Three-dimensional vaginal sonography in obstetrics and gynaecology.

Great strides have recently been made in obstetrics and gynaecology secondary to the development of high-performance transvaginal ultrasound (TVS) instruments. However, even this advanced technology can provide only two-dimensional (2D) views of three-dimensional (3D) structures. Although an experienced examiner can easily piece together sequential 2D planes for creating a mental 3D image, individual sectional planes cannot be achieved in a 2D image because of various difficulties. Today, 3D TVS can portray not only individual image planes, it can also store complex tissue volumes which can be digitally manipulated to display a multiplanar view, allowing a systematic tomographic survey of any particular field of interest. The same technology can also display surface rendering and transparency views to provide a more realistic 3D portrayal of various structures and anomalies. The current review provides examples and discussions of the various applications in obstetrics, gynaecology and assisted reproduction in which 3D TVS is a useful supplement to image modality.