A prospective evaluation of magnetic resonance cholangiopancreatography in patients with suspected bile duct obstruction

The occurrence of mutations in peripheral myelin protein 22 is one of the genetic mechanisms associated with Dejerine-Sottas neuropathy (DSN). On direct sequencing 2 of such patients we have found the first mutation in the third transmembrane domain associated with this neuropathy and the fourth Ser72Leu. We propose that the Ser72 may be a "hot spot" for DSN and that this should be considered for molecular analysis.     

Diagnostic usefulness of magnetic resonance cholangiopancreatography (MRCP) in comparison with retrograde cholangiopancreatography (ERCP) for cholelithiasis

PURPOSE: To elucidate MRCP diagnostic usefulness compared to ERCP. PATIENTS, METHODS: 29 MRCP performed patients diagnosed by ERCP were studied. RESULTS: MRCP showed 92%, 67% sensitivity and 73%, 100% specificity in choledocholithiasis (CBD) and cholecystolithiasis (GB), respectively. MRCP revealed 4.0 false positive and 1.5 false negative in CBD and GB, respectively. MRCP could detect 22 stones out of 33 in CBD and 13 out of 42 in GB. As for the maximal diameter, MRCP depicted 31% for less than 5 mm and 100% for over 6 mm in CBD. In GB, 7% for less than 5 mm, 83% for 6-10 mm and 100% for over 11 mm. CONCLUSION: Although the depection of tiny stone is limited, MRCP is a useful diagnostic tool for cholelithiasis, especially choledocholithiasis.     

Clinical significance of magnetic resonance cholangiopancreatography (MRCP) compared to endoscopic retrograde cholangiopancreatography (ERCP)

BACKGROUND AND STUDY AIMS: The clinical importance of magnetic resonance cholangiopancreatography (MRCP) as a noninvasive diagnostic modality for investigation of the biliary tree and pancreatic duct system is under debate. Using endoscopic retrograde cholangiopancreatography (ERCP) as the gold standard, this study determined in a prospective, blinded fashion the sensitivity and further statistic values of MRCP findings for evaluation of the biliary and pancreatic tract. PATIENTS AND METHODS: Seventy-eight patients referred for ERCP were studied prospectively with MRCP and ERCP during a 12-month period. All images were interpreted on a blinded basis by two radiologists. Any dilations, strictures, and intraductal abnormalities were recorded and correlated with the clinical diagnoses. RESULTS: MRCP images of diagnostic quality were obtained in 76 of the 78 patients (97%). Magnetic resonance cholangiography (MRC) showed sensitivities (and positive predictive values) of 71% (62%) for recognition of normal bile ducts, 83% (91%) for recognition of dilation, 85% (100%) for recognition of strictures, 77% (91%) for correct stricture location, and 80% (100%) for diagnosing bile duct calculi. In addition, the sensitivity of MRC in classifying benign and malignant strictures was 50% and 80%, respectively. The statistical values (sensitivity and positive predictive value) for magnetic resonance pancreatography findings were determined for the recognition of normal pancreatic ducts (33% and 50%), recognition of dilation (62% and 100%), recognition of strictures (76% and 87%) and correct location (66% and 100%), diagnosis of benign strictures (87% and 87%) and malignant strictures (60% and 75%), and for diagnosing pancreatic duct stones (60% and 100%). CONCLUSIONS: MRCP is capable of providing diagnostic information equivalent to ERCP in many patients, and should be applied whenever established techniques provide no results, or inadequate results.     

Magnetic resonance cholangiography for evaluation of cholestatic jaundice in neonates and infants

Distinguishing extrahepatic biliary atresia from other causes of cholestasis in neonates and infants is important because surgical intervention before 2 months of age allows for long-term survival. The purpose of this prospective study was to evaluate the usefulness of magnetic resonance (MR) cholangiography in differentiating biliary atresia from other causes of cholestatic jaundice in neonates and infants. Nine anicteric infants (control group) aged 10 to 224 days (mean +/- SD, 8 +/- 65 days) and 15 neonates and infants with cholestatic jaundice, aged 22 to 142 days (mean +/- SD, 71 +/- 37) underwent MR cholangiography. The final diagnosis of extrabiliary atresia (6 patients) was based on laparotomy findings (4 patients) or autopsy (2 patients), while neonatal hepatitis (9 patients) was diagnosed according to the liver biopsy findings and clinical recovery during follow-up. Percutaneous liver biopsies were performed in all 15 patients. Results showed that the gall bladder and common bile duct (CBD) could be visualized using MR cholangiography in all patients in the control group. Nonvisualization of the CBD (6/6 patients) and demonstration of a small gall bladder (6/6 patients) characterized MR cholangiography findings in patients with biliary atresia. MR cholangiography failed to depict the CBD in one infant with hepatitis. We conclude that demonstration of the CBD by MR cholangiography in neonates and infants with cholestasis can be used to exclude the diagnosis of biliary atresia. In patients with cholestatic jaundice considered for exploratory laparotomy, preoperative MR cholangiography is recommended to avoid unnecessary surgery.     

Three-dimensional contrast-enhanced magnetic resonance angiography of the thoracic vasculature

Magnetic resonance angiography (MRA) has become a useful non-invasive imaging technique for the assessment of vascular disease. Due to limitations such as respiratory motion artefacts, saturations problems, and long acquisition times, applications of MRA in the thorax have largely been restricted to imaging of the aorta. The recent introduction of breath-hold three-dimensional (3D) contrast-enhanced MRA promises not only to enhance conventional MR protocols for aortic imaging, but to extend the clinical indications of MRI to diseases affecting other vascular structures of the thorax, most notably the pulmonary arteries. This article describes the technical aspects of contrast-enhanced 3D MRA and reviews existing and potential future clinical applications.     

Use of oral superparamagnetic contrast media in cholangiopancreatography with TSE single-shot magnetic resonance

It is well known that the cellular concentration of alpha-tocopherol (alpha-toc) is about 10-fold greater than that of gamma-tocopherol (gamma-toc) despite the ingestion of a large amount of gamma-toc in the diet. Recently, this discrimination of tocopherol is considered to be attributed to alpha-tocopherol transfer protein (alpha-TTP) which binds to alpha-toc in preference to the other forms of tocopherol in the liver. In the present study, developmental changes in expression of alpha-TTP after birth were investigated using rats with respect to plasma changes of tocopherols. The expression of alpha-TTP in the neonatal rat liver, which was very low immediately after birth, increased steadily during the two weeks of life before weanling and reached the adult level at four weeks. During the suckling period, the plasma ratio of alpha-toc to gamma-toc linearly increased, because plasma alpha-toc which was low immediately after birth, increased rapidly during the period, while gamma-toc remained unchanged. The increase in the ratio seemed to correlate with the developmental expression of alpha-TTP in the liver during this period.     

Three-dimensional display of cardiac structures using reconstructed magnetic resonance imaging

It is sometimes difficult to understand the three-dimensional (3D) relationship of cardiac and mediastinal structures despite advances in magnetic resonance (MR) imaging techniques. We present a low-cost system for 3D reconstruction of the major mediastinal structures by processing the MR imaging data on a NeXT workstation. MR images of multisection, multiphase, spin-echo techniques stored in a picture archiving and communication system (PACS) data base were used for the reconstruction. The computer program obtained the contours of the multiple components of the mediastinal structures by the combination of automatic and manual procedure. The bundled software of a 3D kit was used for surface rendering of hidden surface removal, shading of the visible parts of the surfaces, perspective transformation, and motion parallax by rotation of the surfaces. 3D reconstruction was performed in 15 patients with cardiac diseases, and the 3D-reconstructed images were compared with the plain chest x rays of the patients. The 3D presentation clearly showed the complex anatomy of cardiovascular diseases and helped elucidate the misconceptions in the interpretation of the plain chest x rays. Our 3D images are used for education and should be viewed by medical students and beginners in radiology at an individual pace with plain chest radiographs, MR images, and legends. Although applied to the heart and the great vessels in this report, this system is also applicable to other structures.     

Surgical treatment of obstructive jaundice

Genetically engineered structural variants of human beta2-microglobulin (beta2m) were produced by sequence exchange with mouse beta2m for the purpose of examining species-specific antigenic determinant expression. For aggregate mapping, mouse and human beta2m, which differ by 30% in their primary sequence of 99 amino acids, were prepared as chimeric (human X mouse) molecules and expressed in the FO-1 beta2m-null human melanoma cell line. A chimera containing residues 1-69 from human beta2m (and residues 70-99 from mouse beta2m) induced expression of the epitopes defined by the anti-beta2m monoclonal antibodies (mAb) BBM.1, NAMB-1, and L368; the reverse chimera did not, although HLA class I heavy chain was evident on the cell surface as determined with the TP25.99 mAb. For fine dissection of the epitopes defined by these mAbs, site-directed mutants of beta2m were prepared by replacement of individual amino acids in human beta2m with the dimorphic residue from mouse beta2m. Substitutions were made at each divergent residue between positions 1 and 66 and, as controls for COOH-terminal modification, a series of residues between positions 75 and 94. Replacement of amino acids 38, 44, and 45, but not 16 other dimorphic residues in the linear stretch from residue 1 to residue 66, resulted in the loss of, or gross reduction in, binding by mAbs BBM.1 and NAMB-1. A reduction in binding was also observed for mAb L368. These data provide strong evidence that the antigenic epitopes defined by these mAb map to a region including S3 and its adjacent intra-beta-strand turn of the three-stranded beta-pleated sheet of beta2m. The mapping of these epitopes is consistent with their accessibility in the assembled major histocompatibility complex class I molecule and indicates that the region from amino acid 38 to 45 is an important structural feature in the "foreignness" of human and mouse beta2m.     

Sarcoidosis presenting as obstructive jaundice

Sarcoidosis is an uncommon disorder characterized by a multi-systemic granulomatous disease of undetermined etiology and pathogenesis. The diagnosis is established by the presence of a compatible clinical illness and by histologic demonstration of noncaseating epithelioid cell granulomas in the affected organs. Accurate diagnosis requires a thorough evaluation to exclude infectious and neoplastic diseases that can mimic sarcoidosis. Although all organs and systems can be affected, the lungs and intrathoracic lymph glands are the most common sites of involvement. We describe an unusual case of extrapulmonary sarcoidosis presenting as obstructive jaundice.     

Magnetic resonance cholangiopancreatography: a novel approach to the evaluation of suspected pancreaticobiliary neoplasms

BACKGROUND: Magnetic resonance cholangiopancreatography (MRCP) is a new noninvasive diagnostic method for pancreaticobiliary (PB) imaging without endoscopy, sedation, or iodinated contrast. The purpose of this study was to evaluate the ability of MRCP to depict pancreatic and biliary ductal anatomy compared to that of endoscopic retrograde cholangiopancreatography (ERCP) and to evaluate the ability of MRCP to accurately diagnose PB neoplasms. METHODS: Twenty patients had MRCP, and 17 also had ERCP. All studies were read prospectively by experienced reviewers blinded to other imaging data. Pathologic diagnosis was made in all patients. RESULTS: Bile duct dilatation seen by ERCP in 14 of 17 patients was correctly identified by MRCP in all 14 patients, and normal ducts were correctly identified by MRCP in the other 3 patients. The pancreatic duct was visible on MRCP in the pancreatic head in 17 of 20 patients, the body in 17 of 20 patients, and the tail in 15 of 20 patients. At ERCP, pancreatic duct dilatation was present in 11 cases and was identified by MRCP in 10 of them. Eighteen of 20 patients had malignant PB neoplasms. MRCP indicated PB neoplasm in 19 patients. Seventeen of these 19 patients had histologically confirmed malignant neoplasms pathologically, whereas 2 had benign pathology (both chronic pancreatitis). Among the 17 patients who also had ERCP, MRCP and ERCP correctly agreed on a final diagnosis of malignant neoplasm in 14 cases. In the three cases in which MRCP and ERCP disagreed on a final diagnosis, MRCP was correct in one and incorrect in two. CONCLUSIONS: MRCP can accurately and noninvasively delineate PB ductal anatomy and diagnose PB neoplasms comparably to ERCP. MRCP is an interesting new noninvasive method for evaluating patients with suspected PB neoplasms.     

Demonstration of microcystic disease of the pancreas by magnetic resonance cholangiopancreatography: report of a case

A case of microcystic disease of the pancreas which was clearly demonstrated by magnetic resonance cholangiopancreatography (MRCP) is reported herein. Cystic dilatation of the pancreatic duct was recognized by computed tomography scanning and endoscopic retrograde cholangiopancreatography (ERCP). Furthermore, the existence of microcystic clusters surrounding the dilated pancreatic duct were clearly visualized by MRCP. These microcystic clusters were strongly suspected preoperatively of having caused dilatation of the major pancreatic duct. Based on these findings, a distal pancreatectomy was performed. The operative specimen showed no accumulation of mucin and no evident lesions in the dilated pancreatic duct, being inconsistent with the entity of a mucus-producing tumor. Pathological examination revealed that the inner parts of microcysts constituted columnar epithelium with mucus production and papillary growth. Thus, a final histological diagnosis of intraductal papillary adenoma with idiopathic pancreatic duct ectasia was confirmed. In conclusion, MRCP, being a less aggressive diagnostic procedure than ERCP, proved extremely useful for obtaining precise information on cystic lesions of the pancreas in this patient.     

Three-dimensional tracking of axonal projections in the brain by magnetic resonance imaging

The relationship between brain structure and complex behavior is governed by large-scale neurocognitive networks. The availability of a noninvasive technique that can visualize the neuronal projections connecting the functional centers should therefore provide new keys to the understanding of brain function. By using high-resolution three-dimensional diffusion magnetic resonance imaging and a newly designed tracking approach, we show that neuronal pathways in the rat brain can be probed in situ. The results are validated through comparison with known anatomical locations of such fibers.     

Functional and metabolic evaluation of the athlete's heart by magnetic resonance imaging and dobutamine stress magnetic resonance spectroscopy

BACKGROUND: The question of whether training-induced left ventricular hypertrophy in athletes is a physiological rather than a pathophysiological phenomenon remains unresolved. The purpose of the present study was to detect any abnormalities in cardiac function in hypertrophic hearts of elite cyclists and to examine the response of myocardial high-energy phosphate metabolism to high workloads induced by atropine-dobutamine stress. METHODS AND RESULTS: We studied 21 elite cyclists and 12 healthy control subjects. Left ventricular mass, volume, and function were determined by cine MRI. Myocardial high-energy phosphates were examined by 31P magnetic resonance spectroscopy. There were no significant differences between cyclists and control subjects for left ventricular ejection fraction (59+/-5% versus 61+/-4%), left ventricular cardiac index (3.4+/-0.4 versus 3.4+/-0.4 L x min(-1) x m[-2]), peak early filling rate (562+/-93 versus 535+/-81 mL/s), peak atrial filling rate (315+/-93 versus 333+/-65 mL/s), ratio of early and atrial filling volumes (3.0+/-1.0 versus 2.6+/-0.6), mean acceleration gradient of early filling (5.2+/-1.4 versus 5.8+/-1.9 L/s2), mean deceleration gradient of early filling(-3.1 +/- 0.9 versus -3.2 +/- 0.7 L/s2), mean acceleration gradient of atrial filling (3.6+/-1.8 versus 4.5+/-1.7 L/s2), and atrial filling fraction (0.23+/-0.06 versus 0.26+/-0.04, respectively). Cyclists and control subjects showed similar decreases in the ratio of myocardial phosphocreatine to ATP measured with 31P magnetic resonance spectroscopy during atropine-dobutamine stress (1.41+/-0.20 versus 1.41+/-0.18 at rest to 1.21+/-0.20 versus 1.16+/-0.13 during stress, both P=NS). CONCLUSIONS: Left ventricular hypertrophy in cyclists is not associated with significant abnormalities of cardiac function or metabolism as assessed by MRI and spectroscopy. These observations suggest that training-induced left ventricular hypertrophy in cyclists is predominantly a physiological phenomenon.     

Saline magnetic resonance arthrography in the evaluation of glenohumeral instability

Sixty-five patients underwent magnetic resonance (MR) shoulder arthrography. Forty-eight of these patients underwent examination under anesthesia (EUA). MR images were retrospectively evaluated for signs felt to be imaging indicators of shoulder instability, including evaluation of various capsular measurements and the presence of glenoid labral tears, as well as Hill-Sachs fractures. Statistical analysis of the results showed that no correlation between capsular indicators with EUA-documented instability was found. However, there was a statistically significant correlation between the presence of a Bankart cartilaginous deformity (p = 0.000) and Hill-Sachs fractures (p = 0.022) with EUA-documented instability. Sensitivity to labral tears was 89% and specificity was 98%, whereas Hill-Sachs fracture detection was 69% and 87%, respectively. We believe that MR saline arthrography is of benefit in the evaluation of the anterior labrum when unenhanced MR imaging is inconclusive, and we speculate on the role of MR arthrography as a primary investigative tool.     

Current therapy of obstructive jaundice due to cholelithiasis

On recent development of apparatus and techniques of ultrasonography and endoscopy we prefer to try the following procedures for removing jaundice instead of surgical operation: 1) Percutaneous Transhepatic Biliary Drainage (PTBD) 2) Endoscopic Retrograde Biliary Drainage (ERBD) 3) Endoscopic Naso-Biliary Drainage (ENBD) 4) Endoscopic Sphincterotomy (EST). After removing the jaundice and inflammation of bile duct, we try following procedures for elimination of gallstone: 1) endoscopic mechanical lithotripter (EML) 2) (Extracorporeal shock wave lithotripsy (ESWL) And we have got the excellent results.     

A case of biliary cystadenoma with obstructive jaundice

Biliary cystadenoma is a rare cause of obstructive jaundice. We report a case of a 78-year-old Japanese man with biliary cystadenoma presenting repetitive abdominal pain and jaundice. Ultrasound sonography revealed a hyperechoic mass in the left lateral lobe of the liver. Histological examination revealed a biliary cystadenoma. Intracystic hemorrhage was assumed to be the cause of obstruction of the bile ducts.