Two-dimensional and three-dimensional sonography of conjoined twins

Purpose. The aim of this study was to evaluate and compare the diagnostic capabilities of 2-dimensional (2D) and 3-dimensional (3D) sonography for the study of conjoined twins. Methods. Four pregnant women with an initial 2D sonographic diagnosis of conjoined twins were examined with color Doppler sonography, 3D multiplanar sonography, and orthogonal plane imaging and 3D surface rendering. Results. All 4 cases of conjoined twins were initially diagnosed with either transvaginal or transabdominal 2D sonography. 3D sonography afforded more realistic views and demonstrated more clearly the linking areas and surface anomalies, but 2D and color Doppler sonography provided more definitive and specific information about shared organs. Conclusions. Although 2D sonography is the primary modality for diagnosing and evaluating conjoined twins, color Doppler and 3D sonography can sometimes provide additional information that assists in the clinical management of these twins. 3D sonography also provides images that are easier for parents to understand, which can help them with decision making. (C) 2002 John Wiley Sons, Inc.