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Biomedical subjects

I Beranek

Publications and source records attributed to I Beranek.

10 recordsLinked to original sources
PubMed1978

Development of a method of evaluating cardiac performance using interactive computer graphics.

The authors discuss an objective method of analyzing local wall motion to detect and measure the pattern of contraction of the left ventricle using computer graphics. The method's advantages include: (a) the use of modular hardward and software, which can be extended and upgraded; (b) a minimal expenditure of time and money; (c) uniformly calculated results; and (d) a graphic and legible report.

Computers↗
PubMed1978

Renal blood flow changes following mannitol infusion.

The effect of mannitol infusion on the renal physiology, was evaluated in experimental animals and in man. In animals plasma flow and glomerular filtration rate were determined by the PAH extraction and by the innulin clearance technique. In patients renal blood flow measurements were carried out using the Xenon133 washout technique. Baseline studies were obtained and repeated following the intravenous infusion of 20% mannitol. A significant increase in total renal blood flow could be demonstrated in experimental animals, but only a minimal increase of total flow was demonstrated in man following the infusion of mannitol. This observation suggests that the diuretic effect of mannitol is very likely due to the osmotic effect in the tubule causing increased interstitial renal pressure rather than by an increase of actual renal blood flow. This observation is supported by the clinical experience that mannitol remains a powerful diuretic in even hypotensive patients with low renal blood flow.

Animals↗
PubMed1977

Approximation of the left ventricle by a cone of revolution using biplane measurements.

A new method based only on area measurements was developed for calculating left ventricular volume from biplane (RAO and LAO) left ventriculograms; the ventricle was approximated by a cone of revolution. Twenty-three patients with normal and 23 patients with abnormal left ventricles were studied. The Dodge method provided reference values. There was no significant difference between values for EDV calculated by either method; values for ESV calculated by the cone method were consistently higher, but the error is acceptable. The cone method provides results similar to those obtained by the corrected Dodge method, eliminating the problem of choosing and measuring the long axis.

Cineangiography↗
PubMed1977

Comparison of the left ventricular volume using the Ahlkerg and Dodge methods.

Single plane cine left ventriculography was performed in 24 patients, 12 with normal and 12 with abnormal ventricular shapes. End diastolic and systolic volume and ejection fractions were calculated by two methods (Ahlberg and Dodge). The volumes and ejection fraction from either method were not significantly different. If calculated manually, the Ahlberg method took ten times longer than the Dodge method. At present some steps are difficult but a computer can perform the measurements and calculations, and print the results for ventricular areas.

Angiocardiography↗
PubMed1976

Nonsurgical closure of large arteriovenous fistulas.

We report a nonsurgical closure of large postnephrectomy arteriovenous fistulas in two patients. To out knowledge, this method has not previously been attempted because of the large size of the communication and the risk of pulmonary embolization. However, the development of new embolization techniques makes a nonsurgical approach feasible and safe.

Adolescent↗
PubMed1976

Comparison of ejection fraction calculated by nine different volume calculation methods.

Single plane right anterior oblinque ventriculography was performed on 25 patients with normal left ventricular contraction and on 25 with left ventricular akinesia or dyskinesia. The value of the left ventricular ejection fraction (EF) was calculated by 9 different methods, including a new one utilizing the mathematical model of a cone. All methods tested were appropriate for inter-group comparisons of EF. For inter-individual comparisons, however, only those methods described by Davila, Chapman, Dodge, Beranek, and our new method, are appropriate.

Angiocardiography↗