Enhancement kinetics of normal ovaries on dynamic contrast-enhanced MR imaging

The objective was to determine the enhancement kinetics of the normal ovaries in healthy women on dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging.

Twenty-one women who had normal ovulatory cycles (volunteers; mean age=26.3 years, range=20-35), normal hormone profile, and apparently normal ovaries on ultrasonographic scan underwent DCE-MR imaging on a 1.5-T system (Philips Medical Systems, Gyroscan Intera, Best, The Netherlands) using a phased array pelvic coil. Sequential images with an imaging time of 14.4s per dynamic image were acquired before and after injection of a contrast bolus at 30s and at 1, 2, 3, 4, and 5 min. On postprocessing examination the following measurements were obtained for ovarian and muscle tissue: the signal intensity value per dynamic study, early phase enhancement rate, time to peak enhancement (Tp), and percentage of wash-out at the fifth minute were determined. Data of the ovaries and skeletal muscle were compared using Wilcoxon's rank sum test.

Most of the mean values of the postcontrast signal intensity measurements, the mean values of the early phase enhancement rate, and the percentage of wash-out at the fifth minute were found to be significantly higher in ovary than in muscle (p<0.05). The mean values of Tp, on the other hand, were nonsignificantly lower in ovary than in muscle (p>0.05). On the examination of the mean signal intensity-time data graphics the ovary showed a tendency toward greater and quicker enhancement and wash-out.

In our opinion, DCE-MR imaging, which determines contrast enhancement such as wash-in and wash-out kinetics, can provide knowledge of ovarian vascularization. Thus, by using DCE-MR imaging, determination of these vascularization changes in various ovarian diseases may provide us with additional parameters in the diagnosis of and treatment strategies for ovarian diseases.