The Development and Application of the Hair Diameter Index (HDI)
January 2021
in “
Hair transplant forum international
”
TLDR The Hair Diameter Index (HDI) was created to help plan hair restoration surgery after finding that visual hair density is linked to hair count and thickness, not volume.
In 2021, a study was conducted to investigate the Hair Volume Index (HVI), a proposed measurement system for evaluating visual hair density. The results, however, did not support the idea that scalp coverage was related to the measured volume of hair in a given area. Instead, visual density was found to be correlated with the number of hairs and the hair shaft diameter. This led to the development of the Hair Diameter Index (HDI). The HDI was then applied in hair restoration surgery for follicular unit excision (FUE) donor area planning and graft implantation density.
