Congenital anomalies of the pancreaticobiliary tract: findings on MR cholangiopancreatography (MRCP) using half-Fourier-acquisition single-shot turbo spin-echo sequence (HASTE).

The clinical significance of magnetic resonance cholangiopancreatography (MRCP) using half-Fourier acquisition single-shot turbo spin-echo (HASTE) in the evaluation of congenital anomalies of pancreaticobiliary tract was demonstrated in 56 patients (man: 31, women: 25; age: 0-60 years old, mean 15 years old) with suspected congenital anomalies of pancreaticobiliary tract. The image quality and characteristics were assessed. MRCP using HASTE with a phased array coil can be used as a non-invasive method for the evaluation of congenital anomalies of the pancreaticobiliary tracts.

[Clinical application of endoscopic ultrasonography (EUS) for gastrointestinal diseases].

Endoscopic mucosal resection (EMR) has been widely employed as a minimally invasive surgical procedure for early digestive cancers. Moreover, many recent reports emphasize the usefulness of endoscopic ultrasonography (EUS) for diagnosis of early gastrointestinal cancers. Generally, the normal gastrointestinal wall is visualized as having five layers by endosonographic probes of 7.5, 12, or 20 MHz. Delineation of these layers is the most important point for feature of EUS. Only mucosal cancers that are disclosed as hypoechoic masses within the first to second layer are indicated for EMR. The development of further extracorporeal applications such as color Doppler, 3-D, and aspiration biopsy EUS will contribute to the increased use of EUS in the near future.

Intraductal papillary tumors of the pancreas. Histopathologic correlation of MR cholangiopancreatography findings.

PURPOSE: To evaluate MR cholangiopancreatography (MRCP) findings of intraductal papillary tumors of the pancreas and correlate them with histopathology. MATERIAL AND METHODS: Seventeen patients with intraductal papillary tumor of the pancreas underwent MRCP before surgery. MRCP findings were correlated to histopathology with regard to the presence of septa and excrescent nodules in the cystic lesion, communication between the cystic lesion and the main pancreatic duct (MPD), degree of dilatation of MPD, and dilatation of the common bile duct (CBD). RESULTS: MRCP demonstrated septa in 17 cases (100%), excrescent nodules in 8 cases (47.1%), communication between the intraductal papillary tumor and the MPD in 14 cases (82.3%), dilatation of MPD over 50% in 6 cases (35.3%), and dilatation of CBD in 3 cases (17.6%). These findings showed excellent correlation with histopathology. The septum on MRCP corresponded with a layer of connective tissue with pancreatic duct epithelium. Excrescent nodules in the carcinomas consisted not only of malignant cells, but also of dysplasia and adenoma. Excrescent nodules in adenomas were consistent not only with minimal papillary growth of adenoma, but also with proliferation of fibrosis, and hematoma and organized fibrin with minimal fibrosis. Pancreatic tissue was affected by chronic pancreatitis in all cases. Cases with dilatation of CBD on MRCP were due to microscopic invasion by the carcinoma. CONCLUSION: MRCP appearances of intraductal papillary tumors are well correlated with the findings at histopathology.

Renal cell carcinomas in von Hippel-Lindau disease; tumor detection and management.

Twenty-seven renal cell carcinomas (RCCs) found in one family affected with von Hippel-Lindau disease were examined using ultrasound (US), CT, MRI and angiography. The sensitivity of the tumor detection using different imaging modalities was evaluated by macroscopic pathology (solid or cystic) and size (exceeding 2cm in diameter or not). In 18 of the RCC's exceeding 2cm in diameter (eight solid and ten cystic), all lesions were detected on US, CT, and MRI. However, on angiography, solid RCCs were detected in 88%, and cystic RCCs were detected in 60%. In nine RCCs less than 2cm in diameter (seven solid and two cystic), solid RCCs were detected in 86% on US, 86% on CT, 80% on MRI, and 43% on angiography, but cystic RCCs were detected in 50% on only CT and MRI. From the pathologic correlation, even renal simple cystic lesions in VHL are considered premalignant lesions and they had better be removed if the residual renal function after surgery is preserved. In case of the observation, they should be followed carefully using thin slice thickness dynamic CT to discover the wall irregularity, septation and irregular contour.

Delineation of simulated vascular stenosis with Gd-DTPA-enhanced 3D gradient echo MR angiography: an experimental study.

PURPOSE: The purpose of this experimental study was to evaluate the influence of contrast material concentration and flow velocity on pulsatile flow in Gd-DTPA-enhanced 3D gradient echo MR angiographic sequence. METHOD: In vivo flow experiments were performed in Plexiglas phantoms with artificial stenosis (50% stenotic ratio and 20 mm stenotic length) attached to a cardiac pump that generated physiological pulsatile flow similar to that of the bloodstream in a closed circuit. We used a steady-state gradient echo sequence with different TEs (6, 3, and 1.4 ms). A TR of 15 ms was used for all parameters. The concentration of Gd-DTPA varied from 0 to 2.0 mmol/L and flow velocities from 25 to 80 cm/s. We measured the degree of stenosis and length of stenosis in comparison with the actual values. RESULTS: The degree and length of stenosis on 3D gradient echo MR angiographic images were markedly influenced by the velocity of the flow and concentration of Gd-DTPA. The degree of stenosis was overestimated when the flow was fast or when the concentration of Gd-DTPA was low. When the concentration of Gd-DTPA was low, stenosis was elongated. These effects were less prominent on short TE (1.4 ms) sequence. CONCLUSION: The stenotic lesions were markedly overestimated on MR angiographic images obtained with Gd-DTPA-enhanced fast 3D gradient echo sequence. Spin dephasing can be compensated for almost entirely by a high concentration of Gd-DTPA and/or a short TE sequence.

Local extension of pancreatic carcinoma: assessment with thin-section helical CT versus with breath-hold fast MR imaging--ROC analysis.

PURPOSE: To compare contrast material-enhanced thin-section helical CT with breath-hold contrast-enhanced MR imaging for sensitivity in the detection of pancreatic adenocarcinoma and for accuracy in local tumor staging. MATERIALS AND METHODS: Fifty-seven patients (37 men, 20 women aged 42-28 years) suspected of having pancreatic adenocarcinoma were examined. The final diagnosis was confirmed at surgery to be pancreatic cancer in 31 patients; the other 26 patients were deemed not to have pancreatic cancer. All patients underwent both CT and MR imaging (turbo spin-echo and fast low-angle shot) studies. Image quality and pancreatic enhancement were subjectively evaluated. All CT scans and MR images were assessed by two independent observers by using a five-point scale for the detection of tumor and of invasion into the peripancreatic tissue, portal vein, and/or peripancreatic artery. Receiver operating characteristic curves for CT and MR imaging were analyzed. RESULTS: At visual analysis, pancreatic enhancement at CT and at MR imaging was comparable, but depiction of vessels was superior at helical CT. Detectability of tumor was comparable. Helical CT was significantly superior to MR imaging in diagnostic imaging of invasion into the peripancreatic tissue, portal vein, and/or peripancreatic artery (P < .01). CONCLUSION: Thin-section dynamic CT is more sensitive than MR imaging for detection of peripancreatic and vascular invasion in patients with pancreatic cancer.

The effects of transjugular intrahepatic portosystemic shunt on portal hypertensive gastropathy.

In addition to variceal bleeding, haematemesis may occur due to haemorrhagic gastritis in patients with portal hypertension. This has been known as portal hypertensive gastropathy (PHG). We have evaluated the effects of the transjugular intrahepatic portosystemic shunt (TIPS) on portal venous pressure (PVP) and endoscopic gastric mucosal changes observed in patients with portal hypertension. We performed TIPS in 12 patients with complications due to portal hypertension as follows: variceal bleeding in nine patients (bleeding from oesophageal varices in seven and gastric varices in two), refractory ascites in three and haemorrhage from severe PHG in one. Endoscopic examinations were performed before and after TIPS for all patients. Changes of PVP and gastric mucosal findings on endoscopy were analysed. Before TIPS, PHG was seen in 10 patients. Portal venous pressure decreased from an average of 25.1+/-8.8 to 17.1+/-6.2 mmHg after TIPS (P<0.005). On endoscopy, PHG improved in nine of 10 patients. Oesophagogastric varices improved in eight of 11 patients. In one patient with massive haematemesis, haemorrhage from severe PHG completely stopped after TIPS. Because TIPS effectively reduced PVP, this procedure appeared to be effective for the treatment of uncontrollable PHG.

Unusual gastric polyp showing submucosal proliferation of glands: case report and literature review.

We report an unusual pedunculated polyp in the stomach in a 41-year-old woman. She was hospitalized because of epigastric discomfort. Endoscopy revealed a polyp with a long stalk in the fundus of the stomach. The polypectomyzed polyp measured 23 x 18 x 9 mm and was characterized by submucosal proliferation of glands and cystic dilatation. The surface of the polyp was covered with gastric mucosa of fundic or pyloric gland type. The glandular structures consisted of various types of lining cells, including pyloric or mucous-neck cell type, surface mucous (foveolar) cell type, parietal-like cells, and somatostatin-positive cells. The submucosal glandular or cystic elements were connected with the overlying gastric mucosa through a defect of the muscularis mucosa, suggesting that this polyp may have been formed by the heterotopic inverted downgrowth of mucous glands into the submucosa. We discuss the histogenesis of this rare polyp and present a review of the literature.

Mucin-producing tumor of the pancreas: diagnostic value of diffusion-weighted echo-planar MR imaging.

PURPOSE: To determine whether diffusion-weighted echo-planar magnetic resonance (MR) imaging can help differentiate mucin-producing tumors of the pancreas from other cystic lesions. MATERIALS AND METHODS: Diffusion-weighted echo-planar 1.5-T MR imaging was performed in patients with mucin-producing tumor (n = 15), pseudocyst (n = 15), or serous microcystic tumor (n = 2). Images were obtained with diffusion-sensitizing gradients of 30 and 300 sec/mm2. The apparent diffusion coefficient (ADC) was calculated. RESULTS: At 30 sec/mm2, all cystic lesions had very high signal intensity. The dilated main pancreatic duct was depicted in eight patients with mucin-producing tumor and in six with pseudocyst. The mean (+/- standard deviation) ADCs of mucin-producing tumors (2.7 x 10(-3) mm2/sec +/- 0.9 x 10(-3)) and pseudocysts (3.2 x 10(-3) mm2/sec +/- 1.0 x 10(-3) were significantly lower (P < .01) than those of serous cysts or cerebrospinal fluid (5.8 x 10(-3) mm2/sec +/- 2.0 x 10(-3)). At 300 sec/mm2, cysts and the main pancreatic ducts had high signal intensity in cases of mucin-producing tumor, indicative of the presence of mucinous products in both the cystic cavity and the main pancreatic duct. The signal intensity of cystic fluid in pseudocysts was high on diffusion-weighted images, but that of the pancreatic duct was decreased (ADC = 5.1 x 10(-3) mm2/sec +/- 1.7 x 10(-3)). CONCLUSION: Diffusion-weighted MR imaging can help characterize cystic lesions of the pancreas. Findings-suggestive of viscous fluid in mucin-producing tumors are present on such images.

Single-shot MR cholangiopancreatography of neonates, infants, and young children.

OBJECTIVE: This study was undertaken to assess the usefulness of MR cholangiopancreatography (MRCP) with a half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence as a noninvasive imaging technique to evaluate biliary or pancreatic disease in young children. SUBJECTS AND METHODS: We prospectively examined 45 children (mean age, 3 years) with MRCP using HASTE on a 1.5-T MR imaging unit. MRCP images were obtained in 1.4 sec without breath-hold. A body phased array coil and fat saturation technique were used for data collection. On the basis of the surgical (n = 19) and ERCP (n = 7) findings, clinical data, and follow-up observation, 21 children were deemed to have no significant abnormality. The other 24 children were found to have pancreaticobiliary disease, including congenital biliary atresia in five neonates, choledochal cyst in six infants, and anomalous connections between the bile and pancreatic ducts in four infants and nine young children. In children without abnormality, the MRCP images were graded for the depiction of normal structures. The findings obtained by MRCP were correlated with the surgical or ERCP results. RESULTS: HASTE MRCP showed the first branch of the intrahepatic duct, the common hepatic duct, the gallbladder, and the common bile duct in most children. In the 21 children with no abnormalities, the main pancreatic duct was visible in two of six neonates, in four of five infants, and in all 10 young children. The diagnostic accuracy of MRCP was 100% in patients with choledochal cysts, 100% in those with congenital biliary atresia, and 69% in those with anomalous connections between the bile and pancreatic ducts. CONCLUSION: MRCP using HASTE with a phased array coil is a noninvasive technique for revealing the pancreaticobiliary tract in young children.

Small cell carcinoma of the stomach: a case report.

A case of a gastric small cell carcinoma discovered incidentally by screening ultrasonography is presented. Ultrasonography demonstrated a subcardial metastatic lymph node and multiple hepatic metastatic lesions. Upper GI series and gastroendoscopy revealed a large ulcerated tumor in the cardia of the stomach, and a Borrmann type II tumor, 4 x 2.5 cm, was found in the resected stomach. We describe the radiological findings of the upper GI series, ultrasonography, CT, and gastroendoscopy, and review the literature.

Transjugular intrahepatic portosystemic shunt: initial clinical experience and three-year follow-up.

To define the role of transjugular intrahepatic portosystemic shunt (TIPS), we prospectively studied 12 patients undergoing this procedure for variceal bleeding, refractory ascites, and hemorrhagic gastropathy due to portal hypertension. The TIPS creation was successful in 11 patients, and portal pressure immediately decreased an average of 8.3 cm H2O. Esophageal varices improved in six of seven patients, but gastric varices with spleno- or gastro-renal shunt did not change in three of four patients. A hemorrhage from portal hypertensive gastropathy was controlled immediately. Ascites improved in all six patients. Hepatic encephalopathy newly developed in four patients, but was controllable with medical treatment. During the follow-up period (mean, 25 months), shunt dysfunction was evident in eight of 10 patients. Stenosis and occlusion of the shunt were successfully treated by redilatation and/or placement of an additional stent. The cumulative survival rate was 73% at one year and 64% at two years. These results suggest that TIPS is a safe and effective treatment for uncontrollable complications due to portal hypertension, but is not effective for gastric varices with spleno- or gastro-renal shunt. Careful follow-up and shunt revision are necessary for the maintenance of shunt patency.

MR cholangiopancreatography using HASTE (half-Fourier acquisition single-shot turbo spin-echo) sequences.

OBJECTIVE: Images of breath-hold MR cholangiopancreatography (MRCP) using HASTE (half-Fourier acquisition single-shot turbo spin-echo) sequences were taken in healthy volunteers. The technique was then evaluated as a noninvasive alternative to direct cholangiopancreatography in patients with pancreaticobiliary diseases. SUBJECTS AND METHODS: Forty healthy volunteers and 56 patients with various pancreaticobiliary diseases were examined by MRCP using HASTE with 128 echo train lengths on a 1.5-T MR unit. A body phased-array coll was used for data collection. Imaging times were 2 sec for the single-slice technique with a 20-mm slice thickness and 18 sec for sequential acquisition by the multislice technique with a 5-mm slice thickness (effective TE, 87 msec). We used the healthy volunteers to determine our ability to detect normal structures. The results obtained by HASTE for both patient groups were correlated with imaging by percutaneous transhepatic cholangiography or endoscopic retrograde cholangiopancreatography. RESULTS: In all healthy volunteers, HASTE-MRCP showed both the common bile duct and the main pancreatic duct. Cystic ducts were visualized in 88% of these volunteers by HASTE-MRCP, and branches of pancreatic ducts were visualized in 75% by HASTE-MRCP. The diameter and length of dilated or stenotic ducts seen on HASTE-MRCP were correlated with percutaneous transhepatic cholangiography or endoscopic retrograde cholangiopancreatography images in 56 diseased patients. Not only the position of stenosis or dilatation but also the distal portion of the stenosis was visualized by HASTE-MRCP. CONCLUSION: Breath-hold HASTE-MRCP with a phased-array multicoil consistently allows for high-quality images of both normal and diseased pancreaticobiliary tracts. This technique can be used as a noninvasive screening method for pancreaticobiliary diseases in the majority of patients.

Clinical evaluation of gastric fundic gland polyps without familial polyposis coli.

BACKGROUND: Assessments were made of 63 cases of fundic gland polyposis (FGP) unassociated with adenomatosis coli. These cases were evaluated by radiological examination over 2 years follow-up. All polyps were pathologically confirmed by endoscopic biopsies. METHODS: Most cases were asymptomatic when diagnosed during mass radiological surveys of the upper gastrointestinal tract. The majority of patients ranged in age from 40-60 years, and the polyps numbered fewer than 20 in 55 cases (87.3%). Polyps were detected in the fundic glands using the congo red test and by biopsies. RESULTS: All serum gastrin values were within the normal range. During the course of this study, the polyps of 13 cases (20.6%) increased and those of three cases (4.8%) decreased or resolved completely. CONCLUSION: From these findings it is considered that FGP are observed in stomachs with less atrophy, and that polyps follow courses in which they increase, decrease, disappear, along with atrophy.

Real-time high resolution ultrasonography of solid breast masses: use of a 10-MHz mechanical sector transducer with a water bag.

We evaluated the diagnostic accuracy of real-time high-resolution ultrasonography (RHUS) for solid breast masses, using a 10-MHz mechanical sector transducer with a water bag. A total of 103 breast nodules in 100 women were analyzed. The nodules consisted of 42 carcinomas, 10 fibroadenomas, 38 mastopathies, and 13 miscellaneous lesions. Of them, 72.8% were less than 2 cm in size. Diagnostic accuracy was correlated with the size and pathology of the nodules. Sensitivity, specificity, and accuracy were 95.2%, 83.6%, and 88.3% for carcinomas, 90.0%, 88.2%, and 88.3% for fibroadenomas, and 50.0%, 98.5%, and 80.6% for mastopathies, respectively. The overall rate of diagnostic accuracy was 74.8%. The rate of accuracy according to mass size were 87.3% (-1 cm), 87.2% (1-2 cm), 88.0% (2-5 cm) and 100% (5 cm-). False positive cases (n = 10) included seven mastopathies, two granulomas, and one fibroadenoma. False negative cases (n = 2) included one fibroadenoma and one abscess. RHUS, using a 10-MHz mechanical sector transducer, was an excellent method for the diagnosis of solid breast masses.

Development of a 2,048 x 2,048-pixel image intensifier-TV digital radiography system. Basic imaging properties and clinical application.

RATIONALE AND OBJECTIVES: A 2,048 x 2,048-pixel matrix image intensifier (II)-TV digital radiography system has been developed. Potential clinical applications of this new II-TV system were investigated. METHODS: Basic imaging properties were assessed with clinical applications to gastrointestinal (GI) tract and chest examinations. RESULTS: Basic imaging properties showed improvement of modulation transfer functions (MTFs) from the 1,024 x 1,024- to the 2,048 x 2,048-pixel matrix and approximated the screen-film system at low spatial frequencies. Receiver operating characteristic (ROC) curves of simulated linear shadows improved similarly. Clinical applications showed that the image quality of the 2,048 x 2,048-pixel matrix was comparable with that of the screen-film system for upper GI and chest radiography, but the image quality of the screen-film system was better for the lower GI tract. CONCLUSIONS: The authors' II-TV digital radiography system is clinically applicable to gastrointestinal and chest examinations.

Gastrointestinal examinations with digital radiography.

Basic imaging properties and clinical usefulness of an upgraded digital radiography system were evaluated. The system, which has 1,024 x 1,024 and 2,048 x 2,048 matrices, was upgraded with smaller focal spots (0.3 and 0.8 mm) and reduced thickness of the photoconductive layer of the video camera. Screen-film and digital images (with and without postprocessing) of the upper and lower gastrointestinal (GI) tract were used in the clinical evaluation. Overall modulation transfer functions of the upgraded digital system were comparable to those of the screen-film system, especially at the lower spatial frequency. Threshold contrasts of the two systems were similar despite a 50% reduction in incident exposure for the digital system. For the upper GI tract, digital images processed with unsharp masking techniques were comparable in quality to screen-film images before and after upgrade of the system. For the lower GI tract, screen-film images were better than digital images, except for those produced with a 2,048 x 2,048 matrix with unsharp masking. Further evaluation of the system for examination of other parts of the body seems warranted.

Differential diagnosis of gastric adenoma and type IIa early gastric cancer.

The endoscopic and radiographic findings of 45 gastric adenomas in 39 patients were followed for 6 months to 13 years and compared with type IIa early gastric cancer observed in 9 patients. Difficulties in the differential diagnosis of these disorders were evaluated. The following features were suggestive of gastric adenomas: clustered lesion; protuberance with gentle slope; smooth surface; and relatively young patients. Discrimination of adenoma from type IIa early gastric cancer is often difficult by visual observation alone; biopsy was essential in most patients. A group III adenoma verified on biopsy should be followed closely because the lesion may harbor a cancer (so-called carcinoma-in-adenoma) or a cancer may later develop.

[Pathogenesis and prevention of gastrointestinal complications following transcatheter arterial embolization].

Prospective evaluation of gastrointestinal complications after transcatheter arterial embolization (TAE) was performed on 149 TAEs of 133 patients with endoscopy in order to evaluate whether the use of antiulcer medication can prevent such complications. In 21 of 141 TAEs (14%) there developed gastrointestinal complications. The incidence of complications with administration of H2-blocker was 30.4%, whereas the incidence with administration of PGE1 and without medication were 2.8% (p less than 0.01) and 9.0%, respectively. It has been suggested that such complications are mainly due to backflow of the embolic materials to the gastric artery. These findings indicates that decrease of gastric mucosal blood flow due to backflow of the embolic materials to the gastric artery cause the gastrointestinal complications.

Radiological findings of vanishing tumor of the stomach.

Four lesions in three patients with so-called vanishing tumor of the stomach are described. Two patients had one lesion each and the third patient two lesions. The lesions were localized in the gastric cardia, angle, and antrum. Radiological findings of these tumors showed a round tumor with smooth surface and regular margins. The edges of the tumors were gently sloping, while the mucosa surrounding the tumor was edematous. The time interval until these tumors disappeared was five days, 20 months, 12 months and seven months, respectively. When the soft appearance of a gastric tumor is suspected in UGI examination, the patient should be re-examined after a month or more, to avoid unnecessary surgery.