DHI (Direct Hair Implantation) hair transplantation is a modern hair transplantation technique where grafts are directly placed into the skin using a special pen (Choi pen). In this method, channel opening and graft placement are done in one step.

In the DHI technique, grafts are loaded into a specially designed Choi pen and implanted directly into the scalp. This way, grafts are placed with minimum time and maximum precision.