Three-dimensional ultrasound: display modalities in obstetrics

Three-dimensional ultrasound (3DUS) has recently been introduced into clinical practice. Various techniques are available for display of the volume data. We review the importance of selecting the proper display option and rendering mode depending on the specific diagnostic question. Current display options include (1) arbitrary planar images similar to conventional two-dimensional US images, (2) surface rendering with emphasis on soft tissues or skeletal detail, (3) stereo viewing using liquid crystal glasses or red/blue glasses, and (4) cine review of gated studies. Rotation of volume data also is important in understanding/comprehending patient anatomy. The range of rotation angles varies depending on the clinical setting. Also data storage requirements increase as the number of views increases.