hello4dFounded Date: Mar 13, 2017. Operating Status: Active. Also Known As: Helo4D, Hello4D. Legal Name: Helo4D. Company Type: For Profit.What is 2D, 3D and 4D? 2D is the standard black and white ultrasound. This type of ultrasound is recommended for babies that are 20 weeks and younger. 2D is the preferred type of imaging