Biomedical subjects
Publications and source records attributed to W A Fuchs.
The pharmacokinetic behaviour of intravascular renal and biliary contrast agents is being evaluated with help of CT-densitometry. Contrast enhancement is best with high-dose bolus injection and rapid sequence CT-scanning of at least 4 cuts per minute.
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Explore the source record for details and available documents.
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The medical evaluation and requisite radiologic examinations for the cancer patient are presented. Adequate clinical staging is essential for determining prognosis, optimal therapeutic plan, and evaluation of therapy results. Newer radiologic methods allow more detailed evaluation and determination of disease stage.
In computer tomography of the abdomen the amount of diagnostic information obtained depends on the organ system examined and correlates with the topographical anatomy. The information gained by this non-invasive method results from the demonstration of contour alteration and from inherent density differences. Although at this point in time, while the process of evaluation is still in progress, it is too early to formulate definitive guidelines on the indications for computer tomography of the abdomen, we suggest, on the basis of experience hitherto, that computer tomography of the adrenals and the pancreas is better than the previously known image-producing diagnostic methods. The overall diagnostic value of computer tomography of the liver and spleen, depending on the pathology in question, is apparently at least equal to sonography, nuclear medicine and angiography. Computer tomography of the gastrointestinal tract and the kidneys, when compared to other diagnostic radiographic and sonographic investigations, at present adds little information, and for this reason has limited application in these systems. In contrast to this is the highly instructive computer tomographic examination of the extrarenal retroperitoneal space.
Biliary excretion of iotroxamat (ITX) and ioglycamide (IGL) in cholecystectomized dogs fitted with a Thomas duodenal cannula is compatible with saturation kinetics exhibiting maximal excretory velocities of 2.23 +/- SD 0.18 and 1.22 +/- 0.19 mumol/min/kg, respectively. While biliary excretion of ITX obeyed classical Michaelis Menten kinetics, the data obtained with IGL suggested a more complex process. The choleretic effects of both contrast agents (23.6 +/- SD 2.29 and 25.8 +/- 2.21 microliter of excreted substance) were comparable. On the basis of these results and in view of the similar toxicity of the two contrast agents in animals, it may be expected that ITX will have advantages over IGL for intravenous cholangiography.
Percutaneous biopsy of the pancreas with a fine needle aimed by ultrasound was carried out on 26 patients with sonographically proven carcinoma of the pancreas. The accuracy of this method was correlated with other radiological techniques. Needle biopsy of the pancreas proved an informative and economical procedure, since the sonographic demonstration of a pancreatic mass otherwise requires additional radiological and endoscopic investigations.
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Between 1972 and 1975, exploratory laparotomies were carried out on 52 otherwise untreated patients with histologically verified Hodgkin's disease in stages I, II and III following lymphography. 84% of patients with negative lymphograms had histologically normal lymph nodes. 16% of negative lymphograms were shown to have to have histologically positive lymph nodes. Two out of eight patients diagnosed as positive on lymphography (25%) proved to be false positives caused by extensive lymph node involution. The diagnostic accuracy lymphography was therefore 83%. Surgical exploration was of value only in histologically positive cases. Post-operative control by means of lymphanigiography is essential for the evaluation of the course of Hodgkin's disease.
21% of 81 patients with malignant neoplasms of the ovaries had lymphographic evidence of metastases in regional iliac and aortic lymph nodes. The frequency of lymphatic metastases in various stages was approximately the same (FIGO stage I = 17%, II = 21%, III = 19%). About one fifth of patients therefore had to be restaged. Lymphography should be used for staging routinely, even if a laparotomy is planned.
Contrast agents for oral and intravenous cholecysto-cholangiography are iodinized lipophilic compounds with marked albumin binding. Their selective uptake by the liver occurs because of the presence of a membrane transport system and preferential binding to the hepatic cytoplasmatic proteins. Peroral contrast agents are conjugated. The canalicular excretion is an active carrier-mediated process limited by a transport maximum. Intravenous contrast agents are potent choleretics. Bile salts are important for intestinal absorption and hepatic excretion of the contrast agents. Pharmacological agents do not improve the biliary excretion of contrast compounds. The value of various investigation techniques is discussed.
Frequency and type of pulmonary and pleural involvement in collagen disease (rheumatoid arthritis, progressive systemic scleroderma, polymyositis-dermatomyositis and lupus erythematodes are analysed on the basis of literature and of own cases with particular regard to the roentgenographic appearance.
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With the help of selected examples, the angiographic criteria for traumatic parenchymal organ lesions were presented. The indication for angiography in children accident patients with blunt trauma must be set up carefully. The necessity of early angiographic examination in terms of the treatment to be implemented was pointed out.
The clinical indications for ultrasonography in diseases of the abdominal organs are systematically presented and discussed. The use of the gray-scale technique leads to an appreciable improvement in diagnostic potential, due in particular to the demonstration of small vascular structures. Consistency of tissue structures, the topographic-anatomical relationship between organs, and localization of space-occupying lesions are readily determined by sonography with a minimum of discomfort and stress for the patient.
The hemodynamic changes during intravenous urography were studied in 120 non-selected patients (60 patients with bolus injection, 60 with infusion: 30 of each group with methylglucamine ioxitalamate, while the other 30 with sodium methylglucamine diatrizoate). There was a uniform statistically significant increase in heart rate (p less than 10(-9) as well as in cardiac output (p less than 10(-9)) (measured by means of a non-invasive impedance method). The observed changes were more marked following bolus injection than infusion. With the application of methylglucamine ioxitalamate the increase in heart rate, but not in cardiac output, was significantly less (p less than 0,01) than with that of sodium methylglucamine diatrizoate.