Imaging in the Preoperative Assessment of Conjoined Twins1

• Published in: Radiographics Vol. 21; no. 5; p. 1187
• Main Authors: Catherine A. Kingston, Kieran McHugh, Jeevan Kumaradevan, Edward M. Kiely, Lewis Spitz
• Format: Journal Article
• Language: English
• Published: Radiological Society of North America 01-09-2001
• ISSN: 0271-5333; 1527-1323

Conjoined twins are rare and present a unique challenge to pediatric surgeons and radiologists. Planning of surgical separation
is aided by accurate preoperative imaging. Such twins are classified according to the most prominent site of connection: the
thorax (thoracopagus), abdomen (omphalopagus), sacrum (pygopagus), pelvis (ischiopagus), skull (craniopagus), face (cephalopagus),
or back (rachipagus). The area of fusion largely determines the imaging modalities used. Thoracic conjunction is most common
and requires cardiac assessment. Magnetic resonance imaging and computed tomography provide excellent anatomic and bone detail,
demonstrating organ position, shared viscera, and limited vascular anatomy. Contrast material radiography allows evaluation
of the gastrointestinal and urogenital tracts, and a shared liver requires assessment of anatomy, vascularization, and biliary
drainage. Angiography helps define specific vascular supply, which is useful in determining the distribution of shared structures
between the twins at surgery. Each set of conjoined twins is unique. An imaging strategy to accurately define anatomic fusion,
vascular anomalies, and other associated abnormalities is important for surgical planning and prognostic information.