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Y H Auh

Publications and source records attributed to Y H Auh.

At least 37 records · Page 2Linked to original sources
PubMed1998

Anatomical communications of the perirenal space.

There are controversies over the anatomical communications between the perirenal space and the adjacent extraperitoneal spaces. Clinical studies, mainly based on CT, show fluid collections extending into the adjacent space; into the bare area of the liver on the right, into the superior extraperitoneal space on the left, towards the midline from each perirenal space, and into the lower retroperitoneal space of the abdomen and pelvis. There are certain constant anatomical barriers limiting free extension of fluid or pathology. The pattern of fluid collection in the perirenal space and extension into the adjacent extraperitoneal space is relatively consistent although it varies with the amount and nature of the pathological fluid collection. This pictorial review illustrates anatomical barriers and CT findings of perirenal fluid collections and their extension into adjacent extraperitoneal spaces.

Adult↗
PubMed1998

MR cholangiopancreatography of pancreaticobiliary diseases: comparing single-shot RARE and multislice HASTE sequences.

OBJECTIVE: In this study, we compared the single-shot rapid acquisition with relaxation enhancement (RARE) sequence with the multislice half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence to assess the ability of each technique to show various pancreaticobiliary diseases using MR cholangiopancreatography. SUBJECTS AND METHODS: MR cholangiopancreatography was performed using both the single-shot RARE and the multislice HASTE pulse sequences in 80 consecutive subjects in whom we had proof of a range of diagnoses. The study population included healthy subjects (n = 9), patients with benign lesions (n = 41), and patients with malignant lesions (n = 30). We analyzed each image using the following criteria: the cause of the lesions, the image quality (i.e., the amount of artifact and the sharpness of anatomic structures such as the right and left hepatic ducts, the extrahepatic bile duct, and the main pancreatic duct), and the reviewers' preference of images. The images were evaluated independently by two radiologists who were unaware of the results of the other cholangiopancreatographic sequence and of the diagnosis. RESULTS: Artifacts were less prominent in images that were obtained using the single-shot RARE sequence (p = .0192); however, the sharpness of anatomic structures was the same using either sequence (p = .1673). For images that were obtained using the single-shot RARE technique, the sensitivity, specificity, and accuracy in distinguishing malignant from other abnormalities were 83%, 78%, and 80%, respectively; for the multislice HASTE technique, these values were 77%, 72%, and 74%, respectively (p > .05). Disease-specific accuracy in determining the correct diagnosis was 54% and 59%, respectively (p > .05). In patients in whom all the ducts needed to be defined, the single-shot RARE technique was preferred to the multislice HASTE technique (p < .01). CONCLUSION: The single-shot RARE technique shows fewer artifacts and is preferred to the multislice HASTE technique. However, both techniques show the same degree of sharpness of anatomic structures, both are able to reveal malignant diseases, and both provide enough information to determine a specific diagnosis.

Adult↗
PubMed1998

Usefulness of CT in patients with intestinal obstruction who have undergone abdominal surgery for malignancy.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of CT in determining the causes of intestinal obstruction in patients who have undergone abdominal surgery for malignancy. MATERIALS AND METHODS: We analyzed the CT scans of 55 patients with benign (n = 26) or malignant (n = 29) intestinal obstruction that developed after abdominal surgery for malignancy. After calculating the diagnostic accuracy of interpretations by three radiologists, we compared CT findings for benign and malignant intestinal obstructions with respect to peritoneal involvement patterns and other ancillary findings. Multivariate logistic regression analysis was used to determine the diagnostic performance of CT in revealing causes of obstruction. RESULTS: Diagnostic accuracies of the three radiologists were 67%, 75%, and 78%. CT findings indicating malignant obstruction were a mass at the site of obstruction or prior surgery, lymphadenopathy, or an abrupt transition zone and irregular bowel wall thickening at obstructed sites (p < .05). Conversely, the chance for benign obstruction increased when CT revealed mesenteric vascular changes, a large amount of ascites, or a smooth transition zone and smooth bowel wall thickening at the obstructed site (p < .05). With multivariate logistic regression analysis using two variables (a mass at the site of obstruction or prior surgery and lymphadenopathy), we calculated the overall accuracy of CT as 84% (46/55 patients). CONCLUSION: CT is useful in differentiating benign from malignant intestinal obstructions in patients who have undergone abdominal surgery for malignancy. However, CT has limitations in patients not having a demonstrable peritoneal mass.

Abdomen↗
PubMed1998

Vasculature in hepatocellular carcinoma after transcatheter arterial chemoembolization: comparison of power and color Doppler sonography.

The purpose of this study was to compare power Doppler sonography with conventional color Doppler sonography for the detection of the vascularity of hepatocellular carcinomas after transcatheter arterial chemoembolization. Of the 93 embolized hepatocellular carcinomas, hypervascularity was demonstrated in 36 on angiography; power Doppler sonography correctly identified pulsatile flow signals in 33 (92%) of these 36, whereas color Doppler sonography identified flow signals in 24 (67%). A statistically significant difference was noted when the sizes of the nodules were 30 mm or less. Despite technical difficulties, such as flash artifact, power Doppler sonography is superior to color Doppler sonography for detection of hypervascularity, especially in small embolized nodules of hepatocellular carcinoma (30 mm or less in diameter).

Adult↗
PubMed1997

The value of pancreatoscopy in patients with mucinous ductal ectasia.

We report here on three cases of mucinous ductal ectasia in which the diagnosis was suggested by abdominal computed tomography and finally established by duodenoscopy with pancreatoscopy. Duodenoscopic examination of the ampulla of Vater demonstrated a patulous papillary orifice and extrusion of viscid mucus. Pancreatoscopic examination was carried out in all three patients, and characteristic findings such as papillary or villous mucosal projections coated with whitish gelatinous mucus were noted. In patients with mucinous ductal ectasia in whom the radiographic findings are equivocal, pancreatoscopic examination may provide valuable information for the differential diagnosis of amorphous filling defects in the main pancreatic duct, and may provide information that helps to determine the extent of the pathology and the resection margin.

Adenocarcinoma, Mucinous↗
PubMed1997

Extrahepatic biliary diseases: 3D MR cholangiopancreatography compared with endoscopic retrograde cholangiopancreatography.

PURPOSE: To assess the diagnostic value of three-dimensional (3D) magnetic resonance (MR) cholangiopancreatography versus endoscopic retrograde cholangiopancreatography (ERCP) in various pancreaticobiliary diseases. MATERIALS AND METHODS: Forty-six consecutive adult patients suspected to have extrahepatic biliary disease were examined. Breath-hold 3D steady-state free-precession MR cholangiopancreatography was performed. Correct determination of the level of biliary obstruction (n = 23) and of the cause of lesions (n = 46) was independently assessed with both MR cholangiopancreatography and ERCP by two readers blinded to the diagnosis. Results were compared. The overall diagnostic accuracies of both modalities also were compared. RESULTS: Level of obstruction was accurate in 91% (21 of 23) with MR cholangiopancreatography and in 83% (19 of 23) with ERCP (P > .05). The sensitivity, specificity, and accuracy in distinguishing malignant from benign lesions were 81%, 92%, and 87%, respectively, for MR cholangiopancreatography and 71%, 92%, and 83%, respectively, for ERCP. However, the differences were not significant (P > .05). The overall diagnostic accuracies of MR cholangiopancreatography and ERCP were 72% and 61% (P > .05), respectively. CONCLUSION: 3D MR cholangiopancreatography not only is fast and reliable in evaluating the extrahepatic bile duct, but also offers a diagnostic value equivalent to that of ERCP.

Adult↗
PubMed1997

Xanthogranulomatous cholecystitis: CT features with emphasis on differentiation from gallbladder carcinoma.

PURPOSE: To evaluate the computed tomographic (CT) features of xanthogranulomatous cholecystitis (XGC) and to distinguish it from gallbladder carcinoma. MATERIALS AND METHODS: Retrospective analysis was performed in 11 patients with XGC and 17 patients with gallbladder carcinoma in which the wall was thickened. The following CT features were analyzed: maximum wall thickness, intramural hypoattenuated nodules, mucosal line, patterns of wall thickening and enhancement, and the presence of stones. The changes outside the gallbladder were also compared. RESULTS: The mean thickness of the gallbladder wall was 1.8 cm in patients with XGC and 2.1 cm in patients with gallbladder carcinoma. Intramural hypoattenuated nodules were seen in all patients with XGC but in only seven patients with gallbladder carcinoma (P = .008). The mucosal line was observed in nine patients with XGC and in six with gallbladder carcinoma (P = .02). The gallbladder wall was more diffusely thickened in patients with XGC (10 of 11 patients) than in patients with gallbladder carcinoma (seven of 17 patients) (P = .01). The occurrence of changes outside the gallbladder did not differ statistically significantly. CONCLUSION: Because of a statistically significant overlap of CT features, only when intramural hypoattenuated nodules occupy a large area of the thickened gallbladder wall can the diagnosis of XGC be highly suggestive. The diagnosis of XGC at CT may indicate a less aggressive surgical approach.

Adult↗
PubMed1997

Differentiation of simple and strangulated small-bowel obstructions: usefulness of known CT criteria.

PURPOSE: To evaluate the usefulness of known computed tomographic (CT) criteria for the differentiation of simple and strangulated small-bowel obstructions. MATERIALS AND METHODS: CT scans of 84 patients with simple (n = 43) and strangulated (n = 41) small-bowel obstructions caused by adhesions, hernia, and volvulus were reviewed retrospectively. Diagnoses were made with surgery (n = 55) and during clinical follow-up (n = 29). CT criteria evaluated were configuration of obstructed bowel loop, target sign, bowel wall thickening and enhancement, changes in mesentery and mesenteric vasculature, and amount and attenuation of ascites. RESULTS: CT findings that enabled the detection of strangulated obstructions were poor or no enhancement of bowel wall (sensitivity, 34%; specificity, 100%) and a serrated beak (sensitivity, 32%; specificity, 100%). When these two findings were excluded from analysis, a large amount of ascites, an unusual course of mesenteric vasculature, and diffuse engorgement of mesenteric vasculature were shown to be useful CT findings for performing multivariate regression analysis. Application of these five CT findings enabled identification of 35 (85%) of 41 patients with strangulated obstructions. CONCLUSION: Detecting a combination of selected, known CT criteria increases the diagnostic accuracy of CT to enable differentiation of simple and strangulated small-bowel obstructions.

Contrast Media↗
PubMed1997

Usefulness of CT in patients with ischemic colitis proximal to colonic cancer.

OBJECTIVE: The purpose of this study was to assess the usefulness of CT scans for distinguishing ischemic from tumoral segments in patients with colonic carcinoma complicated by proximal bowel ischemia. MATERIALS AND METHODS: CT scans of 20 patients with ischemic colitis proximal to obstructing colonic carcinoma were reviewed retrospectively. The concomitant presence of ischemia was proven on pathologic examinations in 12 patients and on barium enema studies in the remaining eight patients. CT scans were analyzed for the involved site and length, bowel wall thickness, enhancing pattern of both tumoral and ischemic segments, and changes in the pericolic space. The results of tumor staging on CT scans were compared with those of pathologic findings. RESULTS: Distinction of ischemic from tumoral segments could be made on CT in 15 (75%) of the 20 patients. Of the 20 patients, 18 had ischemic segments contiguously proximal to the tumoral segment, and the remaining two patients had a skipped zone with intervening normal mucosa. Tumoral segments were irregularly thickened in most patients. Maximum thickness ranged from 0.8 to 4.5 cm (mean, 2.0 cm). Most often the ischemic segment was concentrically and smoothly thickened, ranging from 0.6 to 1.5 cm (mean, 1.0 cm). The tumoral segments enhanced heterogeneously in 12 patients and enhanced homogeneously in the remaining eight, whereas ischemic segments enhanced homogeneously in 14 (70%) patients and heterogeneously in six. On CT scans, we saw the target or double halo sign in four (20%) patients. Pericolic vascular engorgement was 19 patients, two of whom were overstaged because pericolic vascular engorgement was interpreted as tumor infiltration. CONCLUSION: Although CT findings are not specific for certain groups of patients, they are often helpful in distinguishing tumoral from ischemic segments in patients with ischemic colitis proximal to colonic carcinoma. An understanding of this pathologic entity may increase the accuracy of CT for staging colonic carcinoma.

Aged↗
PubMed1997

Gastrointestinal involvement in Henoch-Schönlein syndrome: CT findings.

OBJECTIVE: The purpose of this study was to describe the CT features of gastrointestinal involvement in seven patients with Henoch-Schönlein syndrome. CONCLUSION: Although the incidence of Henoch-Schönlein syndrome is low, it should be considered when CT scans show multifocal areas of bowel-wall thickening, mesenteric edema, vascular engorgement, and nonspecific lymphadenopathy. It should be considered especially in young patients with acute gastrointestinal symptoms.

Adolescent↗
PubMed1997

ERCP and CT findings of ectopic drainage of the common bile duct into the duodenal bulb.

OBJECTIVE: The purpose of this study was to evaluate ERCP and CT findings of ectopic drainage of the common bile duct into the duodenal bulb. CONCLUSION: Although rare, the diagnosis of ectopic drainage of the common bile duct into the duodenal bulb is important to prevent inadvertent damage during biliary tract or gastric surgery and to clarify the cause of chronic peptic ulcers.

Adult↗
PubMed1997

Benign biliary strictures associated with recurrent pyogenic cholangitis: treatment with expandable metallic stents.

OBJECTIVE: The purpose of this study was to determine the long-term effectiveness of expandable metallic stents in benign biliary strictures associated with recurrent pyogenic cholangitis and the differences in primary patency of the various types of stents deployed. SUBJECTS AND METHODS: During a 20-month period, 26 metallic stents (19 Gianturco-Rosch Z stents and seven Strecker stents) were used to treat benign biliary strictures associated with recurrent pyogenic cholangitis in 23 patients (11 men and 12 women; mean age, 42 years; range, 30-78 years). Insertion routes were percutaneous transhepatic biliary drainage tracts for 16 stents, T-tube tracts for seven stents, and retrograde endoscopic routes for three stents. The deployed locations were common hepatic or common bile ducts for 11 stents, right or left hepatic ducts for 10 stents, and segmental ducts for five stents. RESULTS: The initial technical success rate was 100%. Two stents in one patient migrated spontaneously. Primary stent patency for the remaining 24 stents was 34 months (range, 3-58 months). Primary stent patency of the Gianturco-Rosch Z and Strecker stents was 50 and 10 months, respectively (p < .05). Primary stent patency for the intrahepatic and extrahepatic ducts was 50 and 18 months, respectively (p = .05). Primary patency rates for all stents at 6, 12, 24, and 36 months were 92%, 75%, 67%, and 46%, respectively. The causes of stent obstruction were recurrent stone or sludge in eight stents and epithelial hyperplasia in five stents. CONCLUSION: We believe that metallic stent placement is not an effective long-term treatment technique for benign biliary stricture associated with recurrent pyogenic cholangitis.

Adult↗
PubMed1996

CT differentiation of tuberculous peritonitis and peritoneal carcinomatosis.

OBJECTIVE: The purpose of this study was to determine the potential of CT for distinguishing tuberculous peritonitis from peritoneal carcinomatosis in 135 clinically or pathologically proven cases. MATERIALS AND METHODS: Abdominal CT scans in 135 patients of tuberculous peritonitis (n = 42) and peritoneal carcinomatosis (n = 93) with documented omental, mesenteric, or peritoneal pathology were retrospectively reviewed. CT findings were evaluated in each group of patients for the morphologic appearance of mesenteric or omental abnormalities as well as for visualization of the spleen and liver, the lymph nodes, and ascites. Statistical comparisons using multivariate logistic regression analysis were performed to adjust for the differences in CT findings between the two groups. RESULTS: Mesenteric changes were more commonly seen in patients with tuberculous peritonitis (98%) than in patients with peritoneal carcinomatosis (70%) (p < .01). Micronodules (less than 5 mm in diameter) were noted in approximately one half of patients with tuberculous peritonitis or peritoneal carcinomatosis, but macronodules (> or = 5 mm in diameter) were much more frequently seen in patients with tuberculous peritonitis (52%) than in patients with peritoneal carcinomatosis (12%) (p < .01). The omentum appeared to be more irregularly infiltrated in peritoneal carcinomatosis patients (p < .01). The thin omental line covering the infiltrated omentum was seen in 13 patients with tuberculous peritonitis but in only four patients with peritoneal carcinomatosis (p < .01). In peritoneal or extraperitoneal masses in patients with tuberculous peritonitis, a low-density center was seen in 18 cases (43%) and calcification was noted in six cases (14%). The prevalences of splenomegaly and splenic calcification were higher in patients with tuberculous peritonitis. Using multivariate analysis, we calculated the sensitivity of CT for predicting tuberculous peritonitis and peritoneal carcinomatosis as 69% and 91%, respectively. CONCLUSION: Although most CT findings that we analyzed overlap these diseases, using a combination of CT findings increased our ability to distinguish tuberculous peritonitis from peritoneal carcinomatosis.

Adult↗
PubMed1994

Loculated fluid collections in hepatic fissures and recesses: CT appearance and potential pitfalls.

The peritoneum invaginates into the liver parenchyma normally, as a normal anatomic variation, or pathologically and then fissures and furrows are formed. There are four normal fissures: fissures for the ligamentum teres, ligamentum venosum, and gallbladder and the transverse fissure. Fissures caused by normal anatomic variations include accessory fissures and furrows created by diaphragmatic indentation. Pathologic fissures occur secondary to traumatic or iatrogenic causes or as a result of liver cirrhosis. When ascites, hemoperitoneum, or infected ascites is loculated in the fissures or recesses, it may be mistaken for a liver cyst, intrahepatic hematoma, or liver abscess. When peritoneally disseminated tumor cells are implanted into these spaces, they may mimic intrahepatic focal lesions. Because the clinical consequences for these entities are very different, exact localization of the lesions may be crucial in the diagnosis and management of the lesions. Complete understanding of the liver surface anatomy and awareness of these situations may prevent a misdiagnosis of a focal intrahepatic abnormality.

Humans↗
PubMed1994

In vitro MR imaging of the resected stomach with a 4.7-T superconducting magnet.

PURPOSE: To study the effects of formalin fixation, signal intensity characteristics of the stomach-wall layers, and findings suggestive of cancerous invasion to the stomach wall in vitro with magnetic resonance (MR) imaging in humans. MATERIALS AND METHODS: MR images of nine specimens of stomach cancer and 29 normal specimens were obtained at 4.7 T; 26 of the normal specimens were fixed in 10% formalin for 2 hours to 187 days before imaging. The field gradient was 10 G/cm; the spatial resolution, 0.1 mm. RESULTS: The mucosal, submucosal, and proper-muscle layers were clearly identifiable. The submucosa of the fresh specimens had the lowest signal intensity of all specimens on both T1- and T2-weighted images (P < .01). No statistical correlation existed between signal intensity and duration of fixation. Tumor invasion was detected in seven of eight specimens with mucosal invasion, all eight specimens with submucosal invasion, and three of six specimens with muscle invasion. CONCLUSION: In vitro MR imaging enabled differentiation of all three layers of the stomach wall, detection of the cancer, and measurement of the depth of invasion.

Formaldehyde↗
PubMed1994

Exophytic adenocarcinoma of the stomach: CT findings.

OBJECTIVE: Exophytic adenocarcinomas of the stomach are tumors that have large extraluminal portions. Exophytic growth of gastric carcinoma is rare, and such tumor may be confused with gastric leiomyosarcoma. The purpose of this study was to assess the CT findings of exophytic adenocarcinoma of the stomach and to determine their value in distinguishing between it and gastric leiomyosarcoma. MATERIALS AND METHODS: Twenty patients with exophytic adenocarcinomas of the stomach confirmed by surgery or endoscopic biopsy were included in the study. CT scans were assessed retrospectively for the size, location, and character of the mass and the presence of adjacent thickening of the gastric wall and outlet obstruction. RESULTS: The masses were from 5 to 14 cm in diameter (mean, 9 cm). The mass was in the gastric antrum in 11 cases, the body of the stomach in six cases, the body and antrum in two cases, and the gastric fundus and body in one case. CT showed an exogastric mass with a variable degree of internal low density or necrosis in all 20 cases. Thickening of the gastric wall adjacent to the mass appeared to be a specific finding of exogastric adenocarcinoma (n = 14); it was not seen in reported cases of leiomyosarcoma. Gastric outlet obstruction was seen in four cases, and ulcer was detected in eight cases. The degree of low density or necrosis within the mass was minimal in eight cases, moderate in seven cases, and severe in five cases. CONCLUSION: Our results suggest that CT findings of thickening of the gastric wall adjacent to an exogastric mass, representing spread of cancer to adjacent gastric wall, and/or gastric outlet obstruction are typical of exophytic adenocarcinoma of the stomach and allow distinction between it and gastric leiomyosarcoma.

Adenocarcinoma↗
PubMed1993

Therapeutic percutaneous aspiration of hepatic abscesses: effectiveness in 25 patients.

OBJECTIVE: The objective of this study was to evaluate the effectiveness of sonographically guided needle aspiration and systemic antibiotic therapy for the treatment of hepatic abscesses. SUBJECTS AND METHODS: From June 1989 to September 1991, sonographically guided needle aspiration and systemic antibiotics were used to treat 25 consecutive patients with 25 hepatic abscesses. Among 36 patients with hepatic abscesses who were admitted to the hospital during that time, six had antibiotic therapy only; of these, three had microabscesses, two had abscesses less than 3.0 cm in diameter, and one refused needle aspiration. Four patients had surgical external drainage (three had cholelithiasis in addition to hepatic abscesses, and one did not respond to needle aspiration). Two patients treated in 1989 had drainage via an indwelling catheter, which was the preferred method at that time. The remaining 24 patients and one patient who had needle aspiration followed by surgical drainage made up the study group. Seventeen of the hepatic abscesses were caused by pyogenic organisms, six by amoeba, and two by unknown organisms. Eighteen abscesses (72%) were aspirated once, four (16%) were aspirated twice in 8 days, two (8%) were aspirated three times in 14 days, and one (4%) was aspirated four times in 10 days. Persistent fever, pain and tenderness in the right upper quadrant, and leukocytosis were the indications for multiple aspirations. Follow-up sonography was performed to evaluate the outcome of treatment. RESULTS: In 16 cases (64%), the abscesses disappeared within a mean of 84 days. In eight cases (32%) with only partial follow-up, the patients were asymptomatic at the time of discharge and the abscesses were markedly smaller on the last follow-up sonograms (mean, 43 days). One patient (4%) did not respond to aspiration and had surgical drainage. The length of hospitalization varied from 5 to 42 days (mean, 22 days). In patients who became afebrile during the treatment, the fever had lasted from 0 to 10 days (mean, 3 days). Only one patient had a complication of the procedure, a pleural effusion that was treated conservatively. CONCLUSION: Our results show that sonographically guided needle aspiration combined with antibiotic therapy is effective as the initial treatment for hepatic abscesses.

Adult↗