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Hyung Jin Won

Publications and source records attributed to Hyung Jin Won.

10 recordsLinked to original sources
PubMed2006

Contrast-enhancing hepatic eosinophilic abscess during the hepatic arterial phase: a mimic of hepatocellular carcinoma.

OBJECTIVE: Our objective was to review CT, MR, angiographic, and sonographic images obtained in patients with histopathologically proven contrast-enhancing hepatic eosinophilic abscesses during the hepatic arterial phase. CONCLUSION: On CT, MR, and angiographic images, eosinophilic abscess in the liver can show contrast enhancement during the hepatic arterial phase. If patients have peripheral hypereosinophilia or are at low risk for hepatocellular carcinoma or hepatic metastasis, those with small arterial-enhancing hepatic nodules need further preoperative evaluation, such as a sonographically guided biopsy.

Adult↗
PubMed2006

MDCT of small-bowel disease: value of 3D imaging.

OBJECTIVE: Our objective is to show the various clinical applications of MDCT enterography for evaluating small-bowel disease, with a focus on the added value of 3D imaging. CONCLUSION: MDCT and refined 3D imaging processes can offer a full examination of the small bowel as well as powerful information about the bowel and its surrounding structures.

Acute Disease↗
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

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↗
PubMed2005

Biliary ductal evaluation of hilar cholangiocarcinoma: three-dimensional direct multi-detector row CT cholangiographic findings versus surgical and pathologic results--feasibility study.

The study was conducted, with institutional review board approval and informed patient consent, to assess the feasibility and diagnostic effectiveness of three-dimensional direct multi-detector row computed tomographic (CT) cholangiography for determining the extent of bile duct invasion by hilar cholangiocarcinoma. Eleven patients underwent contrast material-enhanced direct multi-detector row CT cholangiography of the primary and secondary biliary confluence levels and then surgical resection. In most patients, CT cholangiography was tolerable and yielded excellent or good opacification of the biliary tree. CT cholangiography enabled a correct diagnosis of the extent of ductal involvement at all 11 primary confluence levels and at 18 of the 19 secondary confluence levels. Three secondary confluences, which could not be analyzed owing to nonopacification or poor opacification, proved to be involved by hilar cholangiocarcinoma. The authors conclude that three-dimensional direct multi-detector row CT cholangiography is accurate and feasible for defining the extent of ductal invasion by hilar cholangiocarcinoma, especially in patients with preliminary biliary drainage.

Adult↗
PubMed2005

Can MRCP replace the diagnostic role of ERCP for patients with choledochal cysts?

BACKGROUND: MRCP is rapidly replacing diagnostic ERCP in various pancreaticobiliary diseases. This study was designed to evaluate the accuracy of MRCP in detecting and determining the extent of choledochal cysts, as well as associated ductal anomalies or lesions. METHODS: The study design was an 8-year retrospective survey conducted at a tertiary referral center, Asan Medical Center (University of Ulsan College of Medicine, Seoul, Korea). There were 72 patients with choledochal cysts. All patients underwent both MRCP and ERCP. MRCP findings were compared with those of ERCP as the criterion standard. RESULTS: The overall detection rate of MRCP for choledochal cysts was 96% (69/72). The sensitivity, the specificity, the positive predictive value, and the negative predictive value of MRCP for classifying choledochal cysts according to Todani's classification were 81%, 90%, 86%, and 86% in type I, respectively; 73%, 100%, 100, and 95% in type III, respectively; 83%, 90%, 80%, and 91% in type IVa, respectively; 100%, 100%, 100%, and 100% in type IVb, respectively; and 100%, 100%, 100%, and 100% in type V, respectively. The sensitivity, the specificity, and the accuracy of MRCP for detecting ductal anomalies were 83%, 90%, and 86%, respectively. The detection rate of MRCP for concurrent cholangiocarcinoma and choledocholithiasis was 87% (13/15) and 100% (8/8), respectively. CONCLUSIONS: MRCP showed overall good accuracy in the detection and the classification of choledochal cysts and revealed associated cholangiocarcinoma and choledocholithiasis with excellent accuracy. MRCP, therefore, may supersede the diagnostic role of ERCP for the patients with choledochal cysts. However, MRCP showed limited capacity to detect minor ductal anomalies or small choledochocele.

Adolescent↗
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↗
PubMed2005

Protocol optimization of multidetector computed tomography colonography using pig colonic phantoms.

OBJECTIVE: The introduction of multidetector computed tomography (CT) increases the possibility of enhanced polyp detection using CT colonography. The effects of collimation and tube currents on polyp detection were investigated in pig colonic phantoms to determine the optimal scanning parameters. MATERIALS AND METHODS: Twenty pig colons were prepared, and polyps with diameters ranging from 3 mm to 15 mm were created and randomly distributed. There was a total of 60 polyps; 20 polyps were 3 to 5 mm in size, 21 polyps 6 to 9 mm, and 19 polyps 10 to 15 mm. The pig colons were sealed, distended with air, submerged in water, and were arranged to mimic the in vivo arrangement. CT was performed using a 4-row multidetector CT scanner with collimations of 1, 2.5, and 5 mm, a pitch of 1.75, and mA of 100. A low-dose protocol (mA of 50) was added with a collimation of 1 mm. Two blinded observers independently analyzed the datasets. RESULTS: : The overall sensitivities of CT colonography were 94.2% with 1-mm collimation, 80% with 2.5-mm collimation, and 75% with 5-mm collimation. Considering the sensitivity of each protocol for the size of the polyps, the 1-mm collimation protocol had a sensitivity of 87.5% for 3- to 5-mm polyps, 95.2% sensitivity for 6- to 9-mm polyps, and 100% sensitivity for 10- to 15-mm polyps; the 2.5-mm protocol had 50%, 92.9%, and 97.4% sensitivities, respectively; and the 5-mm protocol had 47.5%, 88.1%, and 89.5% sensitivities, respectively, for the respective polyp size group. A significant difference in sensitivity among the protocols was present in the 3- to 5-mm polyps. No significant difference was seen between the standard- and the low-dose protocols. CONCLUSIONS: The sensitivity of multidetector CT colonography for detecting polyps larger than 5 mm is robust over a range of collimation in pig colonic phantoms. However, reliable detection of polyps 5 mm or smaller requires a 1-mm collimation. Sensitivity is not influenced by lowering the mA from 100 to 50.

Animals↗
PubMed2003

Value of four-dimensional ultrasonography in ultrasonographically guided biopsy of hepatic masses.

OBJECTIVE: To assess the value of four-dimensional ultrasonography (dynamic three-dimensional ultrasonography with the added dimension of time) in ultrasonographically guided biopsy procedures of focal hepatic masses. METHODS: Four-dimensional ultrasonographically guided biopsy experiments using a freehand technique were performed in phantoms that simulated human liver tissue and had target material. After the protocol was determined and Institutional Review Board approval was obtained, 12 patients underwent four-dimensional ultrasonographically guided biopsy of focal hepatic masses by informed consent. Planar images using 3 orthogonal planes plus a volume-rendered image were used for real-time guidance during the biopsy procedure. RESULTS: Four-dimensional ultrasonography improved visualization of biopsy devices in all 12 patients (100%) regardless of minor changes in transducer position during the biopsy procedures. Four-dimensional ultrasonography allowed more intuitive apprehension of the spatial relationship of the needle and the target lesion and thus helped in adjusting the needle to an optimal prefiring position in 8 patients (67%). With regard to procedure time, four-dimensional ultrasonographically guided biopsy was comparable with standard two-dimensional ultrasonographically guided techniques. CONCLUSIONS: Compared with standard two-dimensional ultrasonographically guided biopsy, four-dimensional ultrasonography provides improved visualization of biopsy devices and more perceptible information on the spatial relationship between the biopsy needle and the target lesion.

Biopsy, Needle↗