36.    Clinical studies in hair transplantation using digital imaging. 
Andreas Finner(1), Kevin McElwee(1), David Zloty(1), Rolf Hoffmann(2), Jerry Shapiro(1) 1.Department of Dermatology and Skin Science, University of British Columbia, Vancouver, Canada, 2.Dermaticum, Freiburg, Germany.

Introduction: Hair transplantation (HT) is the most successful treatment option in androgenetic alopecia (pattern hair loss) with recent advancements in technique. But quantitative evidence based on data on regrowth is still lacking. This is partly due to general difficulties when assessing hair growth. Unique problems in HT studies include variations in technique, inadequate sample size, incomplete follow-ups and a lack of reproducible methods. Trichoscan® (TS) is a recently developed tool to measure hair growth parameters. Materials and Methods: For TS, a magnified photo of a circular target area of 1.8 cm² is entered into a digital imaging software to calculate hair growth parameters. For repeated measurements, the target area is either marked by a pin-point temporary tattoo or an angioma is used as a landmark. A pilot study was initiated to observe hair density in a recipient target area before and after HT. The number of hairs transplanted into the target area is counted. TS is performed before the procedure and after 2 weeks, 4 and 6 months. Results and Discussion: TS is a practical method to assess hair density and has received good patient feedback. Exact data collection is crucial, as slight changes in pigment, hair length and location can influence results. Results show a partial initial decrease in hair density and thicker, denser hair on follow-up visits. The initial decrease is most likely due to shock loss, which has never been documented before. Conclusion: From digital imaging techniques, such as TS, we expect new insights into the dynamics of hair growth following HT and preassessment of donor area density for improved planning of procedures. With further improvement, computerized methods may eventually play an important role in evaluations of different HT techniques.