Development of the Prosencephalic Structures, Ganglionic Eminence, Basal Ganglia and Thalamus at 11+3 to 13+6 Gestational Weeks on 3D Transvaginal Ultrasound Including Normative Data

Objectives: To show the development of ganglionic eminence, basal ganglia and thalamus/hypothalamus in week 11+3 to 13+6 by transvaginal 3D ultrasound. Methods: : To visualize the prosencephalic structures surrounding the 3rd ventricle, 285 volume blocks from 402 fetuses examined were selected in a prospective transvaginal 3D study to compare ultrasound images of ganglionic eminence, basal ganglia, thalamus/hypothalamus with embryological sections. In addition, measurements of the described structures were made in 104 fetuses to quantify the embryological development. Results: : The sonomorphologic characteristics of ganglionic eminence, basal ganglia and thalamus/ hypothalamus are described in 71 % of the fetuses examined. Measurements of the structures in 57% of the fetuses, show the following results: axGE ap = 0.17 + 0.112*CRL; axGE/I = 0.888 + 0.048*CRL; axGE/BG = 0.569 + 0.041*CRL; coGE/BG = 0.381 + 0.048*CRL; coTh lat = -0.002 + 0.135*CRL; coTh/HyT = 3.68 + 0.059*CRL; co3.V lat = 0.54 + 0.008*CRL Conclusion: Transvaginal 3D neurosonography allows visualization and measurement of normal structures in the fetal prosencephalon at 11+3 to 13+6 weeks of gestation including details of ganglionic eminence (GE), basal ganglia (BG), and thalamus/hypothalamus (Th/HyT). Further scientific work is needed before using the results to decide pathological changes in patients.