[Hepatocellular carcinoma with fatty metamorphosis].
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Publications and source records attributed to Joon Koo Han.
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BACKGROUND: In this study, we evaluated the CT findings of patients with hepatoid adenocarcinoma of the stomach. METHODS: The CT scans of eight patients (seven males and one female; age range 44-70 years; mean age 59 years) with histologically proven hepatoid adenocarcinoma of the stomach were retrospectively evaluated by two radiologists in consensus. Scans were evaluated for gastric wall thickening, involved site enhancement, adjacent organ invasion, lymphadenopathy, distant metastases, and venous tumor thrombosis. RESULTS: Tumors appeared as eccentric wall thickening (n = 8) and heterogeneous enhancement (n = 7). Adjacent organ invasions were noted to liver (n = 3), pancreas (n = 2), and esophagus (n = 1). All eight patients had a regional lymphadenopathy larger than 8 mm in its short axis. Distant metastases (liver, n = 4; non-regional lymph node, n = 1) were also noted. Venous tumor thrombosis was identified in the portal vein (n = 3), splenic vein (n = 1), main portal vein (n = 1), or right gastroepiploic vein (n = 1) in the regions near primary gastric tumors or metastatic masses. CONCLUSION: On CT scans, hepatoid adenocarcinoma of the stomach appears as an eccentric gastric wall thickening and shows a strong tendency for liver and lymph node metastasis and venous invasion around the primary gastric tumor or a metastatic hepatic mass.
The purpose of this study was to validate the saline-enhanced bipolar radiofrequency ablation (RFA) technique using a perfused electrode to increase RF-created coagulation necrosis, to compare that technique with monopolar RFAs and to find appropriate concentrations and volumes of perfused NaCl solution for the bipolar RFA. A total of 90 ablations were performed in explanted bovine livers. In the initial experiments to determine appropriate conditions for bipolar RFA, we created five thermal ablation zones in each condition, with instillations of varied concentrations (0.9-36%) or injection rates (30 mL/hr-120 mL/hr) of NaCl solution. After placement of one or two 16-gauge open-perfused electrodes into bovine livers, the NaCl solution was instilled into the tissue through the electrode. In the second part of the study, 10 ablation zones were created using one or two perfused electrodes for each of five groups under different conditions: a conventional monopolar mode with 0.9% NaCl solution (group A) or with 6% NaCl solution (group B), a simultaneous monopolar mode with 6% NaCl solution (group C) and a bipolar mode with 6% NaCl solution (groups D and E). RF was applied to each electrode for 20 min in groups A, B, C, and E, or for 10 min in group D. During RFA, we measured the tissue temperature 15 mm from the electrode. The temperature changes during the RFA and the dimensions of the ablation zones were compared among the groups. Bipolar RFA created larger short-axis diameters of coagulation necrosis with 6% NaCl solution (35.8 +/- 15 mm) than with 0.9% NaCl solution (17 +/- 9.7 mm) (P < 0.05). However, concentrations of NaCl solution above 6% did not further increase the extent of coagulation necrosis. In addition, bipolar RFA with 6% NaCl solution instillation at a rate of 1.0 mL/min (37.9 +/- 5.4 mm) or 2.0 mL/min (35.6 +/- 9.3 mm) produced larger diameters at the mid-point between the electrodes of the ablated lesion than did 0.5 mL/min (25.8 +/- 9.3 mm) (P < 0.05). The bipolar mode showed a more rapid increase in temperature at the mid-point between the two probes, up to 60 degrees C, than did the monopolar modes (P < 0.05). In addition, the bipolar RFA (group E) treated for 20 min showed a larger value of the short-axis diameter than did the conventional or simultaneous monopolar modes (P < 0.05), and bipolar RFA (group D) treated for 10 min, showed similar results with conventional monopolar modes treated for 20 min (P > 0.05): 31.0 +/- 5.4 mm (group A); 28.8 +/- 3.8 mm (group B); 25.5 +/- 6.4 mm (group C); 32.6 +/- 4.2 mm (group D); 49.4 +/- 5.0 mm (group E). Bipolar RFA with instillation of 6% NaCl solution through an open perfusion system demonstrates better efficacy in creating a larger ablation zone than does conventional or simultaneous monopolar modes at the various times examined. Therefore, hypertonic saline-enhanced bipolar RFA seems to be a promising approach for treating larger liver tumors.
PURPOSE: To describe the incidence, types, and findings of biliary complications in living donor liver transplantation (LDLT) and to determine the roles of interventional procedures. MATERIALS AND METHODS: Twenty-four biliary complications among 161 LDLT patients (24/161, 14.9%) were identified. These complications were divided into two groups according to the initial manifestation time, i.e., "early" (<60 days) or "late". The CT and cholangiographic findings were reviewed regarding the presence of a stricture or leak and the location, and length, shape, and degree of the stricture. Both groups were categorized into three subgroups: leak, stricture, and both. The type of interventional procedures used and their roles were determined. RESULTS: Early complications were identified in 14 of the 24 patients (58%) and late complications in 11 (46%). One patient showed both early and late complications. Biliary stricture was detected in 10 patients, leak in 10, and both in 5. By cholangiography, all strictures were irregular and short (mean length 15 +/- 6 mm) at the anastomotic site and complete obstruction was observed in 2 patients with late stricture. Twenty-three of the 24 patients were treated using percutaneous and/or endoscopic drainage procedures with or without balloon dilatation. Seventeen (74%) showed a good response, but reoperations were inevitable in 6 (26%). All patients except those with complete obstruction showed a favorable outcome after interventional management. CONCLUSION: Biliary leaks and strictures are predominant complications in LDLT. Most show good responses to interventional treatment. However, complete obstruction needs additional operative management.
The volume-rendering technique uses computed tomography data to produce simulated images of conventional barium and endoscopic studies of the stomach. Various gastric lesions are detected on volume-rendered images, and submucosal tumors are easily differentiated from mucosal lesions by means of the overlying bridging fold. Lesions that are only manifested by a change of mucosal color (early gastric cancer type 2b) or a loss of mucosal detail (gastritis) are difficult to detect from volume-rendered images, however. In cases of gastric neoplasm and varix, both the extraluminal pathologies of the lesion and the relation between the intraluminal and extraluminal components can be evaluated simultaneously.
OBJECTIVE: To determine the CT features capable of differentiating hepatocellular carcinoma (HCC) with bile duct tumor invasion (BDTI) from intraductal cholangiocarcinoma (IDCC). METHODS: Multiphasic CT images of 14 patients with HCC with BDTI and 18 patients with IDCC were retrospectively reviewed. Analysis of the CT findings included the size, location, and margin of the intraductal mass, the enhancement pattern of intraductal lesions, degree of ductal dilatation, presence of downstream ductal dilatation and ductal wall thickening, presence of parenchymal mass and its size, continuity of parenchymal mass with intraductal mass, and liver cirrhosis. Objective evaluation of the enhancement patterns of intraductal tumors was done by measuring the CT attenuation coefficients of the tumors and the uninvolved hepatic parenchyma in each phase. Among these findings, statistically significant variables were then determined using Fisher exact test or Mann-Whitney test. RESULTS: Significant variables that helped differentiating HCC with BDTI from IDCC included the presence of parenchymal mass, liver cirrhosis, and the hyperattenuating intraductal tumor on the hepatic arterial phase (HAP). On unenhanced images, the tumor-to-liver contrast of IDCC (16.7 +/- 8.1) was greater than that of HCC with BDTI (6.4 +/- 10.4), but on HAP, that of HCC with BDTI (26.5 +/- 28.2) was greater than that of IDCC (5.9 +/- 18.7) (P < 0.05). In addition, there was a significant difference in the enhancement ratio of the intraductal tumors on portal venous phase (PVP) between the 2 conditions (P = 0.003). CONCLUSIONS: Several objective and subjective multiphasic CT findings may help differentiating HCC with BDTI from IDCC.
The extrahepatic biliary system is one of the unusual locations of extrapulmonary neuroendocrine carcinoma. To our knowledge, there has been no report describing the imaging findings of this rare malignancy of the biliary tree. We report 3 large-cell neuroendocrine carcinomas and a small-cell carcinoma arising from the biliary system. Biliary tumors showing on computed tomography an aggressive invasion to the liver or extensive lymph node involvement should raise the suspicion of their being high-grade neuroendocrine tumors.
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract and are defined by their expression of KIT (CD117). This article includes 109 pathologically proven GISTs, with emphasis on their various computed tomography (CT) features. Although the images of GISTs on the CT scan are often distinct from those of epithelial tumors, radiologists should be familiar with these features for the accurate diagnosis of GISTs.
OBJECTIVE: To determine the computed tomography (CT) features capable of differentiating hepatocellular carcinoma (HCC) with bile duct tumor invasion (BDTI) from intraductal cholangiocarcinoma (IDCC). METHODS: Multiphasic CT images of 14 patients with HCC with BDTI and 18 patients with IDCC were retrospectively reviewed. Analysis of the CT findings included the size, location, and margin of the intraductal mass; enhancement pattern of intraductal lesions; degree of ductal dilatation; presence of downstream ductal dilatation and ductal wall thickening; presence of a parenchymal mass and its size; continuity of the parenchymal mass with the intraductal mass; and liver cirrhosis. Objective evaluation of the enhancement patterns of intraductal tumors was done by measuring the CT attenuation coefficients of the tumors and the uninvolved hepatic parenchyma in each phase. Among these findings, statistically significant variables were then determined using the Fisher's exact test or Mann-Whitney U test. RESULTS: Significant variables that helped to differentiate HCC with BDTI from IDCC included the presence of a parenchymal mass, liver cirrhosis, and a hyperattenuating intraductal tumor on the hepatic arterial phase (HAP). On unenhanced images, the tumor-to-liver contrast of IDCC (16.7+/-8.1) was greater than that of HCC with BDTI (6.4+/-10.4), but on the HAP, that of HCC with BDTI (26.5+/-28.2) was greater than that of IDCC (5.9+/-18.7) (P<0.05). In addition, there was a significant difference in the enhancement ratio of the intraductal tumors on the portal venous phase between the 2 conditions (P=0.003). CONCLUSIONS: Several objective and subjective multiphasic CT findings may help to differentiate HCC with BDTI from IDCC.
Cholangiocarcinomas that involve areas from the peripheral intrahepatic duct to the distal common duct have similar morphologic features, and traditional classification schemes based on the location of the involved ducts sometimes overlap. Nevertheless, cholangiocarcinoma is usually classified as either intrahepatic or extrahepatic, and intrahepatic cholangiocarcinoma is further classified as either peripheral or hilar. However, the distinction between peripheral intrahepatic cholangiocarcinoma and hilar cholangiocarcinoma is largely based on the site of origin. Therefore, in some tumors that arise peripheral to the secondary bifurcation of one of the hepatic ducts, clear differentiation between the two types of cholangiocarcinoma is not always possible. In addition, the distinction between hilar cholangiocarcinoma and extrahepatic cholangiocarcinoma is not clearly defined. The different biologic behaviors of the tumors seem to be caused by their varying locations and their size at the time of diagnosis. Further molecular or biochemical investigation is needed to support the "field theory," which states that all cholangiocarcinomas are biologically the same tumor originating from the same biliary epithelium.
Helical computed tomography (CT) is useful in identifying postoperative anatomic changes, complications, and tumor recurrence in gastric cancer patients who have undergone gastrectomy. Postoperative anatomic changes can usually be identified on consecutive CT scans. Complications include anastomotic leakage, duodenal stump leakage, intraabdominal bleeding, wound complications, and other less common complications (postoperative pancreatitis, retention of surgical foreign bodies, diffuse peritonitis). The degree and extent of bowel wall thickening is important in diagnosing tumor recurrence; however, CT lacks specificity. Large or conglomerated lymph node metastases can be easily diagnosed at CT; however, small solitary or focal metastases may not be detected or differentiated from nonmetastatic nodes. Ascites, a common finding with peritoneal seeding in gastrointestinal tumors, is well depicted at CT. Hematogenous metastases from gastric carcinoma are most frequently seen in the liver and are best demonstrated with helical CT performed during the portal venous phase of enhancement (sensitivity >90% for the detection of lesions >1 cm). The sophisticated surgical procedures used in gastrectomy can alter normal anatomy and make image interpretation difficult; thus, familiarity with the appearance of postoperative anatomic changes, complications, and tumor recurrence is essential for accurate CT evaluation of affected patients.
Most radiologists are unfamiliar with peripheral T-cell lymphoma (PTCL) because PTCL represents a relatively small proportion of lymphomas and has a lower prevalence in Western countries. The World Health Organization classification of lymphoid neoplasms announced in 1999 resolved criticisms about lymphoma classification and aroused new interest in PTCL. The specific clinicopathologic entities of PTCL have particular primary locations and particular clinical and pathologic features. Radiologic images of patients with pathologically proved PTCL were retrospectively reviewed; clinical and pathologic data were also reviewed. PTCL involves various organs including the sinonasal cavity, airway, intestinal tract, skin, lymph nodes, liver, lung, and musculoskeletal system. The pattern of disease involvement in PTCL is not random. There is a correlation between specific clinicopathologic entities and the primary site of involvement, although the findings in the disseminated stage of disease do not allow differential diagnosis. It is significant that the radiologic features or locations of several entities are different from those of lymphoma with the B-cell phenotype. Radiologic demonstration of disease progression beyond the primary site is clinically important because systemic dissemination in most of the entities leads to a dramatic change in the prognosis.
With the increased temporal resolution available in dynamic computed tomography (CT) and magnetic resonance imaging (MRI), hepatic arterioportal shunts are now more frequently encountered than in the past. The condition occurs in various hepatic diseases in which portal or hepatic venous flow is compromised. The underlying mechanism and the degree of shunt affect its appearance at dynamic imaging. The dynamic CT and MRI findings have been summarized as early enhancement of peripheral portal veins, and wedge-shaped transient parenchymal enhancement during the hepatic arterial phase. Recognition of arterioportal shunt can suggest the presence of a previously unsuspected disorder and avoids false-positive diagnosis or overestimation of a hepatic disease. Familiarity with the pathophysiology of arterioportal shunt also allows investigation of the hepatic hemodynamic changes occurring in various hepatic diseases.
OBJECTIVE: To evaluate the utility and advantages of the coaxial snare technique in the retrieval of tubular foreign bodies. MATERIALS AND METHODS: Using the coaxial snare technique, we attempted to retrieve tubular foreign bodies present in seven patients. The bodies were either stents which were malpositioned or had migrated from their correct position in the vascular system (n=2), a fragmented venous introducer sheath (n=1), fragmented drainage catheters in the biliary tree (n=2), or fractured external drainage catheters in the urinary tract (n=2). After passing a guidewire and/or a dilator through the lumina of these foreign bodies, we introduced a loop snare over the guidewire or dilator, thus capturing and retrieving them. RESULTS: In all cases, it was possible to retrieve or reposition the various items, using a minimum-sized introducer sheath or a tract. No folding was involved. In no case were surgical procedures required, and no complications were encountered. CONCLUSION: The coaxial snare technique, an application of the loop snare technique, is a useful and safe method for the retrieval of tubular foreign bodies, and one which involves minimal injury to the patient.
OBJECTIVE: To compare the in-vitro efficiency of a hypertonic saline (HS)-enhanced bipolar radiofrequency (RF) system with monopolar RF applications by assessing the temperature profile and dimensions of RF-created coagulation necrosis in bovine liver. MATERIALS AND METHODS: A total of 27 ablations were performed in explanted bovine livers. After placement of two 16-gauge open-perfused electrodes at an interelectrode distance of 3 cm, 5% HS was instilled into tissue at a rate of 1 mL/min through the electrode. Seventeen thermal ablation zones were created in the monopolar mode (groups A, B), and ten more were created using the two open-perfused electrodes in the bipolar mode (group C). RF was applied to each electrode for 5 mins (for a total of 10 mins, group A) or 10 mins (for a total of 20 mins, group B) at 50W in the sequential monopolar mode, or to both electrodes for 10 min in the bipolar mode (group C). During RF instillation, we measured tissue temperature at the midpoint between the two electrodes. The dimensions of the thermal ablation zones and changes in impedance and wattage during RFA were compared between the groups. RESULTS: With open-perfusion electrodes, the mean accumulated energy output value was lower in the bipolar mode (group C: 26675+/-3047 Watt s) than in the monopolar mode (group A: 28778+/-1300 Watt s) but the difference was not statistically significant (p > 0.05). In the bipolar mode, there were impedance rises of more than 700 ohm during RF energy application, but in the monopolar modes, impedance did not changed markedly. In the bipolar mode, however, the temperature at the mid-point between the two probes was higher (85 degrees C) than in the monopolar modes (65 degrees C, 80 degrees C for group A, B, respectively) (p < 0.05). In addition, in HS-enhanced bipolar RFA (group C), the shortest diameter at the midpoint between the two electrodes was greater than in either of the monopolar modes: 5.4+/-5.6 mm (group A); 28.8+/-8.2 mm (group B); 31.2+/-7.6 mm (group C) (p < 0.05) CONCLUSION: Using an open perfusion system, HS-enhanced bipolar RFA more efficiently created larger areas of thermal ablation and higher tissue temperatures than monopolar RFA.
OBJECTIVE: We wanted to determine whether combined radiofrequency ablation (RFA) and acetic acid-hypertonic saline solution (AHS) instillation can increase the extent of thermally mediated coagulation in in vivo rabbit liver tissue. We also wished to determine the optimal concentration of the solution in order to maximize its effect on extent of the RFA-induced coagulation. MATERIALS AND METHODS: Forty thermal ablation zones were produced in 40 rabbits by using a 17-gauge internally cooled electrode with a 1-cm active tip under ultrasound guidance. The rabbits were assigned to one of four groups: group A: RFA alone (n=10); group B: RFA with 50% AHS instillation (n=10); group C: RFA with 25% AHS instillation (n=10); group D: RFA with 15% AHS instillation (n=10). A range of acetic acid concentrations diluted in 36% NaCl to a total volume of 1 mL were instilled into the liver before RFA. The RF energy (30W) was applied for three minutes. After RFA, in each group, the maximum diameters of the thermal ablation zones in the gross specimens were compared. Technical success and the complications that arose were evaluated by CT and on the basis of autopsy findings. RESULTS: All procedures are technically successful. There were six procedure related complications (6/40; 15%): two localized perihepatic hematomas and four chemical peritonitis. The incidence of chemical peritonitis was highest for group B with the 50% AHS solution instillation (30%). With instillation of 15% AHS solution, a marked decrease of tissue impedance (24.5+/-15.6 ohm ) and an increase of current (250 mA) occurred as compared to RFA alone. With instillation of the solutions before RFA (group B, C and D), this produced a greater mean diameter of coagulation necrosis than the diameters for rabbits not instilled with the solution (group A) (p < 0.05). However, there was no significant difference between group B, C, and D. CONCLUSION: Combined AHS instillation and RFA can increase the dimension of coagulation necrosis in the liver with a single application. A low concentration of AHS (15%) showed similar effects in increasing the extent of RF-induced coagulation, but there were less side effects as compared to the high concentration of AHS.
OBJECTIVE: To determine whether saline-enhanced dual probe bipolar radiofrequency ablation (RFA) using perfused-cooled electrodes shows better in-vitro efficiency than monopolar or single probe bipolar RFA in creating larger coagulation necrosis. MATERIALS AND METHODS: RF was applied to excised bovine livers in both bipolar and monopolar modes using a 200 W generator (CC-3; Radionics) and the perfused-cooled electrodes for 10 mins. After placing single or double perfused-cooled electrodes in the explanted liver, 30 ablation zones were created at three different regimens: group A; saline-enhanced monopolar RFA, group B; saline-enhanced single probe bipolar RFA, and group C; saline-enhanced dual probe bipolar RFA. During RFA, we measured the tissue temperature at 15 mm from the electrode. The dimensions of the ablation zones and changes in the impedance currents and liver temperature during RFA were then compared between the groups. RESULTS: The mean current values were higher for monopolar mode (group A) than for the bipolar modes (groups B and C): 1550+/-25 mA in group A, 764+/-189 mA in group B and 819+/-98 mA in group C (p < 0.05). The volume of RF-induced coagulation necrosis was greater in group C than in the other groups: 27.6+/-2.9 cm(3) in group A, 23.7+/-3.8 cm(3) in group B, and 34.2+/-5.1 cm(3) in group C (p < 0.05). However, there was no significant difference between the short-axis diameter of the coagulation necrosis in the three groups: 3.1+/-0.8 cm, 2.9+/-1.2 cm and 4.0+/-1.3 cm in groups A, B and C, respectively (p > 0.05). The temperature at 15 mm from the electrode was higher in group C than in the other groups: 70+/- 18 degrees C in group A, 59+/-23 degrees C in group B and 96+/-16 degrees C in group C (p > 0.05). CONCLUSION: Saline-enhanced bipolar RFA using dual perfused-cooled electrodes increases the dimension of the ablation zone more efficiently than monopolar RFA or single probe bipolar RFA.
OBJECTIVE: This study was undertaken for the purpose of describing the CT features of intra-abdominal extra-hepatic metastases from gastrointestinal stromal tumors in patients who were treated with imatinib. MATERIALS AND METHODS: Eleven patients with intra-abdominal extra-hepatic metastases from gastrointestinal stromal tumors, who were treated with imatinib between May 2001 and December 2003, were included in this study. The clinical findings and CT scans were retrospectively reviewed. The metastatic lesions were assessed according to the location, size (greatest diameter), attenuation, and the enhancing pattern before and after imatinib treatment. RESULTS: Prior to the treatment, the sizes and attenuation values of the metastatic lesions ranged from 5 to 20 cm and from 63 to 131 H, respectively. The metastatic lesions showed a heterogeneous enhancement pattern on the contrast-enhanced CT scans. After the treatment, the metastatic lesions became smaller in all 11 patients, and the corresponding attenuation value ranged from 15 to 51 H. The metastatic lesions became homogeneous and cystic in appearance on the follow-up CT scans, mimicking ascites. CONCLUSION: Intra-abdominal extra-hepatic metastases of patients with gastrointestinal stromal tumors treated with imatinib may appear as well-circumscribed cystic lesions on contrast-enhanced CT. These metastases are likely to become smaller and resemble ascites, but may persist indefinitely on the followup CT.