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Biomedical subjects

Mi-Suk Park

Publications and source records attributed to Mi-Suk Park.

At least 19 recordsLinked to original sources

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↗

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↗

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↗

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↗

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↗

Capecitabine combined with gemcitabine (CapGem) as first-line treatment in patients with advanced/metastatic biliary tract carcinoma.

BACKGROUND: Biliary tract carcinoma is an aggressive cancer, with median survival rarely exceeding 6 months. There is currently no established palliative standard of care. A Phase II trial was conducted to study a combination of oral capecitabine and gemcitabine (CapGem) as first-line therapy in patients with advanced and/or metastatic biliary carcinoma. METHODS: Patients with unresectable or metastatic intrahepatic or extrahepatic biliary duct carcinoma and gallbladder carcinoma were enrolled. Eligible patients had histologically or cytologically confirmed, measurable adenocarcinoma and had not received prior therapy with capecitabine or gemcitabine. Treatment consisted of intravenous (i.v.) gemcitabine (1000 mg/m(2) on Days 1 and 8) plus oral capecitabine (650 mg/m(2) twice daily on Days 1-14) every 3 weeks for up to 6 cycles. Tumor response, survival, and safety were determined. RESULTS: A total of 44 patients were evaluable. Primary tumor sites were: intrahepatic (n = 14) and extrahepatic biliary duct (n = 16); gallbladder (n = 7); and ampulla (n = 7). Fourteen (32%) patients had a partial response and 15 (34%) patients had stable disease. Median time to disease progression and overall survival were 6.0 (range, 3.8-8.1) and 14 (range, 11.4-16.6) months, respectively. The 1-year survival rate was 58%. No Grade 4 adverse events were seen. Transient Grade 3 neutropenia/thrombocytopenia and manageable (almost invariably Grade 2) nausea, diarrhea, and hand-foot syndrome were the most common adverse events. CONCLUSIONS: CapGem is an active and well tolerated first-line combination chemotherapy regimen for patients with advanced/metastatic biliary tract carcinoma that offers a convenient home-based therapy.

Adult↗

A Phase II study of capecitabine combined with gemcitabine in patients with advanced gallbladder carcinoma.

Capecitabine and gemcitabine are used in the treatment of a variety of solid tumors including pancreatic and biliary tract carcinomas. The authors evaluated survival, response, and toxicity associated with using a combination of capecitabine and gemcitabine to treat patients with unresectable or metastatic gallbladder adenocarcinoma (GBC). Eligible patients had histologically- or cytologically-confirmed GBC, no prior systemic therapy with capecitabine or gemcitabine, Karnofsky Performance Status 70%, serum total bilirubin up to three times normal, and measurable disease. Treatment consisted of gemcitabine 1000 mg/m2 IV on Days 1 and 8 concurrent with administration of capecitabine 1000 mg/m2 PO BID on Days 1 through 14, on a 3-week cycle. Tumor response was assessed by the response evaluation criteria in solid tumors (RECIST criteria) and survival was calculated from initiation of CapGem therapy. A total of 24 patients were enrolled. Median age at the time of diagnosis was 62 years (range, 41-78 years). Fourteen patients had undergone prior surgery. Results showed that eight patients achieved partial response (33%) with an additional 10 patients achieving stable disease (42%). The overall median time to disease progression was 6.0 months (95% CI, 3.8-8.1 months) and overall survival was 16 months (95% CI, 13.8-18.3 months). The one-year survival rate was 58%. No Grade 4 toxicity was seen. Transient Grade 3 neutropenia/ thrombocytopenia and manageable nausea, hand-foot syndrome and anorexia were the most common toxicities. Our study shows that CapGem is an active and well-tolerated chemotherapy regimen in patients with advanced GBC.

Adult↗

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↗

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↗

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↗

Scirrhous gastric carcinoma: endoscopy versus upper gastrointestinal radiography.

PURPOSE: To compare the accuracy of upper gastrointestinal (UGI) series and endoscopic examination in the diagnosis and localization of scirrhous gastric carcinoma. MATERIALS AND METHODS: Seventy-two patients with pathologically proved scirrhous gastric carcinoma in surgical specimens were included. Preoperative reports at UGI series and endoscopic examination, which included impressions on the location and extent of the tumor, were compared with pathology reports, and the accuracy of the preoperative reports was calculated. Two gastrointestinal radiologists retrospectively reviewed the appearance of mucosa at UGI series. RESULTS: Preoperative diagnoses at endoscopy were Borrmann type IV carcinoma in 28 patients (39%), type III carcinoma in 29 (40%), early gastric carcinoma in seven (10%), lymphoma in six (8%), atrophic gastritis in one (3%), and type II carcinoma in one (3%). Preoperative diagnoses at UGI series were type IV carcinoma in 44 patients (61%), type III carcinoma in 25 (35%), lymphoma in two (3%), and early gastric carcinoma in one (1%). Pathology reports were compared with the preoperative reports, and tumor location and extent were correct in the endoscopic examination reports of 24 patients (33%) and the UGI series reports of 49 patients (68%). In 68 patients, UGI series revealed thickened and irregular folds in 62 (91%), ulceration in 42 (62%), and nodularity in 22 (32%) at consensus review. Endoscopic biopsy samples were positive for malignancy in 66 patients (93%). CONCLUSION: UGI series is superior to endoscopic examination in the diagnosis and localization of scirrhous gastric carcinoma.

Adenocarcinoma, Scirrhous↗

Primary malignant melanoma of the rectum: CT findings in eight patients.

PURPOSE: To retrospectively evaluate computed tomographic (CT) findings in patients with pathologically proved primary malignant melanoma of the rectum. MATERIALS AND METHODS: CT scans of eight patients (three men and five women; age range, 38-74 years; mean age, 62 years) with histologically proved primary rectal malignant melanomas were retrospectively evaluated by two radiologists in consensus. Scans were evaluated for the involved site, approximate size and morphologic appearance of the primary mass, degree of perirectal infiltration, and presence or absence of lymphadenopathy, bowel obstruction, and distant metastases. RESULTS: All of the tumors were located in the distal rectum just above the anal verge. The approximate average sizes of the tumors were as follows: length, 4.8 cm (range, 3.8-6.9 cm); width, 3.8 cm (range, 2.8-5.2 cm); and mean diameter, 4.3 cm (range, 3.3-5.8 cm). Tumors usually appeared as polypoid or fungating intraluminal masses (n = 7). Perirectal infiltration commonly extended to the pelvic side wall or the presacral space (n = 5). All eight patients had lymphadenopathy, frequently larger than 3 cm in diameter (n = 3), which most commonly involved the perirectal lymph node station (n = 7). There was no evidence of bowel obstruction in any of the patients. Distant metastasis involving the liver was noted in one patient. CONCLUSION: On CT scans, primary rectal malignant melanomas appeared as bulky intraluminal fungating masses in the distal rectum, focally expanding and obscuring the lumen without causing obstruction, with perirectal infiltration and frequently enlarged lymph nodes.

Adult↗

Small (<or= 2 cm) hepatic lesions in colorectal cancer patients: detection and characterization on mangafodipir trisodium-enhanced MRI.

OBJECTIVE: The purpose of this study was to evaluate whether mangafodipir trisodium (MnDPDP)-enhanced MRI improves the detection and characterization of small ( 2.0 cm). The differences between MnDPDP-enhanced MRI and helical CT with regard to the detection rates for hepatic lesions and metastases and with regard to the false-positive rates for hepatic metastases were analyzed using the McNemar test. The performances of MnDPDP-enhanced MRI and helical CT in indicating metastases of focal liver lesions were analyzed using receiver operating characteristic curves. RESULTS: No statistically significant differences were seen between MnDPDP-enhanced MRI and helical CT in the detection of all hepatic lesions (p = 0.383) and small lesions (p = 0.210). However, concerning the differentiation between benign and metastatic lesions, MnDPDP-enhanced MRI was superior to helical CT both for all hepatic lesions (p = 0.023) and for small lesions (p = 0.015), and remained better when the analyses were restricted to patients with histopathologic confirmation (p = 0.023 for both). MnDPDP-enhanced MRI changed the diagnosis of hepatic metastasis in nine (13.0%) of 69 patients. Of 12 metastases that were found on MnDPDP-enhanced MRI and missed on helical CT, 11 lesions (91.7%) were small. MnDPDP-enhanced MRI showed a significantly greater detection rate than helical CT for small hepatic metastases (p = 0.022). MnDPDP-enhanced MRI was better when the analyses were restricted to patients with histopathologic confirmation (p = 0.043). CONCLUSION: Although MnDPDP-enhanced MRI is equal to helical CT in detection of both all hepatic lesions and small lesions in patients with colorectal carcinoma, it is superior to CT in characterization of the lesions.

Adult↗

Early biliary complications of laparoscopic cholecystectomy: evaluation on T2-weighted MR cholangiography in conjunction with mangafodipir trisodium-enhanced 3D T1-weighted MR cholangiography.

OBJECTIVE: Our aim was to assess preliminary experience with combined conventional T2-weighted and mangafodipir trisodium (MnDPDP)-enhanced T1-weighted MR cholangiography in evaluating early biliary complications of laparoscopic cholecystectomy. SUBJECTS AND METHODS: Conventional heavily T2-weighted MR cholangiography with MnDPDP-enhanced T1-weighted MR cholangiography and ERCP were performed in seven patients with high clinical suspicion of biliary complications after laparoscopic cholecystectomy. The final diagnoses of complications were classified according to the presence and degree of bile duct injury, bile leakage, and retained stones. RESULTS: The diagnoses on MR cholangiography were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 3), partial strictures of the common bile duct with bile leakage (n = 1), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). The final diagnoses at surgery (n = 2) and ERCP (n = 5) were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 2), partial strictures of the common bile duct with bile leakage (n = 2), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). MR cholangiography accurately yielded the same findings as the final diagnoses, except in one case with partial stricture of the bile duct with bile leakage (overdiagnosed as complete occlusion on MR cholangiography). CONCLUSION: Combined conventional T2-weighted and MnDPDP-enhanced T1-weighted MR cholangiography may eliminate the use of other studies for the imaging of biliary complications after cholecystectomy if this preliminary data can be verified in a larger study.

Adult↗

Acute cholecystitis at T2-weighted and manganese-enhanced T1-weighted MR cholangiography: preliminary study.

Twelve patients with symptoms of acute cholecystitis underwent heavily T2-weighted and mangafodipir trisodium-enhanced T1-weighted magnetic resonance (MR) cholangiography and cholescintigraphy before they underwent cholecystectomy. On T2-weighted MR cholangiographic images, morphologic evidence of outflow obstruction of the gallbladder was definitive in seven patients, equivocal in one, and absent in four. In all 12 patients, biliary dynamics depicted at manganese-enhanced T1-weighted MR cholangiography agreed completely with those depicted at hepatobiliary scintigraphy. T2-weighted MR cholangiography combined with manganese-enhanced T1-weighted MR cholangiography provides not only morphologic information but also functional information about the biliary system.

Acute Disease↗