Determination of Placental Blood Flow by External Monitoring of ^113mIn

Summary

A simple and noninvasive technique was developed to evaluate the blood perfusion rate within human placenta. The method is based on monitoring the accumulation of the isotope ^113mIn in the placental intervillous space using a single detector as a measuring device. The result was expressed as an accumulation index calculated from the tracer appearance curve. The In accumulation index was significantly lower in preeclamptic patients than in the controls, but with a marked overlapping. The In index was significantly correlated with the simultaneously recorded maternal minute volume, 24-hour estrogen excretion and birthweight. No correlation was found with the placental weight or Laakso’s perfusion index. Uterine contractions induced a significant decrease in the In index. The authors conclude that the In accumulation index can be used as an objective measure of the placental blood flow.

Es wurde eine einfache nicht invasive Technik entwickelt, um die Blutperfusionsrate in der menschlichen Plazenta zu bestimmen. Die Methode basiert auf der Feststellung der Akkumulation des radioaktiven Isotops ^113m-I n in dem plazentaren intervillösen Raum durch Gebrauch eines einfachen Detektors als Meßinstrument. Das Resultat wird dargestellt als ein Akkumulations-Index, welcher aus der Tracer-Erscheinungskurve berechnet wird. Der In-Akkumulationsindex lag gegenüber den Kontrollen bei präeklamptischen Patienten signifikant tiefer.

Der Index hatte eine signifikante Korrelation zu dem simultan aufgezeichneten mütterlichen Minutenvolumen, bzw. zur 24 Std. Östrogen-Exkretion und zum Geburtsgewicht. Keine Korrelation wurde gegenüber dem Plazentagewicht bzw. dem „Laakso’s perfusion index“ gefunden. Uteruskontraktionen induzierten einen signifikanten Abfall des In-Index.

Die Autoren schließen, daß der In-Akkumulations-Index als ein objektives Maß des plazentaren Blutflusses verwendet werden kann.

• References

• 1 Antar M. A, Spencer R. P. Dynamics of placental and uterine blood flow. Obstet. and Gynec 1972; 40: 385.
• 2 Janish H, Leodorter S. Plazentainsuffizienz und functionsdiagnostik mit radioisotopen. Z. Geburtsh. Perinat 1973; 117: 11.
• 3 Dixon H. G, Browne J. C, Davey D. Chorio-decidual and myometrial blood-flow. Lancet II. 1963: 7304.
• 4 Hosain F, McIntyre P. A, Poulose K, Stern H. S, Wagner H. N. Binding of trace amounts of ionic indium-113m to plasma transferrin. Clin. chim. Acta 1969; 24: 69.
• 5 Laakso L, Kivikoski A, Mäkelä S, Paasio J. P. Gamma camera examination of pregnant uterus and placental perfusion. Acta obstet. gynecol. scand 1970; 49: 355.
• 6 Lange R. D, Dynelius R. Blood volume changes during normal pregnancy. Clinics in Haematology 1973; 2: 433.
• 7 Lehtovirta P, Kuikka J, Rekonen A, Pyörälä T. Haemodynamic alterations produced by changes in posture with special reference to the usefulness of isotope ¹¹³mIn radiocardiography. Ann. clin. Res 1972; 4: 285.
• 8 Lippert T. H, Fridrich R, Hindemann P, Kubli F, Ruettgers H. Critical assessment of the xenon washout technic for measurement of placental blood flow. Gynec. Invest 1973; 4: 14.
• 9 Merwe E. L, Lotter M. G, Heerden P. D. R, Slabber C. F, Bester J. Absorbed dose calculations for ^113mIn placental scanning. J. Nucl. Med 1971; 11: 31.
• 10 Munck O, Lysgaard H, Pontonnier G, Le Fever H, Lassen N. A. Measurement of blood flow through uterine muscle by local injection of ¹³³Xe. Lancet. 1964: 1421.
• 11 Olkkonen H, Suonio S, Helin M. Numerical analysis of cardiopulmonary blood volumes in ¹¹³mIn radiocardiography. Phys. Med. Biol., in press.
• 12 Rourke J. E, Marchall L. D, Shelley T. M. A simple rapid assay of estrogens in pregnancy. Amer. J. Obstet. Gynec 1968; 100: 331.
• 13 Suonio S, Olkkonen H, Haring P. Placental blood flow in pregnancies complicated by hypertensive disease. A clinical study using the ^99mTc accumulation method. Scand. J. Obstet. Gynec. in press.
• 14 Suonio S, Jalkanen M, Olkkonen H, Castren O. Effect of isoxuprine on placental blood flow in normal and hypertensive patients during last trimester of pregnancy. Int. J. Gynec. Obstet 1975; 13: 225.
• 15 Suonio S, Olkkonen H. A method for assessment of placental blood flow using ^99mfc pertechnetate. Scand. J. Obstet. Gynec. in press.
• 16 Suonio S, Simpanen A. L, Olkkonen H, Haring P. Effect of the left lateral recumbent position compared to the supine and upright positions on placental blood flow in normal late pregnancy. Ann. clin. Res 1976; 8: 22.
• 17 Suonio S, Ryynänen M, Olkkonen H, Castren O. Ritodrine hydrochloride induced cardiopulmonary and placental hemodynamic changes in normal and hypertensive late pregnancy. Submitted.
• 18 Wochner R. D, Adatepe M, van Amburg A, Potchen E. J. A new method for estimation of plasma volume with the use of the distribution space of indium-113m-transferrin. J. Lab. Clin. Med 1970; 75: 711.
• 19 Wright F. W. Placental localisation by isotope scanning with indium-113m. Results in 200 patients. Brit. Med. J 1970; 2: 636.