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Biomedical subjects

R N Gibson

Publications and source records attributed to R N Gibson.

72 records · Page 4Linked to original sources
PubMed1986

The radiology of fibrolamellar hepatoma.

Seven patients with fibrolamellar hepatoma were examined with computed tomography (CT), ultrasonography and angiography. On CT the tumours were large, of low attenuation, had a well-defined edge and some contained areas of calcification or necrosis. Ultrasonography revealed well-defined masses of mixed echogenicity, occasionally involving the portal vein. In one patient there was dilatation of the intrahepatic biliary tree. Arteriography showed vascular tumours with involvement of the portal vein in five cases and compression of the inferior vena cava in five cases. CT and ultrasonography are the most useful radiological investigations for suggesting the diagnosis of fibrolamellar hepatoma which should be considered in the case of any large solitary well-defined hepatic tumour in the noncirrhotic liver of a young person.

Adolescent↗
PubMed1986

The left-sided pancreas.

Ultrasonography (US) performed in nine patients (two with pancreatic carcinoma, one with hepatomegaly, six with no relevant abdominal disease) showed the pancreas to lie wholly to the left of the aorta. This not uncommon location may give rise to difficulty in demonstrating the pancreas on real-time US scans. The superior mesenteric vessels and splenic vein remain useful landmarks for locating the head of the pancreas in this position.

Aged↗
PubMed1986

Bile duct obstruction: radiologic evaluation of level, cause, and tumor resectability.

In a prospective study of 65 patients with bile duct obstruction, various radiologic modalities were compared for their capability to demonstrate the level and cause of obstruction and to indicate accurately tumor resectability. Ultrasound (US) was performed in 65 patients, computed tomography (CT) in 51, direct cholangiography (DC) in 57, and angiography in 35. The level of obstruction was correctly indicated by US in 95% of patients and by CT in 90%, and the cause was correctly indicated by US in 88%, by CT in 63%, and by DC in 89%. In predicting tumor resectability, US was correct in 71% of patients, compared with 42% for CT, 58% for DC, and 25% for angiography. US therefore appears to be the single most useful modality in the evaluation bile duct obstruction.

Bile Duct Neoplasms↗
PubMed1986

Cholangitis after endoscopic sphincterotomy in patients with stricture of the biliary duct.

Five patients with stricture of the common hepatic bile duct underwent endoscopic treatment without relief from cholangitis or successful stricture dilation. A Roux-en-Y hepaticojejunostomy was performed upon four patients who are now symptom-free. Endoscopic sphincterotomy leads to bactobilia and increases the risk of cholangitis, particularly in patients with residual obstruction of the bile duct. Although endoscopic treatment may have a role in patients at high risk, there is uncertainty about the long term results and the risk of progressive liver damage. In the majority of patients, the results of operation for benign stricture of the bile duct are such that operative repair is the treatment of choice.

Adolescent↗
PubMed1985

Decreased biliary excretion of piperacillin after percutaneous relief of extrahepatic obstructive jaundice.

The biliary excretion of piperacillin has been assessed in 11 patients with obstructive jaundice due to hilar cholangiocarcinoma. After a 1-g intravenous dose administered 30 min before preliminary percutaneous transhepatic cholangiography, no drug was detected in the bile of seven patients; in four others, drug concentrations were far below the corresponding level in serum. After a period of external biliary drainage of up to 28 days, levels of antibiotic in bile after intravenous administration were only minimally increased. The results suggest that although the impairment of hepatic function may be improved by external biliary decompression when assessed by a fall in plasma bilirubin, the biliary elimination of piperacillin and related beta-lactam antibiotics may remain impaired for prolonged periods.

Adult↗
PubMedDate not supplied

MRI of the liver.

MRI of the liver is a powerful imaging modality for detection and characterization of liver pathology. MRI technology continues to evolve with developments in scanner hardware performance and refinements in imaging sequences, particularly in respect to fast imaging techniques, improving the quality of images that can be routinely achieved. Fast imaging techniques allow dynamic contrast-enhanced scanning to assist in lesion detection and characterization. An array of tissue-specific contrast agents are also becoming available; the clinical utility of some of these agents is yet to be fully established. An overview of scanning technique, contrast media, and the role of MRI in liver lesion detection and characterization is presented, with a review of the typical imaging characteristics of common focal and diffuse hepatic diseases. Where possible, emphasis has been placed on features that allow distinction between the various pathologic entities described.

Contrast Media↗
PubMedDate not supplied

Carotid artery stenosis--reassessment of the Doppler criteria.

Few previous studies of the accuracy of duplex Doppler in the assessment of carotid artery stenosis have looked at the accuracy in excluding disease in populations with a significant number of normal arteries. In addition, few studies have compared different criteria for stenosis. Duplex Doppler was used to evaluate the carotid arteries in 80 patients. Two well-described methods for analysing Doppler traces were used and the results were compared with those obtained from non-selective digital subtraction angiography. On the basis of these findings, the Doppler criteria used for carotid stenosis were redefined in terms of changes in peak velocity rather than Doppler frequency shift. Using these criteria, the sensitivity of Doppler in identifying carotid stenosis was 97% (98% sensitivity for greater than 50% stenosis) and specificity was increased from 84% to 93%.

Adult↗
PubMedDate not supplied

Duplex Doppler ultrasound of the ligamentum teres and portal vein: a clinically useful adjunct in the evaluation of patients with known or suspected chronic liver disease or portal hypertension.

The prevalence and potential value of the detection of signs of portal hypertension by duplex Doppler ultrasound (DDU) of the ligamentum teres and portal vein in patients with known or suspected chronic liver disease and/or portal hypertension was studied in 136 consecutive patients undergoing clinical assessment including that of liver histopathology. Portal hypertension was considered to be present when any of the following DDU signs, previously demonstrated to be specific for portal hypertension, were present: an enlarged and/or patent para-umbilical vein, portal vein obstruction or hepatofugal flow in the portal vein. Of 123 patients with parenchymal liver disease, eighty-three had cirrhosis and, of these, portal hypertension was detected on DDU criteria in 86% of alcoholic cirrhotics and 67% of non-alcoholic cirrhotics. Of the 42 patients with non-cirrhotic liver disease, 1 of 7 patients with metastatic liver disease and 3 of 5 patients with alcoholic hepatitis had DDU signs of portal hypertension. Thus, in patients with parenchymal liver disease, DDU had a sensitivity of 73%, specificity of 90% and predictive values of 94 and 62% for positive and negative studies respectively for the detection of cirrhosis. In all 14 patients with portal hypertension secondary to vascular occlusive diseases, DDU examination of the ligamentum teres, portal vein and hepatic vein gave an accurate guide to the site of the occluding lesion. The high positive predictive value of DDU and its ability to aid in localizing the site of increased resistance to flow through the liver suggest that DDU of the ligamentum teres and portal vein is a potentially useful non-invasive adjunct in the assessment of patients with suspected or known liver disease or portal hypertension.

Humans↗
PubMedDate not supplied

Ileocolic intussusception in large cell lymphoma of the terminal ileum. Report of a case.

A case of an adult patient with ileocolic intussusception secondary to a lymphoma of the terminal ileum is reported. On the computed tomograms, a target mass, with the outer rim representing the annular tumour of the terminal ileum and the eccentric rim of low attenuation representing the mesentery, is described. Ultrasound patterns are those of parallel hypoechoic areas separated by hyperechoic stripes seen on longitudinal sections, and of a rounded mass of low echogenicity, exhibiting two hyperechoic concentric ring-like areas within it, on transverse scans. The appearances of the barium examinations are also described. The English literature is reviewed.

Humans↗