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Kyoung Won Kim

Publications and source records attributed to Kyoung Won Kim.

At least 19 recordsLinked to original sources
PubMed2006

Macrovesicular hepatic steatosis in living liver donors: use of CT for quantitative and qualitative assessment.

PURPOSE: To determine prospectively the diagnostic performance of unenhanced computed tomography (CT) in the assessment of macrovesicular steatosis in potential donors for living donor liver transplantation by using same-day biopsy as a reference standard. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. A total of 154 candidates, including 104 men (mean age, 30.2 years +/- 10.3 [standard deviation]) and 50 women (mean age, 31.8 years +/- 11.2), underwent same-day unenhanced CT and ultrasonography-guided liver biopsy. Histologic degree of macrovesicular steatosis was determined. Three liver attenuation indices were derived: liver-to-spleen attenuation ratio (CT(L)(/S)), difference between hepatic and splenic attenuation (CT(L)(-S)), and blood-free hepatic parenchymal attenuation (CT(LP)). Regression equations were used to quantitatively estimate the degree of macrovesicular steatosis. Limits of agreement between estimated macrovesicular steatosis and the reference standard were calculated. Receiver operating characteristic analyses were used to determine the performance of each index for qualitative diagnosis of macrovesicular steatosis of 30% or greater. The cutoff value that provided a balance between sensitivity and specificity and the highest cutoff value that yielded 100% specificity were determined. RESULTS: Limits of agreement were -14% to 14% for CT(L)(/S) and CT(L)(-S) and -13% to 13% for CT(LP). Performance in diagnosing macrovesicular steatosis of 30% or greater was not significantly different among indices (P > .05). Cutoff values of 0.9, -7, and 58 were determined for CT(L)(/S), CT(L)(-S), and CT(LP), respectively, and provided a balance between sensitivity and specificity. Cutoff values of 0.8, -9, and 42 were determined for CT(L)(/S), CT(L)(-S), and CT(LP), respectively, and yielded 100% specificity for all indices, with corresponding sensitivities of 82%, 82%, and 73% for CT(L)(/S), CT(L)(-S), and CT(LP), respectively. CONCLUSION: Diagnostic performance of unenhanced CT for quantitative assessment of macrovesicular steatosis is not clinically acceptable. Unenhanced CT, however, provides high performance in qualitative diagnosis of macrovesicular steatosis of 30% or greater.

Adult↗
PubMed2006

Endovascular stent placement for interposed middle hepatic vein graft occlusion after living-donor liver transplantation using right-lobe graft.

Middle hepatic vein (MHV) reconstruction is performed to drain the right paramedian sector to prevent hepatic venous congestion (HVC). The aim of the present study was to evaluate endovascular stent placement in patients with stenosed and/or occluded interposition vein graft (IVG) to segment V hepatic vein (V5) and segment VIII hepatic vein (V8) after living-donor liver transplantation (LDLT). The procedure was performed in 11 recipients; 7 underwent it within 24 hours of LDLT. The following parameters, including technical success, clinical success, complications, patient survival data, and serial computed tomography (CT) findings during follow-up, were documented retrospectively. Technical success was defined as both successful stent placement and resolution of stenosis or occlusion with copious flow of contrast medium through the stent, while clinical success was defined as both improvement of liver function tests (LFTs) and reduction or disappearance of hepatic low-attenuation areas on follow-up CT scans taken within 1 week of stent placement. Technical success was achieved in 10 of 11 patients (91%), and clinical success was achieved in 9 of 11 patients (82%). Acute thrombotic occlusion of the stent-inserted hepatic vein occurred in 1 patient 1 day following stent placement. During the mean follow-up period of 468 days (range, 13-891 days), 9 patients survived and 2 patients died. No death was directly related to stent placement or its related complications. The low-attenuation area in the involved hepatic segment V (S5) and/or VIII (S8) area prior to stent placement disappeared completely on follow-up CT scans performed at 3-12 days (mean, 5.4 days) after stent placement in all 9 patients with clinical success. No attenuation change occurred even in cases with chronic occlusion of the stent-inserted hepatic veins. In conclusion, though IVG to V5 and V8 remains controversial, the treatment of their stenosis or occlusion is safe and effective, even during their immediate postoperative period.

Adult↗
PubMed2006

Flat polyps of the colon: detection with 16-MDCT colonography--preliminary results.

OBJECTIVE: This study evaluates the ability of contrast-enhanced, 16-MDCT colonography to display flat colonic lesions when a very narrow slice thickness (1 mm) is used. CONCLUSION: Less than 50% of flat lesions in our population could be visualized by blinded and unblinded review. Before they could be visualized, flat lesions were 2 mm or greater in height and 7 mm or greater in diameter. Lesions with a height of 1 mm or less were not seen on CT colonography. Contrast enhancement, location on a haustral fold, and abnormal 2D and 3D morphology contributed to lesion conspicuity.

Aged↗
PubMed2006

Comparison of mangafodipir trisodium- and ferucarbotran-enhanced MRI for detection and characterization of hepatic metastases in colorectal cancer patients.

OBJECTIVE: The purpose of our study was to evaluate the validity of mangafodipir trisodium-enhanced versus ferucarbotran-enhanced MRI in the detection and characterization of hepatic lesions in colorectal cancer patients. MATERIALS AND METHODS: Forty-one patients who were known to have or suspected of having hepatic metastasis from colorectal carcinoma underwent mangafodipir trisodium- or ferucarbotran-enhanced MRI in block randomization methods. Two radiologists independently reviewed the MR images to determine the number of hepatic lesions and to characterize the lesions as malignant or benign. Each lesion was assessed according to its size (small, 2 cm in diameter) on both mangafodipir trisodium- or ferucarbotran-enhanced MRI. The data were correlated with the reference diagnosis: histopathology and intraoperative sonography (n = 16); intraoperative sonography (n = 4); and imaging and clinical diagnosis with follow-up (> 3 months; n = 21). The detection rates and diagnostic accuracies of hepatic lesions on both sets of MR images were assessed using Fisher's exact test. RESULTS: Eighty-two hepatic lesions (53 metastatic and 29 benign) were identified in 41 patients. No significant differences were seen between mangafodipir trisodium- and ferucarbotran-enhanced MRI for detecting all hepatic lesions (p = 0.183), small hepatic lesions (p = 0.299), all metastases (p = 0.695), and small metastases (p = 0.689). The diagnostic accuracies of mangafodipir trisodium- and ferucarbotran-enhanced MRI showed no significant differences in all hepatic lesions (p = 0.624) and small hepatic lesions (p = 0.641). CONCLUSION: Mangafodipir trisodium- and ferucarbotran-enhanced MRI are similar in hepatic lesion detection and characterization in colorectal cancer patients.

Adult↗
PubMed2006

Contrast-enhanced sonography for prostate cancer detection in patients with indeterminate clinical findings.

OBJECTIVE: The purpose of our study was to evaluate the usefulness of contrast-enhanced sonography for prostate cancer detection in patients with an indeterminate prostate-specific antigen (PSA) level (4-10 ng/mL) and negative findings on digital rectal examination. SUBJECTS AND METHODS: Forty-eight patients underwent gray-scale, color Doppler, and contrast-enhanced sonography examinations and then sonographically guided biopsy. Contrast-enhanced sonography was performed using Levovist at a mechanical index of 1.1-1.4. The performances of the three methods for cancer detection were compared according to biopsy site and patient. RESULTS: Sensitivity by biopsy site was greater on contrast-enhanced sonography (68%) than on gray-scale (39%) and color Doppler (41%) sonography (p > or = 0.05), whereas the specificity and overall accuracy by biopsy site (82% and 77% for gray-scale sonography, 84% and 79% for color Doppler sonography, and 83% and 81% for contrast-enhanced sonography, respectively) were not different for the three methods (p > 0.05). The concordance score for sonography and biopsy results by patient was not different for gray-scale (6.4 +/- 1.8), color Doppler (6.3 +/- 0.6), and contrast-enhanced sonography (6.5 +/- 0.7) (p = 0.281). CONCLUSION: Contrast-enhanced sonography could improve only the sensitivity for cancer detection in analysis by biopsy site but did not improve the overall performance of sonography in patients with an indeterminate PSA level and negative digital rectal examination.

Aged↗
PubMed2006

Bloodborne metastatic tumors to the gastrointestinal tract: CT findings with clinicopathologic correlation.

OBJECTIVE: In this essay, we illustrate the CT features of bloodborne metastases to the gastrointestinal tract from various malignancies with an emphasis on clinicopathologic correlation. CONCLUSION: Familiarity with CT findings of bloodborne metastases to the gastrointestinal tract and an understanding of the disease spread pattern in common primary cancers will be helpful not only in detecting metastatic disease but also in minimizing the possibility of mistaking metastasis for another metachronous malignancy.

Adult↗
PubMed2006

Unusual malignant tumors of the gallbladder.

OBJECTIVE: The purpose of this pictorial essay is to review the spectrum of unusual malignant tumors of the gallbladder and to illustrate their radiologic features. CONCLUSION: Radiologic findings of unusual malignant gallbladder tumors are varied and overlap with those of ordinary gallbladder carcinoma. Despite their rarity, being familiar with the wide spectrum of radiologic findings of these unusual tumors is helpful to improve diagnostic accuracy.

Adult↗
PubMed2006

MDCT Findings of renal trauma.

OBJECTIVE: The purposes of this pictorial essay are to show MDCT findings of renal trauma and describe the indications and protocol for MDCT. CONCLUSION: CT is indicated when patients have gross hematuria, hypotension, lumbar spinal injury, and fractures of lower ribs or the transverse process. The CT examination must be designed specifically for urinary tract evaluation, and MDCT is especially useful for this purpose. Injury to the kidney is graded I to V according to degree of laceration and amount of hematoma.

Adult↗
PubMed2006

Hepatic hemangiomas with arterioportal shunt: sonographic appearances with CT and MRI correlation.

OBJECTIVE: The purpose of this study was to summarize and illustrate the sonographic appearance of hepatic hemangiomas with arterioportal shunt and to correlate them with CT and MRI findings. CONCLUSION: High-flow hepatic hemangiomas tend to be seen as hypoechoic lesions at sonography. In the presence of fatty infiltration in the liver, they may accompany peritumoral low-echoic areas presumably caused by peritumoral sparing of fatty infiltration similar to a hyperattenuating or hyperintense peritumoral rim on unenhanced CT or MR chemical shift imaging. Color Doppler sonography may reveal intratumoral flows, large feeding arteries, and reversal of portal flow around the tumor. Knowledge of such sonographic findings may ensure an accurate sonographic diagnosis of these tumors.

Adult↗
PubMed2006

Unusual mesenchymal liver tumors in adults: radiologic-pathologic correlation.

OBJECTIVE: Our purpose was to review a broad spectrum of mesenchymal liver tumors in adults and present their cross-sectional imaging characteristics including radiologic-pathologic correlation. CONCLUSION: Cross-sectional imaging findings of mesenchymal liver tumors in adults are varied and some may overlap with others or even with more common malignant epithelial tumors. However, in some cases, their appearances at cross-sectional imaging studies may reflect characteristic abnormalities that suggest a specific diagnosis. Therefore, familiarity with the radiologic findings of mesenchymal liver tumors and understanding their pathological background is important for increasing the accuracy of radiologic diagnosis.

Adult↗
PubMed2006

Assessment of the therapeutic response of hepatocellular carcinoma treated with transcatheter arterial chemoembolization: comparison of contrast-enhanced sonography and 3-phase computed tomography.

OBJECTIVE: The purpose of this study was to compare contrast-enhanced sonography with 3-phase computed tomography (CT) in assessing the therapeutic response of hepatocellular carcinomas (HCCs) treated with transcatheter arterial chemoembolization (TACE). METHODS: Twenty-nine nodular HCCs treated with TACE were examined with contrast-enhanced sonography, 3-phase helical CT, and conventional angiography. Contrast-enhanced sonographic and CT findings were interpreted separately and prospectively for the presence or absence of contrast enhancement in the treated HCCs. Conventional angiography served as the reference standard. RESULTS: Intratumoral enhancement was seen in 19 HCCs (61%) on contrast-enhanced sonography and 12 HCCs (39%) on CT. Enhancement patterns on sonography were blush in 8 (42%), branching in 2 (11%), nodular in 4 (21%), and stippled in 5 (26%). Of the 19 HCCs with intratumoral enhancement on contrast-enhanced sonography, 13 (68%) showed tumor staining on angiography. Of the 12 HCCs without intratumoral enhancement on sonography, 1 (8%) showed tumor staining on angiography. The sensitivity and specificity of contrast-enhanced sonography in depicting flow in HCCs treated with TACE were 93% and 65%, respectively. The sensitivity and specificity of 3-phase CT were 64% and 100%. CONCLUSIONS: Contrast-enhanced sonography is a more sensitive imaging method than 3-phase CT in depicting vascularity in HCCs treated with TACE.

Adult↗
PubMed2005

Gastric cancer staging at multi-detector row CT gastrography: comparison of transverse and volumetric CT scanning.

PURPOSE: To prospectively evaluate the accuracy of multi-detector row computed tomography (CT) gastrography for preoperative staging of gastric cancer, with pathologic and surgical results as the reference standard. MATERIALS AND METHODS: This study was approved by the institutional review board, and patients gave written informed consent. One hundred six patients (72 male, 34 female; mean age, 56 years) with endoscopically proved gastric cancer underwent unenhanced and contrast material-enhanced multi-detector row CT gastrography, with effervescent granules used as oral contrast material. Two experienced radiologists independently evaluated the depth of tumor invasion into the gastric wall (tumor staging), the involvement of regional lymph nodes (nodal staging), and the presence or absence of metastasis (metastatic staging) on transverse and volumetric CT images, which included images produced with multiplanar reformation and a virtual endoscopic technique. TNM staging of each tumor was compared with the pathologic and surgical results. Diagnostic accuracy in TNM staging was analyzed. RESULTS: Gastric cancer was detected in 92 (87%) of 106 study patients with transverse CT imaging and in 104 (98%) with volumetric CT imaging. The overall accuracy of the tumor staging was 77% with transverse CT imaging and 84% with volumetric CT imaging (P < .001). The overall accuracy for lymph node staging was 62% with transverse CT imaging and 64% with volumetric CT imaging (P = .057). For staging of metastases, there was no difference between transverse and volumetric CT imaging (86% for both) (P > .99). CONCLUSION: Multi-detector row CT gastrography with multiplanar reformation and virtual endoscopy, compared with transverse CT imaging, can improve the accuracy of preoperative staging of gastric cancer. This difference was significant for tumor staging but not for the staging of lymph nodes and metastases.

Adult↗
PubMed2005

False-negative results at multi-detector row CT colonography: multivariate analysis of causes for missed lesions.

PURPOSE: To determine causes of false-negative results at multi-detector row computed tomographic (CT) colonography and determine presumptive causes with logistic regression analysis. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. The study included 394 colonic segments in 31 men and 25 women at high risk for colorectal cancer (mean age +/- standard deviation, 60.2 years +/- 9.3 for men and 56.8 years +/- 13.3 for women). Multi-detector row CT colonography and colonoscopy (reference standard) were performed in a blinded manner, and the results were compared. CT colonographic findings were interpreted in consensus by two readers using a primary two-dimensional with three-dimensional problem-solving approach. Adequacy of colonic preparation and distention was recorded. Sensitivity and specificity were obtained with 95% confidence intervals (CIs). Lesions missed at CT colonography were retrospectively reassessed to identify why they were missed, and, if the causes were not apparent, logistic regression analysis was performed to determine the presumptive causes. RESULTS: Colonic preparation and distention were optimal in 17 patients (30%) but suboptimal in 37 (66%) and poor enough to make the results nondiagnostic in two (4%). Twenty-nine of 63 lesions were missed at CT colonography. When all flat, sessile, and pedunculated lesions (n = 63) were included, sensitivities were 75% (nine of 12; 95% CI: 48%, 100%) for lesions 10 mm or larger and 79% (19 of 24; 95% CI: 65%, 93%) for those 6 mm or larger. When only sessile and pedunculated lesions (n = 60) were included, corresponding sensitivities were 100% (nine of nine; 73%, 100%) and 90% (19 of 21; 78%, 100%), respectively. All three missed lesions larger than 10 mm were flat, and all three flat lesions were missed. Two 3-mm high lesions, including one invasive adenocarcinoma, were misinterpreted as feces at blinded image review; one 1-mm high tubular adenoma with adenocarcinoma foci could not be visualized even in retrospect. Sessile or pedunculated polyps 5 mm or smaller were significantly more likely to be missed than those 6 mm or larger (adjusted odds ratio, 11.6; P = .027). CONCLUSION: Aside from inadequate bowel preparation and/or distention, flat lesions and small polyps are the two main causes for missed lesions at multi-detector row CT colonography.

Adenocarcinoma↗
PubMed2005

Hepatic artery pseudoaneurysms in adult living-donor liver transplantation: efficacy of CT and Doppler sonography.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of contrast-enhanced CT and Doppler sonography in the diagnosis of hepatic artery pseudoaneurysm after adult living-donor liver transplantation (LDLT). CONCLUSION: Because patients with hepatic artery pseudoaneurysm after LDLT can have diverse clinical presentations, routine imaging follow-up is important for early detection. Although Doppler sonography is limited in showing the pseudoaneurysm, contrast-enhanced CT, especially MDCT with CT arteriography, is effective in showing it in most patients.

Adult↗
PubMed2004

Differentiation of extrahepatic bile duct cholangiocarcinoma from benign stricture: findings at MRCP versus ERCP.

PURPOSE: To retrospectively evaluate criteria for differentiating extrahepatic bile duct cholangiocarcinoma from benign cause of stricture at magnetic resonance cholangiopancreatography (MRCP) and to compare diagnostic accuracy with this modality versus endoscopic retrograde cholangiopancreatography (ERCP). MATERIALS AND METHODS: MRCP and ERCP images in 50 patients (27 with cholangiocarcinoma [18 men, nine women; mean age, 58 years] and 23 with benign cause of stricture [13 men, 10 women; mean age, 60 years]) were retrospectively reviewed to assess the appearance of bile duct strictures. Final diagnosis was based on surgical or biopsy findings. Strictures were described according to their imaging appearance (irregular or smooth margins, asymmetric or symmetric narrowing, abrupt narrowing or gradual tapering, and presence or absence of double-duct sign). Sensitivity, specificity, and accuracy of MRCP and ERCP were calculated by using ratings of confidence in image-based diagnosis. Lengths of stricture were electronically measured and compared by using the Student t test. RESULTS: Among cholangiographic criteria for malignant biliary stricture, irregular margins and asymmetric narrowing were more common in cholangiocarcinomas (24 [89%] of 27 patients) than in benign strictures (six [26%] and eight [35%] of 23 patients, respectively). Sensitivity, specificity, and accuracy of the two methods for differentiation of malignant from benign causes of biliary stricture were 81% (22 of 27), 70% (16 of 23), and 76% (38 of 50), respectively, for MRCP and 74% (20 of 27), 70% (16 of 23), and 72% (36 of 50), respectively, for ERCP. Mean length (+/- standard deviation) of cholangiocarcinomas was 30.0 mm +/- 8.5, and that of benign strictures was 13.6 mm +/- 9.1 (P <.001). CONCLUSION: Accuracy of MRCP is comparable with that of ERCP. Regardless of modality, a lengthy segment of extrahepatic bile duct stricture with irregular margin and asymmetric narrowing suggests cholangiocarcinoma, and a short segment with regular margin and symmetric narrowing suggests benign cause.

Adult↗
PubMed2004

Hepatic venous congestion after living donor liver transplantation with right lobe graft: two-phase CT findings.

PURPOSE: To describe and determine clinical importance of two-phase computed tomographic (CT) findings of hepatic venous congestion after living donor liver transplantation (LDLT) with right lobe graft. MATERIALS AND METHODS: Forty-eight patients underwent two-phase (hepatic arterial phase and portal venous phase [PVP]) CT at 1, 2, and 4 weeks after LDLT. Images were evaluated for hepatic attenuation difference in areas of hepatic venous congestion, opacification of hepatic and peripheral portal veins in those areas, and changes in findings at follow-up CT. CT findings were correlated with serum bilirubin level. Fisher exact test and mixed model were applied. Histopathologic specimens were obtained in six patients. RESULTS: Thirty patients (62%) had attenuation difference in segments V and VIII of right lobe transplant at initial CT scanning. Opacification of hepatic or peripheral portal veins was seen in 17 (63%) and 27 (100%) hyperattenuating areas of congestion during PVP and in none and three (19%) of 16 hypoattenuating areas, respectively. At 4-week follow-up CT, attenuation difference decreased in volume in 11 of 16 patients with hypoattenuation during PVP. All 14 patients with hyperattenuation showed no change in volume, but attenuation difference had decreased or disappeared. Histopathologic specimens showed evidence of hepatic venous congestion in all six patients. Hypoattenuation was seen at PVP CT in all three patients with severe hepatic venous congestion at histopathologic examination. Serum bilirubin level was significantly different between patients with hypoattenuation and those with hyperattenuation during PVP (P =.035) and between patients with hypoattenuation and those without attenuation difference (P =.009). CONCLUSION: Areas possibly related to hepatic venous congestion after LDLT have variable attenuation at CT; decreased enhancement during PVP correlates with increased postoperative serum bilirubin level, which indicates severity of hepatic venous congestion.

Adult↗
PubMed2004

Pyogenic hepatic abscesses: distinctive features from hypovascular hepatic malignancies on contrast-enhanced ultrasound with SH U 508A; early experience.

The aim of this study was to investigate the feasibility of contrast-enhanced US (conE US) in differentiating pyogenic hepatic abscesses (PyHAs) from hypovascular hepatic malignancies. conE US images of 16 PyHAs in 12 patients were evaluated retrospectively and were compared with those of 22 hypovascular hepatic malignancies in 12 patients. The conE US images were obtained at 30, 90, 150 and 270 s after a bolus injection of 4 g of SH U 508A (Levovist, Schering; 300 mg/mL). The images were specifically analyzed for the shape (round or ovoid, lobulating or coalescent according to the complexity), the margin (sharp or ill-defined), and the pattern of contrast agent enhancement of the lesion (internal and rim enhancement). In our experience, as to the shape of the lesion, PyHAs were usually coalescent (94%), and hepatic malignancies were more frequently round or ovoid (36%) or lobulating (50%) (p < 0.0001). The margin of the lesion was usually sharp in PyHAs (81%), whereas it was more commonly ill-defined (59%) in hepatic malignancies (p = 0.02). Whereas PYHAs usually produced no internal enhancement (94%), diffuse (73%) or peripheral (27%) hypoechoic intratumoral enhancement was seen in hepatic malignancies (p < 0.0001). This study shows that conE US is potentially useful in differentiation of PyHAs from hypovascular hepatic malignancies. PyHAs usually produce characteristic features, such as coalescent appearance, sharp boundary of necrotic cavity, and lack of internal enhancement on conE US.

Adult↗