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Ki Whang Kim

Publications and source records attributed to Ki Whang Kim.

At least 19 recordsLinked to original sources
PubMed2007

Hepatic MRI using the double-echo chemical shift phase-selective gradient-echo technique.

OBJECTIVE: The objective of our study was to describe the merits and drawbacks of the double-echo chemical shift phase-selective gradient-echo technique for hepatic MRI. CONCLUSION: With complementary information from two different dynamic imaging sets in conjunction with errorless subtraction between in- and out-of-phase images, the double-echo chemical shift phase-selective gradient-echo technique provides useful information regarding unpredictable variations in intra- or extralesional lipid content, allowing detailed assessment of focal lesions during hepatic MRI.

Adipose Tissue↗
PubMed2006

Detection of hepatic metastasis: manganese- and ferucarbotran-enhanced MR imaging.

PURPOSE: To compare the mangafodipir trisodium (MnDPDP)-enhanced and ferucarbotran-enhanced magnetic resonance imaging (MRI) for the detection of hepatic metastases. MATERIAL AND METHODS: Twenty patients with known hepatic metastasis underwent MR imaging using mangafodipir trisodium and ferucarbotran in at least 1-day intervals. Thirty-eight metastases were confirmed either histologically or clinically. Two radiologists independently reviewed the MnDPDP-enhanced and ferucarbotran-enhanced sets in a random order. The sensitivity and accuracy of lesion detection and the ability to distinguish a benign lesion from a malignant lesion were compared by the areas (Az) under the receiver operating characteristic (ROC) curve. The lesion-liver contrast-to-noise ratios (CNR) were compared by paired t-test. RESULTS: The overall accuracy for detecting metastases was not significantly different between the MnDPDP set (Az=0.912 and 0.913 for reader 1 and 2, respectively) and the SPIO set (Az=0.920 and 0.950). The CNR at the MnDPDP-enhanced images and the SPIO-enhanced images were not significantly different (P=0.146). CONCLUSION: Both MnDPDP- and ferucarbotran-enhanced MRI have a comparable accuracy in detecting hepatic metastasis.

Adult↗
PubMed2006

Imaging findings of biliary and nonbiliary complications following laparoscopic surgery.

Laparoscopic techniques are evolving for a wide range of surgical procedures although they were initially confined to cholecystectomy and exploratory laparoscopy. Recently, surgical procedures performed with a laparoscope include splenectomy, adrenalectomy, gastrectomy, and myomectomy. In this article, we review the spectrum of complications and illustrate imaging features of biliary and nonbiliary complications after various laparoscopic surgeries. Biliary complications following laparoscopic cholecystectomy include bile ductal obstruction, bile leak with bile duct injury, dropped stones in the peritoneal cavity, retained CBD stone, and port-site metastasis. Nonbiliary complications are anastomotic leakage after partial gastrectomy, gangrenous cholecystitis after gastrectomy, hematoma at the anastomotic site following gastrectomy, gastric infarction after gastrectomy, port-site metastasis after gastrectomy, hematoma after splenectomy, renal infarction after adrenalectomy, and active bleeding after myomectomy of the uterus.

Biliary Tract Diseases↗
PubMed2006

A case of mesenteric cystic lymphangioma: fat saturation and chemical shift MR imaging.

Mesenteric cystic lymphangioma is an uncommon lesion that may be difficult to diagnose radiologically. In our case, a septate cystic mass showed fluid attenuation on a computed tomography scan. We were able to define the fat content within the cystic tumor by magnetic resonance (MR) imaging. The presence of fat within an intra-abdominal cystic mass is suggestive of a dermoid cyst, cystic lymphangioma, or lymphocele. The pathologic diagnosis revealed a cystic lymphangioma, which originated from the mesentery. Although the MR imaging features of dermoid cysts and lymphangiomas are well known, the demonstration of fat content by chemical shift and fat saturation MRI has not yet been reported for a cystic lymphangioma.

Diagnosis, Differential↗
PubMed2006

Mangafodipir trisodium-enhanced MRI for the detection and characterization of focal hepatic lesions: is delayed imaging useful?

PURPOSE: To investigate the usefulness of early and delayed hepatic MRI after mangafodipir trisodium (Mn-DPDP) administration for the detection and characterization of focal hepatic lesions. MATERIALS AND METHODS: Forty-five patients (31 males and 14 females, mean age = 61 years) with a total of 113 hepatic lesions (mean size = 3.5 cm) were included in this study (15 with hepatocellular carcinoma (HCC, N = 35), 20 with hepatic metastasis (N = 63), five with hemangioma (N = 10), three with cholangiocarcinoma (CC, N = 3), and two with liver abscess (N = 2)). T1-weighted gradient-echo MR images were obtained before and after Mn-DPDP administration, with a mean 18-hour delayed imaging. A qualitative analysis (including the size and signal intensity (SI)) and quantitative analysis (including enhancement and lesion-liver contrast-to-noise ratio (CNR)) were performed on pre- and postcontrast early and delayed MR images. RESULTS: Compared to postcontrast early imaging, 17 (48.6%) of 35 HCCs showed higher SI, 16 (45.7%) showed no SI change, and two (5.7%) showed lower SI on delayed imaging. All 63 metastases, 10 hemangiomas, three CCs, and two abscesses showed no SI change. On delayed imaging, ring enhancement was noted in 53 metastases (84.1%), three hemangiomas (30.0%), and one abscess (50.0%), but was not seen in HCCs or CCs. Eight metastases (12.7%) also showed ring enhancement on postcontrast early imaging. No newly detected hepatic lesions were revealed on postcontrast delayed MR images compared to postcontrast early images. Regarding CNR, the HCCs showed a significant increase in CNR from postcontrast early to delayed images after administration of Mn-DPDP (P < 0.01). However, none of the metastases, hemangiomas, CCs, and abscesses showed a significant increase of CNR from postcontrast early to delayed images. CONCLUSION: Postcontrast delayed MR images after Mn-DPDP administration were helpful in distinguishing hepatocellular from nonhepatocellular lesions, but were not useful for lesion detection and had limited utility for lesion characterization, since benign and malignant hepatic lesions looked the same.

Adult↗
PubMed2006

Hyperintense nodules on non-enhanced T1-weighted gradient-echo magnetic resonance imaging of cirrhotic liver: fate and clinical implications.

PURPOSE: To investigate the fate of hyperintense hepatic nodules on nonenhanced T1-weighted (T1w) gradient-echo (GRE) magnetic resonance (MR) images in cirrhotic patients. MATERIALS AND METHODS: A total of 79 cirrhotic patients with hyperintense nodules (>5 mm) on precontrast opposed-phase (repetition time (TR)/echo time (TE) = 140/2.7 msec) GRE images from initial MRI without T2-weighted (T2w) hyperintensity or arterial hypervascularity were subjected to analysis of subsequent MR images obtained at intervals of 12-56 months (mean = 24.5 months). Multiplicity of hyperintense nodules (group A, up to 8; group B, >8) was correlated with follow-up changes. RESULTS: Group B patients were younger (P = 0.003) than group A patients (mean = 47.5 and 56.2 years, respectively). In 66 group A patients, 39 out of 143 lesions (27%) were enlarged, including 20 malignantly transformed or borderline lesions. Of the 104 lesions (the eight largest lesions in each patient) in 13 group B patients, only three (2.9%) were enlarged. The results of best- and worst-case analyses showed that overall the lesions were benign in 91% and 82% of patients, respectively. CONCLUSION: T1w hyperintense nodules without T2w hyperintensity or arterial hypervascularity in the cirrhotic liver are benign in most cases. In younger patients with numerous macronodules, almost all of these lesions follow a benign course.

Adult↗
PubMed2006

Variation of the time to aortic enhancement of fixed-duration versus fixed-rate injection protocols.

OBJECTIVE: The objective of the study was to clarify whether a fixed-duration injection protocol is useful in determining the optimal scan delay time without the need for a bolus-tracking technique. MATERIALS AND METHODS: Three hundred eighteen patients underwent a helical CT examination using a bolus-tracking technique. All the examinations were performed after administering a nonionic contrast medium (300 or 370 mg I/mL; 2 mL/kg of body weight for patients weighing < or = 75 kg, 150 mL for those weighing > 75 kg). The patients were assigned to one of three groups according to the injection protocol. The injection rate was alternated to 3 or 4 mL/sec in group 1. The injection duration was 38 or 47 sec in groups 2 and 3, respectively. The aortic arrival time and the 100-H threshold time in each patient were measured. The mean values and the variations in the aortic arrival time and 100-H threshold time according to the injection protocols and the contrast media were compared. RESULTS: The mean variations (+/- SD) of aortic arrival times and 100-H thresholds in group 2 (aortic arrival time = 16.1 +/- 2.7 sec, 100-H threshold time = 19.6 +/- 2.9 sec) were smaller than in groups 1 (16.3 +/- 3.0 sec and 19.9 +/- 3.7 sec, respectively) and 3 (16.8 +/- 3.5 sec and 20.4 +/- 4.1 sec, respectively). However, the range of aortic arrival times and 100-H threshold times was more than 10 sec for all groups. The mean aortic arrival time and 100-H threshold time for all patients were 16.5 and 20.0 sec, respectively, and did not vary significantly with the injection protocol and concentration of contrast medium. CONCLUSION: The individual variations of the aortic arrival and 100-H threshold times can be reduced using a fixed-duration injection technique, but there are still substantial variations. Therefore, a bolus-tracking technique is recommended for optimal timing of arterial phase scanning.

Adult↗
PubMed2006

Optimal scan window for detection of hypervascular hepatocellular carcinomas during MDCT examination.

OBJECTIVE: The purpose of this study was to define the optimal scan window for acquiring arterial phase images in the detection of hypervascular hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: Biphasic arterial phase CT examinations were performed using a 16-MDCT scanner on 198 patients (159 men and 39 women; mean age, 59 years; age range, 25-82 years) with nodular HCC. All examinations were performed after administering 120-150 mL of a nonionic contrast media (370 mg I/mL) at a rate of 3-4 mL/s. The scan delay--the interval between when the bolus-tracking program detected the threshold enhancement of 100 H in the abdominal aorta and the start of the first arterial scan-was progressively lengthened by 2-second intervals, from 10 seconds in group 1 to 20 seconds in group 6. The second arterial phase scan was started 6 seconds after the end of the early scan. A tube collimation of 1.5 mm, a table feed of 18 mm per rotation, an image thickness of 3 mm, and 3-mm increments were used. The duration of each phase scan was 4.5-8.8 seconds. Tumor-to-liver attenuation difference (TLAD) at the first (TLAD1) and second (TLAD2) arterial phase images were compared lesion by lesion. Four observers assigned subjective ratings of visual conspicuity and individual preferences for each phase in each group. RESULTS: The mean threshold time (100 H) was 18.4 +/- 3.1 seconds, and 97% of patients were within the range of 13-24 seconds. The mean TLAD1 of groups 3 to 6 and the mean TLAD2 of groups 1 to 5 were all comparable; they were also all significantly (p < 0.005) higher than the mean TLAD1 of groups 1 and 2 and the mean TLAD2 of group 6. In groups 1 and 2, the mean TLAD2 was significantly higher than the mean TLAD1 (p < 0.001); in groups 5 and 6, the mean TLAD1 was significantly higher than the mean TLAD2 (p < 0.001). In groups 3 and 4, the mean TLAD1 and TLAD2 were similar. The visual conspicuity and individual preferences were higher for the first-phase image in groups 3 to 6 and the second-phase image in groups 1 and 2. CONCLUSION: The optimal scan window for arterial phase images in the detection of HCC seems to be approximately 14-30 seconds from the 100-H threshold.

Adult↗
PubMed2006

Solid pseudopapillary tumor of the pancreas: typical and atypical manifestations.

OBJECTIVE: The purpose of this pictorial essay is to illustrate the various appearances of solid pseudopapillary tumor of the pancreas. CONCLUSION: Solid pseudopapillary tumor of the pancreas is a rare neoplasm usually found in young women. Typical solid pseudopapillary tumor is characterized by a well-encapsulated mass with varying amounts of intratumoral hemorrhage. However, the tumor can have an atypical appearance, such as metastasis, ductal obstruction, parenchymal and extracapsular invasion, simulation of islet cell tumor, intratumoral calcification, and occurrence in a male patient. The typical and atypical manifestations of solid pseudopapillary tumor can be visualized with cross-sectional imaging.

Adult↗
PubMed2006

Optimal TE for SPIO-enhanced gradient-recalled echo MRI for the detection of focal hepatic lesions.

OBJECTIVE: The objective of our study was to determine the optimal TE for superparamagnetic iron oxide (SPIO)-enhanced gradient-recalled echo (GRE) MRI for the detection of focal hepatic lesions. MATERIALS AND METHODS: Ferucarbotran-enhanced GRE sequences, performed on a 1.5-T MR system, were used to evaluate 131 lesions (38 hepatocellular carcinomas, 37 metastases, 21 hemangiomas, 7 cholangiocarcinomas, 15 cysts, and 13 miscellaneous lesions) at four different TEs: 9, 13.5, 18, and 22.5 milliseconds. The lesion-to-liver signal difference-to-noise ratio (SDNR) was compared among the four GRE sequences by paired Student's t tests and among lesion types by an independent samples Student's t test. The McNemar test was used to compare the sensitivity for the detection of focal hepatic lesions. Wilcoxon's signed rank test was used to compare the subjective lesion conspicuity. RESULTS: The SDNRs of lesions on GRE images obtained at a TE of 13.5 milliseconds (mean +/- SD, 60 +/- 24) were significantly (p < 0.001) higher than those at TEs of 9 (55 +/- 23), 18 (55 +/- 22), and 22.5 milliseconds (47 +/- 19). The SDNR was highest at a TE of 13.5 milliseconds for SPIO-uptake lesions and was comparable on images obtained with TEs of 18 and 13.5 milliseconds for non-SPIO-uptake lesions. The non-SPIO-uptake lesions showed a significantly higher SDNR than the SPIO-uptake lesions at a TE of 22.5 milliseconds (p = 0.007). The overall sensitivity for lesion detection was not significantly different among the four GRE sequences, and the subjective ratings of lesion conspicuity were comparable for images obtained using TEs of 8, 13.5, and 18 milliseconds, but the ratings of lesion conspicuity were significantly lower for images obtained using a TE of 22.5 milliseconds (p < 0.001). CONCLUSION: For ferucarbotran-enhanced MRI, lesion SDNR was highest on images obtained using a TE of 13.5 milliseconds, but the sensitivity and lesion conspicuity were comparable at TEs of 9 and 18 milliseconds. The SDNR of liver lesions varied according to the lesion's potential capability of taking up SPIO agents.

Adult↗
PubMed2005

Mucosa-associated lymphoid tissue lymphoma of the esophagus coexistent with bronchus-associated lymphoid tissue lymphoma of the lung.

Non-Hodgkin's lymphoma very rarely involves the esophagus, occurring in less than 1% of patients with gastrointestinal lymphoma. A few cases of mucosa-associated lymphoid tissue (MALT) lymphoma of the esophagus have been reported in the English literature. To our knowledge, there has been no report of MALT lymphoma of the esophagus coexistent with bronchus-associated lymphoid tissue lymphoma (BALT) of the lung. This report details the radiological and clinical findings of this first concurrent case.

Aged↗
PubMed2005

Focal eosinophilic necrosis versus metastasis in the liver: the usefulness of two-phase dynamic CT.

OBJECTIVE: The purpose of our study was to evaluate the usefulness of dual-phase dynamic CT in the differentiation of focal eosinophilic necrosis of the liver and metastasis. CONCLUSION: Undetected isoattenuating lesions on arterial phase images that have an indistinct margin, a nonspherical shape, and a homogenous enhancement pattern on portal venous phase images suggest focal eosinophilic necrosis rather than metastasis. Two-phase dynamic CT was found to be useful at differentiating focal eosinophilic necrosis from metastasis.

Adult↗
PubMed2005

Preoperative evaluation of common bile duct stones in patients with gallstone disease.

OBJECTIVE: Our objective was to suggest criteria for selection of a preoperative diagnostic technique for patients with gallstone disease. CONCLUSION: Use of MR cholangiography preferentially before laparoscopic cholecystectomy, on patients who have a moderate or high risk of common bile duct stones, can significantly reduce purely diagnostic endoscopic retrograde cholangiography.

Case-Control Studies↗
PubMed2005

Preoperative MRI of potential living-donor-related liver transplantation using a single dose of gadobenate dimeglumine.

OBJECTIVE: This article evaluates the feasibility of single-dose gadobenate dimeglumine-enhanced MRI as both an angiographic and biliary contrast medium for making a preoperative evaluation of the donor candidates for a living-donor-related liver transplantation. SUBJECTS AND METHODS: Eleven right hepatic lobe donors underwent MRI examinations using T1- and T2-weighted imaging and T2-weighted MR cholangiography (MRC). The MR angiography (MRA) and contrast-enhanced (CE) T1-weighted MRC images then were obtained after injecting a single dose of gadobenate dimeglumine. One radiologist and one surgeon prospectively reviewed all the MRI examinations for hepatic vascular and biliary abnormalities and compared them with the surgical findings and intraoperative cholangiograms. In addition, two blinded reviewers evaluated the two sets of MRC (T2-weighted MRC set and T2-weighted MRC plus CE-T1-weighted MRC set) retrospectively and recorded the anatomic types of the hilar biliary branching pattern along with their confidence in the interpretation. RESULTS: Prospective analysis detected the following vascular variants: hepatic arterial variation in two patients, portal venous variation in one, and a significantly large accessory hepatic vein (> 5 mm) in one. Biliary variants also were identified in two patients. All the MRI findings on the vascular and biliary anatomy were corroborated intraoperatively. Retrospective analysis showed that the mean diagnostic confidence in the combined set was significantly higher than that of the T2-weighted MRC alone by both reviewers (p < 0.05). CONCLUSION: Obtaining both MRA and CE-T1-weighted MRC is feasible using a single dose of gadobenate dimeglumine. Therefore, gadobenate dimeglumine-enhanced MRI might play a role as a preoperative imaging technique for the vascular and biliary evaluation of potential living donors.

Adolescent↗
PubMed2004

Burkitt's lymphoma representing periportal infiltrating mass on CT.

Imaging findings of secondary hepatic lymphoma have been reported as variable, ranging from single or multiple small nodules to diffuse infiltrative tumor patterns. We hear present a rare case report concerning aggressive B cells, secondary Burkitt's lymphoma in non-AIDS demonstrating a surprising periportal lymphoma infiltration, without upper abdominal lymphadenopathy or splenomegaly on the sonography and CT scans. Clinically, the case was characterized by atypical and highly aggressive course, with the patient presenting an abruptly developed obstructive jaundice with rapidly deteriorating hepatic function that could be indicative of cholestatic hepatitis, which differs in its clinical manifestations from hepatic lymphoma without functional deterioration in respect of its non-tissue destructive growth pattern. We suggest that hepatic lymphoma can sometimes be consistent with periportal infiltrating homogeneous mass, with no lymphadenopathy or splenomegaly on the imaging examination, with a predictable aggressive clinical course of the disease and poor prognosis.

Abdomen↗
PubMed2004

CT findings of surgically verified acute invasive small bowel anisakiasis resulting in small bowel obstruction.

Acute invasive small bowel anisakiasis is an extremely rare cause of small bowel obstruction. The authors report a case of surgically verified small bowel anisakiasis resulting in small bowel obstruction. A 54-year-old man presented with suddenly developed diffuse abdominal pain after ingestion of raw fish. The peripheral blood examination showed leukocytosis without eosinophilia. CT showed a long segment of thickened small bowel accompanied by a focal narrowed portion and combined with ascites. When these findings are noted in patients with a history of recent ingestion of raw or undercooked fish, the diagnosis of small bowel anisakiasis should be considered in order to avoid application of unnecessary surgical treatment, in spite of the severity of the abdominal pain and bowel obstruction.

Anisakiasis↗
PubMed2004

Detection and characterization of focal hepatic lesions: mangafodipir vs. superparamagnetic iron oxide-enhanced magnetic resonance imaging.

PURPOSE: To compare the mangafodipir-enhanced magnetic resonance (MR) and superparamagnetic iron oxide (SPIO)-enhanced images for their ability to detect and characterize focal hepatic lesions. MATERIALS AND METHODS: Unenhanced, mangafodipir-enhanced, and SPIO-enhanced hepatic MR images obtained from 64 patients were analyzed. A total of 121 hepatic lesions were included: 66 hepatocellular carcinomas (HCCs), 26 metastases, 14 hemangiomas, 5 cysts, 3 cholangiocarcinomas, 4 focal nodular hyperplasias (FNHs), 2 abscesses, and 1 adenoma. Two radiologists independently reviewed the two sets of images in a random order: 1) the unenhanced and mangafodipir-enhanced images (the mangafodipir set) and 2) the unenhanced and SPIO-enhanced images (the SPIO set). This study compared the accuracy of lesion detection, the ability to distinguish between a benign and malignant lesion, and the ability to distinguish between the hepatocellular and nonhepatocellular origins of the lesions using the areas (Az) under the receiver operating characteristic (ROC) curve. RESULTS: The overall accuracy for detecting focal lesions was significantly higher (P < 0.05) with the SPIO set (Az = 0.846 and 0.871 for readers 1 and 2, respectively) than with the mangafodipir set (Az = 0.716 and 0.766). Most of the lesions detected only with the SPIO-enhanced MR images by the readers were small HCCs. For lesions larger than 15 mm, the sensitivities of the two contrast enhancement techniques were similar for both readers. The accuracy of the mangafodipir and SPIO sets in distinguishing between benign and malignant lesions was comparable. The accuracy for distinguishing between the hepatocellular and nonhepatocellular origins of the lesions was significantly higher (P < 0.05) using the mangafodipir set (Az = 0.897 and 0.946) than using the SPIO set (Az = 0.741 and 0.833). CONCLUSION: SPIO- and mangafodipir-enhanced images were comparable for detection of focal hepatic lesions other than small HCCs, which were better detected on the SPIO-enhanced images. Mangafodipir-enhanced images are likely better than the SPIO-enhanced images for distinguishing between focal liver lesions with a hepatocellular or nonhepatocellular origin.

Adult↗