the function and kinetics of bile and complements findings obtained by MRC.     

Normal intrahepatic bile ducts: CT depiction

Visualization of intrahepatic bile ducts (IHBDs) at computed tomography (CT) has previously been considered evidence of biliary obstruction. The authors have found that hepatic CT enhanced with contrast material and with the use of ceramic scintillation detectors allows frequent visualization of normal IHBDs. One hundred patients without imaging, laboratory, or clinical evidence of hepatobiliary or pancreatic disease were prospectively examined to assess the frequency of visualization, location, and size of IHBDs. IHBDs were visualized in 40% of the patients and had an average size of 2.0 mm in the central part of the liver and 1.8 mm in the peripheral part of the liver. Ducts were seen in the right lobe more often than in the left lobe. There was no statistically significant relationship between visualization of IHBDs and patient age. Demonstration of IHBDs on current CT scanners is a normal finding and does not indicate biliary obstruction.     

Early biliary complications of laparoscopic cholecystectomy: evaluation on T2-weighted MR cholangiography in conjunction with mangafodipir trisodium-enhanced 3D T1-weighted MR cholangiography

OBJECTIVE: Our aim was to assess preliminary experience with combined conventional T2-weighted and mangafodipir trisodium (MnDPDP)-enhanced T1-weighted MR cholangiography in evaluating early biliary complications of laparoscopic cholecystectomy. SUBJECTS AND METHODS: Conventional heavily T2-weighted MR cholangiography with MnDPDP-enhanced T1-weighted MR cholangiography and ERCP were performed in seven patients with high clinical suspicion of biliary complications after laparoscopic cholecystectomy. The final diagnoses of complications were classified according to the presence and degree of bile duct injury, bile leakage, and retained stones. RESULTS: The diagnoses on MR cholangiography were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 3), partial strictures of the common bile duct with bile leakage (n = 1), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). The final diagnoses at surgery (n = 2) and ERCP (n = 5) were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 2), partial strictures of the common bile duct with bile leakage (n = 2), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). MR cholangiography accurately yielded the same findings as the final diagnoses, except in one case with partial stricture of the bile duct with bile leakage (overdiagnosed as complete occlusion on MR cholangiography). CONCLUSION: Combined conventional T2-weighted and MnDPDP-enhanced T1-weighted MR cholangiography may eliminate the use of other studies for the imaging of biliary complications after cholecystectomy if this preliminary data can be verified in a larger study.     

LC术中选择性胆道造影85例

目的：探讨腹腔镜胆囊切除术（laparoscopic cholecystectomy,LC）中选择性胆道造影的临床价值。方法：回顾性分析2003年3月～2006年12月在LC术中行胆道造影的85例临床资料。结果：95％术中造影成功,造影发现胆总管结石12例,胆道变异2例,胆胰管异常汇合3例。结论：LC术中胆道造影操作简单方便,选择性术中胆道造影可有效防止术后胆总管残留结石的发生,同时,可及时发现胆道解剖变异,避免术中意外胆道损伤,值得临床推广应用。     

Preoperative depiction of hepatocellular carcinoma: ferumoxides-enhanced MR imaging versus triple-phase helical CT

PURPOSE: To compare ferumoxides-enhanced magnetic resonance (MR) imaging with triple-phase helical computed tomography (CT) for the preoperative depiction of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Seventy consecutive patients with a total of 79 HCC nodules underwent ferumoxides-enhanced MR imaging and triple-phase helical CT before surgery. The diagnosis of HCC was established by means of pathologic examination after surgical resection in all patients. MR images obtained with all sequences and triple-phase helical CT images were reviewed independently by three radiologists on a segment-by-segment basis. Accuracy for diagnosis of HCC was assessed by applying receiver operating characteristic (ROC) analysis to observations of 78 hepatic segments with at least one HCC nodule and 70 segments without HCC. RESULTS: The diagnostic accuracy of findings at ferumoxides-enhanced MR imaging (with mean area-under-the-ROC-curve [A(z)] values for the three observers of 0.986, 0.979, and 0.980) was significantly higher (P <.001) than that of findings at triple-phase helical CT (with mean A(z) values for the three observers of 0.945, 0.948, and 0.964). The mean sensitivity of MR imaging (95%, 222 of 234 segments) was also significantly higher than that of triple-phase helical CT (88%, 205 of 234 segments) (P =.001, McNemar test). The mean specificity was 97% (261 of 270 segments) for MR imaging and 98% (264 of 270 segments) for CT, but this difference was not significant (P =.754, McNemar test). CONCLUSION: Ferumoxides-enhanced MR imaging is superior to triple-phase helical CT for the preoperative depiction of HCC.     

MR imaging of normal extrahepatic bile ducts

Abdominal scans of 48 patients without evidence of biliary tree or pancreatic head pathology were retrospectively evaluated to determine how often the normal common bile duct (CBD) could be visualized, as well as to determine which projections and pulse sequences optimized its visualization. Axial sequences with long repetition time (TR) and for echo time (TE) intervals (2,000-2,500 and 60-80 ms, respectively) were the most useful, identifying the normal CBD in 15 of 30 diagnostic studies. Axial sequences using short TR/TE intervals (300-800 and 20-25 ms, respectively) were less informative, identifying the CBD in only eight of 30 studies. Coronal studies were not useful, identifying the CBD in only one of 10 long TR/TE pulse sequences.     

Anatomic variations of intrahepatic bile ducts in the general adult Egyptian population: 3.0-T MR cholangiography and clinical importance

Objective

To describe the anatomical variations occurring in intrahepatic bile ducts (IHDs) and their frequencies in general adult Egyptian population using 3.0-T MR cholangiography (MRC) as well as its clinical importance to reduce the biliary complications of hepatobiliary surgery.

Materials and methods

MRC was applied to a study group of 106 subjects (26 potential liver donors and 80 volunteers). Anatomical variations in IHDs were classified based on the variable insertion of right posterior hepatic bile duct (RPHD) using Huang classification.

Results

According to this classification, the frequencies of each type were as follows: Huang A1 (typical pattern): 63.2% (n = 67), Huang A2: 10.4% (n = 11), Huang A3: 17% (n = 18), Huang A4, 7.5% (n = 8), and Huang A5: 1.9% (n = 2). Total frequency for atypical types (i.e. A2, A3, A4 and A5) was 36.8%. No significant difference was detected in the distance between RPHD insertion to the junction of right and left hepatic duct in-between these Huang types. This distance was short (<1 cm) in 21 of subjects under Huang A classification. Twenty-one donors underwent intraoperative cholangiograms, of which twenty (95.2%) had similar classification in both intraoperative and MRC findings.

Conclusion

The incidence of variant biliary anatomy in general Egyptian population (36.8%) as well as the presence of Huang type A with short distance (<1 cm) between RPHD insertion and junction of right and left hepatic duct (19.8%) enhance the importance of MRC as a pre-operative tool before hepato-biliary surgical procedures to reduce post-operative biliary complications.     

Double common bile duct: curved-planar reformatted computed tomography (CT) and gadobenate dimeglumine-enhanced MR cholangiography

We present the case of a 61-year-old female with double common bile duct (CBD) with an opening into the lesser curvature of the stomach. We discuss the role of curved-planar reformatted computed tomography (CT) and gadobenate dimeglumine (Gd-BOPTA)-enhanced T1-weighted MRI in confirming the diagnosis of this uncommon disease.     

MR cholangiography and CT cholangiography of pediatric patients with choledochal cysts.

OBJECTIVE: We report our experience using MR cholangiography and CT cholangiography in pediatric patients with choledochal cysts. SUBJECTS AND METHODS: Fourteen patients (two boys, 12 girls; mean age, 7.8 years) with either a preoperative diagnosis of choledochal cyst or a surgical finding of choledochal cyst underwent non-breath-hold MR cholangiography using T2-weighted fat-suppressed fast spin-echo sequences with a 1.5-T magnet, and CT cholangiography with IV infusion of meglumine iodoxamic acid. Radiologic findings were correlated with findings from surgery, operative cholangiography, or percutaneous transhepatic cholangiography. RESULTS: The biliary tree was visualized in all 14 patients with MR cholangiography and in 13 patients (92.9%) with CT cholangiography. In the 11 preoperative cases of choledochal cyst, MR cholangiography correctly showed all cysts and CT cholangiography showed 10 cysts (90.9%). The quality of images on CT cholangiography and MR cholangiography was comparable. The sensitivity of CT cholangiography and MR cholangiography in revealing intrahepatic stones was 83.3% and 66.7%, respectively; the specificity for both techniques was 100%. The rate of detecting the pancreatic duct and the common channel by CT cholangiography and MR cholangiography was 63.6% and 45.5% respectively. After surgery, CT cholangiography was superior to MR cholangiography in revealing the location of biliary-enteric anastomosis and the extent of anastomotic narrowing. CONCLUSION: Because non-breath-hold MR cholangiography is not invasive and does not use ionizing radiation and potentially toxic contrast agents, it is recommended as the imaging technique of choice in children with choledochal cysts. CT cholangiography can be considered as an adjunct after surgery and in patients in whom MR cholangiography is unsatisfactory.