G H Chung

Chonbuk National University Hospital, Sŏul, Seoul, South Korea

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Publications (7)36.52 Total impact

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    ABSTRACT: Our objective was to determine the therapeutic efficacy and safety of radiofrequency ablation in the treatment of hepatocellular carcinoma (HCC) in patients with decompensated cirrhosis. Nineteen patients with 26 HCC nodules (range, 0.8-5 cm; mean, 1.96 cm) and decompensated liver cirrhosis (mean Child score, 10.7) were treated with radiofrequency ablation using cooled-tip electrodes and a 200-W generator. Radiofrequency ablation was performed under the guidance of sonography or CT. Procedure-related complications, therapeutic efficacy, each patient's survival, changes in blood test results--that is, serum aminotransferase and bilirubin--and changes in the Child score before and after ablation therapy were analyzed. To assess the therapeutic response of the tumor to radiofrequency ablation, we performed contrast-enhanced CT after the procedure and during follow-up. Complete necrosis without marginal recurrence at the 6-month follow-up was attained in 23 lesions (88.5%). During follow-up (mean, 13.3 months), one patient experienced a remote tumor recurrence in the liver. The median survival time was 12.0 +/- 1.7 months. Two patients died of liver failure--one at 2 months and one at 4 months after treatment. The other patients were followed for at least 6 months (range, 6-28 months; mean, 12 months). The first and second weeks after therapy, the serum aminotransferase and bilirubin levels were significantly higher than were pretreatment levels (p < 0.05). However, 3 weeks after therapy, those figures were nearly restored to the pretreatment levels. The mean Child scores 3 weeks after radiofrequency ablation (10.8) were similar to those before treatment (10.7). Radiofrequency ablation can be used selectively for treatment of HCC in patients with decompensated cirrhosis but has the potential to aggravate the preexisting hepatic dysfunction.
    No preview · Article · May 2006 · American Journal of Roentgenology
  • YK Kim · HS Kwak · CS Kim · GH Chung · YM Han · JM Lee
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    ABSTRACT: Purpose: To compare the sensitivity, positive predictive value, and diagnostic accuracy of superparamagnetic iron, oxide (SPIO)-enhanced magnetic resonance (MR) imaging with those of 16-detector row computed tomography (CT) for the detection of hepatocellular carcinoma (HCC) in patients with hepatitis B-induced cirrhosis. Materials and Methods: Institutional Review Board approval was obtained for this study, and informed consent was obtained from all patients. A total of 44 patients (36 men, eight women; age range, 35-67 years) with 59 HCCs and mild liver cirrhosis (Child-Pugh score A or B) underwent multiphasic CT and SPIO-enhanced MR imaging. The diagnosis of HCC was established at surgical resection (n = 31) and percutaneous biopsy (n = 28). SPIO-enhanced MR imaging was composed of T2-weighted turbo spin-echo and T2*-weighted gradient-echo sequences. Multiphasic CT consisted of four phases (ie, early arterial, late arterial, portal venous, and equilibrium). Three observers independently analyzed each image in random order. Sensitivity, positive predictive value, and diagnostic accuracy were calculated by using the alternative free-response receiver operating characteristic analysis for multi-detector row CT and SPIO-enhanced MR imaging. Results: Although not significant (P >.05), the area under the receiver operating characteristic curve for SPIO-enhanced MR imaging (mean, 0.90) was higher than that for multidetector row CT (mean, 0.82) for all observers. Also, although no significant difference was demonstrated by any of the three observers (P >.05), there was a trend toward increased sensitivity on both a per-lesion and a per-patient basis for SPIO-enhanced MR imaging (mean, 84.7% and 94.7%, respectively) compared with multidetector row CT (mean, 76.9% and 88.6%, respectively). No significant difference in positive predictive value was observed between modalities. SPIO-enhanced MR imaging and multiphasic CT show similar diagnostic accuracy, sensitivity, and positive predictive value for the detection of HCC in patients with relatively mild hepatitis B-induced cirrhosis. (c) RSNA, 2005
    No preview · Article · Feb 2006 · Radiology
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    ABSTRACT: 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. 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. 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). 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.
    No preview · Article · Jan 2006 · American Journal of Roentgenology
  • G.H. Chung · Y.M. Han · S.H. Jeong · C.R. Jack Jr
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    ABSTRACT: BACKGROUND AND PURPOSE: The purpose of this study was to assess supplementary motor area (SMA) activation during motor, sensory, word generation, listening comprehension, and working memory tasks by using functional MR imaging (fMRI). Human supplementary motor area (SMA) has been shown to play roles in motor control and other various functions such as sensory, speech expression, and memory. However, topographical localizations of these functions in the SMA remain unclear. The purpose of this study was to assess SMA activation during motor, sensory, word generation, listening comprehension, and working memory tasks by using functional MR imaging (fMRI). METHODS: Sixteen healthy right-handed subjects (nine men and seven women) were imaged on a Siemens 1.5T system. Whole-brain functional maps were acquired by using blood oxygenation level-dependent echo-planar imaging sequences in the axial plane. Each paradigm consisted of five epochs of activation versus the control condition. The activation tasks consisted of left-finger complex movement, heat sensory stimulation of the left hand, word generation, listening comprehension, and working memory. The reference function was a boxcar waveform. Activation maps were thresholded at an uncorrected P = .0001. The thresholded activation maps were placed into MNI (Montreal Neurologic Institute) stereotactic coordinates, and the anatomic localization of activation within the SMA was compared across tasks. RESULTS: SMA activation was observed in 16 volunteers for the motor task, 11 for the sensory task, 15 for the word generation task, five for the listening comprehension task, and 15 for the working memory task. Although not statistically significant, qualitative differences in the location of activation within the SMA were present by task. The rostral aspects of the SMA tended to activate during word generation and working memory tasks, and the caudal aspect of the SMA tended to activate during the motor and sensory tasks. Right (contralateral) SMA activation was observed during the motor and sensory tasks, and left SMA activation during the word generation and memory tasks. CONCLUSION: Our results suggest that SMA is involved in a variety of functional tasks, including motor, sensory, word generation, and working memory. Some are tasks that are traditionally associated with this area (such as motor and sensory), and others are not (such as word generation and working memory). Qualitatively, the anterior and posterior portions of the SMA appeared to be engaged by different types of tasks.
    No preview · Article · Jan 2005 · American Journal of Neuroradiology
  • Y M Han · J K Kim · B S Roh · H Y Song · J M Lee · Y H Lee · S Y Lee · G H Chung · C S Kim · M H Sohn · K C Choi
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    ABSTRACT: To evaluate the efficacy of selective arterial embolization in symptomatic renal angiomyolipoma (AML) and the change in angiomyogenic components during long-term follow-up after embolization. Fourteen adult patients with symptomatic AMLs underwent 16 selective arterial embolizations. The embolic materials used were absolute alcohol with (n = 5) or without (n = 3) iodized oil, Gianturco coils (n = 4), and polyvinyl alcohol foam powder with gelatin sponge (n = 2). Follow-up ultrasonography and computed tomography (CT) were performed in six and 14 patients, respectively. The effectiveness of selective arterial embolization was evaluated on the basis of the area of the angiomyogenic components in the AML on initial and follow-up images and clinical improvement. All patients showed devascularization of the tumor on the postembolization angiograms. In 13 patients, clinical symptoms disappeared. The follow-up period was 7-72 months (mean, 33 months). One patient underwent nephrectomy at 7 months after embolization because of a large cystic lesion found at 1 month. In long-term CT follow-up (> or =12 months) in 12 patients, nearly all angiomyogenic components disappeared, but fatty components partially shrank with liquefactive necrosis in tumors. Selective arterial embolization is an effective and safe treatment of AML. The angiomyomatous components crucial for the prevention of bleeding were very sensitive to the embolization.
    No preview · Article · Aug 1997 · Radiology
  • Y M Han · H Y Song · J M Lee · S I Cho · G H Chung · C S Kim · M H Sohn · K C Choi
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    ABSTRACT: To evaluate therapeutic effects and complications of a covered Gianturco stent for esophagorespiratory fistulae. Of 95 patients with esophageal carcinomas, 10 had esophagorespiratory fistulae and were treated with a silicone-covered Gianturco stent. The authors retrospectively assessed patients' food intake capacity and delayed problem of the stent. All fistulae were occluded without immediate complications. Two patients could swallow all foods; four, most foods; three soft foods; and one, only liquids. Clinical problems occurred between 1 and 24 weeks in four patients: reopened fistula (n = 1), recurrent fistula (n = 1) (both patients were successfully treated with another esophageal stent), and dyspnea (n = 2) due to tracheal compression by stent and tracheal invasion by tumor (one patient was treated with a tracheal stent). A silicone-covered modified Gianturco stent is effective for palliation of esophagorespiratory fistulae caused by esophageal cancer. Simultaneous use of a tracheal stent is recommended for extrinsic tracheal narrowing by the proximal tip of the stent and invasion by tumor.
    No preview · Article · May 1996 · Radiology
  • J M Lee · H Y Song · Y M Han · G H Chung · M H Sohn · C S Kim · K C Choi
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    ABSTRACT: To evaluate the effectiveness of balloon dacryocystoplasty (DCP) in the treatment of complete and partial obstruction of the nasolacrimal system (NLS). Fluoroscopically guided balloon DCP was attempted in 57 eyes of 50 consecutive patients with complete obstruction of the NLS and 24 eyes of 22 patients with partial obstruction of the NLS. With nasal endoscopic guidance, a 0.018-inch guide wire was introduced through the superior punctum into the inferior meatus of the nasal cavity and pulled out through the nare with a hemostat. A deflated angioplasty balloon catheter was introduced in a retrograde direction over the guide wire, and the balloon was dilated. Initial technical and clinical success was achieved in 29 of 57 eyes (51%) with complete obstruction and 17 of 24 eyes (71%) with partial obstruction. The 2-year cumulative clinical patency rates were 25% and 20% for partial and complete obstructions, respectively. The overall cumulative patency rate for all 81 eyes was 23%. Balloon DCP is simple and safe but has high failure and recurrence rates.
    No preview · Article · Sep 1994 · Radiology