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Young-Min Han

Publications and source records attributed to Young-Min Han.

At least 19 recordsLinked to original sources
PubMed2006

A delayed case of renal artery pseudoaneurysm presented with gross hematuria and azotemia in solitary kidney following percutaneous nephrostomy: treated by transcatheter coil embolization.

Renal arteriovenous fistula or pseudoaneurysms developing after invasive procedures are either asymptomatic or show only transient symptoms. We describe here a case of symptomatic renal artery pseudoaneurysm that presented with gross hematuria and azotemia. The pseudoaneurysm of renal artery was diagnosed by ultrasonography and abdominal magnetic resonance imaging (MRI), and it was successfully treated by percutaneous transcatheter coil embolization. A high index of suspicion is essential for the early diagnosis and treatment of delayed gross hematuria in patients with history of percutaneous nephrostomy.

Aged, 80 and over↗
PubMed2006

Comparison of gadobenate dimeglumine-enhanced dynamic MRI and 16-MDCT for the detection of hepatocellular carcinoma.

OBJECTIVE: The objective of our study was to compare the diagnostic performance of gadobenate dimeglumine-enhanced MRI with that of 16-MDCT for the detection of hepatocellular carcinoma using receiver operating characteristic (ROC) curve analysis. MATERIALS AND METHODS: Thirty-one patients with 53 hepatocellular carcinomas underwent gadobenate dimeglumine-enhanced dynamic MRI and multiphasic CT using 16-MDCT within a mean interval of 5 days (range, 3-9 days). The dynamic MRI examination was performed using 3D fat-saturated volumetric interpolated imaging and sensitivity encoding on a 1.5-T unit. Both dynamic MRI and multiphasic MDCT included dual arterial phase images. Three observers independently interpreted the CT and MR images in random order, separately, and without patient identifiers. The diagnostic accuracy of each technique was evaluated using the alternative-free response ROC method. The sensitivity and positive predictive values were also calculated. RESULTS: The sensitivities of gadobenate dimeglumine-enhanced MRI for all observers were significantly higher than those of MDCT for all the lesions and for lesions 1.0 cm or smaller (p < 0.05); however, for lesions larger than 1.0 cm, the sensitivities of the two imaging techniques were similar. The mean area under the ROC curve (A(z)) of gadobenate dimeglumine-enhanced MRI (0.87 +/- 0.03 [SD]) was higher than that of MDCT (0.83 +/- 0.04), but no significant difference was found between them (p = 0.31). The number of false-positive findings on dynamic MRI was slightly higher than on MDCT, but no significant difference in the positive predictive value between the two imaging techniques was detected (observer 1, p = 0.06; observer 2, p = 0.13; observer 3, p = 1.00). CONCLUSION: Gadobenate dimeglumine-enhanced MRI has a higher sensitivity for small hepatocellular carcinomas (</= 1 cm) but a higher false-positive rate due to nonspecific enhancement of benign lesions, such as arterioportal shunt, leading to no significant difference of overall accuracy when compared with MDCT.

Adult↗
PubMed2005

Comparison of temporary and permanent stent placement with concurrent radiation therapy in patients with esophageal carcinoma.

PURPOSE: To assess the clinical effectiveness of temporary metallic stent placement with concurrent radiation therapy in patients with esophageal carcinoma by comparing it with permanent stent placement with concurrent radiation therapy. MATERIALS AND METHODS: Covered retrievable expandable nitinol stents were placed in 47 patients with esophageal carcinoma 1 week before starting radiation therapy; the stents were electively removed 4 weeks after placement in 24 patients (group A), while not electively removed in the other 23 patients (group B). In cases of complications, the stents were also removed from patients in groups A and B. The dysphagia score, complications (severe pain, granulation tissue formation, stent migration, esophagorespiratory fistula, and hematemesis), tumor overgrowth/regrowth, reintervention rates, and dysphagia-progression-free and overall survival rates were compared in the two groups. RESULTS: Stent placement or removal was technically successful and well tolerated in all patients. The dysphagia score was significantly improved in both groups after stent placement (P < .01). Each of the stent-related complications was less in group A than in group B but there was no significant difference. However, the total number of patients with one or more than one complications and who needed related reinterventions was significantly less in group A than in group B (P = .042 and .030, respectively). Tumor overgrowth/regrowth and the total number of patients who required related reinterventions was not significantly different (P = 1.00 and .517, respectively). Dysphagia-progression-free and overall survival rates were significantly longer in group A than in group B (P = .005 and .001, respectively). CONCLUSION: Temporary placement of a covered retrievable expandable metallic stent with concurrent radiation therapy for patients with esophageal carcinoma is beneficial for reducing complications and related reinterventions and for increasing resultant survival rates compared with permanent esophageal stent placement.

Adult↗
PubMed2005

Stents in common iliac vein obstruction with acute ipsilateral deep venous thrombosis: early and late results.

PURPOSE: To evaluate, by imaging and clinical follow-up, the effectiveness and long-term results of stent placement in cases of common iliac vein obstruction associated with ipsilateral deep vein thrombosis (DVT). MATERIALS AND METHODS: Retrospective analysis of 22 patients (13 women, nine men; median age, 58 years) with common iliac vein obstruction with ipsilateral DVT was performed for this study. All patients presented with leg edema or pain and were treated with catheter-directed thrombolysis (1,000-2,000 U urokinase per kg body weight per hour; n = 19), aspiration thrombectomy (n = 21), or angioplasty (n = 14) followed by stent placement (n = 22) via an ipsilateral popliteal vein approach (right, n = 2; left, n = 20) under ultrasonographic (US) guidance. Patients were then followed by duplex US, and patency rates were determined by Kaplan-Meier survival analysis. RESULTS: The mean procedure time was 15 hours (range, 1-23 hours) and the mean urokinase dose was 1,980,000 U (range, 600,000-3,600,000 U) before the implantation of 27 stents. Three patients did not receive urokinase. The technical success rate was 96% (26 of 27 stents) and the clinical success rate was 95% (21 of 22 patients). The causes of common iliac vein obstruction were May-Thurner syndrome (n = 16), pelvic mass (n = 2), and unknown (n = 4). The early complications included upward stent migration in one patient and a spinal epidural hematoma in another. The late complication was partial stent obstruction, which was successfully treated by thrombolysis and angioplasty in one patient. Follow-up lasted 1-41 months (mean, 21.4 months). Overall, the 1-year and 2-year primary patency rates were both 95% and the 1-year and 2-year secondary patency rates were both 100%. CONCLUSION: Directed catheter thrombolysis and aspiration of DVT are relatively safe, and the use of stents improves patency results in cases of common iliac vein obstruction.

Adult↗
PubMed2005

Comparison of renal damage by iodinated contrast or gadolinium in an acute renal failure rat model based on serum creatinine levels and apoptosis degree.

This study was undertaken to compare renal damage, as determined by serum creatinine and degree of apoptosis, caused by iodinated contrast or gadolinium in an acute renal failure (ARF) rat model. Rats were divided into three groups; controls (n=3), a CT contrast medium group (n=9), and an MR contrast medium group (n=9). The CT and MR groups were further subdivided into three groups, namely, low, standard, and high dose subgroups. Renal function was evaluated by determining serum creatinine levels; before ARF, and 48 hr after ARF and contrast administration. Apoptosis was assayed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). No significant creatinine level differences were observed between the CT and MR groups (p=0.116). Degrees of apoptosis in the renal cortex and medulla were more severe in the CT contrast medium group than in the control or MR contrast medium group (p<0.05). The study shows that CT contrast medium did not aggravate renal function more so than MR contrast medium in this ARF rat model. However, apoptosis examination in the renal cortex and medulla indicated that CT contrast medium induced more severe apoptosis than MR contrast medium (p<0.05). We conclude that CT contrast medium can be used for renal imaging studies when subjects are well hydrated and preventive medication is administered.

Acute Kidney Injury↗
PubMed2004

In vivo 1H MR spectroscopic findings in traumatic contusion of ICR mouse brain induced by fluid percussion injury.

PURPOSE: The purpose of this study was to investigate the proton metabolic differences of the right parietal cortex with experimental brain contusions of ICR mouse induced by fluid percussion injury (FPI) compared to normal controls and to test the possibility that 1H magnetic resonance spectroscopy (MRS) findings could provide neuropathologic criteria in the diagnosis and monitoring of traumatic brain contusions. MATERIALS AND METHODS: A homogeneous group of 20 ICR male mice was used for MRI and in vivo 1H MRS. Using image-guided, water-suppressed in vivo 1H MRS with a 4.7 T MRI/MRS system, we evaluated the MRS measurement of the relative proton metabolite ratio between experimental brain contusion of ICR mouse and healthy control subjects. RESULTS: After trauma, NAA/Cr ratio, as a neuronal marker decreased significantly versus controls, indicating neuronal loss. The ratio of NAA/Cr in traumatic brain contusions was 0.90+/-0.11, while that in normal control subjects was 1.13+/-0.12 (P=0.001). The Cho/Cr ratio had a tendency to rise in experimental brain contusions (P=0.02). The Cho/Cr ratio was 0.91+/-0.17, while that of the normal control subjects was 0.76+/-0.15. However, no significant difference of Glx/Cr was established between the experimental traumatic brain injury models and the normal controls. DISCUSSION AND CONCLUSIONS: The present 1H MRS study shows significant proton metabolic changes of parietal cortex with experimental brain contusions of ICR mouse induced by FPI compared to normal controls. In vivo 1H MRS may be a useful modality for the clinical evaluation of traumatic contusions and could aid in better understanding the neuropathologic process of traumatic contusions induced by FPI.

Animals↗
PubMed2003

Flared polyurethane-covered self-expandable nitinol stent for malignant biliary obstruction.

PURPOSE: To determine the technical efficacy and safety of a flared polyurethane-covered self-expandable nitinol stent in the management of malignant biliary obstruction and to evaluate its clinical efficacy by estimating stent patency and patient survival rates. MATERIALS AND METHODS: Thirteen patients with common bile duct strictures (nonhilar) caused by malignant disease were treated by placement of 13 nitinol stents. The stents used include a flared section in the proximal portion (12 mm in diameter and 10 mm in length) and a section in the remnant portion that is fully covered with high-elasticity polyurethane, with an unconstrained diameter of 10 mm and a total length of 50-80 mm. Patient survival and stent patency rates were calculated with use of Kaplan-Meier survival analysis. The follow-up bilirubin and serum amylase and lipase levels were calculated, and the differences in means were evaluated with use of a Wilcoxon signed-rank test. The average follow-up duration was 22.9 weeks (range, 8-56 weeks). RESULTS: Placement was successful in all cases. The 30-day mortality rate was 0%. The survival rates were 38% and 24% at 20 and 50 weeks, respectively. Seventy-seven percent of study patients had adequate palliative drainage during their the remainder of their lives. The stent patency rates were 71% and 48% at 20 and 50 weeks, respectively. Three patients (23%) presented with stent occlusion requiring repeat intervention. There were no procedure-related complications such as proximal or distal migration. No complications occurred other than stent occlusion. One patient's stent was removed under endoscopic guidance 15 weeks after its insertion. Bilirubin levels had significantly decreased 1 week after stent insertion (P <.001). CONCLUSION: Preliminary results suggest that placement of a flared polyurethane-covered self-expandable nitinol stent is feasible and effective in achieving biliary drainage. The stents do not migrate, but there is tumor ingrowth into the flared portion of the stent. Treatment of a larger group of patients will be mandatory to validate these long-term results.

Adult↗
PubMed2002

Polyurethane-covered self-expandable nitinol stent for malignant biliary obstruction: preliminary results.

PURPOSE: To evaluate the immediate and long-term results in ten patients with malignant biliary obstruction using a polyurethane-covered, self-expandable nitinol stent. METHODS: A nitinol stent, fully covered with high-elasticity polyurethane, with an unconstrained diameter of 10 mm and a total length of 60-80 mm, was placed transhepatically under fluoroscopic guidance in ten patients. The length of the biliary obstruction varied between 30-50 mm. The follow-up examination included a clinical assessment, serum bilirubin measurement, and ultrasound examinations at one-month intervals in all patients. RESULTS: Initial stent deployment was successful in eight patients. Two patients experienced proximal migration, which was solved by insertion of two, uncovered Wallstents. One patient had the stent removed after two weeks because of severe nausea and vomiting. One patient had delayed migration of the covered stent after 40 weeks. The follow-up duration was 3-40 weeks (Mean: 16.9 weeks). Seven patients died (3-26 weeks) and three patients survived (24-40 weeks). The bilirubin measurements in all patients had significantly decreased one week after stent insertion. The levels of amylase and lipase had did not increase after stent insertion. CONCLUSIONS: A polyurethane-covered, self-expandable nitinol stent can be used effectively and safely in the treatment of malignant biliary obstruction. The preliminary results are favorable, but there is a need for further large studies to determine both long-term survival and patency.

Adult↗
PubMed2002

Creation of an intra-atrial communication with a new Amplatzer shunt prosthesis: preliminary results in a swine model.

A nitinol shunt device was applied in six minipigs to create a precise intra-atrial shunt. This self-expanding shunt device consists of two retention disks of 2-8 mm, a 4 mm connecting waist with a 10 mm eccentric hole. It requires a 7 Fr introducer sheath. The device is attached to the delivery cable with a microscrew. Placement technique is identical to that of Amplatzer septal occluder. Balloon dilation was performed immediately and 1 month after placement. One animal died from general anesthesia before device placement. Left atrial angiography showed a patent intra-atrial shunt in 5/5 pigs immediately and 4/4 in 1- to 3-month follow up. Postmortem examination demonstrated patent shunts partially or completely neoendothelialized. The shunt device was found to be an effective and safe way to create a permanent atrial communication.

Alloys↗
PubMedDate not supplied

Spinal epidural hematoma after thrombolysis for deep vein thrombosis with subsequent pulmonary thromboembolism: a case report.

A 38-year-old male was initially admitted for left leg swelling. He was diagnosed as having deep vein thrombosis (DVT) in the left leg and a pulmonary thromboembolism by contrast-enhanced chest computed tomography (CT) with delayed lower extremity CT. The DVT was treated by thrombolysis and a venous stent. Four hours later, he complained of severe back pain and a sensation of separation of his body and lower extremities; he experienced paraplegia early in the morning of the following day. Magnetic resonance imaging showed a spinal epidural hematoma between T11 and L2, which decompressed following surgery. We, therefore, report a case of a spinal epidural hematoma after thrombolysis in a case of DVT with a pulmonary thromboembolism.

Adult↗
PubMedDate not supplied

Fluoroscopically guided feeding tube insertion for relief of postoperative gastrointestinal anastomotic obstruction and leakage.

PURPOSE: To evaluate the feasibility and effectiveness of feeding tube insertion and enteral feeding for the treatment of postoperative gastrointestinal anastomotic obstruction and leakage. MATERIALS AND METHODS: From June 1999 to June 2002, thirty-four cases of postoperative gastrointestinal anastomotic obstruction and leakage after surgery for gastric carcinoma were treated by insertion of a feeding tube under fluoroscopic guidance. Twenty-one patients were male and 13 were female. The patients' ages ranged from 39 to 74 years (mean age: 61 years). All the patients experienced vomiting, and 15 patients had anastomotic site or duodenal stump leakage. We evaluated the feasibility of feeding tube insertion for enteral feeding to improve the obstruction and facilitate leakage site closure, and the patients' nutritional benefit was also evaluated by checking the serum albumin level between pre- and post-enteral feeding via the feeding tube. RESULTS: Thirty-two patients (94%) were successfully managed by feeding tube insertion, but the remaining two were not managed, and this was due to severe angulations at the anastomotic site. The procedure times for feeding tube insertion ranged from 15 to 60 minutes (mean time: 45 minutes). Twenty-eight patients experienced symptomatic relief of gastrointestinal obstruction, and they were able to resume a normal regular diet after feeding tube removal. Three patients underwent stent insertion due to recurrent symptoms, and one patient underwent jejunostomy feeding due to the presence of a persistent leakage site. Eleven patients achieved leakage site closure after enteral feeding via a feeding tube. The serum albumin level was significant, increased from pre-enteral feeding (2.65 +/- 0.37 g/dL) to the post-enteral feeding (3.64 +/- 0.58 g/dL) via the feeding tube (p < 0.001). The duration of follow-up ranged from one to 53 months (mean: 23 months). CONCLUSION: The insertion of a feeding tube for enteral feeding under fluoroscopic guidance is safe, and it provides effective relief from gastrointestinal anastomotic site obstruction and leakage after gastric surgery. Moreover, our findings indicate that feeding tube insertion for enteral feeding may be used as the primary procedure to treat postoperative anastomotic obstruction and leakage.

Adult↗
PubMedDate not supplied

Ruptures of the medial head of the gastrocnemius ("tennis leg"): clinical outcome and compression effect.

UNLABELLED: The purpose of this study is to describe the clinical outcome of conservative treatment in patients with rupture of the medial head of the gastrocnemius ("tennis leg") occurring during exercise and training and the effect of the compression treatment. MATERIALS AND METHODS: Thirty patients (conservative treatment=15; compression treatment=15), aged 30-45 years, with clinically suspected rupture of the medial head of the gastrocnemius occurring during exercise and training were referred for ultrasonography (US) examination. All patients underwent US of the affected and contralateral asymptomatic limb. Follow-up clinical evaluation and US imaging of all patients each were performed at 1-week intervals during the month after injury and at 2-week intervals during the following 6 months. US findings were analyzed with respect to the integrity of the musculotendinous junctions of the gastrocnemius, the presence of a fluid collection, and the union time of the medial head of the gastrocnemius with the soleus muscle. In addition, we analyzed the clinical outcome of the compression treatment. RESULTS: Of the 30 patients who had an initial US examination after their injury, partial rupture of the medial head of the gastrocnemius muscle was identified in 11 patients (36.7%); the remaining 19 patients were diagnosed with complete rupture. Fluid collection between the medial head of the gastrocnemius and the soleus muscle was identified in 25 patients (83.3%). First union of the medial head of the gastrocnemius with the soleus muscle in the compressive group was significantly rapid than that of the conservative group (4.25 vs. 3.25 weeks; P=.02). Fluid collection between the two muscles after 1 month in the compressive group was significantly smaller than that in the conservative group (8.9 vs. 4.5 mm; P=.01). CONCLUSIONS: Early compressive treatment in patients with rupture of the medial head of the gastrocnemius decreases the hemorrhage amount and can be possible for early ambulation.

Adult↗
PubMedDate not supplied

Focal eosinophilic infiltration of the liver mimicking hepatocellular carcinoma: case reports.

Focal eosinophilic infiltration is a rare disease entity that in patients with malignancies may mimic malignant hepatic nodules. We describe two cases in which focal eosinophilic infiltration of the liver, as well as primary liver cancer, occurred. In these patients, imaging findings similar to those observed in hepatocellular carcinoma (HCC) were noted: Enhancement at dynamic magnetic resonance (MR) imaging substantially increased perfusion at computed tomography during hepatic arteriography (CTHA) and a perfusion defect at computed tomography during arterial portography (CTAP).

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Detection of small hypervascular hepatocellular carcinomas in cirrhotic patients: comparison of superparamagnetic iron oxide-enhanced MR imaging with dual-phase spiral CT.

OBJECTIVE: To compare the performance of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) maging at 1.5T and dual-phase spiral computed tomography (CT) for the depiction of small hypervascular hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: Forty-three patients with 70 small nodular HCCs (5-20 mm; mean, 13.7 mm) were examined. Diagnosis was based on the results of surgical biopsy in 22 patients and by the combined assessment of MR imaging, lipiodol CT, alpha feto-protein levels, and angiographic findings in 21. MR imaging consisted of respiratory-triggered turbo spin-echo T2-weighted imaging, T1-weighted fast low-angle shot, and T2* -weighted fast imaging with steady-state precession imaging before and after SPIO enhancement. CT imaging was performed with 5-mm collimation and 1:1.4 pitch, and began 30 and 65 secs after the injection of 150 mL of contrast medium at a rate of 3 mL/sec. Two blinded observers reviewed all images independently on a segment-by-segment basis. Diagnostic accuracy was evaluated using receiver operating characteristics(ROC) analysis. RESULTS: The mean areas (Az) under the ROC curves were 0.85 for SPIOenhanced MR imaging and 0.79 for dual-phase spiral CT (p <.05). The mean sensitivity of SPIO-enhanced MR imaging was significantly higher than that of CT (p <.05), i.e. 70.6% for MR imaging and 58.1% for CT. MR imaging had higher false-positive rates than dual-phase spiral CT, but the difference was not statistically significant (3.7% vs 3.3%) (p >.05). CONCLUSION: SPIO-enhanced MR imaging is more sensitive than dual-phase spiral CT for the depiction of small hypervascular hepatocellular carcinomas.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Diagnosis and follow-up US evaluation of ruptures of the medial head of the gastrocnemius ("tennis leg").

OBJECTIVE: The purpose of this study was to demonstrate the ultrasonographic (US) findings of rupture and the healing process of the medial head of the gastrocnemius ("Tennis Leg"). MATERIALS AND METHODS: Twenty-two patients (age range: 30 to 45 years) with clinically suspected ruptures of the medial head of the gastrocnemius were referred to us for US examination. All the patients underwent US of the affected limb and the contralateral asymptomatic limb. Follow-up clinical evaluation and US imaging of all patients were performed at two-week intervals during the month after injury and at one-month intervals during the following six months. RESULTS: Of the 22 patients who had an initial US examination after their injury, partial rupture of the medial head of the gastrocnemius muscle was identified in seven patients (31.8%); the remaining 15 patients were diagnosed with complete rupture. Fluid collection between the medial head of the gastrocnemius and the soleus muscle was identified in 20 patients (90.9%). The thickness of the fluid collection, including the hematoma in the patients with complete rupture (mean: 9.7 mm), was significantly greater than that seen in the patients with partial tear (mean: 6.8 mm) (p < 0.01). The primary union of the medial head of the gastrocnemius with the soleus muscle in all the patients with muscle rupture and fluid collection was recognized via the hypoechoic tissue after four weeks. CONCLUSION: Ultrasonography is a useful imaging modality for the diagnosis and follow-up examination for the patients suffering with rupture of the medial head of the gastrocnemius.

Adult↗