Use of spectral imaging for documentation of skin parameters in face lift procedure

摘要

In rhytidectomy the postoperative edema (swelling) and ecchymosis (bruising) can influence the cosmetic results. Evaluation of edema has typically been performed by visual inspection by a trained physician using a four-level or, more commonly, a two-level grading'1'. Few instruments exist capable of quantitatively assessing edema and ecchymosis in skin. Here we demonstrate that edema and ecchymosis can be objectively quantitated in vivo by a multispectral clinical imaging system (MSCIS). After a feasibility study of induced stasis to the forearms of volunteers and a benchtop study of an edema model, five subjects undergoing rhytidectomy were recruited for a clinical study and multispectral images were taken approximately at days 0, 1,3, 6, 8, 10, 15, 22 and 29 (according with the day of their visit). Apparent concentrations of oxy-hemoglobin, deoxy-hemoglobin (ecchymosis), melanin, scattering and water (edema) were calculated for each pixel of a spectral image stack. From the blue channel on cross-polarized images bilirubin was extracted. These chromophore maps are two-dimensional quantitative representations of the involved skin areas that demonstrated characteristics of the recovery process of the patient after the procedure. We conclude that multispectral imaging can be a valuable noninvasive tool in the study of edema and ecchymosis and can be used to document these chromophores in vivo and determine the efficacy of treatments in a clinical setting.