MR imaging of ampullary carcinomas

The added value of MRI in distinguishing malignant and benign ampullary strictures: a multicenter retrospective study

PURPOSE

To investigate the added value of using contrast-enhanced magnetic resonance imaging (MRI) in conjunction with contrast-enhanced computed tomography (CT) for differentiating malignant and benign ampullary strictures.

MATERIALS AND METHODS

The present retrospective study included 90 patients with ampullary strictures who underwent preoperative contrast-enhanced CT and contrast-enhanced MRI at two tertiary institutions. The image sets (i.e., CT alone vs. combined CT and MRI) were evaluated by three abdominal radiologists, who used a five-point Likert scale to score their confidence for diagnosing malignancy in patients with ampullary strictures. Diagnostic accuracy was calculated using receiver-operating characteristic (ROC) curve analysis, sensitivity, specificity, and accuracy. Additionally, interobserver agreement regarding the scoring of potential malignancies of the ampullary strictures was assessed.

RESULTS

The addition of contrast-enhanced MRI to contrast-enhanced CT showed a significant improvement in predicting malignant ampullary strictures in all three observers (p = 0.007, 0.001, and 0.002) using ROC curve analysis, and a significant improvement was observed in diagnostic sensitivity and accuracy for predicting malignancy (p = 0.016 and 0.029 for observer 1; p = 0.023 and 0.010 for observer 2; and p = 0.010 and 0.011 for observer 3). The interobserver agreement for the five-point scale in determining malignancies of the ampullary strictures was 0.86 for CT alone and 0.93 for the combined set of CT and MRI.

CONCLUSION

The addition of contrast-enhanced MRI to CT provided added value for differentiating malignant from benign ampullary strictures.

Late/delayed gadolinium enhancement in MRI after intravenous administration of extracellular gadolinium-based contrast agents: is it worth waiting?

The acquisition of images minutes or even hours after intravenous extracellular gadolinium-based contrast agents (GBCA) administration ("Late/Delayed Gadolinium Enhancement" imaging; in this review, further termed LGE) has gained significant prominence in recent years in magnetic resonance imaging. The major limitation of LGE is the long examination time; thus, it becomes necessary to understand when it is worth waiting time after the intravenous injection of GBCA and which additional information comes from LGE. LGE can potentially be applied to various anatomical sites, such as heart, arterial vessels, lung, brain, abdomen, breast, and the musculoskeletal system, with different pathophysiological mechanisms. One of the most popular clinical applications of LGE regards the assessment of myocardial tissue thanks to its ability to highlight areas of acute myocardial damage and fibrotic tissues. Other frequently applied clinical contexts involve the study of the urinary tract with magnetic resonance urography and identifying pathological abdominal processes characterized by high fibrous stroma, such as biliary tract tumors, autoimmune pancreatitis, or intestinal fibrosis in Crohn's disease. One of the current areas of heightened research interest revolves around the possibility of non-invasively studying the dynamics of neurofluids in the brain (the glymphatic system), the disruption of which could underlie many neurological disorders.

Differentiation of malignant from benign ampullary strictures: A prediction nomogram based on MR imaging and clinical findings

PURPOSE

To construct a predictive nomogram based on contrast-enhanced magnetic resonance imaging (MRI) and clinical findings for differentiating malignant from benign ampullary strictures.

METHOD

In this retrospective study, 76 patients with ampullary strictures (51 benign and 25 malignant) who underwent contrast-enhanced MRI were enrolled. Imaging findings were evaluated independently by two abdominal radiologists who reached consensus. Clinical findings were also collected. Significant findings for malignant ampullary strictures were assessed by univariable and multivariable logistic regression analyses. Based on the results of multivariable analysis, a nomogram to differentiate malignant from benign ampullary strictures was developed and internally validated.

RESULTS

In multivariable analysis, presence of an ampullary mass (odds ratio [OR]: 8.42, p = 0.047), bulging ampulla (OR: 8.32, p = 0.033), diffusion restriction of the ampulla (OR: 42.76, p = 0.004) on MRI, and jaundice (OR: 12.41, p = 0.019) were significant predictors of malignant ampullary strictures. A predictive nomogram was constructed using these findings. Among them, diffusion restriction of the ampulla showed the highest OR and predictor score on the nomogram. The calibration plots for internal validation achieved strong agreement between the predicted probabilities and the actual rates of malignant ampullary strictures.

CONCLUSION

A combination of significant contrast-enhanced MRI and clinical findings of ampullary mass, bulging ampulla, diffusion restriction of the ampulla, and jaundice may be useful in the prediction of malignant ampullary stricture.

Evaluation of Imaging Findings of Pancreatobiliary and Intestinal Type Periampullary Carcinomas with 3.0T MRI

RATIONALE AND OBJECTIVES

The aim of this study was to differentiate pancreatobiliary and intestinal type periampullary carcinomas using dynamic contrast MRI and MRCP (Magnetic Resonance Cholangiopancreatography) with diffusion-weighted imaging (DWI) MATERIALS AND METHODS: MRI and MRCP images of 70 patients with pathologically proven periampullary adenocarcinoma were included. MRCP image features, extra-ampullary features, enhancement patterns, and apparent diffusion coefficient (ADC) values derived from b-values of 1000 s/mm² were evaluated by two radiologists independently. The interclass correlation coefficient (ICC) or Cohen's kappa statistic was used to evaluate the interobserver agreement.

RESULTS

51 patients were diagnosed with pancreatobiliary type carcinomas, and 19 with intestinal type. In the pancreatobiliary subtype, the distal wall of the common bile duct was usually irregular (p = 0.047). Although the progressive enhancement pattern was evident in the pancreatobiliary type, an oval filling defect in the distal common bile duct was found to be more common in the intestinal type (p<0.001). The pancreatic duct cut-off sign (p<0.001), gastroduodenal artery involvement (p <0,001), and lymphadenopathy (p<0.05) were mostly observed in pancreatobiliary carcinomas. The ADCmin, ADCmean, and ADCmax values of the pancreatobiliary type carcinomas were all lower compared to the intestinal type carcinomas (p <0.05).

CONCLUSION

The oval filling defect seen in MRI and MRCP examinations suggests intestinal type, whereas the progressive contrasting pattern of the masses with irregular narrowing in the distal margin of the common bile duct, the pancreatic duct cut-off sign, gastroduodenal artery involvement, lymphadenopathy, and low ADC values indicate pancreatobiliary type carcinomas.

Efficacy of Endoscopic Ultrasonography in Evaluation of Undetermined Etiology of Common Bile Duct Dilatation on Abdominal Ultrasonography

BACKGROUND The cause of common bile duct (CBD) dilatation cannot be determined by imaging modalities in many patients. The aim of this study was to assess the value of endoscopic ultrasonography (EUS) in detecting the cause of CBD dilatation in patients in whom ultrasonography could not demonstrate the cause of dilation. METHODS Prospectively, 152 consecutive patients who were referred for evaluation of dilated CBD (diameter ≥7 mm) of undetermined origin by ultrasonography were included in this study. All the patients underwent EUS. Final diagnoses were determined by using endoscopic retrograde cholangiopancreatography (ERCP), EUS-guided fine needle aspiration (FNA), surgical exploration, or follow-up for at least 10 months. Patients with choledocholithiasis were referred for ERCP and sphincterotomy, and patients with operable tumors were referred for surgery.Patients with inoperable tumors underwent biliary stenting with or without tchemoradiotherapy. RESULTS 152 patients (54% female) with dilated CBD were included. Mean (±SD) age of the patients was 60.4 (±17.3) years. The mean CBD diameter for all study group in transabdominal ultrasonography and EUS were 11.7 millimeter and 10.1 millimeter, respectively. Most of the patients with dilated CBD and abnormal liver function test (LFT) had an important finding in EUS and follow-up diagnosis including peri-ampullary tumors. Mean diameter of CBD in patients with and without abnormal LFT were 10.5 IU/L and 12.1 IU/L, respectively. Final diagnoses included choledocholithiasis in 32 (21.1%),passed CBD stone in 35 (23%), opium-induced CBD dilation in 14 (9.2%), post-cholecystectomy states in 20 (13.1%), ampullary adenoma/carcinoma in 15 (15.8%), cholangiocarcinoma in 14 (9.2%), and pancreatic head cancer in9 (5.9%) patients. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EUS for patients with abnormal EUS were 89.5%, 100.0%, 100.0%, 91.2%, and 90.9%, respectively. CONCLUSION After diagnosis of CBD dilation by transabdominal ultrasonography, EUS may be a reasonable choice for determining the etiology of dilated CBD and tumor staging.

Comparison of preoperative evaluation of malignant low-level biliary obstruction using plain magnetic resonance and coronal liver acquisition with volume acceleration technique alone and in combination

Background

To evaluate the clinical value of plain magnetic resonance (MR) imaging (including magnetic resonance cholangiopancreatography, MRCP) and coronal liver acquisition with volume acceleration (LAVA) technique in the diagnosis and preoperative assessment of malignant low-level biliary obstruction.

Methods

Forty-one patients with confirmed malignant low-level biliary obstruction were examined by plain MR, MRCP and coronal LAVA techniques. Group 1, plain MR (including MRCP); group 2, coronal LAVA; group 3, plain MR and coronal LAVA. Assessments included positioning, qualitative diagnosis and preoperative evaluation. The results were compared with pathological, endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography results.

Results

There were 14 pancreatic adenocarcinoma, 12 distal common bile duct carcinoma, 10 ampullary carcinoma, and 5 duodenal carcinoma cases. There was no significant difference in accuracy of the three groups’ positioning diagnoses, 87.8, 90.2, and 92.7 %, respectively. The accuracy of the qualitative diagnoses was lower in group 1 at 78.0 %, but not significantly different in groups 2 and 3 at 92.7 and 95.1 %, respectively (P = 0.031, and 0.039, group 1 vs groups 2 and 3, respectively). Thirty-three patients underwent open surgery. There were 19 adjacent organ involvements, 9 vascular involvements, 13 lymph node metastases and 6 liver metastases. 22 patients were verified surgically and histologically for resectable lesions. Plain MR with coronal LAVA imaging showed 85.4 % accuracy, 90.9 % sensitivity, 78.9 % specificity, 83.3 % positive and 88.2 % negative predictive value for resectability.

Conclusions

Plain MR and coronal LAVA techniques are potential noninvasive tools for diagnosis and preoperative assessment of malignant low-level biliary obstruction.

Electronic supplementary material

The online version of this article (doi:10.1186/s40001-015-0188-3) contains supplementary material, which is available to authorized users.

Adult bile duct strictures: role of MR imaging and MR cholangiopancreatography in characterization

Bile duct strictures in adults are secondary to a wide spectrum of benign and malignant pathologic conditions. Benign causes of bile duct strictures include iatrogenic causes, acute or chronic pancreatitis, choledocholithiasis, primary sclerosing cholangitis, IgG4-related sclerosing cholangitis, liver transplantation, recurrent pyogenic cholangitis, Mirizzi syndrome, acquired immunodeficiency syndrome cholangiopathy, and sphincter of Oddi dysfunction. Malignant causes include cholangiocarcinoma, pancreatic adenocarcinoma, and periampullary carcinomas. Rare causes include biliary inflammatory pseudotumor, gallbladder carcinoma, hepatocellular carcinoma, metastases to bile ducts, and extrinsic bile duct compression secondary to periportal or peripancreatic lymphadenopathy. Contrast material-enhanced magnetic resonance (MR) imaging with MR cholangiopancreatography is extremely helpful in the noninvasive evaluation of patients with obstructive jaundice, an obstructive pattern of liver function, or incidentally detected biliary duct dilatation. Some of these conditions may show characteristic findings at MR imaging-MR cholangiopancreatography that help in making a definitive diagnosis. Although endoscopic retrograde cholangiopancreatography with tissue biopsy or surgery is needed for the definitive diagnosis of many of these strictures, certain MR imaging characteristics of the narrowed segment (eg, thickened wall, long-segment involvement, asymmetry, indistinct outer margin, luminal irregularity, hyperenhancement relative to the liver parenchyma) may favor a malignant cause. Awareness of the various causes of bile duct strictures in adults and familiarity with their appearances at MR imaging-MR cholangiopancreatography are important for accurate diagnosis and optimal patient management.

Cancer of the ampulla of vater: current evaluation and therapy

Ampullary cancer is a relatively rare cancer of the digestive tract. In contrast to pancreatic cancer, ampullary cancer is often curable if detected at an early stage. The evaluation and management of ampullary cancer is similar to, but distinct from, that of other pancreaticobiliary tumors. This manuscript will review the current evaluation, diagnosis, and therapy of patients with ampullary cancer. The diagnosis of ampullary cancer is complicated by its similar clinical presentation to pancreatic cancer as well as its nonspecific laboratory findings. Diagnostic modalities such as ERCP, EUS, and biopsy are necessary for differentiating the 2 cancers, and noninvasive imaging techniques such as MRI and CT may be used for tumor staging. Although pancreaticoduodenectomy is considered the primary curative surgical option, consensus guidelines regarding adjuvant and neoadjuvant chemoradiation therapies are lacking.

Review of the investigation and surgical management of resectable ampullary adenocarcinoma

BACKGROUND

Ampullary adenocarcinoma is considered to have a better prognosis than either pancreatic or bile duct adenocarcinoma. Pancreaticoduodenectomy is associated with significant mortality and morbidity. Some recent publications have advocated the use of endoscopic papillectomy for the treatment of early ampullary adenocarcinoma. This article reviews investigations and surgical treatment options of ampullary tumours.

METHODS

A systematic review of English-language articles was carried out using an electronic search of the Ovid MEDLINE (from 1996 onwards), PubMed and Cochrane Database of Systematic Reviews databases to identify studies related to the investigation and management of ampullary tumours.

RESULTS

Distinguishing between ampullary adenoma and adenocarcinoma is challenging given the inaccuracy of endoscopic biopsy, for which high false negative rates of 25-50% have been reported. Endoscopic ultrasound is the most accurate method for local staging of ampullary lesions, but distinguishing between T1 and T2 adenocarcinomas is difficult. Lymph node metastasis occurs early in the disease process; it is lowest for T1 tumours, but the risk is still high at 8-45%. Case reports of successful endoscopic resection and transduodenal ampullectomy of T1 adenocarcinomas have been published, but their duration of follow-up is limited.

CONCLUSIONS

Optimal staging should be used to distinguish between ampullary adenoma and adenocarcinoma. Pancreaticoduodenectomy remains the treatment of choice for all ampullary adenocarcinomas.

Added value of diffusion-weighted MR imaging in the diagnosis of ampullary carcinoma

PURPOSE

To evaluate the added value of diffusion-weighted magnetic resonance (MR) imaging in diagnostic performance of conventional MR imaging for diagnosis of ampullary carcinoma.

MATERIALS AND METHODS

This retrospective study was institutional review board approved, and informed consent was waived. Twenty-three patients with malignant ampullary obstruction and 39 patients with benign ampullary obstruction were included. Qualitative (signal intensity and enhancement pattern) and quantitative (apparent diffusion coefficient [ADC]) analyses were conducted for visible or expected locations of duodenal papillae. Two observers independently reviewed conventional MR images and subsequently reviewed combined conventional and diffusion-weighted MR images. A five-point scale for likelihood of ampullary carcinoma was used. Fisher exact test and Mann-Whitney U test were used for comparing groups, and diagnostic performance (receiver operating characteristic [ROC] curve analysis), accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were evaluated.

RESULTS

Visible or expected duodenal papillae in benign group showed isointensity (27-38 of 39, 69%-97%) and similar enhancement pattern (27 of 39, 69%) to that of normal duodenal wall more frequently than in malignant group (seven to 18 of 23 [30%-78%] and three of 23 [13%], respectively) on conventional MR images (P < .05). On diffusion-weighted images, 21 of 23 (91%) ampullary carcinomas showed hyperintensity, whereas all benign cases showed isointensity compared with normal duodenal wall (P < .001). Mean ADC of ampullary carcinomas (1.23 × 10(-3) mm(2)/sec) was significantly lower than that of benign group (1.69 × 10(-3) mm(2)/sec) (P < .001). Diagnostic performance (area under ROC curve [Az]) of both observers improved significantly after additional review of diffusion-weighted images; Az improved from 0.923 to 0.992 (P = .029) for observer 1 and from 0.910 to 0.992 (P = .025) for observer 2. In addition, diagnostic accuracy, sensitivity, specificity, PPV, and NPV of combined conventional and diffusion-weighted MR images were higher than those of conventional MR images alone.

CONCLUSION

Addition of diffusion-weighted imaging to conventional MR imaging improves detection of ampullary carcinoma when compared with conventional MR imaging alone.

Linear endoscopic ultrasonography vs magnetic resonance imaging in ampullary tumors

AIM: To assess linear endoscopic ultrasound (L-EUS) and magnetic resonance imaging (MRI) in biliary tract dilation and suspect small ampullary tumor.

METHODS: L-EUS and MRI data were compared in 24 patients with small ampullary tumors; all with subsequent histological confirmation. Data were collected prospectively and the accuracy of detection, histological characterization and N staging were assessed retrospectively using the results of surgical or endoscopic treatment as a benchmark.

RESULTS: A suspicion of ampullary tumor was present in 75% of MRI and all L-EUS examinations, with 80% agreement between EUS and histological findings at endoscopy. However, L-EUS and histological TN staging at surgery showed moderate agreement (κ = 0.54).

CONCLUSION: L-EUS could be a useful adjunct as a diagnostic tool in the evaluation of patients with suspected ampullary tumors.

Groove pancreatitis: A Case Report and Review of the Literature

Groove pancreatitis is a rare form of segmental chronic pancreatitis. It involves the anatomic space between the head of the pancreas, the duodenum and the common bile duct. It was first described in the early 1970s, but it remains largely unfamiliar to most physicians. Radiological diagnosis can be challenging, as it is often difficult to differentiate it from other entities. The differential diagnosis from pancreatic head carcinoma may be difficult and recognition of subtle differences between these two entities is extremely important as the management differs significantly. Groove pancreatitis can be managed by conservative medical treatment, and surgery is reserved only for patients with persistent and severe clinical symptoms. We present a case of a 27 year-old male with groove pancreatitis and discuss the Magnetic Resonance Imaging (MRI) appearance of this entity as well as the differential diagnosis.

Differential features of pancreatobiliary- and intestinal-type ampullary carcinomas at MR imaging

PURPOSE

To define the differential imaging features of pancreatobiliary- and intestinal-type ampullary carcinomas at magnetic resonance (MR) imaging and to correlate these features with pathologic findings.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board; informed consent was waived. Fifty patients with surgically confirmed ampullary carcinoma and preoperative MR results were included. Two radiologists, blinded to histologic type of cancer, evaluated imaging findings in consensus. Univariate and multiple logistic regression analysis were performed to define imaging findings that were useful for differentiation of the two types of carcinomas.

RESULTS

On the basis of hematoxylin-eosin and immunohistochemical staining, 35 patients were classified as having pancreatobiliary type; and 15 patients, intestinal type. At MR, all of 15 intestinal carcinomas were nodular, whereas 16 (46%) of 35 pancreatobiliary carcinomas were infiltrative. Intestinal carcinomas were isointense (13 [87%] of 15) to hyperintense (two [13%] of 15), whereas 34% (12 of 35) of pancreatobiliary carcinomas manifested as hypointense compared with the duodenum on T2-weighted MR images (P = .034). Intestinal carcinoma commonly manifested with an oval filling defect at the distal end of the bile duct on MR cholangiopancreatographic (MRCP) images (11 [73%] of 15 vs four [11%] of 35 in pancreatobiliary type) (P < .001). At endoscopy, intestinal carcinoma manifested with an extramural protruding mass (n = 15, 100%) with a papillary surface (n = 11, 73%), whereas pancreatobiliary carcinoma manifested with intramural protruding (n = 5, 28%) or ulcerating (n = 1, 6%) gross morphologic features (P = .047) with a nonpapillary surface (n = 17, 94%) (P < .001). Multiple logistic regression analysis showed that an oval filling defect at the distal end of the bile duct was the only independent finding for differentiating intestinal from pancreatobiliary carcinoma (P = .027).

CONCLUSION

An oval filling defect at the distal end of the bile duct on MRCP images and an extramural protruding appearance with a papillary surface at endoscopy are likely to suggest intestinal ampullary carcinoma.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Magnetic resonance imaging of gallbladder and biliary system

Gallbladder and biliary system pathologic component is a spectrum of benign and malignant conditions. Standard magnetic resonance imaging techniques when used together with magnetic resonance cholangiopancreatography (MRCP) can evaluate gallbladder and biliary system pathologic conditions. Inflammatory diseases are characterized by thickening and intense mucosal contrast enhancement of the affected bile ducts and or gallbladder wall. Postinflammatory changes can be appreciated on MRCP with short or long segment strictures of the bile ducts. Serial contrast-enhanced images show reactive inflammatory changes in the liver parenchyma. Neoplastic diseases of the gallbladder and the biliary tree are evaluated on T2-weighted fat-suppressed echo train and serial contrast-enhanced images and their obstructive effect can be displayed on MRCP images. In this paper, we will review the spectrum of MRI findings of gallbladder and biliary system pathologic conditions.

State-of-the-art magnetic resonance imaging of pancreatic cancer

Technical advances of magnetic resonance imaging (MRI), including ultrahigh-field magnetic resonance at 3.0 T, parallel imaging techniques, and multichannel receive coils of the abdomen, have promoted MRI of the pancreas. For adenocarcinoma, which is the most common malignant pancreatic tumor, helical CT has been most often used for detection and staging, but it has limitations in the detection of small cancers 2 cm in diameter or less (sensitivity, 63%). Moreover, it is not very accurate in determining nonresectability, because small liver metastases, peritoneal carcinomatosis, and subtle signs of vascular infiltration may be missed. At ultrahigh field at 3.0 T, gadolinium-enhanced MRI using volume-interpolated 3-dimensional gradient-recalled echo pulse sequences with near-isotropic voxels are very useful for detection of subtle abnormalities. Mangafodipir-enhanced MRI reveals a very high tumor-pancreas contrast, which helps to diagnose small cancers. Contrast-enhanced MRI is a problem-solving tool in case of equivocal CT: it helps to differentiate between cancer and focal pancreatitis. Neuroendocrine carcinoma may present with a spectrum of appearances at MRI, but the primary tumor and liver metastases are hypervascular in approximately 70%. In this article, pancreas imaging protocols for 1.5 and 3.0 T are explained. We present the imaging features of pancreatic cancer and the important questions in staging, which should be addressed by the radiologist.

Usefulness of fat-suppressed T1-weighted MRI using orally administered superparamagnetic iron oxide for revealing ampullary carcinomas

OBJECTIVE

To evaluate the value of adding fat-suppressed (FS) T1-weighted magnetic resonance imaging (MRI) with orally administered superparamagnetic iron oxide (SPIO) to the 3-dimensional dynamic MRI for revealing ampullary carcinomas.

MATERIALS

Twenty-five patients with ampullary carcinoma who underwent MRI with orally administered SPIO, including a FS T1-weighted fast low-angle shot (FLASH) sequence, a respiratory-triggered turbo spin-echo (RT-TSE) sequence, and the 3-phasic 3-dimensional dynamic images, were enrolled in this study. About 5 min before the examination, a mixture of 8.4 mg of SPIO and 300 mL water was administered orally to all patients. The images were compared quantitatively by measuring the tumor-pancreas (duodenum) contrast-to-noise ratio and, qualitatively, by evaluating tumor conspicuity. Three separate sets of images, that is, the dynamic set, the combination of the dynamic set, and the RT-TSE, and the combination of the dynamic set and the FLASH were analyzed by 2 observers in consensus.

RESULTS

For the tumor-pancreas (duodenum) contrast-to-noise ratio, the FLASH was significantly higher than those of the dynamic set and RT-TSE (P < 0.05). The tumor conspicuity with the combination of the dynamic set and the FLASH was also significantly better than those of the dynamic set, and the combination of the dynamic set and RT-TSE (P = 0.001). For 15 tumors that were surgically confirmed, the combined reading of the FLASH imaging and dynamic set allowed more accurate surgical staging (14/15, 93.3%) than did the dynamic imaging set or the combined reading of the dynamic set and RT-TSE (11/15, 73.3%).

CONCLUSIONS

Addition of the FS FLASH image using orally administered SPIO to the dynamic MRI is useful for revealing ampullary carcinoma.

Differentiation of ampullary tumor from benign papillary stricture by thin-section multidetector CT

The objective of this paper was to determine the criteria for differentiation of ampullary tumor from benign papillary stricture using thin-section multidetector CT images. Multidetector CT images with 2.5 mm slice-thickness in 57 consecutive patients (24 with ampulla of Vater tumor and 33 with benign papillary stricture) with extrahepatic duct dilatation due to ampullary obstruction were reviewed retrospectively. The papilla/papillary mass was evaluated regarding size, homogeneity of enhancement, attenuation value, and the diameters of extrahepatic duct and main pancreatic duct were measured. The measurability, enhancement pattern, the attenuation value of papilla/papillary mass on portal venous phase, and the maximum diameters of extrahepatic duct and main pancreatic duct were different between two groups. Multiple logistic regression analysis showed the papilla/papillary mass size was the only independently differentiating variable of ampullary tumor from benign stricture (P = 0.016) with an odds ratio of 2.424 (95% confidence interval, 1.179-4.903). The most appropriate cutoff value of papilla/papillary mass size was 12.3 mm with 91.7% sensitivity, 92.3% specificity, and 92.0% accuracy. Ampullary tumor and benign papillary stricture could be effectively differentiated by thin-section multidetector CT based on papilla/papillary mass size.

Preoperative evaluation of pancreaticobiliary tumor using MR multi-imaging techniques

AIM: To evaluate the clinical value of MR multi-imaging techniques in diagnosing and preoperative assessment of pancreaticobiliary tumor.

METHODS: MR multi-imaging techniques, including MR cross-sectional imaging, MR cholangiopancreatography (MRCP) and 3D dynamic contrast-enhanced MR angiography (3D DCE MRA), were performed to make prospective diagnosis and preoperative evaluation in 28 patients with suspected pancreaticobiliary tumors. There were 17 cases of pancreatic adenocarcinoma, 8 cases of biliary system carcinoma and 3 cases of non-neoplastic lesions.

RESULTS: Using MR multi-imaging techniques, the accuracy in diagnosing the patients with pancreaticobiliary tumors was 89.3% (25/28). The accuracy in detecting the range of tumor invasion was 80.3% (57/71). The sensitivity, specificity, accuracy, positive and negative predictive value of MR multi-imaging techniques in preoperative assessment of the resectability of pancreaticobiliary tumor were 83.3%, 89.5%, 88.0%, 71.4%, and 94.4%, respectively. There was well diagnostic consistency between MR multi-imaging techniques and CT (κ = 0.64, P<0.01). The fusion image could be made from MRCP and 3D DCE MRA images.

CONCLUSION: MR multi-imaging techniques can integrate the advantages of various MR images. The non-invasive “all-in-one” MR imaging protocol is the efficient method in diagnosing, staging and preoperative assessment of pancreaticobiliary tumor.

Malignant biliary obstruction: value of imaging findings

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

Evaluation and management of periampullary tumors

Periampullary cancers make up 5% of all gastrointestinal cancers. The complexity of the periampullary anatomy makes determination of the origin of some of these tumors difficult. However, advances in imaging have helped with diagnosis as well as defining the extent of the lesion and its potential resectability. For many of these tumors, surgery is the recommended treatment. However, endoscopic removal is being extended to different lesions with encouraging preliminary results. Improvements in overall prognosis for periampullary tumors will be limited until diagnosis can be established earlier in the course of the disease and adjuvant therapies become more effective.

Periampullary Tumors: High-Spatial-Resolution MR Imaging and Histopathologic Findings in Ampullary Region Specimens

PURPOSE

To prospectively determine the magnetic resonance (MR) signal intensity characteristics of structures of the ampullary region and to assess the potential use of MR imaging in evaluation of the extent of periampullary tumors in resected specimens.

MATERIALS AND METHODS

Twenty-five specimens from the ampullary region obtained in four autopsy cases without periampullary tumors and in 21 patients with periampullary tumors were examined with a 1.5-T MR system and a circular surface coil with 5-inch (12.7-cm) diameter. High-spatial-resolution MR images were obtained with field of view of 100 x 100 mm, matrix of 256 x 256 or 512 x 256, and section thickness of 2 mm. MR imaging findings were compared with histopathologic findings. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of high-spatial-resolution MR imaging for assessment of tumor invasion into surrounding tissues were evaluated by two radiologists.

RESULTS

T1- and T2-weighted MR images clearly depicted normal structures in the ampullary region that included Oddi muscle, duodenal wall, common bile duct, and pancreas; these findings corresponded well with histologic findings. In 20 (95%) of 21 tumors, high-spatial-resolution MR imaging depicted location and extension of periampullary tumors precisely. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of high-spatial-resolution MR imaging for assessment of tumor invasion into surrounding tissue were 88%, 100%, 96%, 100%, and 94%, respectively.

CONCLUSION

In this study, MR imaging correctly depicted location, extension, and origin of tumor. High-spatial-resolution MR imaging has potential for presurgical staging of tumors in this region.

The role of endoscopy in the evaluation and treatment of patients with pancreaticobiliary malignancy

This is one of a series of statements discussing the utilization of GI endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy prepared this text. In preparing this guideline, a MEDLINE literature search was performed, and additional references were obtained from the bibliographies of the identified articles and from recommendations of expert consultants. When little or no data exist from well-designed prospective trials, emphasis is given to results from large series and reports from recognized experts. Guidelines for appropriate utilization of endoscopy are based on a critical review of the available data and expert consensus. Further controlled clinical studies are needed to clarify aspects of this statement, and revision may be necessary as new data appear. Clinical consideration may justify a course of action at variance to these recommendations.