PubMed Health⌕ Search

Biomedical subjects

Jeong-Sik Yu

Publications and source records attributed to Jeong-Sik Yu.

At least 19 recordsLinked to original sources
PubMed2007

Hepatic MRI using the double-echo chemical shift phase-selective gradient-echo technique.

OBJECTIVE: The objective of our study was to describe the merits and drawbacks of the double-echo chemical shift phase-selective gradient-echo technique for hepatic MRI. CONCLUSION: With complementary information from two different dynamic imaging sets in conjunction with errorless subtraction between in- and out-of-phase images, the double-echo chemical shift phase-selective gradient-echo technique provides useful information regarding unpredictable variations in intra- or extralesional lipid content, allowing detailed assessment of focal lesions during hepatic MRI.

Adipose Tissue↗
PubMed2006

Pure epidural cavernous hemangioma of the cervical spine that presented with an acute sensory deficit caused by hemorrhage.

Pure epidural cavernous hemangioma of the spine without vertebral involvement is rare. Due to the slow growth of this lesion, the most common symptoms are chronic pain, myelopathy, and radiculopathy. In our case, the patient complained of an acute onset sensory deficit of the C4 dermatome. An MRI revealed an epidural mass with an acute hematoma. Here, we report a case of a pure epidural cavernous hemangioma that presented with acute neurologic symptoms caused by intralesional hemorrhage and an acute epidural hematoma, which were demonstrated on the patient's MRI.

Cervical Vertebrae↗
PubMed2006

Hyperintense nodules on non-enhanced T1-weighted gradient-echo magnetic resonance imaging of cirrhotic liver: fate and clinical implications.

PURPOSE: To investigate the fate of hyperintense hepatic nodules on nonenhanced T1-weighted (T1w) gradient-echo (GRE) magnetic resonance (MR) images in cirrhotic patients. MATERIALS AND METHODS: A total of 79 cirrhotic patients with hyperintense nodules (>5 mm) on precontrast opposed-phase (repetition time (TR)/echo time (TE) = 140/2.7 msec) GRE images from initial MRI without T2-weighted (T2w) hyperintensity or arterial hypervascularity were subjected to analysis of subsequent MR images obtained at intervals of 12-56 months (mean = 24.5 months). Multiplicity of hyperintense nodules (group A, up to 8; group B, >8) was correlated with follow-up changes. RESULTS: Group B patients were younger (P = 0.003) than group A patients (mean = 47.5 and 56.2 years, respectively). In 66 group A patients, 39 out of 143 lesions (27%) were enlarged, including 20 malignantly transformed or borderline lesions. Of the 104 lesions (the eight largest lesions in each patient) in 13 group B patients, only three (2.9%) were enlarged. The results of best- and worst-case analyses showed that overall the lesions were benign in 91% and 82% of patients, respectively. CONCLUSION: T1w hyperintense nodules without T2w hyperintensity or arterial hypervascularity in the cirrhotic liver are benign in most cases. In younger patients with numerous macronodules, almost all of these lesions follow a benign course.

Adult↗
PubMed2006

Hepatic metastases: perilesional enhancement on dynamic MRI.

OBJECTIVE: Our purpose was to determine whether the perilesional parenchymal enhancement of hepatic metastases could be correlated with tumoral enhancement on arterial phase images or tumor size on dynamic MRI. MATERIALS AND METHODS: One hundred thirty-four lesions of hepatic metastases in 44 patients were subjected to a retrospective analysis of the dynamic MR images obtained with 3D spoiled gradient-echo sequences. The thickness of the enhancing rim on arterial phase images was regarded as a summation of the enhancing component of tumor periphery and perilesional enhancement, which were estimated by the tumor size on precontrast T1-weighted images. The presence of wedge-shaped perilesional enhancement was also correlated with the lesion size. RESULTS: Except for 17 diffusely enhanced lesions, lesion size was comparable between the lesions with (n = 87; 26 +/- 19 [SD] mm) and without rim enhancement (n = 30; 27 +/- 23 mm) on the arterial phase dynamic MR images (p > 0.05). The degree of peripheral tumoral enhancement showed an inverse correlation (r = -0.389) with the thickness of the circumferential perilesional enhancement (p < 0.001). The mean size of the lesions with wedge-shaped perilesional enhancement (n = 44; 33 +/- 20 mm) was larger than that of the other lesions (n = 90; 25 +/- 19 mm) (p = 0.016). CONCLUSION: The degree of circumferential perilesional enhancement of hepatic metastases on arterial phase dynamic MR images would be independent of the lesion size but inversely correlated with the degree of peripheral tumoral vascularity. An understanding of these features may help tumor characterization and should prompt hypotheses and studies of microvascular phenomena in tumoral and epitumoral environments.

Adult↗
PubMed2005

Capecitabine combined with gemcitabine (CapGem) as first-line treatment in patients with advanced/metastatic biliary tract carcinoma.

BACKGROUND: Biliary tract carcinoma is an aggressive cancer, with median survival rarely exceeding 6 months. There is currently no established palliative standard of care. A Phase II trial was conducted to study a combination of oral capecitabine and gemcitabine (CapGem) as first-line therapy in patients with advanced and/or metastatic biliary carcinoma. METHODS: Patients with unresectable or metastatic intrahepatic or extrahepatic biliary duct carcinoma and gallbladder carcinoma were enrolled. Eligible patients had histologically or cytologically confirmed, measurable adenocarcinoma and had not received prior therapy with capecitabine or gemcitabine. Treatment consisted of intravenous (i.v.) gemcitabine (1000 mg/m(2) on Days 1 and 8) plus oral capecitabine (650 mg/m(2) twice daily on Days 1-14) every 3 weeks for up to 6 cycles. Tumor response, survival, and safety were determined. RESULTS: A total of 44 patients were evaluable. Primary tumor sites were: intrahepatic (n = 14) and extrahepatic biliary duct (n = 16); gallbladder (n = 7); and ampulla (n = 7). Fourteen (32%) patients had a partial response and 15 (34%) patients had stable disease. Median time to disease progression and overall survival were 6.0 (range, 3.8-8.1) and 14 (range, 11.4-16.6) months, respectively. The 1-year survival rate was 58%. No Grade 4 adverse events were seen. Transient Grade 3 neutropenia/thrombocytopenia and manageable (almost invariably Grade 2) nausea, diarrhea, and hand-foot syndrome were the most common adverse events. CONCLUSIONS: CapGem is an active and well tolerated first-line combination chemotherapy regimen for patients with advanced/metastatic biliary tract carcinoma that offers a convenient home-based therapy.

Adult↗
PubMed2005

A Phase II study of capecitabine combined with gemcitabine in patients with advanced gallbladder carcinoma.

Capecitabine and gemcitabine are used in the treatment of a variety of solid tumors including pancreatic and biliary tract carcinomas. The authors evaluated survival, response, and toxicity associated with using a combination of capecitabine and gemcitabine to treat patients with unresectable or metastatic gallbladder adenocarcinoma (GBC). Eligible patients had histologically- or cytologically-confirmed GBC, no prior systemic therapy with capecitabine or gemcitabine, Karnofsky Performance Status 70%, serum total bilirubin up to three times normal, and measurable disease. Treatment consisted of gemcitabine 1000 mg/m2 IV on Days 1 and 8 concurrent with administration of capecitabine 1000 mg/m2 PO BID on Days 1 through 14, on a 3-week cycle. Tumor response was assessed by the response evaluation criteria in solid tumors (RECIST criteria) and survival was calculated from initiation of CapGem therapy. A total of 24 patients were enrolled. Median age at the time of diagnosis was 62 years (range, 41-78 years). Fourteen patients had undergone prior surgery. Results showed that eight patients achieved partial response (33%) with an additional 10 patients achieving stable disease (42%). The overall median time to disease progression was 6.0 months (95% CI, 3.8-8.1 months) and overall survival was 16 months (95% CI, 13.8-18.3 months). The one-year survival rate was 58%. No Grade 4 toxicity was seen. Transient Grade 3 neutropenia/ thrombocytopenia and manageable nausea, hand-foot syndrome and anorexia were the most common toxicities. Our study shows that CapGem is an active and well-tolerated chemotherapy regimen in patients with advanced GBC.

Adult↗
PubMed2005

Focal eosinophilic necrosis versus metastasis in the liver: the usefulness of two-phase dynamic CT.

OBJECTIVE: The purpose of our study was to evaluate the usefulness of dual-phase dynamic CT in the differentiation of focal eosinophilic necrosis of the liver and metastasis. CONCLUSION: Undetected isoattenuating lesions on arterial phase images that have an indistinct margin, a nonspherical shape, and a homogenous enhancement pattern on portal venous phase images suggest focal eosinophilic necrosis rather than metastasis. Two-phase dynamic CT was found to be useful at differentiating focal eosinophilic necrosis from metastasis.

Adult↗
PubMed2004

Early biliary complications of laparoscopic cholecystectomy: evaluation on T2-weighted MR cholangiography in conjunction with mangafodipir trisodium-enhanced 3D T1-weighted MR cholangiography.

OBJECTIVE: Our aim was to assess preliminary experience with combined conventional T2-weighted and mangafodipir trisodium (MnDPDP)-enhanced T1-weighted MR cholangiography in evaluating early biliary complications of laparoscopic cholecystectomy. SUBJECTS AND METHODS: Conventional heavily T2-weighted MR cholangiography with MnDPDP-enhanced T1-weighted MR cholangiography and ERCP were performed in seven patients with high clinical suspicion of biliary complications after laparoscopic cholecystectomy. The final diagnoses of complications were classified according to the presence and degree of bile duct injury, bile leakage, and retained stones. RESULTS: The diagnoses on MR cholangiography were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 3), partial strictures of the common bile duct with bile leakage (n = 1), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). The final diagnoses at surgery (n = 2) and ERCP (n = 5) were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 2), partial strictures of the common bile duct with bile leakage (n = 2), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). MR cholangiography accurately yielded the same findings as the final diagnoses, except in one case with partial stricture of the bile duct with bile leakage (overdiagnosed as complete occlusion on MR cholangiography). CONCLUSION: Combined conventional T2-weighted and MnDPDP-enhanced T1-weighted MR cholangiography may eliminate the use of other studies for the imaging of biliary complications after cholecystectomy if this preliminary data can be verified in a larger study.

Adult↗
PubMed2003

Acute cholecystitis at T2-weighted and manganese-enhanced T1-weighted MR cholangiography: preliminary study.

Twelve patients with symptoms of acute cholecystitis underwent heavily T2-weighted and mangafodipir trisodium-enhanced T1-weighted magnetic resonance (MR) cholangiography and cholescintigraphy before they underwent cholecystectomy. On T2-weighted MR cholangiographic images, morphologic evidence of outflow obstruction of the gallbladder was definitive in seven patients, equivocal in one, and absent in four. In all 12 patients, biliary dynamics depicted at manganese-enhanced T1-weighted MR cholangiography agreed completely with those depicted at hepatobiliary scintigraphy. T2-weighted MR cholangiography combined with manganese-enhanced T1-weighted MR cholangiography provides not only morphologic information but also functional information about the biliary system.

Acute Disease↗
PubMed2002

Predisposing factors of bile duct injury after transcatheter arterial chemoembolization (TACE) for hepatic malignancy.

The purpose of this study was to investigate the predisposing factors of bile duct injury after transcatheter arterial chemoembolization (TACE) for treatment of hepatic malignancy. For patients (n = 31) with TACE-related bile duct injuries during a 36-month period, final diagnoses of the tumor, the liver profile, presence of portal vein thrombosis, total number and mode of the TACE just before the development of bile duct injury were compared, respectively with those of patients without bile duct injury n = 234) after TACE. The incidence of bile duct injury was higher in the patients with non-hepatocellular tumors than in patients with hepatocellular carcinoma (p <0.01), and higher in Child-Pugh class A patients than in B or C patients (p <0.01). Segmental or subsegmental TACE tended to induce bile duct injury more frequently than the proximal TACE (p = 0.01). Portal vein thrombosis, the total number of TACEs, total amount of iodized oil, and the usage of gelatin sponge were not closely related to bile duct injuries after TACE (p >0.05). It was concluded that the chance of bile duct injury after TACE is increased in non-cirrhotic livers with good liver profile and to the more selective embolization of distal arterial branches.

Adenocarcinoma↗
PubMed2002

Magnetic resonance imaging of arterioportal shunts in the liver.

Localized perfusional variations are being seen more frequently in magnetic resonance imaging (MRI) as the increased reliance of the optimized arterial-phase contrast-enhanced strategies has become more commonplace. Many of these findings are related to the various organic or functional arterioportal shunts in the liver. The associated alterations in physiologic flow, decreased or absent portal venous flow, and increased arterial flow result in a regional display of high signal intensity on arterial-phase dominant contrast-enhanced MRI. For accurate diagnosis and planning of patient management, the etiology of the shunt should be distinguished as tumor related or not, and it may need to be differentiated from a hypervascular tumor. Depending on the chronicity of diminished portal flow, substantial parenchymal changes may ensue, including focal fat sparing or the finding of functional infarct, either of which can be demonstrated on static MRI. This article reviews and illustrates the MRI findings of localized tumor-related and nontumorous arterioportal shunts in the liver.

Adult↗
PubMed2002

Mucinous versus nonmucinous gastric carcinoma: differentiation with helical CT.

PURPOSE: To assess the capability of helical computed tomography (CT) to assist in the differentiation between mucinous and nonmucinous gastric carcinomas, with a focus on the thickened stomach wall itself. MATERIALS AND METHODS: In 62 patients with pathologically proved mucinous (n = 21) or nonmucinous (n = 41) gastric carcinomas, contrast material-enhanced helical CT images were obtained. The gross appearance, contrast enhancement pattern, predominant thickened layer, and degree of enhancement were retrospectively evaluated. Statistical analyses were performed with Fisher exact, chi(2), and Student t tests. A P value of less than.05 was considered to indicate a statistically significant difference. RESULTS: The most common type of gross appearance in both carcinomas was fungating: It occurred in 71% of patients with mucinous carcinomas and in 59% of patients with nonmucinous carcinomas. The next most common gross appearance type was ulcerative (24% of patients) in nonmucinous carcinomas and diffusely infiltrative (29% of patients) in mucinous carcinomas (P =.009). The most common contrast enhancement pattern was homogeneous (61% of patients) in nonmucinous carcinomas and layered (62% of patients) in mucinous carcinomas (P =.001). These findings were significantly different. The predominantly affected thickened layer was the high-attenuating inner layer or the entire layer (88% of patients) in nonmucinous carcinomas and the low-attenuating middle or outer layer (57% of patients) in mucinous carcinomas. Only two mucinous tumors showed miliary punctate calcifications in infiltrative lesions. CONCLUSION: Helical CT may assist in distinguishing mucinous from nonmucinous gastric carcinoma, primarily on the basis of enhancement pattern, predominant layer of the thickened wall, gross appearance, and presence of calcifications.

Adenocarcinoma, Mucinous↗
PubMed2002

Radiographic findings of primary B-cell lymphoma of the stomach: low-grade versus high-grade malignancy in relation to the mucosa-associated lymphoid tissue concept.

OBJECTIVE: We undertook this study to assess how well double-contrast radiography and CT allow radiologists to differentiate low-grade from high-grade mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach. MATERIALS AND METHODS: We retrospectively reviewed the upper gastrointestinal radiographs and contrast-enhanced CT scans of 57 patients with pathologically proven primary gastric lymphoma (low-grade [n = 29] and high-grade [n = 28] MALT lymphoma). RESULTS: On upper gastrointestinal radiography, ulceration (39%) was the most common finding in low-grade lymphoma, whereas polypoid appearance (38%) was the most common in high-grade lymphoma. In the 29 patients (33 lesions) with low-grade MALT lymphoma, upper gastrointestinal radiography revealed 13 ulcerative lesions (39%), 10 nodular lesions (30%), four infiltrative lesions (12%), two polypoid lesions (6%), and four combined lesions (12%). In the 28 patients (29 lesions) with high-grade lymphoma, upper gastrointestinal radiography revealed 11 polypoid lesions (38%), nine infiltrative lesions (31%), six ulcerative lesions (20%), one nodular lesion (3%), and two combined lesions (7%). On CT, thickening of the gastric wall in low-grade lymphoma (range, 0.3-2.5 cm; mean, 0.8 cm) was much less than that in high-grade lymphoma (range, 0.7-8.0 cm; mean, 2.5 cm). Abdominal lymphadenopathy was less frequent in low-grade lymphoma (14%) than in high-grade lymphoma (75%). CONCLUSION: Most low-grade lymphomas show superficial spreading lesions, such as mucosal nodularity, shallow ulcer, and minimal fold thickening, on upper gastrointestinal radiography, whereas most high-grade lymphomas show mass-forming lesions or severe fold thickening.

Adult↗
PubMedDate not supplied

Radiologic findings of gastrointestinal tract involvement in hepatocellular carcinoma.

PURPOSE: The purpose of this work was to evaluate the radiologic findings of gastrointestinal (GI) tract involvement in hepatocellular carcinoma (HCC) and to discuss mechanisms of spread. METHOD: Eighteen patients with histologically proven GI tract metastasis in HCC for 4.5 years underwent CT and five also underwent upper GI (UGI) series. The cases were classified according to the mode of spread, based on the radiologic findings. RESULTS: The involved portion of the GI tract was the stomach (n = 11), duodenum (n = 4), and colon (n = 4). The mode of spread was direct invasion from a contiguous primary tumor (n = 12), hematogenous metastasis (n = 3), peritoneal seeding (n = 1), and undetermined (n = 2). In cases of direct invasion from contiguous primary tumors, CT revealed GI tract invasion directly from bulky hepatic masses (n = 9) or daughter masses at the portion of the bowel wall contiguous to the hepatic masses (n = 3). In cases of hematogenous spread, CT revealed an intramural mass in the stomach and duodenum (n = 2) or a diffuse thickening of the wall of the stomach (n = 1). In the case of peritoneal seeding, CT revealed multiple small nodules in the right paracolic gutter, omentum, and mesentery with invasion to the colon. CONCLUSION: GI tract involvement in HCC shows various radiologic findings according to the mode of spread, but the most common finding is direct invasion of the stomach, duodenum, or colon from contiguous primary tumor.

Carcinoma, Hepatocellular↗