RENOGRAFIYA RADIO ISOTOPE (Latin ren a kidney + Greek grapho to write, represent) — the method of a research of function of kidneys consisting in continuous graphic registration of changes of content of radioactive material separately in each kidney after its intravenous administration. As radioactive materials use radio pharmaceuticals (see) — dietilentriaminopentaatsetat (DTPA), marked 99m Tc, to-ry is filtered by renal balls, or gippuran (see), marked 131 I or 125 I, to-ry cosecretes renal tubules. Various mechanism of removal of these drugs allows to estimate separately a condition of glomerular filtering and canalicular secretion (see. Kidneys, physiology ). Speed of removal of radio pharmaceutical drug (RFP) from a kidney gives an idea as well of a condition of uric ways.
The indication for R. of river is suspicion of a disease of kidneys. Repeated P.p. it is applied to a research of dynamics patol. process in a kidney, estimates of efficiency of drug or operational treatment. There are no absolute contraindications for R. of river, however pregnant, and also nursing mothers are not recommended to appoint this research.
The river of river is carried out by means of the clinical radio count — direct P.p., or the gamma camera supplied with the electronic computer — computer R. of river (see. Radio isotope diagnostic units ).
Rubles of river carry out in position of the patient sitting or lying. Detectors of the radio count have from a back, as a rule, at the level of I lumbar vertebra at 5 cm from the centerline to the left and to the right that approximately corresponds to a projection of kidneys. The last can be precisely determined by data rentgenol. researches or stsintigrafiya.
At a research on the gamma camera — a renostsintigrafiya (see. Stsintigrafiya ) — the detector is installed from a back so that its vertical diameter was over a backbone, and horizontal at the level of I lumbar vertebra. Duration of a research makes of 15 min. (at renal failures of easy degree) up to 30 min.
At a research preservation of an immovability of a body of the patient concerning the detector is required.
RFP enter intravenously in a dose at the rate on 1 kg of weight: for 131 I-gippurana — 0,2 mkkyur (7,4 kBq), for 99m Ts-DTPA — 1 mkkyur (37 kBq). At a renostsintigrafiya these quantities make respectively 6,7 mkkyura (250 kBq) and 22,9 mkkyur (850 kBq). The size of beam load of the patient makes for 131 I-gippurana 0,25 is glad (2,5 mGy), for 99m Ts-DTPA — 0,2 is glad (2,0 mGy).
Results of a research represent curve (renogramma), reflecting change of content of radio pharmaceutical drug in a kidney. With technical capabilities, napr, during the use of the domestic radio count like Karpograf or gamma cameras, the supplied COMPUTER, receive, except renogramm, the curve characterizing clarification of body tissues from RFP (see. Clearance ), and also the curve reflecting intake of drug in a bladder. R.'s modification by the river, at a cut is carried out record of a curve from area of a bladder, carries the name of a radio-isotope renotsistografiya (see. Bladder, methods of a research ). Receipt in a kidney of the first portion of the blood containing RFP causes bystry raising of a renogramma, amplitude to-rogo reflects the volume of the arriving portion of blood. For this reason the first piece of a curve (a vascular segment) is allocated as characterizing blood supply of a kidney (fig., a). After sharp first rise increase of amplitude of a curve (a secretory segment) at the expense of a delay of RFP in proximal tubules (gippuran) or in renal balls (DTPA) is noted further, slower. Then the maintenance of RFP in a kidney begins to decrease due to its removal in a bladder (an excretory segment).
In the analysis of a renogramma consider a number of quantitative indices. The ratio of levels of raising of vascular segments renogramm the right and left kidneys indirectly characterizes passability of renal arteries. Time of achievement of a maximum of a curve (it is normal — 3 — 5 min. from the moment of introduction of RFP) reflects processes of glomerular filtering (at a research with DTPA) and canalicular secretion (at a research with gippurany). Time of decrease in a curve for 50% (it is normal for a gippu-wound — 9 — 10 min., for DTPA — 10 — 12 min.) characterizes a condition of upper uric ways.
At various damages of kidneys characteristic changes of indicators renogramm take place, to-rye not only allow to reveal dysfunction of each kidney and to define its degree, but also to suggest about character patol. process. Lack of essential raising of a curve is characteristic of a nonfunctioning kidney (fig., b). The slowed-down decrease in a curve demonstrates obstruction of uric ways at safety of function of a parenchyma (fig., c). Decrease in amplitude of a vascular segment at safety of temporary indicators demonstrates disturbance of passability of a renal artery.
At a radio isotope research of a kidney by means of the gamma camera supplied with the COMPUTER along with the curves reflecting removal of RFP receive also the image of distribution of drug in fabrics — to a stsintigramm (see. Stsintigrafiya ). Existence stsintigramm, RFP received through different time terms after introduction to a circulatory bed, allows to define most precisely an arrangement of kidneys, to visually estimate process of removal of RFP and to choose the analyzed zones (a so-called zone of interest) for plotting of accumulation and removal of RFP — schedules «activity — time» (tsvetn. fig. 1 — 6). Both P.p options. have undoubted advantage in assessment of function of kidneys in comparison with rentgenol. by methods as registration is made continuously and allows to give a quantitative assessment of a functional condition of kidneys at low beam loading. The river of river is the most sensitive method of assessment of function of kidneys, especially at early stages of development patol. process.
Bibliography: Lindenbraten L. D. and F. M Lyass. Medical radiology, M., 1979; Lopatkin N. A., Glazer Yu. Ya. and Mazo E. B. Radio isotope diagnosis in an uronefro-logiya, M., 1977; Minkin R. B. and Emanuel W. I. Metodika of the analysis of a radio isotope renogramma, Medical radio-gramophones., t. 17, No. 11, page 34, 1972; Radioisotope renography, ed. by M. Kolar, Praha, 1972.
G. A. Zubovsky.