ABSTRACT
The authors described the principle and algorithms of the separation of a summary radionephrogram into constituents, reflecting the contribution of a radiopharmaceutical, uptaken by neutrons, and RP in the surrounding tissues. The authors proposed a correct method for estimation (using the first constituent) of the efficacy indicator of RP uptake by the kidneys (Q-parameter) and the indicator of the mean time of transit (t) in the kidneys of RP uptaken by their parenchyma. The results of testing of the proposed methods of Q and t calculation were presented. Values of these parameters were determined in health and in essential hypertension, I and II degree, pyelonephritis, chronic nephritis (latent and hypertensive types), stenosis of the renal artery, obstruction of the upper urinary tracts, and in one kidney. These results indicate the physiological adequacy of the employed mathematical models, proving the diagnostic informative value of the calculated indicators.
Subject(s)
Radioisotope Renography/methods , Humans , Iodohippuric Acid , Kidney/physiology , Kidney Diseases/diagnostic imaging , Kidney Diseases/physiopathology , Mathematics , Models, Biological , Time FactorsABSTRACT
A method for measuring circulating plasma volume (CPV) by diluting T-1824 indicator is described, making allowance for the exponential pattern of labeled serum albumin elimination from the vascular bed. The method consists in double collection of blood samples after intravenous injection of the indicator, computation of the constant of its extravasation rate, and extrapolation to the zero time. Analysis of the results obtained by this method and CPV values derived from the hematocrit and circulating blood volume--(CBV) estimated with the help of Albert table (1971), as well as with CPV value derived from the hematocrit and CBV measured by impedance method in 22 patients with slight uncomplicated ventral and diaphragmal hernias has demonstrated high linear correlation coefficients, +0.77 and +0.78 (p less than 0.01), respectively.
Subject(s)
Blood Volume Determination/methods , Evans Blue , Female , Humans , MaleABSTRACT
In an acute experiment, performed in 10 dogs with application of radiological methods, zones of the vertebral part of the intercostal arteries reservoirs and extent of their anastomization with each other both in transversal and longitudinal directions have been stated. The vertebral part of the reservoir of each intercostal artery supplies with blood that half of the corresponding segment of the spinal column, which has the same name, and tissues around, and spreads to the adjoining caudal segment.
Subject(s)
Spinal Cord/anatomy & histology , Thoracic Vertebrae/anatomy & histology , Animals , Dogs , Spinal Cord/blood supplyABSTRACT
On the basis of radiocardiographic and radiocirculatory examination of the central and cerebral hemodynamics in 130 patients with dyscirculatory encephalopathy (DE) caused by essential hypertension and atherosclerosis, the authors have demonstrated that the development of DE is facilitated by disturbances of the central and peripheral hemodynamics. In turn, DE reduces the function of the autoregulatory mechanisms of the cerebral blood flow and leads to insufficiency of compensatory adaptive possibilities of the cardiovascular system. It is recommended that not only cerebral disorders but also the type (hyperkinetic, hypokinetic, eukinetic) of the blood circulation in these patients be taken into consideration in selecting the optimal method of treatment.
Subject(s)
Brain Diseases/etiology , Hemodynamics , Hypertension/complications , Intracranial Arteriosclerosis/physiopathology , Brain Diseases/physiopathology , Cerebrovascular Circulation , Humans , Hypertension/physiopathology , Plethysmography, Impedance , Serum Albumin, Radio-IodinatedABSTRACT
A technique of quantitative RCG analysis is proposed and tested. It enables the unbiased evaluation of regional hemodynamics phases and of the relation between blood flow rate in arterial and venous beds. The technique is based on calculating the first derivative of the radiocirculogram. The specially developed program may be executed by the computer (ZBM EC).
Subject(s)
Angiography/methods , Computers , Phlebography/methods , Angiography/instrumentation , Blood Flow Velocity , Cerebrovascular Circulation , Humans , Mathematics , Phlebography/instrumentation , SoftwareABSTRACT
The paper is concerned with the description of a mathematical model of the kinetics of radiopharmaceutical drugs (RPD) in the right heart with due regard for its two-compartmental structure. A formula has been obtained to describe a right heart radiogram (RHRG) for any RPD entry into the heart (with any type of entry function). It has been shown that in case of an impulsed entry a RHRG curve is described by the following formula (formula; see text) which is a biexponential one. The above formula shows that the determination of phi 1 and phi 2 factor on a curve gives an opportunity to obtain exact information on the correlation of cardiac chamber volumes (the auricle and ventricle). The authors point a possibility of using a RHRG curve for the determination of cardiac output and rate. The formulas obtained are of particular value for analysis of the curves of radiocardiography with 133Xe.