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Biomedical subjects

K Selin

Publications and source records attributed to K Selin.

31 records · Page 2Linked to original sources
PubMed1983

Effects of iohexol and metrizoate on myocardial blood flow and metabolism.

In 10 patients coronary sinus blood flow (CSBF) was measured during and after injection of iohexol and meglumine-Na-Ca metrizoate in the left coronary artery. Oxygen saturation, lactate concentration and hematocrit were determined in the aorta and coronary sinus before and after a second injection of the two contrast media. The increase in CSBF was significantly more marked and sustained after injection of metrizoate than after iohexol and myocardial arterio-venous oxygen difference was significantly lower. Myocardial oxygen consumption and lactate metabolism were not adversely affected by any of the contrast media. The fall in hematocrit in coronary sinus blood was significantly greater after metrizoate.

Contrast Media↗
PubMed1982

Shrinking pleuritis with atelectasis.

During a 10-year period 28 patients with shrinking pleuritis with atelectasis (SPA) were observed and operated upon. This lesion has been given different names in the literature, for instance rounded atelectasis, pleuroma, pulmonary pseudotumour, and lung folding. All patients except two were operated upon because of a diagnosis of pulmonary tumour. However, at operation no tumour was found. The aetiology and pathogenesis of SPA are discussed on the basis of X-ray, operative, and histopathological findings.

Diagnosis, Differential↗
PubMed1982

Coronary angiography with Iopamidol.

Iopamidol, a new non-ionic contrast medium with low osmolality, was compared with Isopaque Coronar during selective coronary angiography in 16 patients. Iopamidol caused significantly less bradycardia, less ECG changes and less fall in blood pressure than Isopaque Coronar. No subjective adverse effects such as chest pain, vomiting, nausea or sensation of heat occurred. The results indicate that Iopamidol has advantages as a contrast medium for coronary angiography.

Adult↗
PubMed1980

The diagnosis of atrial myxomas. Difficulties and pitfalls.

Altogether seven patients with the preoperative diagnosis of atrial myxoma were admitted to our hospital in 1968-78 and referred for surgery. In two patients no tumour was found at operation. In one of them the reason for the misinterpretation was severely malformed mitral leaflets. In the other the contrast medium was injected into a pulmonary vein, which caused a contrast defect due to inadequate mixing.

Adult↗
PubMed1979

Visual evaluation of microscopic mottle.

According to Rose the resolution of an imaging system is under certain conditions limited by noise rather than by the finite geometric response as expressed by the modulation transfer function. In order to investigate whether this applies to clinical radiography as well, a technique for magnification of roentgen films has been devised, making possible visual evaluation of microscopic noise.

Methods↗
PubMed1979

Influence of microscopic mottle on the definition of small image details.

By a special technique of enlarging films, a microscopic mottle caused by quantum fluctuations was demonstrated. It was found to affect depiction of small details in such a way as to suggest that it would be of importance for determining resolution capacity, especially in high-speed radiography. Thus, the modulation transfer function appears not to be the only factor determining radiographic resolution. The resolution of high-speed screens may be improved if the film speed is reduced, which leads to a diminished microscopic mottle.

Photography↗
PubMed1978

Medichrome film as an alternative to silver-free recording systems.

A shortage of silver is forcing film manufacturers to lower the silver content of radiographic films. No further lowering seems possible without film quality being adversely affected. Various ways to solve the silver problem in the future are discussed and colour radiography is regarded as one solution since it makes possible a high degree of immediate recovery of silver. The feasibility and proper use of the only colour film available, Medichrome, is discussed. Suitable screens in order to compensate for the low sensitivity of the film without loss of image quality and a strong light source containing a monochromatic sodium lamp for inspection of dense areas are recommended.

Radiography↗
PubMed1977

High-density failure of radiographic films.

The recording of weak signals of high spatial frequency emanating from intensifying screens has been analysed in different films at varying densities. Even if the gamma value is kept constant over a wide range of densities, the recording of these signals is impaired at high densities above a certain optimum density, coinciding with the lower part of the straight part of the characteristic curve. The recording of these signals appears to be related to the number of silver halide grains per unit area available for signal recording rather than to the contrast as represented by the gamma value. When the density of the image is increased more grains are precipitated in creating the background density, leaving a smaller number of grains unaffected for the signals added on top of the background. If the signal frequency is high and the amplitude is low the remaining grains appear to become too few and too scattered for a proper recording, so that the signal cannot appear in the image. Since this occurs at densities where the film is not usually considered to be overexposed the phenomenon is called high-density failure. Different films may display great differences in high-density failure even if the sensitivity is the same.

Technology, Radiologic↗
PubMed1975

Influence of secondary radiation on image quality.

On the basis of observations concerning non-screen films and xerox plates a theory is proposed as to how the image quality is impaired by secondary radiation. The theory includes an explanation of why xerox plates and industrial roentgen films of a high silver content are less affected by secondary radiation than conventional roentgen films.

Radiographic Image Enhancement↗
PubMedDate not supplied

Vectorcardiographic changes during cardioangiography with iodixanol and ioxaglate.

AIM: To compare the electrophysiological effects of two contrast media (CM), the non-ionic dimer iodixanol and the ionic dimer ioxaglate using computerised dynamic vectorcardiography (VCG) during coronary angiography. METHODS: The study was designed as a double-blind, three-period crossover, randomised comparison between iodixanol (320 mg I/ml) and ioxaglate (320 mg I/ml). Group 1 (HVV) received ioxaglate (H) in the first injection in the left coronary artery (LCA) and iodixanol (V) in the following injections. Group 2 (VHH) received iodixanol in the first injection in LCA and ioxaglate in the following injections. The first three injections in the LCA were subjected to electrocardiographic analysis. RESULTS: For five out of six VCG variables, there was a significant difference in response between iodixanol and ioxaglate. For these five variables, the deviations from baseline were greater in the ioxaglate than in the iodixanol group (P<0.05). The most pronounced effects from ioxaglate were seen on the ST-segment and T-wave. CONCLUSIONS: Iodixanol caused less pronounced electrophysiological changes than ioxaglate, especially during the repolarisation phase. Vectorcardiography is a sensitive and reproducible technique for detecting electrophysiological effects induced by CM.

Adult↗
PubMedDate not supplied

Shrinking pleuritis with atelectasis. Specificity of abnormalities present at conventional radiography of the lung.

Radiographic appearances claimed to be typical of shrinking pleuritis with atelectasis (SPA) were tested by mingling chest films from 6 SPA patients with those from 56 cancer cases. Two radiologists were asked to interpret the films independently, make a diagnosis, and state what abnormalities could be distinguished. No single abnormality or combination of abnormalities was found to be pathognomonic and the wish to diagnose the SPA cases led to misdiagnosis of cancer in one of 56 cases by each radiologist. To prevent underdiagnosis of cancer, further examinations are required. Careful follow-up of SPA cases, if they are not operated upon, is recommended.

Diagnosis, Differential↗