OP07.05: Sonoembryology of the fetal posterior fossa at 11 + 3 to 13 + 6 gestational weeks on three‐dimensional transvaginal ultrasound. (September 2016) - Altmann, R.; Scharnreitner, I.; Scheier, T.; Mayer, R.; Arzt, W.; Scheier, M.A.