Preoperative CT and MR imaging of ischiopagus twins

Each case of conjoint twins is unique. Preoperative imaging is helpful to determine the feasibility of separation. Shared and separate organs can be delineated; and operative technique and problems anticipated. We performed ultrasonography, CT, magnetic resonance imaging, and arteriography preop-eratively on ischiopagus conjoint twins. The single most helpful study was CT performed during a bolus intravenous contrast medium injection into one twin. Arteriography was also very helpful. The other studies were complementary but added little additional structural details. Sedation of conjoint twins is complicated yet crucial for optimal imaging studies. A combination of oral and intramuscular sedation was used and worked well for all of the studies.