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Yon Mi Sung

Publications and source records attributed to Yon Mi Sung.

12 recordsLinked to original sources
PubMed2006

Pulmonary sclerosing hemangioma presenting as solitary pulmonary nodule: dynamic CT findings and histopathologic comparisons.

OBJECTIVE: The purpose of this study was to describe the dynamic CT findings of pulmonary sclerosing hemangioma presenting as a solitary pulmonary nodule and to compare these findings with histopathologic findings. CONCLUSION: On dynamic CT, sclerosing hemangioma has strong and rapid enhancement attributed histopathologically to the presence of hemangiomatous or papillary components in the tumor.

Adult↗
PubMed2006

18F-FDG PET/CT of thymic epithelial tumors: usefulness for distinguishing and staging tumor subgroups.

UNLABELLED: The purpose of our study was to assess the usefulness of integrated PET/CT using 18F-FDG for distinguishing thymic epithelial tumors according to the World Health Organization (WHO) classification. METHODS: Thirty-three patients (age range, 34-68 y; mean age, 54.6 y) with thymic epithelial tumors, who underwent both integrated PET/CT and enhanced CT, were included. The clinicopathologic stages, maximum standardized uptake values (SUVs), and uptake patterns of tumors on integrated PET/CT images, and various enhanced CT findings, are described according to the simplified (low-risk [types A, AB, and B1] and high-risk [types B2 and B3] thymomas and thymic carcinomas) subgroups of the WHO classification. Discriminant analysis was performed to determine the relative capabilities of integrated PET/CT and enhanced CT findings to differentiate tumor subgroups. RESULTS: Tumors included 8 low-risk thymomas, 9 high-risk thymomas, and 16 thymic carcinomas. The maximum SUVs of high-risk thymomas (P < 0.001) and low-risk thymomas (P < 0.001) were found to be significantly lower than those of thymic carcinomas. Homogeneous 18F-FDG uptake within tumors was more frequently seen in thymic carcinomas than in high-risk thymomas (P = 0.027) or low-risk thymomas (P = 0.001). The uptake pattern (homogeneous vs. heterogeneous) on integrated PET/CT images and the presence of mediastinal fat invasion on enhanced CT images were found to be useful for differentiating tumor subgroups. In addition, integrated PET/CT helped detect lymph node metastases, which were not identified on enhanced CT in 2 patients. CONCLUSION: Integrated PET/CT was found to be useful for differentiating subgroups of thymic epithelial tumors and for staging the extent of the disease.

Adenocarcinoma↗
PubMed2004

Retroperitoneal arteriovenous malformation extending through the inferior vena cava into the heart and causing inferior vena cava dissection.

We present a case of retroperitoneal arteriovenous malformation extending through the inferior vena cava into the heart, which was associated with dissection of the inferior vena cava in a 32-year-old female. Computed tomography and magnetic resonance imaging showed a double-lumen inferior vena cava and a rod-like solid component attached to a sac-like lesion in the right heart chambers. Digital subtraction angiography showed an arteriovenous malformation draining to the inner lumen of the inferior vena cava.

Adult↗
PubMed2003

Multidetector CT of bronchiectasis: effect of radiation dose on image quality.

OBJECTIVE: The purpose of our prospective study was to assess the image quality with respect to the radiation dose incurred by multidetector CT (MDCT) in patients with suspected bronchiectasis. SUBJECTS AND METHODS. Image clusters, composed of nine images, using MDCT (120 kVp, a 2.5-mm collimation, a pitch of 6, and 2.5-mm reconstruction intervals) were obtained at each of two levels-the azygous arch and the right inferior pulmonary vein-at 170, 100, 70, 40, 20, and 10 mA. Independently, two chest radiologists assessed and compared the quality of the images obtained at the six milliamperage exposures. Image quality was graded using a 5-point scale with lung and mediastinal window settings. Radiation doses were measured at each of the six milliamperage settings while scanning the whole lung of a thoracic phantom using MDCT. RESULTS: The mean image quality scores at exposures of 170, 100, 70, 40, 20, 10 mA were as follows: 3.9, 3.7, 3.8, 3.2, 2.5, 1.6 at lung window settings and 4.1, 4.3, 4.0, 3.4, 2.3, 1.3 at mediastinal window settings, respectively. Images obtained at 70 mA were rated significantly better than those obtained at 40 mA or less (p < 0.01). The mean radiation dose at 170, 100, 70, 40, 20, 10 mA was 23.72, 14.39, 10.54, 5.41, 2.74, and 1.50 mGy, respectively. CONCLUSION: With a tube current setting as low as 70 mA, MDCT provides images of acceptable quality and volumetric data sets for the evaluation of bronchiectasis. The trade-off of using MDCT rather than conventional high-resolution CT is that the radiation dose is five times higher with MDCT (10.54 mGy) than with conventional high-resolution CT (2.17 mGy with parameters of 120 kVp, 170 mA, 1-mm collimation, and 10-mm intervals).

Adult↗
PubMedDate not supplied

Additional coronal images using low-milliamperage multidetector-row computed tomography: effectiveness in the diagnosis of bronchiectasis.

PURPOSE: The aim of our study was to evaluate the effectiveness of additional coronal images using low-milliamperage multidetector-row computed tomography (CT) in the diagnosis of bronchiectasis. METHODS: Helical volumetric CT scans (120 kVp, 70 mA, 2.5-mm collimation, table speed of 15 mm/s, table rotation time of 1 second) using low-milliamperage multidetector-row CT were obtained through the thorax in 110 patients who were suspected of bronchiectasis. Both axial (2.5-mm section thickness) and coronal (1.3-2.0-mm section thickness) reformatted images were made and sent to picture archiving and communication system (PACS) monitors. Two independent observers assessed CT scans twice; with axial images only and with both axial and coronal images. The detection rates of bronchiectasis were compared between readings with axial images only and with both axial and coronal images by using a nonparametric method of clustered data. Confidence grades were given to the distribution and type of bronchiectasis. RESULTS: With axial images only, the detection rates of bronchiectasis on a per-patient basis were 97% (213/220 patients, kappa = 0.888) whereas with both axial and coronal images, the detection rates were 100% (220/220 patients, kappa = 1.000) (P = 0.0001). Confidence to the distribution of bronchiectasis was greater with both axial and coronal images than with axial images only (P = 0.008). CONCLUSIONS: Additional coronal images using low-milliamperage multidetector-row CT are effective in the diagnosis of bronchiectasis by providing enhanced detection rates and confidence to the distribution of lesions.

Adult↗
PubMedDate not supplied

Selective intra-arterial calcium stimulation with hepatic venous sampling for preoperative localization of insulinomas.

OBJECTIVE: To determine the value of selective intra-arterial calcium stimulation with hepatic venous sampling using serum insulin and C-peptide gradients for the preoperative localization of insulinomas. MATERIALS AND METHODS: Seven consecutive patients (three men and four women aged 15-77 (mean, 42.7) years) with hypoglycemia underwent selective intra-arterial calcium stimulation in conjunction with hepatic venous sampling. Insulin gradients were calculated by an individual blinded to all other preoperative imaging studies and operative findings. In all patients except one, C-peptide gradients were also analyzed. The results were compared with the preoperative findings of ultrasonography, computed tomography, arteriography and endoscopic ultrasonography, as well as with the intraoperative findings of ultrasonography and palpation at surgery. RESULTS: Eight insulinomas (mean diameter, 12.5 mm) were diagnosed after surgery. In six patients, the calcium stimulation test with insulin gradients allowed accurate localization of the pathologic source of insulin secretion. Both C-peptide and insulin gradients substantially increased diagnostic accuracy. In one patient, C-peptide gradients were more helpful than insulin gradients for tumor localization. CONCLUSION: Selective intra-arterial calcium stimulation with hepatic venous sampling is a highly accurate and safe method for the preoperative localization of insulinomas. Additional C-peptide gradients seem to be helpful in assessing tumor location, but further study is needed.

Adult↗
PubMedDate not supplied

Usefulness of multidetector-row CT in the evaluation of reperfused myocardial infarction in a rabbit model.

OBJECTIVE: To evaluate the usefulness of multidetector-row computed tomography(CT) in the evaluation of reperfused myocardial infarction. MATERIALS AND METHODS: Eleven rabbits were subjected to 90-min occlusion of the left anterior descending coronary artery followed by reperfusion. Multidetector-row CT was performed 31 hours+/-21 after the procedure and pre and post-contrast multiphase helical CT images were obtained up to 10 min after contrast injection. The animals were sacrificed after 30 days and histochemical staining of the resected specimens was performed with 2'3'5-triphenyl tetrazolium chloride (TTC). RESULTS: In all 11 cases, the areas of myocardial infarction demonstrated with TTC-staining were identified on the CT images and the lesions showed hypoenhancement on the early phases up to 62 sec and hyperenhancement on the delayed phases of 5 min and 10 min compared with normal myocardial enhancement. The percentage area of the lesion with respect to the left ventricle wall on CT was significantly correlated with that of the TTC-staining results (p < 0.001 for both early and delayed phase CT) according to the generalized linear model analysis. The areas showing hypoenhancement on early CT were significantly smaller than those with hyperenhancement on delayed CT (p < 0.0001). CONCLUSION: Multidetector-row CT may be useful in the detection and sizing of reperfused myocardial infarction.

Animals↗
PubMedDate not supplied

Radiofrequency ablation of rabbit liver in vivo: effect of the pringle maneuver on pathologic changes in liver surrounding the ablation zone.

OBJECTIVE: We wished to evaluate the effect of the Pringle maneuver (occlusion of both the hepatic artery and portal vein) on the pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone in rabbit livers. MATERIALS AND METHODS: Radiofrequency (RF) ablation zones were created in the livers of 24 rabbits in vivo by using a 50-W, 480-kHz monopolar RF generator and a 15-gauge expandable electrode with four sharp prongs for 7 mins. The tips of the electrodes were placed in the liver parenchyma near the porta hepatis with the distal 1 cm of their prongs deployed. Radiofrequency ablation was performed in the groups with (n=12 rabbits) and without (n=12 rabbits) the Pringle maneuver. Three animals of each group were sacrificed immediately, three days (the acute phase), seven days (the early subacute phase) and two weeks (the late subacute phase) after RF ablation. The ablation zones were excised and serial pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone were evaluated. RESULTS: With the Pringle maneuver, portal vein thrombosis was found in three cases (in the immediate [n=2] and acute phase [n=1]), bile duct dilatation adjacent to the ablation zone was found in one case (in the late subacute phase [n=1]), infarction adjacent to the ablation zone was found in three cases (in the early subacute [n=2] and late subacute [n=1] phases). None of the above changes was found in the livers ablated without the Pringle maneuver. On the microscopic findings, centrilobular congestion, sinusoidal congestion, sinusoidal platelet and neutrophilic adhesion, and hepatocyte vacuolar and ballooning changes in liver ablated with Pringle maneuver showed more significant changes than in those livers ablated without the Pringle maneuver (p < 0.05) CONCLUSION: Radiofrequency ablation with the Pringle maneuver created more severe pathologic changes in the portal vein, bile ducts and liver parenchyma surrounding the ablation zone compared with RF ablation without the Pringle maneuver. Therefore, we suggest that RF ablation with the Pringle maneuver should be performed with great caution in order to avoid unwanted thermal injury.

Animals↗
PubMedDate not supplied

The balloon dilatation and large profile catheter maintenance method for the management of the bile duct stricture following liver transplantation.

OBJECTIVE: We wanted to evaluate the therapeutic efficacy of the percutaneous balloon dilatation and large profile catheter maintenance method for the management of patients with anastomotic biliary strictures following liver transplant. MATERIALS AND METHODS: From May 1999 to June 2003, 12 patients with symptomatic benign biliary stricture complicated by liver transplantation were treated with the percutaneous balloon dilatation and large profile catheter maintenance method (1-6 months). The patients were eight males and four females, and their ages ranged from 20 to 62 years (mean age: 44 years). Ten patients underwent living donor liver transplantation and two underwent cadaveric liver transplantation. Postoperative biliary strictures occurred from two to 21 months (mean age: 18 months) after liver transplantation. RESULTS: The initial technical success rate was 92%. Patency of the bile duct was preserved for eight to 40 months (mean period: 19 months) in 10 of 12 (84%) patients. When reviewing two patients (17%), secondary balloon dilatations were needed for treating the delayed recurrence of biliary stricture. In one patient, no recurrent stenosis was seen during the further 10 months follow-up after secondary balloon dilatation. Another patient did not response to secondary balloon dilatation, and he was treated by surgery. Eleven of 12 patients (92%) showed good biliary patency for 8-40 months (mean period: 19 months) of follow-up. CONCLUSION: The percutaneous balloon dilatation and large profile catheter maintenance method is an effective therapeutic alternative for the treatment of most biliary strictures that complicate liver transplantation. It has a high success rate and it should be considered before surgery.

Adult↗
PubMedDate not supplied

The "mini-perc" technique of percutaneous nephrolithotomy with a 14-Fr peel-away sheath: 3-year results in 72 patients.

OBJECTIVE: To assess the efficacy and safety of a "mini-perc" technique of percutaneous nephrolithotomy using a 14-Fr peel-away sheath for the removal of pyelocaliceal stones, and to determine appropriate inclusion criteria. MATERIALS AND METHODS: From July 1999 to June 2002, the medical records and radiographic images of 72 patients who underwent the "mini-perc" technique of percutaneous nephrolithotomy with a 14-Fr peel-away sheath, were reviewed to determine clinical history, stone characteristics, immediate stone free rate, final stone free rate after additional procedures, complications, and hospital stay. We also analyzed the effect of the longest stone diameter, the cumulative longest diameter of stones, the cumulative stone burden, and the stone density on the immediate stone free rate using a Fisher exact test. RESULTS: The only major complication, arterial bleeding, occurred in a patient with Child A liver cirrhosis and was successfully treated by embolization with coils and a gelatin sponge. The immediate stone free rate was 80.6 %, which was significantly influenced by stone diameter but not stone density. The mean hospital stay after the procedure was 3.97 days. CONCLUSION: The "mini-perc" technique of percutaneous nephrolithotomy, which uses the 14-Fr peel-away sheath, is a safe and effective modality for treating renal calculi.

Adolescent↗
PubMedDate not supplied

Long-term results of percutaneous ethanol injection for the treatment of hepatocellular carcinoma in Korea.

OBJECTIVE: To evaluate the long-term follow-up results of percutaneous ethanol injection (PEI) for the treatment of hepatocellular carcinoma (HCC) in Korea. MATERIALS AND METHODS: Sixty-eight nodular HCCs initially detected in 64 patients, were subjected to US-guided PEI as a first-line treatment. Long-term survival rates, local tumor progression rates, and complications were evaluated, as were the influences of tumor size and Child-Pugh class on these variables. RESULTS: No major complications occurred. The overall survival rates of the 64 patients at three and five years were 71% and 39%, and their cancer-free survival rates were 22% and 15%, respectively. The overall survival rate of patients with a small HCC (< or =2 cm) was significantly higher (p = 0.014) than that of patients with a medium-sized HCC (< or =2 cm). The overall survival rate of patients with Child-Pugh class A was significantly higher (p = 0.049) than that of patients with Child-Pugh class B. Of 59 cases with no residual tumor, local tumor progression was observed in ablation zones in 18, and this was not found to be significantly influenced by tumor size or Child-Pugh class. CONCLUSION: The results of our investigation of the long-term survival rates of PEI in HCC patients in Korea (a hepatitis B virus-endemic area) were consistent with those reported previously in hepatitis C endemic areas. Patients with a smaller tumor or a better liver function exhibited superior survival rates.

Adult↗