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Objectives: To compare the accuracy and repeatability of the volume perfusion index (VPI), -a mathematical model for calculation of flow developed by our team-, with the current available indexes for threedimensional power Doppler quantification (VI,FI and VFI) in an experimental in-vitro study. Methods: A phantom of flow was designed by using a mechanical pump generating a pulsatile flow with known values and by using elastic artificial vessels and blood mimicking fluid. A set of three and four-dimensional power Doppler volumes was obtained at different flow settings. Three dimensional volumes were quantified by using the VOCAL software included in the machine’s software. Fourdimensional flow measurement was evaluated by using a previously validated algorithm. Repeatability was evaluated through the intraclass correlation coefficient (ICC)for single unpaired tests and the Bland-Altmann (B-A) plot. Accuracy was tested by comparing the actual values against the obtained indexes with a polynomial regression model. Results: Phantom design was successful in generating a pulsatilelike flow and volumes could be taken in 92% of cases. ICC (95% CI) was 0.34 (0.23–0.51) for VI; 0.41 (0.3–0.51) for FI and 0.56 (0.43–0.69) for VFI. For VPI, it was 0.69 (0.48–0.79). B-A plot showed an inter-observer variability (%) (95% CI) of 48 (23–76) for VI; 62 (33–68) for FI; 29 (21–48) for VFI and 22 (15–29) for VPI. r-value (95% CI) was 0.45 (0.33–0.49) for VI; 0.53 (0.38–0.6) for FI; 0.62 (0.51–0.79) and 0.83 (0.65–0.9) for VPI (P < 0.01). Conclusions: Volume Perfusion Index exhibits a more robust internal validity than the traditional three-dimensional power Doppler indexes and might reflect more accurately actual changes in flow.

magna were assessed. The diagnostic value and image quality was evaluated. In all cases brain anatomy was verified by postnatal neurosonography, fetal/postnatal MRI or by autopsy. Results: Abnormal appearance of the posterior fossa was consistent with complete absence of the cerebellar vermis (Dandy-Walker malformation) in 8 fetuses, vermian hypoplasia in 3 fetuses and Blake’s pouch cyst (BPC) in 5 fetuses. Axial transcerebellar view in all fetuses with posterior brain anomalies at 11+0–13+6 weeks’ showed non-specific enlargement of the posterior fossa. Mid-sagittal view in fetuses with Dandy-Walker malformation demonstrated the absence of border between 4th ventricle and cisterna magna. In contrast in fetuses with BPC normal size of cisterna magna, enlargement of the 4th ventricle with an intact border between these two structures was noted in mid-sagittal view. Conclusions: Assessment of the fetal posterior fossa is possible in 1st trimester of pregnancy by 3-D sonography. A mid-sagittal view retrieved from 3D volume data set of the fetal head demonstrates a good display of the diagnostic landmarks of fetal posterior fossa with appropriate quality of images. By standardizing the approach to image acquisition and display 3D-sonography may potentially improve our understanding of normal fetal brain development and help to increase the detection rate of fetal posterior brain abnormalities in early pregnancy.

Objectives: Non-invasive and accurate measurement of fetal flow remains an elusive matter. Precision of current tools is very limited and relies mainly in operator skills. The aim of this study was to test a tool for indirect flow measurement, by using power Doppler signal and four-dimensional ultrasound (4DPD) and image data simulation and adjustment tools based on mathematical modelling of particles’ vectorial velocities. Methods: Six near term pregnant sheep were surgically instrumented to access fetal aorta by transventricular catheterization. Actual flow through aortic isthmus was measured directly by a PICCO monitor, as well as by pulsed Doppler. Several sets of 4DPD volumes were taken during the procedure. Measurements were stored in an electronic datasheet. A mathematical algorithm for signal normalization was developed for the project by using Mathematica. A differencial equation matrix was generated and obtained data was evaluated through an error adjustment process. Mean velocity at every time was calculated and compared to actual data. The obtained values were plotted against the calculated values. Repeatability was evaluated by using a Bland Altmann test. Results: A total of 30 sets of measurements were collected. A mean of six measurements by cardiac cycle were digitally obtained from the velocity curve. An n by m matrix of data was designed for every set. A mathematically generated flow curve was plotted with the data built through a multi-layer algorithm. Bland Altmann test showed an inter observer variability (95% CI) of 22.3% (11.5–34.3). The r-value for calculated flow was 0.78 (0.73–0.91) (P < 0.05). Conclusions: 4DPD with mathematical modeling overcomes the limitations of two and three-dimensional moving particles measurement and might be an accurate tool for fetal flow measurement.

ng/ml, 49.4 (7-264) pg/ml, 6.8 (3.0–11.9) IU/L and 165 (42373) pmol/L respectively. The median (range) total AFC was 12 (2–39). The total AFC was significantly correlated with serum AMH (r=0.43; P 6.0 mm. Conclusions: The total AFC is significantly correlated with serum AMH levels but not with inhibin-B, FSH or oestradiol. The number of antral follicles measuring 2–6 mm is most closely related to AMH levels and this follicular cohort is most reflective of the quantitative status of ovarian reserve.