Craniopagus twin: pre- and post-natal 3-dimensional virtual and physical models and virtual navigation created with free or open source software-an option for low-resource centers.

BACKGROUND Craniopagus twins represent a rare and complex congenital malformation characterized by conjoined twins fused at the cranium. Craniopagus is challenging for patients' families and surgeons, and accurate confirmation of the extent of cranial fusion is a complex process. Most information regarding the surgical anatomy of this rare condition is obtained through analysis of ultrasonographic, magnetic resonance, or computed tomographic images. A multidisciplinary team plays a key role in obtaining such information and in parental counseling and coordination of various complex processes for optimal postnatal care of these twins. The extent of fusion is usually determined based on conventional clinical methods, such as imaging studies. METHODS Imaging software is being used in recent times to create three-dimensional reconstruction images and for virtual navigation to investigate the skulls and brains of craniopagus twins. However, the acquisition and maintenance costs of such sophisticated medical software may be unaffordable for medical centers in developing countries. To overcome this limitation, we investigated the role of open or free source software for accurate determination of complex malformations of the skull and brain of craniopagus twins.