RE: Skin.

From:"Monson, Frederick C."

Morning Ian,
    No personal experience with this particular problem (instead, experience with vascular corrosion casting), but if I were called, as you have been, I would try the following.
    If you are being supplied with a piece of skin, I would use a non-transparent meth-acrylic polymer, stained after replication with a fluorescent dye that would give a strong emission in the red or green.  I would give the replica some thickness, i.e., 1-2mm., then dissolve the last of the skin away (a la vascular corrosion methodology) with 1N KOH (followed by considerable washing with distilled water and critical point drying).  A piece of the replica is then mounted/suspended in 1.49 R.I. immersion oil in a chamber with an acrylic coverglass bottom.  Finally, view with a confocal system using an inverted scope with objectives that are corrected for acrylic/plastic, and you should be able to generate fairly true 3D images of the replica surface.  I would work towards using the smallest pinhole.  Since the plastic would be opaque, only the surface will provide signal, thus, the image stack should be of contour lines only.  The reconstruction should be a view of the surface of the replica, AND, from the other perspective, a direct representation of the topography of the surface of the skin.  Every image can be viewed as an altitude with precise separation from its neighbors, and it would be possible, after some programming, to analyze each image in the stack for parallel line pairs with measured lengths and separations (e.g., each wrinkle (crevasse) in the surface will have depth, width and length available for automatic image processing/analysis).  In sum, the confocal, as you know, will provide much better resolution on the z-axis for a study of this kind.
    If the skin arrives still attached to the patient, there are likely to be many methods for casting of latex face masks that you can adapt, if the viscosity is sufficiently low to provide the resolution you need.  These materials and methods will have already passed the toxicity and use tests that are so arduous for patient safety measures.  If the casting material is non-transparent (as most of these would be), and fluorescent, the confocal reconstruction method may be the most data-rich way to go.  But, even if the casting material cannot be safely made fluorescent before it is applied, you can certainly stain it after removal from the patient.
    There are software packages, such as "ImageJ" from NIH ( which are not only free and open-source, but constantly upgraded with new capabilities (including writing macros in Java) as well as plugins for lots of morphometric analyses and the handling of stacks from most confocal distributions.  ImageJ also accepts other plug-ins that are Adobe-compliant.
    I offer this recommendation only because I can't imagine trying to generate 3D information from the monster math required when SEM images are the starting points.  On the other hand, if all you are going to do is count crevasses, perhaps that would be even more simple/direct.
Hope this helps,
Fred Monson
Frederick C. Monson, PhD
Center for Advanced Scientific Imaging
Mail to Geology
West Chester University of Pennsylvania
Schmucker II Science Center, Room SS024
South Church Street and Rosedale Avenue
West Chester, PA, 19383
Phone:  610-738-0437
-----Original Message-----
From: Ian Montgomery []
Sent: Wednesday, December 04, 2002 8:23 AM
Subject: Skin.

        Have been asked to make a replica of human skin then from the mask perform 3D analysis of the lines wrinkles etc. Anyone have experience of this type of thing. I'll do a web search but first hand experience would be welcome.

Dr. Ian Montgomery,
Graham Kerr Building,
Institute of Biomedical & Life Sciences,
University of Glasgow,
G12 8QQ.
Tel: 0141 339 8855
Office: 4652
Lab: 6644.

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