Diagnostic Value of Hypotonic-MRCP Combined with LAVA Dynamic Contrast-Enhanced Scan in Duodenal Tumor / 实用放射学杂志

Objective To discuss the value of hypotonic-MRCP combined with LAVA dynamic contrast-enhanced scan in diagnosis of duodenal tumor.Methods Five patients with duodenal adenocarcinomas confirmed by pathology were involved in this study.All cases underwent plain MRI and hypotonic-MRCP and LAVA dynamic contrast-enhanced scans.Results 4 of 5 cases were correctly diagnosed with MR imaging.Imaging signs included:the cavum of descending duodenum appeared as asymmetrical stenosis,masses with soft tissue signal intensity connecting the intestinal wall with wide base,the intestinal wall stiff,the intestinal mucosa destruction.The lesions would be slightly-moderately enhanced at LAVA dynamic enhancement scanning.Conclusion Hypotonic-MRCP combined with LAVA dynamic contrast-enhanced scan can display the direct and indirect sign of duodenal tumors,which was effective in identifying the circumscription of the tumor and its extension.

MRI manifestations of normal pancreas in piglets / 中国医学影像技术

Objective To observe the MRI findings of normal pancreas in piglets. Methods Eight healthy piglets underwent MR examination, and the morphology, size, signal intensity of pancreas were observed. After MR imaging, all piglets were abdominally incised to observe the anatomy of pancreas and pancreatic adjacent structures. The opening of both common bile duct and pancreatic duct were detected during operation. Two piglets were sacrificed after operation and the whole pancreases were dissected for anatomic research. Results The pancreas of piglets was composed of three parts: right lobe, median lobe and left lobe. All the lobes were displayed clearly on MRI. The signal intensity of pancreas was higher than that of liver and spleen on T1WI, whereas lower than that of liver and spleen on T2WI. On MRCP, pancreatic duct was not presented, whereas the common bile duct could be seen clearly. The opening of common bile duct located at superior part of duodenum (nearby the pylorus) and the opening of pancreatic duct situated at duodenal papilla corresponding to pancreatic right lobe. Conclusion MRI can show the pancreas of piglets very well. The morphology of pancreas and features of common bile duct conjunction with pancreatic duct in piglet are different from those in human.

Usefulness of MR Cholangiopancreatography after Intravenous Morphine Administration

PURPOSE: We wanted to assess the usefulness of MRCP after intravenous morphine administration in the evaluation of the hepatopancreatic pancreatico-biliary ductal system. MATERIALS AND METHODS: We studied 15 patients who were suspected of having disease of hepatopancreatic ductal system and they did not have any obstructive lesion on ultrasonography and/or CT. MRCP was acquired before and after morphine administration (0.04 mg/kg, intravenously). Three radiologists scored the quality of the images of the anatomic structures in the hepatopancreatic ductal system. We directly compared the quality of the images obtained with using the two methods and the improvement of the artifacts by pulsatile vascular compression. RESULTS: The MRCP images obtained after intravenous morphine administration were better than those obtained before morphine administration for visualizing the hepatopancreatic ductal system. On direct comparison, the MRCP images obtained after morphine administration were better in 12 cases, equivocal in two cases, and the images before morphine administration were better in only one case. In three patients, MRCP before morphine injection showed signal loss at the duct across the pulsatile hepatic artery. In two of three patients, MRCP after morphine injection showed no signal loss in this ductal area. CONCLUSION: MRCP after intravenous morphine administration enables physicians to see the hepatopancreatic ductal system significantly better and the artifacts caused by pulsation of the hepatic artery can be avoided.

Choledochal Cyst Associated with Cystic Duct Dilatation: Report of Three Cases

Traditionally, it has been accepted that choledochal cysts are cystic dilatations of the extrahepatic duct. The association of this anomaly with cystic dilatations of cystic duct is extremely rare. Here in three cases of choledochal cysts with cystic duct dilatations, unusual variant of choledochal cyst are described. In all three cases, MRCP showed that the dilated cystic duct communicates with a common duct through a wide opening.

MR Imaging Findings of Clonorchiasis

OBJECTIVE: The purpose of this study was to evaluate the MR spectrum and MR cholangiographic imaging findings of clonorchiasis. MATERIALS AND METHODS: We reviewed 26 patients with confirmed clonorchiasis by either stool tests (n=24) or surgery (n=2). MR imaging was performed on a 1.5 T system (GE Medical Systems, Milwaukee, WI) with a torso coil. Axial T1-and T2-weighted, gadolinium-enhanced dynamic images and MR cholangiography were obtained. Image analyses were used to identify abnormalities of the intrahepatic and extrahepatic bile ducts and the presence of hepatobiliary malignancy. All MR examinations were reviewed by the consensus of two abdominal radiologists. RESULT: Intrahepatic bile duct abnormalities were seen in 23 (89%) of the 26 patients. The most common finding was mild dilatation of the intrahepatic bile duct which was found in 21 (81%). "Too many intrahepatic ducts" were found in 16 (62%), wall enhancement and thickening in 21 (81%) and filling defects and ductal stricture in the intrahepatic bile duct in 6 (24%) and 3 (12%) patients, respectively. Extrahepatic ductal dilation was found in 5 (19%) and 9 (35%) revealed hepatobiliary malignancy. CONCLUSION: MR imaging revealed various findings of clonorchiasis, including dilatation, wall enhancement, stricture of the intrahepatic ducts and filling defect within the intrahepatic bile duct.

Mn-DPDP Enhanced T1-weighted Magnetic Resonance Cholangiography: Usefulness in the Diagnosis and Roadmap for the Treatment of Intrahepatic Choledocholithiasis

PURPOSE: To assess the preliminary findings of Mn-enhanced T1-weighted MR cholangiography for the evaluation of intrahepatic choledocholithiasis. MATERIALS AND METHODS: Seven patients with recurrent pyogenic cholangitis underwent conventional heavily T2-weighted and manganese-enhanced T1-weighted MR cholangiography. For the former, the two reviewers focused on intrahepatic ductal dilatation, calculi, and stricture; and for the latter, ductal enhancement. RESULTS: In seven patients, 13 diseased segments were depicted and intrahepatic bile ductal dilatation was present in all 13 of these in all seven patients. Calculi were present in eight segments in six patients, and stricture in four segments in three patients. Of the 13 diseased segmental ducts, six were seen at manganese-enhanced imaging to be filled with contrast material, suggesting a functioning bile duct. CONCLUSION: Combined T2-weighted and mangafodipir trisodium-enhanced T1-weighted MR cholangiography provides both anatomic detail and functional detail of the biliary system. Combined MR cholangiography is useful for the evaluation of intrahepatic choledocholithiasis, demonstrating the stricture and function of the segmental ducts involved.

Utility of MR Cholangiography for Follow-up Examination after Metallic Stent Placement in the Bile Duct

PURPOSE: To evaluate the efficacy of MR cholangiography for follow-up examination after metallic stent placement in the bile duct. MATERIALS AND METHODS: Between December 1999 and June 2000, 15 patients with biliary obstruction in whom metallic biliary stents had been placed underwent MR cholangiography during follow-up examination. The causes of obstruction were hilar cholangiocarcinoma (n=6), common bile duct cancer (n=5), gall bladder cancer (n=1) and pancreatic cancer (n=3). The types of self-expandable metallic stent employed were the nitinol stent (n=2), the Endocoil nitinol stent (n=3), the Ultraflexed Diamond stent (n=5), and the Wallstent (n=5). Using MR cholangiography, we measured the diameter of that part of the biliary stent which showed high signal intensity, assigning one point if this was less than one third of the stent diameter, two points if between one third and two thirds, and three points if more than two thirds. We decided that a higher score indicated fewer artifacts. RESULTS: The score was 1.7-3 (mean, 2.3) points for the Endocoil nitinol stent, 1.7-2.3 (mean, 2) for the nitinot stent, and 1-3 (mean, 1.7) for the Ultraflex Diamond stant. In most cases, two thirds of the stent diameter was observed. For the Wallstent, the score was 1-1.7 (mean, 1.3) points and the inner portion of the stent was almost invisible. CONCLUSION: MR cholangiography is not useful for follow-up examination after the placement of Wallstents and three other types of nitinol stent in the bile duct.

Usefulness of Superparamagnetic Iron Oxide (SPIO) as a Negative Oral Contrast Agent in MR Cholangiopancreatography

PURPOSE: To evaluate value of superparamagnetic iron oxide (SPIO) as a negative oral contrast agent in MR cholangiopancreatography (MRCP). MATERIALS AND METHODS: Forty-eight patients with suspected biliary tract or pancreatic diseases and six healthy volunteers were enrolled in this study. All MR images were obtained using a 1.5 T MR unit. MRCP using fat-suppressed half-Fourier acquisition single-shot turbo spin echo (HASTE) and turbo spin echo (TSE) techniques were performed and reconstructed with maximal intensity projection (MIP). To determine the most optimal concentration of SPIO to obliterate the high signal intensity of water, a phantom experiment was conducted with various concentrations of SPIO-water mixture. Two radiologists evaluated pre- and postcontrast MRCPs. The contrast enhancement was assessed on the basis of loss of signal intensity in the stomach and duodenum. RESULTS: In the phantom experiment, a significant increase of percentage of signal intensity loss (PSIL) occurred in concentration of 22.4 ugFe/ml (Feridex 1 ml diluted with water 500 ml). Postcontrast MRCP showed an improved image quality compared with precontrast images. The rate of improvement in the diagnosis of diseases of the common bile duct and pancreatic duct was 25% (12/48). CONCLUSION: In patients with suspected biliary tract and pancreatic diseases, the SPIO is useful as a negative oral contrast agent for MRCP and provides an improvement of image quality.

Clinical Significance of the Special Signs of MRCP in Carcinoma of Pancreatic Head / 实用放射学杂志

Objective To research special signs of MRCP,its pathological and clinical significance in carcinoma of pancreatic head.Methods 35 patients with pancreatic head carcinoma confirmed by operation and /or pathology were examined by MR before operation,including SE sequences T_1WI,FSE sequences T_2WI,T_2WI FS and MRCP.Results The special signs of MRCP in pancreatic head cancer were showed in all cases(100%),these signs included:type C1+P1 in 31 cases,type C2+P1 in 2 cases and type C2+P2 in 2 cases.The volumes of pancreatic cancer shown by MRCP were bigger than ones in operated.Conclusion MRCP features of carcinoma of pancreatic head are special.

Evaluation of Three-dimensional Fast Recovery Fast Spin-Echo MRCP in Differentiating Benign from Malignant Causes of Biliary and Pancreatic Duct Dilatation / 实用放射学杂志

Objective To evaluate the diagnostic value of MR cholangiopancreatography(MRCP) using three-dimensional fast recovery fast spin-echo(3D FRFSE) in differentiating benign from malignant causes of biliary and pancreatic duct dilatation.Methods 106 cases suspected biliary and pancreatic duct dilatation underwent 3D FRFSE MRCP.The images were prospectively analysed by two skilled radiologists,and the results were compared with that of surgery,biopsy or follow-up.Results MRCP was successful performed at one time in all cases.On MRCP,the visual rate of intra-and extrahepatic bile duct was 100% and that of main pancreatic duct was 93.4%.80 patients had benign lesions: bile duct lithiasis(n=66),papillitis(n=6),descending part of duodenum diverticulitis(n=2),duodenal adenomatoid hyperplasia(n=1) and chronic pancreatitis(n=5).26 patients had malignant lesions: extrahepatic cholangiocarcinoma(n=9),ampullary carcinoma(n=5),gallbladder carcinoma(n=4) and pancreatic head carcinoma(n=8).The sensitivity,specificity and accuracy in differentiating benign from malignant causes of biliary dilatation were 92.3%,96.3% and 95.3%,respectively.Conclusion 3D FRFSE MRCP plays an important role in diagnosis of differentiating diagnosis of the causes of biliary dilatation in clinical practice.