|
139
QUANTIFYING PROGRESSION OR REVERSAL OF FOLLICULAR MINIATURIZATION
IN ANDROGENETIC ALOPECIA BY IMAGE ANALYSIS
David A. Whiting and Douglas Canfield Baylor
Hair Research and Treatment Center
Histologic analysis of horizontal sections of
scalp biopsies in men and women with androgenetic alopecia
is an established method of measuring progression of hair
loss or hair regrowth. Detailed follicular counts are time
consuming, making this technique problematic for large drug
trials. Digital imaging can provide reproducible information
which can be more precise than that derived from visual microscopic
examination. A method of image analysis was developed to quantify
follicular counts and to size individual follicles. A Nikon
D1 digital camera was attached to an Olympus BX 40 microscope.
The apparatus was linked to a Dell Dimension XPS T500 desktop
computer. An imaging program was used, and data was handled
with automated computer analysis. A large number of biopsies
from different trials were studied. These biopsies had already
been evaluated by visual histologic analysis with the observer
blinded to time and treatment. All biopsies were rephotographed
with the digital camera using a 2x magnification objective.
The entire 4 mm cross-section of a biopsy was photographed.
The images were stored and examined later with similar observer
blinding. All terminal and vellus hairs visible in the papillary
dermis were marked by the investigator. A technician then
mapped each cross-sectional hair shaft area and automated
image analysis was performed. Total hairs in each section
were counted. Hairs were classified into four different groups.
The crosssectional size varied from vellus-like hairs through
intermediate hairs and small terminal hairs to large terminal
hairs. This quantification could yield an average hair diameter
for the entire section and also enumerate the hairs of different
diameters to reflect different stages of the miniaturization
process. The results were analyzed in both active treatment
and placebo groups. They could also be compared to the previous
results from the standard visual follicular counts in histological
sections. Details of these results will be presented.
|