Perfusion of the rat ovary: application of pulsed arterial spin labeling MRI

Pulsed arterial spin labeling was used for mapping ovarian perfusion and measurement of blood velocity in the ovarian artery. Arterial blood was tagged upstream by pulsed slice selective saturation, and saturation transfer due to perfusion was monitored within the rat ovary. The velocity of arterial blood was determined from the dependence of the saturation transfer on the thickness of the saturation slice and the delay between successive saturation pulses. This method allows for determination of arterial velocity, even when the artery itself is not identified in the images. The arterial velocity of blood to the ovary was 3.6+/-0.6 cm x s(-1). The mean ovarian perfusion was 8.7+/-3.5 ml x min(-1) x g(-1) during the surge of luteinizing hormone and 5.9+/-3.0 ml min(-1) x g(-1) during the luteal phase. Arterial labeling can thus be used for following vascular remodeling and angiogenesis during the ovarian cycle by MRI.