OBJECTIVE: To evaluate the usefulness of MR imaging for diseases of the small intestine, emphasizing a comparison with CT. MATERIALS AND METHODS: Thirty-four patients who underwent both CT and MR imaging using FLASH 2D and HASTE sequences were analyzed. All patients had various small bowel diseases with variable association of peritoneal lesions. We compared the detectabilities of CT and MR imaging using different MR pulse sequences. The capability for analyzing the characteristics of small intestinal disease was also compared. RESULTS: MR imaging was nearly equal to CT for detecting intraluminal or peritoneal masses, lesions in the bowel and mesentery, and small bowel obstruction, but was definitely inferior for detecting omental lesions. The most successful MR imaging sequence was HASTE for demonstrating bowel wall thickening, coronal FLASH 2D for mesenteric lesions, and axial FLASH 2D for omental lesions. MR imaging yielded greater information than CT in six of 12 inflammatory bowel diseases, while it was equal to CT in six of seven neoplasms and inferior in five of seven mesenteric ischemia. In determining the primary causes of 15 intestinal obstructions, MR imaging was correct in 11 (73%) and CT in nine (60%) patients. CONCLUSION: MR imaging can serve as an alternative diagnostic tool for patients with suspected inflammatory bowel disease, small intestinal neoplasm or obstruction. is a high-speed, heavily T2-weighted sequence with a great sensitivity for fluid (11). This advance may make it possible to use breath-hold turbo spin-echo MR.
Comparative Study ; Female ; Human ; Inflammatory Bowel Diseases/*diagnosis ; Intestinal Neoplasms/*diagnosis ; Intestinal Obstruction/*diagnosis ; Intestine, Small/*pathology ; *Magnetic Resonance Imaging ; Male ; Middle Age ; *Tomography, X-Ray Computed

There is still no effective treatment for retinal degenerative diseases, in which the loss of photoreceptor cells causes visual loss and eventually blindness. Despite the current studies show that intraocular injection of basic fibrobalst growth factor rescues damaged and dystrophic rat photoreceptor in transgenic animal, there is a few evidence that endogenous neurotrophic factor promotes photorecptor cell survival in retina. In the present study, retinal degeneration (rd)neonate mice were exposed to hyperoixa for 5 days, and then were returned to room air, which was presumed to cause relative hypoxia of nonperfused retina, producing a neovascular response. Using this model, we investigated the effect of relative hypoxia on degenerative process in rd mice. As a control, rd neonate mice were remained at room air from birth. At the postnatal 10, 12, 14, 16, 18 and 21 days, the ratio of total retinal thickness and outer nuclear layer (ONL)thickness, and neovascularization of experimental right eyes were compared with those of control. Extent of vascularization of experimental left eyes was compared with that of left eyes in control group. In rd mice, extraretinal neovascularization was observed in 62%of 93 eyes of the experimental group exposed to hyperoxia. Extent of vascularization in experimental group was smaller than that of in control. There was an oxygen-induced modulation of rates of death in experimental group, where-as the death of photoreceptor progressed in control group. In experimental group, the ratio of total retinal thickness and ONL thickness was higher than that of in control group at 18 and 21 days of age. These results suggest that the relative hypoxia in the rd mice may have rescue effect on photoreceptor in rd mice.
Animals ; Animals, Genetically Modified ; Anoxia ; Blindness ; Cell Survival ; Humans ; Hyperoxia ; Infant, Newborn ; Injections, Intraocular ; Mice* ; Oxygen* ; Parturition ; Photoreceptor Cells ; Rats ; Retina ; Retinal Degeneration* ; Retinaldehyde*

PURPOSE: To assess the malignant potential of small(< or =15mm) portal defects seen on CT arterial portography,the findings of CT hepatic arteriography and lipiodol CT CT were reviewed. MATERIALS AND METHODS: In 91 patientswho underwent both CTAP and CTHA, small portal defects were re-viewed for frequency, multiplicity and location. Weprospectively evauluated changes in the size and enhance-ment pattern of malignant lesions on follow up CTaccording to density on CTHA, location, lipiodol deposits on lipiodol CT, and multiplicity. RESULTS: Among the 91patients, 102 small defects were defected in 42 patients(46%). Small portal defects were benign, malignant, and ofundetermined malignant potential in 77%, 20% and 3% of cases, respectively. Small portal defects that werehyperattenuated on CTHA, and lipiodol deposits on lipiodol CT, were malignant in 42% and 70% of cases,respectively. Location and multiplicity did not show statistically significant variation between benign andmalignant defects. CONCLUSION: Small portal defects are common and there is a high probability that portaldefects smaller than 15mm are benign, even in patients with a known hepatic mass and defect that washyperattenuated on CTHA. If a small defect showed lipiodol deposit on lipiodol CT, malignancy must be suspected.
Angiography* ; Ethiodized Oil* ; Follow-Up Studies ; Humans ; Liver* ; Portography*

PURPOSE: To determine the effects of blood vessels on the size and shape of microwave coagulation. MATERIALS AND METHODS: Microwave coagulation was performed with 60 W output and 60 second duration. In the first experiment five exvivo porcine livers were used to determine the size of the coagulation area and its reproducibility. The second experiment involved the used of two in-vivo porcine livers to determine how adjacent vessels affect the size and shape of coagulation. RESULTS: The result of the first experiment was that the maximum mean diameter of lesions was 1.4 cm +/- 0.1 , reproducible in the range of 1.3 c m -1 .5 cm. In the second experiment, maximum mean diameter was found to be 1.5cm +/- 0.1, reproducible in the range of 1.3 cm - 1.7cm, and the size and shape of the lesion was affected by nearby blood vessels. The shape factor of the lesion, defined as roundness of sphere, was 0.8, but the r a n g e ( 0 . 5 8 -0.92) was wide due to the effect of vascular cooling. This was more prominent in the portal vein than in the hepatic vein, and the minimum diameter of the portal vein which deformed the lesion by more than 1 mm was 0.1 mm. CONCLUSION: Microwave coagulation gives a well-defined lesion, the size of which can be reproduced, but size variation and nonuniformity can be caused by nearby blood vessels.
Animals ; Blood Vessels* ; Hepatic Veins ; Liver ; Microwaves* ; Portal Vein

PURPOSE: To determine the effects of blood vessels on the size and shape of microwave coagulation. MATERIALS AND METHODS: Microwave coagulation was performed with 60 W output and 60 second duration. In the first experiment five exvivo porcine livers were used to determine the size of the coagulation area and its reproducibility. The second experiment involved the used of two in-vivo porcine livers to determine how adjacent vessels affect the size and shape of coagulation. RESULTS: The result of the first experiment was that the maximum mean diameter of lesions was 1.4 cm +/- 0.1 , reproducible in the range of 1.3 c m -1 .5 cm. In the second experiment, maximum mean diameter was found to be 1.5cm +/- 0.1, reproducible in the range of 1.3 cm - 1.7cm, and the size and shape of the lesion was affected by nearby blood vessels. The shape factor of the lesion, defined as roundness of sphere, was 0.8, but the r a n g e ( 0 . 5 8 -0.92) was wide due to the effect of vascular cooling. This was more prominent in the portal vein than in the hepatic vein, and the minimum diameter of the portal vein which deformed the lesion by more than 1 mm was 0.1 mm. CONCLUSION: Microwave coagulation gives a well-defined lesion, the size of which can be reproduced, but size variation and nonuniformity can be caused by nearby blood vessels.
Animals ; Blood Vessels* ; Hepatic Veins ; Liver ; Microwaves* ; Portal Vein

PURPOSE: To evaluate the CT features of inflammatory pseudotumor of the liver with histopathologiccorrelation. MATERIALS AND METHODS: The CT features of 14 cases (ten patients) with pathologically proveninflammatory hepatic pseudotumor were retrospectively analyzed and correlated with resected and biopsy specimens. RESULTS: The size of lesions ranged between 2.0 and 7.0cm (mean, 3.7cm); On unenhanced CT, the masses were seenas ill-defined hypodense lesions, while on contrast-enhanced CT they were heterogeneous and multiseptated, withenhancement of internal septa and peripheral wall (n=10). In four lesions, central low density and peripheralhomogeneous enhancement were seen. On histopathological correlation, the central hypoattenuated area correspondedto chronic inflammalory cell infiltrates with foamy histiocytes, plasmacytes, and lymphocytes, while thehyperattenuated peripheral wall and internal septa represented dense fibrosis. CONCLUSION: In patients in whon CTshows a heterogeneous enhancing mass, inflammatory pseudotumor of the liver should be included in differentialdiagnosis.
Biopsy ; Fibrosis ; Granuloma, Plasma Cell* ; Histiocytes ; Humans ; Liver* ; Lymphocytes ; Plasma Cells ; Retrospective Studies ; Tomography, X-Ray Computed

PURPOSE: To evaluate the usefulness of CT in patients with gastrointestinal fistula. MATERIALS AND METHODS: We retrospectively reviewed the CT scans of 17 patients with various type of gastrointestinal fistula. The presence of these fistulae was confirmed by laparotomy in seven patients and by barium studies in fifteen. We evaluated the diagnostic accuracy of CT in these cases, and in correlation with barium studies and surgical findings, subsequently analyzed the CT findings. We determined the presence or absence of fistula tract, flow diversion of oral contrast media, bowel wall changes adjacent to the fistula tract, and extraluminal manifestations such as soft tissue mass, free air, leakage of oral contrast media, and peritoneal changes. RESULTS: The diagnosis of gastrointestinal fistula was possible on CT in nine (53%) of the 17 patients by using the CT criteria of direct visualization of the fistula tract (n=6) or flow diversion of oral contrast media (n=4). Other ancillary findings included bowel wall thickening adjacent to fistula tract in 15 patients, extraluminal soft-tissue mass in five, extraluminal free air in ten, extraluminal contrast leakage in four, and varying degrees of mesenteric and/or omental infiltration in 15. CONCLUSION: CT scanning is useful for the diagnosis of gastrointestinal fistula, which may be possible if the fistula tract and flow diversion of oral contrast materials are seen. It is also useful for evaluation of the extent of the etiologic disease.
Barium ; Contrast Media ; Diagnosis ; Fistula* ; Humans ; Laparotomy ; Retrospective Studies ; Tomography, X-Ray Computed

Two cases of lymphoepithelial cyst, a very rare cystic lesion of the pancreas, are reported. The patients complained of vague upper abdominal discomfort. One lesion was derived from the head of the pancreas, the other from its neck. Ultrasonographic finding of the former was a cystic lesion with inhomogeneous internal echogenecity, and in both cases, CT showed multiloculated cystic lesions with internal septa. Cysts filled with sebaceous material were excised on operation, and lymphoepithelial cyst was histopathologically confirmed.
Head ; Humans ; Neck ; Pancreas*

PURPOSE: To correlate CT features with peripheral eosinophilia in patients with idiopathic hypereosinophilic syndrome involving the liver. MATERIALS AND METHODS: During the last three years, features of liver involvement in nine of 20 patients with idiopathic hypereosinophilic syndrome were evaluated on CT. The shape and distribution of intrahepatic low densities and the presence of hepatomegaly and/or splenomegaly were reviewed on CT, and the percentage of eosinophils in peripheral blood was also determined. In seven cases, interval change in hepatic lesion and the percentage of eosinophils were reviewed on follow-up examination. RESULTS: On initial CT, varying low-density patterns were seen in the liver in all cases ; hepatomegaly was seen in four cases, and hepatosplenomegaly in two. The percentage of eosinophils was 89% in a case with diffuse patch low densities in the liver, 65-85% in three cases with numerous nodular low density lesions, 12-29% in four cases with multiple (below ten) nodular or small geographic hypodense lesions, and 24% in a case with a single nodular hypodense lesion. On follow-up CT, seven patients showed a decrease in the percentage of eosinophils, and in six, improved intrahepatic low densities were seen. CONCLUSION: On CT, intrahepatic low densities were seen in patients with idiopathic hypereosinophilic syndrome, and these were distributed more extensively when peripheral eosinophilia was more severe. With improvement in peripheral eosinophilia, the low densities also improved.
Eosinophilia* ; Eosinophils ; Follow-Up Studies ; Hepatomegaly ; Humans ; Hypereosinophilic Syndrome* ; Liver* ; Splenomegaly

PURPOSE: To evaluate the diagnostic role of a three-dimensional MR cholangiopancreatography(MRCP) over endoscopic retrograde cholangio- pancreatography(ERCP) in various extrah-epatic biliary disease. MATERIALS AND METHODS: MRCP and ERCP were performed in 45 consecutive patients with suspected extrahepatic biliary diseases. MRCP was obtained using a reverse fast imaging with a steady-state free precession (reverse FISP : PSIF) sequences, and then images were reconstructed by standard MIP algorithm. The predictability of biliary dilatation and level of obstruction of MRCP was evaluated using ERCP as a gold standard. The accuracy distinguishing malignant from benign lesions, and overall diagnostic accuracy were compared between MRCP and ERCP. RESULTS: The sensitivity, specificity and accuracy of MRCP in predicting biliary dilatation were 94.6%, 75.0% and 91.1%, respectively. The level of obstruction was accurate in 87.0% with MRCP. The sensitivity, specificity and accuracy MRCP and ERCP in distinguishing malignant from benign lesions were 76.2%, 87.5% and 82.2% and 71.4%, 83.3% and 77.8%, respectively. The overall diagnostic accuracy was 60.0% with MRCP and 55.6% with ERCP. CONCLUSION: 3D MRCP shows a good diagnostic value compared to that of ERCP, and can replace a ERCP.
Cholangiopancreatography, Endoscopic Retrograde* ; Dilatation ; Humans ; Sensitivity and Specificity