Objectives: Several 2 and 3-dimensional techniques have been used to asses ovarian blood flow and vascularity. All have their advantages and limitations. Spatio-temporal image correlation (STIC) is a 4D method that combines 2D velocity information with 3D vascular maps to provide pulsatile volumetric data across the cardiac cycle. This study was designed to see if this technique could be used to reliably acquire and measure 4D power Doppler data from the whole ovary. Methods: Ten consecutive patients in the early follicular phase of their menstrual cycle were scanned as part of their routine workup before starting fertility treatment (Voluson E8, GE Healthcare). STIC was used by two observers to acquire 4D data from the whole ovary using standardized settings. Each observer acquired two STIC datasets resulting in 4 STIC acquisitions for each ovary. From each acquisition a selected image was analyzed twice by both observers. VOCAL was used to define the ovarian cortex and the histogram applied to generate the vascularity index (VI), flow index (FI) and vascularity flow index (VFI). SPSS was used to calculate intraclass correlation coefficients (ICC) and their 95% confidence intervals. Results: The reliability analysis showed a high level of agreement between the two observers for both data acquisition and analysis for all three indices. The ICCs (95% CI) were indicative of a high degree (>0.9) of both inter and intra observer measurements. Conclusions: This is the first study to show that STIC can be reliably used to acquire and measure 4D power Doppler data from the whole ovary. Previous studies have been limited by the need to apply spherical sampling techniques which is associated with an obvious subjective selection bias. Further work is required to assess the clinical relevance of this technique but it offers a new way to assess whole organ flow in a standardized manner that is less dependent on machine settings and inter-subject variation.