Neuroradiological findings in adult cranially conjoined twins. Case report.

The authors demonstrate the radiological anatomy and review the accepted embryological theories in a case of total craniopagus. These 24-year-old female cranially conjoined twins were studied with computerized tomography (CT) and CT angiography, magnetic resonance (MR) imaging and MR angiography as well as selective arterial digital subtraction (DS) angiography to clarify whether surgical separation was possible. The neuroradiological findings are discussed, taking into consideration both the embryological and surgical literature. The malformation was classified as a total parietooccipitotemporal craniopagus. Whereas CT angiography and MR imaging including MR angiography demonstrated a common superior sagittal sinus, only selective arterial DS angiography revealed a significant arterial and venous cross-flow between the two adjacent temporal lobes. Selective intraarterial DS angiography is required in the neuroradiological evaluation of complex malformations, even when the anatomy of brain and skull can be well demonstrated with high-quality MR and CT studies.