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Biomedical subjects

J H Lim

Publications and source records attributed to J H Lim.

At least 145 records · Page 8Linked to original sources

Transabdominal US staging of gastric cancer.

Penetration of gastric cancer through the wall is important because the treatment modality and prognosis are accordingly different. A prospective study was performed to assess the value of transabdominal ultrasonography in the differentiation of early gastric cancer limited within the mucosa and submucosa from advanced cancer extending into the muscle layer. Fifteen patients with early gastric cancer and 29 patients with advanced gastric cancer were evaluated preoperatively and compared with histological findings. Patients were referred after endoscopy and sonologists were informed of the site of the gastric lesions. Patients ingested 600-800 ml of boiled water and transabdominal ultrasonography of the gastric lesion was accomplished using a commercially available ultrasound equipment with 5.0 and 3.5 MHz transducers. Using the intact middle hyperechoic layer on sonogram as the criterion for early cancer, 10 of 15 patients with early gastric cancer and 27 of 29 patients with advanced gastric cancer were correctly diagnosed (84%). Fourteen of 15 cases with early gastric cancer showed a thickness of the lesion below 1.0 cm, while seven of 29 cases with advanced cancer showed a thickness 1.0 cm or less. We believe that transabdominal sonography may be a valuable method in the differentiation between early and advanced gastric cancer.

Adult↗

Hepatocellular carcinoma in advanced liver cirrhosis: CT detection in transplant patients.

Computed tomography (CT) is being used as the standard pretransplantation imaging for recipients and donors in the evaluation of liver volume, liver reserve function, vascular anatomy, diagnosis of hepatocellular carcinoma and metastasis, and global information of the abdominal cavity. Whereas CT detection of hepatocellular carcinoma in non-cirrhotic patients is satisfactory, detection sensitivity in severely cirrhotic patients is limited, with a reported sensitivity of 53% to 68%. Tumors smaller than 2 cm are more difficult to detect. Innumerable regenerative nodules, localized or diffuse fibrosis, arterioportal shunts, nodular surface, and distorted anatomy in end-stage liver cirrhosis make it difficult to detect small hepatocellular carcinoma. Because of the shortage of cadavers and living donors, judicious use of CT is necessary in the selection of candidates and the decision of priority for liver transplantation in patients with advanced liver cirrhosis.

Carcinoma, Hepatocellular↗

Multiple infarcted regenerative nodules in liver cirrhosis after systemic hypotension due to septic shock: radiologic findings.

We describe a case of multiple infarcted regenerative nodules in a patient with advanced liver cirrhosis who had experienced an episode of septic shock. Sonography showed multiple hypoechoic or isoechoic nodules; contrast-enhanced computed tomography showed multiple, low-attenuating nodules with rim enhancement; and magnetic resonance imaging showed multiple nodules of low, iso-, or high signal intensity. Explanted liver showed coagulation necrosis of multiple regenerative nodules. Peribiliary cysts in chronic liver diseases, liver abscesses, spontaneous necrosis of hepatocellular carcinomas, and metastasis should be differentiated.

Adult↗

Mucocele of the appendix: ultrasonographic and CT findings.

BACKGROUND: Mucocele of the appendix is a rare disease entity, but preoperative diagnosis is very important. With the advent of ultrasonography (US) and computed tomography (CT), it has been possible to preoperatively diagnose mucocele of the appendix. We describe the spectrum of US and CT findings of mucocele of the appendix and the differential points from mimicking diseases. METHODS: We evaluated 17 patients with pathologically proven mucocele of the appendix by using US and CT. Pathologic diagnoses of 17 patients were mucinous cystadenoma in 11 patients, mucinous cystadenocarcinoma in two, and mucosal hyperplasia in four. We analyzed morphologic characteristics of mucocele of the appendix at US and CT. RESULTS: The typical US finding were a cystic mass with variable internal echogenicity, layered wall, and calcification in the wall. The CT finding was a well-encapsulated cystic mass with a wall of variable thickness. Both cases with focal nodular solid enhancing portion in the wall on CT were pathologically proven as mucinous cystadenocarcinoma. CONCLUSION: US and CT were useful methods in diagnosing mucocele of the appendix and differentiating this condition from mimicking diseases. Nodular enhancing lesion in the wall of the mucocele may be a finding suggestive of malignant cause of mucocele.

Adult↗

Iodized oil retention due to postbiopsy arterioportal shunt: a false positive lesion in the investigation of hepatocellular carcinoma.

BACKGROUND: Iodized-oil computed tomography (CT) is useful for the diagnosis of hepatocellular carcinoma, but there may be false-positive results in patients who have undergone some percutaneous transhepatic interventional procedures. The purpose of the present study was to verify the correlation between subsegmental hepatic parenchymal retention of iodized oil on CT and the arterioportal shunt caused by liver biopsy. METHODS: Iodized-oil CT scans were reviewed in 24 patients with hepatic tumors who had liver biopsy and subsequent iodized oil chemoembolization. Iodized oil chemoembolization was performed shortly after biopsy (1-10 days; mean = 2.6 days). The results were correlated with hepatic arteriography, with a special emphasis on the presence of hepatic arterioportal shunt. RESULTS: Wedge-shaped subsegmental retention of iodized oil along or adjacent to the biopsy needle path was observed in iodized-oil CT in 17 of the 24 patients. In three patients, there was subsegmental enhancement on prebiopsy helical dynamic liver CT at the same area of iodized oil retention, and therefore iodized oil retention was considered to be due to hepatocellular carcinoma. In the remaining 13 (54%) patients, the peripheral iodized oil retention was considered to be due to biopsy-induced arterioportal shunt. In all these patients, arterioportal shunt was confirmed by hepatic arteriography. CONCLUSION: Wedge-shaped hepatic parenchymal retention of iodized oil is commonly observed in iodized-oil CT due to biopsy-induced arterioportal shunt, and this appearance should not be confused with a hepatocellular carcinoma.

Arteriovenous Fistula↗

Intraductal mucosal-spreading mucin-producing peripheral cholangiocarcinoma of the liver.

The computed tomographic (CT) appearance of a case of intraductal mucosal-spreading mucin-producing peripheral cholangiocarcinoma of the liver is described in a patient presenting with acute pericardial tamponade due to rupture of the cystically dilated left intrahepatic ducts by mucin hypersecretion. CT showed cystic and tubular dilatation of the intrahepatic ducts of the left and caudate lobes, but there was no grossly visible tumor mass. Pathology showed a single layer of tall columnar tumor cells with short intraluminal papillary projections lining each bile duct; the ducts were markedly dilated because of excessive mucin secretion. There was no gross tumor mass in the bile ducts. The tumor spread diffusely and contiguously along the intrahepatic bile ducts, with minimal invasion to the bile duct wall. To our knowledge, there has been no report about mucosal-spreading peripheral cholangiocarcinoma of the liver.

Bile Duct Neoplasms↗

Acinar cell carcinoma of the pancreas. Ultrasonography and computed tomography findings.

The radiologic findings in two cases of acinar cell carcinoma of the pancreas are described. Sonographic findings were a midrange echogenic mass with heterogeneity, containing some small- and medium-sized low echogenic areas suggesting necrosis. Ultrasonic through-transmission was good. Computed tomography findings were a well-defined, hypodense, large mass having an enhancing, thin capsule. There were multiple small- and medium-sized irregular low-density areas suggesting necrosis. Small punctate calcific foci were present in one case. With these characteristics, acinar cell carcinoma can be distinguished from the locally invasive common adenocarcinoma of the pancreas, but the differentiation from some other less common pancreatic tumors remains difficult.

Adult↗

Inflammatory pseudotumor of the liver. Ultrasound and CT features.

Inflammatory pseudotumor of the liver is characterized by a well-circumscribed, encapsulated inflammatory mass consisting of inflammatory cell infiltration and fibrosis. We report the radiological findings of inflammatory pseudotumor of the liver in two patients with recurrent pyogenic cholangitis, showing a poorly defined, heterogeneous, hypovascular mass, mimicking a tumor. Radiological findings are not characteristic and definitive diagnosis requires needle biopsy or surgery.

Aged↗

Hepatocellular carcinoma presenting only as portal venous tumor thrombosis: CT demonstration.

We describe two cases of hepatocellular carcinoma initially presenting with portal vein tumor thrombi but with no demonstrable tumor in the liver parenchyma outside the portal vein. Both patients had cirrhosis of the liver and had tumor thrombi in the main portal vein and its branches. The tumor thrombi were demonstrated on ultrasonography, CT, angiography as expanding intraluminal masses.

Carcinoma, Hepatocellular↗

Transient subsegmental hepatic parenchymal enhancement on dynamic CT: a sign of postbiopsy arterioportal shunt.

PURPOSE: Our goal was to verify the correlation between the arterioportal shunt caused by liver biopsy injury and wedge-shaped early transient subsegmental parenchymal enhancement (TSPE) of the liver during helical dynamic CT. METHOD: Twenty-one consecutive patients with suspected hepatic tumor underwent percutaneous needle biopsy. Helical dynamic CT scans at arterial, portal venous, and delayed phases were obtained before and after biopsy. CT images were reviewed for the presence of TSPE during the arterial phase of dynamic CT. Hepatic arteriograms were obtained in all patients and reviewed for the presence of arterioportal shunt. RESULTS: Wedge-shaped TSPE was observed on postbiopsy CT in 8 (38%) of the 21 patients along the needle path. In all of these patients subsegmental arterioportal shunt was confirmed by hepatic angiograms. CONCLUSION: Wedge-shaped TSPE is commonly observed along the biopsy needle path and is due to arterioportal shunt caused by biopsy.

Adult↗

Continuation of gas from the right perirenal space into the bare area of the liver.

PURPOSE: It is difficult to explain some CT findings pertaining the anatomic relationship between the bare area of the liver and the right retroperitoneal space on the basis of the traditional three compartment concept of retroperitoneal anatomy. The purpose of this article is to ascertain and illustrate possible communication between the bare area of the liver and the right perirenal space in patients with gas-forming retroperitoneal infection. METHOD: We reviewed CT findings in 24 cases with retroperitoneal gas-forming condition with particular emphasis on the extent of the infection and resultant distribution of gas. RESULTS: CT images showed gas within the right perirenal space extended upward directly into the bare area of the liver in six cases. CONCLUSION: The right perirenal space is considered open toward the bare area of the liver. Therefore, gas within the perirenal space may communicate directly with the bare area of the liver.

Emphysema↗

Opacification of the intrahepatic portal veins during CT hepatic arteriography.

PURPOSE: The purpose of this study was to ascertain the cause of opacification of the portal veins during CT hepatic arteriography (CTHA). METHOD: A total of 155 consecutive patients with hepatocellular carcinoma were evaluated with CTHA as preoperative staging. The opacification of the portal veins during CTHA was categorized as opacification of the main portal vein, right or left branches of the main portal vein (generalized), and segmental or subsegmental portal veins (localized). Hepatic angiography was compared and possible causes were evaluated. RESULTS: One hundred eight (70%) of 155 patients showed intrahepatic portal vein opacification at CTHA: generalized in 60 patients (39%) and localized in 48 patients (31%). Intrahepatic causes were arterioportal shunts due to hepatocellular carcinoma in 20 (19% of 108 patients), previous liver biopsy in 9 (8%), and portal vein thrombosis in 4 (4%). Extrahepatic cause was counted in 57 cases (53%) and was due to inflow of contrast material via nonmesenteric portal circulation through the gastric antrum, duodenum, and/or pancreas. CONCLUSION: Intrahepatic portal veins are frequently opacified during CTHA, and the causes were arterioportal shunts through hepatocellular carcinoma, postbiopsy shunt, portal vein thrombosis, and inflow of contrast material via the nonmesenteric portal circulation.

Adult↗

Detection of hepatocellular carcinoma: combined T2-weighted and dynamic gadolinium-enhanced MRI versus combined CT during arterial portography and CT hepatic arteriography.

PURPOSE: The purpose of this study was to compare the preoperative detectability of hepatocellular carcinomas (HCCs) using combined T2-weighted and dynamic gadolinium-enhanced MRI and combined CT during arterial portography (CTAP) and CT hepatic arteriography (CTHA). METHOD: Thirty-three patients with 43 HCCs underwent T2-weighted and dynamic gadolinium-enhanced MRI and combined CTAP and CTHA. The diagnosis was established by pathologic examination following surgical resection in 26 patients and by biopsy in 7 patients. The MR protocol included fast SE with two TEs (including T2-weighted imaging) and precontrast and gadolinium-enhanced T1-weighted fast multiplanar spoiled gradient-recalled echo images with dynamic study. The MR images of all sequences and the paired CTAP and CTHA images were independently reviewed by three radiologists. Image review was conducted on a segment-by-segment basis. Diagnostic accuracy was evaluated with receiver operating characteristic analysis. RESULTS: The accuracies (Az values) of MRI of all sequences and combined CTAP and CTHA for all observers were 0.960 and 0.959, respectively. The mean sensitivities of MRI and CT were 90 and 94%, respectively. The differences were not statistically significant. The mean specificity of MRI (99%) was significantly higher than that of combined CTAP and CTHA (92%). CONCLUSION: Combined T2-weighted and dynamic gadolinium-enhanced MRI is as accurate as combined CTAP and CTHA for preoperative detection of HCCs.

Adult↗

Radiologic spectrum of intraductal papillary mucinous tumor of the pancreas.

"Intraductal papillary mucinous tumor" is now the preferred term to describe a spectrum of proliferation of the pancreatic ductal epithelium. The tumor produces an excessive amount of mucin and results in progressive dilation of the main pancreatic duct or cystic dilation of the branch ducts, depending on the location of the tumor. This tumor is small and localized in a segment of the main pancreatic duct or in branch ducts, particularly in the branch ducts of the uncinate process, but it may also be diffuse, involving a wide area of the pancreatic ducts. Excessive mucin may impede the pancreatic duct flow and, in turn, produce symptoms of chronic pancreatitis. The following findings are seen on imaging studies: lobulated multicystic dilatation of the branch ducts, diffuse dilatation of the main pancreatic duct, intraductal papillary tumors, elongated or globlike mucous plugs in the dilated ducts, and bulging of the papilla into the duodenal lumen. The diagnosis is suggested at ultrasonography, computed tomography, or magnetic resonance cholangiopancreatography. Endoscopic retrograde cholangiopancreatography is the imaging modality of choice for the diagnosis, because it depicts the communication between the cystically dilated branch ducts and the diffusely dilated main pancreatic duct, as well as intraductal papillary tumor and mucous plugs.

Adenocarcinoma, Mucinous↗

Haptoglobin polymorphism in Korean patients with cardiovascular diseases.

We investigated the relation between hepatoglobin (Hp) polymorphism and plasma lipid levels in 913 Korean subjects. The distribution of Hp phenotypes did not show any significant differences between the healthy controls and the patients with cardiovascular disease. In the control group, however, the subgroup of > or = 50-year-olds had a significantly higher Hp*1 allele frequency than the subgroup <50 years (p < 0.005). This was not seen in the patient group. Hp phenotypes were associated with levels of high-density lipoprotein cholesterol in the hypertensive group. The results indicate that Hp polymorphism, at least in the Korean population, does not predispose to the occurrence of cardiovascular diseases.

Adult↗

The mitochondrial protein import motor.

Mitochondrial proteins are synthesized as precursor proteins in the cytosol and are posttranslationally imported into the organelle. A complex system of translocation machineries recognizes and transports the precursor polypeptide across the mitochondrial membranes. Energy for the translocation process is mainly supplied by the mitochondrial membrane potential (deltapsi) and the hydrolysis of ATP. Mitochondrial Hsp70 (mtHsp70) has been identified as the major ATPase driving the membrane transport of the precursor polypeptides into the mitochondrial matrix. Together with the partner proteins Tim44 and Mge1, mtHsp70 forms an import motor complex interacting with the incoming preproteins at the inner face of the inner membrane. This import motor complex drives the movement of the polypeptides in the translocation channel and the unfolding of carboxy-terminal parts of the preproteins on the outside of the outer membrane. Two models of the molecular mechanism of mtHsp70 during polypeptide translocation are discussed. In the 'trapping' model, precursor movement is generated by Brownian movement of the polypeptide chain in the translocation pore. This random movement is made vectorial by the interaction with mtHsp70 in the matrix. The detailed characterization of conditional mutants of the import motor complex provides the basis for an extended model. In this 'pulling' model, the attachment of mtHsp70 at the inner membrane via Tim44 and a conformational change induced by ATP results in the generation of an inward-directed force on the bound precursor polypeptide. This active role of the import motor complex is necessary for the translocation of proteins containing tightly folded domains. We suggest that both mechanisms complement each other to reach a high efficiency of preprotein import.

Animals↗