Abstract
Two methods utilizing inert gas clearance for the measurement of endometrial blood flow in non-pregnant women have been assessed and compared. A Krypton-85 re-breathing technique allowed measurement of superficial flow by means of an intrauterine semiconductor β-detector probe. Intrauterine instillation of high specific activity Xenon-133 in small volumes of saline allowed endometrial flow measurement by γ camera recording of the rate of clearance. Both these methods permitted calculation of absolute rates of flow and comparison of cyclical changes. Direct comparison of the techniques in the same women, and repeatability studies have shown good agreement, with calculated rates of absolute endometrial blood flow varying within the range 14 - 60 ml per 100 g tissue per minute. Vaginal blood flow measured simultaneously was always significantly lower (36-64%) than endometrial flow.