Supplementary Material for: Demonstration of the Pericallosal Artery at 11-13 Weeks of Gestation Using 3D Ultrasound

Objective: To assess the sonographic visualization of the pericallosal arteries in normal fetuses at 11-13 weeks of gestation using 3D ultrasound. Methods: We prospectively enrolled women with a singleton pregnancy undergoing ultrasound at 11-13 weeks of gestation. A 3D volume with high-definition power Doppler was acquired starting from the sagittal view of the fetal head and stored in the spatiotemporal image correlation mode. The images of the pericallosal arteries were assigned a score of 0 (no visualization), 1 (visualization of the origin) or 2 (visualization of the whole course). A follow-up scan was performed in all cases at 20 weeks of gestation to assess the presence of the corpus callosum. Results: 70 patients were included and the pericallosal arteries were sonographically detectable in all cases. Image scores of 1 and 2 were obtained in 8 and 62 cases, respectively. The whole length of the vessel was between 3.5 and 4.5 mm. The vast majority of those with a score of 2 were beyond 12 completed weeks of gestation. All fetuses showed a normal corpus callosum at midtrimester and no abnormal brain findings after birth. Conclusions: The pericallosal arteries are sonographically visible since the first trimester in 3D ultrasound scans of fetuses found to have a normal corpus callosum at follow-up.