ABSTRACT
We would like to express our great appreciation to GE Medical Systems (Milwaukee, USA) and Kretztechnik (Zipf, Austria) for their technical support of three-and fourdimensional ultrasound technology; and clinical collaborative cooperation. We also thank Mr Yoshihiko Nagao for his skillful work in magnetic resonance imaging, and all image contributors for their very sophisticated and comprehensive images and schemas. Lastly, we greatly appreciate the fetuses who have taught and shown us the truth in utero.
