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Biomedical subjects

U Nyman

Publications and source records attributed to U Nyman.

At least 109 records · Page 6Linked to original sources
PubMed1981

[Functional control of the renal transplant via sequential computerized tomography. First results (author's transl)].

The enhancement of cortex medulla and arteria iliaca can be visualized separately, evaluated densitometrically and represented graphically by means of sequential computerized tomography of the renal transplant following intravenous contrast medium bolus injection. Since this enhancement performance is mainly dependent on perfusion, it is possible to determine the perfusion value of individual measurement areas. For example, a cortical defective perfusion, as is known in rejection, becomes evident as a flattening-out of the initial rise of cortex enhancement and can be distinguished from the largely normal type of curve obtained in acute tubular necrosis (ATN). The angiographically known prolonged "wash-out time' in rejection corresponds to a long-lasting corticomedullary density gradient. Despite restricted informative value because of the relatively small number of patients, it appears that sequential computerized tomography enables differentiation of postoperative anuria.

Adult↗
PubMed1981

[The diagnosis of renal perfusion abnormalities by sequential CT (author's transl)].

Abnormalities of renal perfusion can be recognised more readily by sequential CT than by a plain CT scan or after "static" enhancement with contrast medium. Haemodynamically significant stenoses of the renal arteries and total, or partial, infarct can be diagnosed in this way. Intrarenal and capsular collaterals can be recognised by slow contrast accumulation in the infarcted area, or by the development of contrast in the sub-capsular portion of the cortex. Renal cortical necrosis is very well demonstrated by the absence of cortical perfusion; this is seen, for instance, in the DIC syndrome or during rejection after renal transplant.

Disseminated Intravascular Coagulation↗
PubMed1981

Computer tomography of ovarian dermoid cysts.

Five patients with ovarian dermoid cysts (benign cystic teratomas) were examined by CT. The appearance of these tumours at CT as well as at conventional radiography is discussed. It is concluded that CT adds valuable information in the preoperative evaluation of cystic teratomas.

Adult↗
PubMed1981

Evaluation of transplanted kidneys with computed tomography and ultrasound.

165 computed tomography (CT) and 98 ultrasound (US) examinations were performed in 64 renal transplant patients. The correlations between CT/US, contemporary clinical and retrospective diagnoses were analysed. CT and US are of great help in the post transplantation follow up, particulary when used together. Determination of the cause for unsatisfactory transplant function had always constituted one of the major problems for the clinician involved in the care for organ transplant patients. Traditionally transplant malfunction had been investigated by clinical examination, renography, radionuclearscanning, angiography and needle biopsy. (Nilsson et al. 1968. Starzl et al. 1970. Häyrö 1981). Computed tomography (CT) and ultra sound scanning (US) show promising capacities to differentiate between the alternative causes for diminished transplant function. (Frick et al. 1981, Smith 1981). The purpose of this presentation is to evaluate CT and US in the diagnosis of the various conditions causing impaired function of the transplanted kidney.

Acute Disease↗
PubMed1980

Angiography in angiomatous lesions of the gastrointestinal tract.

Twenty patients with various angiomatous lesions of the gastrointestinal tract, such as right-colon angiodysplasia and manifestations of Rendu-Osler-Weber disease and Klippel-Trenaunay syndrome are reported. During the past 15 years an increasing number of such lesions have been reported, diagnosed mainly by angiography. The major complication from these vascular lesions is bleeding. Angiography is the primary method for their detection because of their often small size and is a prerequisite before surgery when reason exists for anticipating an angiomatous lesion as the source of bleeding. However, in certain cases angiography will fail to demonstrate the vascular abnormality or its full extent.

Adolescent↗
PubMed1980

Effect of pH, buffer and osmolality of different contrast media on aortic blood pressure in the rabbit.

Intra-aortic injections in rabbits of contrast media with a lower osmolality (metrizamide, C29 and ioxaglate) caused significantly less decrease in aortic blood pressure than injections of contrast media with a higher osmolality (diatrizoate, metrizoate and iothalamate) at iodine equivalent concentrations. Increasing the acidity of metrizamide and C29 form pH 7.4 to 5.0 increased the blood pressure fall. Variation of the buffer (phosphate, TRIS and bicarbonate) in metrizamide and C29 solutions at physiologic pH did not cause any difference in response.

Animals↗
PubMed1980

Effects of contrast media on aortic endothelium. Experiments in the rat with non-ionic monomeric and monoacidic dimeric contrast media.

Injury to the aortic endothelium in rats was evaluated under a light microscope by a silver staining method after application of ionic monomeric (diatrizoate and metrizoate), non-ionic monomeric (C29 with different pH and buffers, 593, iohexol and metrizamide) and monoacidic dimeric (ioxaglate) contrast media, and iso- and hypertonic solutions of sodium chloride. In iodine equivalent concentrations the ionic monomers were significantly more toxic than the other contrast media. No significant was found between the non-ionic monomers, monoacidic dimer and sodium chloride solutions equiosmolal to the ionic monomers. Isotonic saline was the least harmful solution.

Animals↗
PubMed1980

Effect of contrast media on femoral blood flow. Comparison between non-ionic and ionic monomeric and monoacidic dimeric contrast media in the dog.

Injections of non-ionic monomeric (metrizamide, C29 and iohexol) and monoacidic dimeric (ioxaglate) contrast media into the femoral artery of dogs caused significantly less increase in the rate of femoral blood flow than the more hypertonic ionic monomeric compound metrizoate at equivalent iodine concentrations. The effect of metrizoate was similar to that of equiosmolal solutions of sodium chloride. Sodium chloride in concentrations equiosmolal with the non-ionic monomers and monoacidic dimer caused less changes in blood flow than these contrast media, but the changes in blood were equal to those of isotonic sodium chloride.

Animals↗
PubMed1980

[Sequence-CT: early enhancement--curves of the healthy kidney].

Ten healthy kidneys were studied by sequence-scans every 15 seconds following i. v. bolus-injection of metrizoate. Enhancement of renal cortex, medulla and the abdominal aorta was measured separately. The curves of the renal parenchyma are summations of three functions: perfusion, diffusion of contrast agent to the interstitial fluid, and accumulation of the enhanced urine and its excretion. The enhancement-curves of the aorta and of the renal cortex show two peaks due to recirculation and high perfusion. The curve of the renal medulla is characterized by a slow rise and lower and wider single peak. Knowledge of the normal enhancement-curves is essential for the evaluation of altered renal perfusion.

Contrast Media↗
PubMed1979

Angiography in leiomyosarcoma of the inferior vena cava--report of two cases.

Two patients with leiomyosarcoma of the suprarenal inferior vena cava are presented. In one case the tumour was misinterpreted as intrahepatic at angiography. In the second case an extrahepatic location was suggested after repeated angiography. The diagnosis should be borne in mind when a large hypovascular mass appears to be located centrally in the liver at coeliac angiography and when ultrasound examination has revealed its solid nature.

Age Factors↗
PubMed1979

Routine celiac angiography in patients with renal cell carcinoma.

Celiac and/or superior mesenteric angiography was done routinely in association with renal angiography on 115 patients with renal cell carcinoma. Metastases were demonstrated in 20 patients on extended angiography. In 10 of these patients no other signs of metastatic disease were noted at diagnosis. In the total clinical diagnostic stydy metastatic spread was present in 41 patients.

Adenocarcinoma↗
PubMed1978

Arterial and venous blood pressure and blood flow following femoral angiography with a new non-ionic contrast medium. An experimental investigation in dogs.

At femoral angiography in dogs the effects of a new non-ionic contrast medium (C29) were compared with those of one non-ionic medium (metrizamide) and one ionic medium (meglumine/sodium diatrizoate) in current use. In the leg subjected to angiography the pressure gradient over the peripheral vessels decreased and the femoral blood flow increased. The changes induced by the ionic medium were significantly greater than those induced by metrizamide and C29, whereas no significant difference between the two non-ionic media was recorded.

Animals↗
PubMed1977

Angiography in hereditary hemorrhagic telangiectasia.

Hereditary hemorrhagic telangiectasia is a vascular disorder with stigmata in any part of the body. The most frequently reported sites of internal lesions are the lungs, liver and gastrointestinal tract. When one lesion is observed on chest radiography or on splanchnic angiography there is reason to include other vascular areas in the investigation. A normal angiographic finding does not exclude the presence of telangiectasia.

Angiography↗