Determination of optical properties of human tissues obtained from parotidectomy in the spectral range of 250 to 800 nm

J Biomed Opt. 2019 Dec;24(12):1-7. doi: 10.1117/1.JBO.24.12.125001.

Abstract

The optical properties of human tissues are an important parameter in medical diagnostics and therapy. The knowledge of these parameters can encourage the development of automated, computer-driven optical tissue analysis methods. We determine the absorption coefficient μa and scattering coefficient <inline-formula>μs'</inline-formula> of different tissue types obtained during parotidectomy in the wavelength range of 250 to 800 nm. These values are determined by high precision integrating sphere measurements in combination with an optimized inverse Monte Carlo simulation. To conserve the optical behavior of living tissues, the optical spectroscopy measurements are performed immediately after tissue removal. Our study includes fresh samples of the ear, nose, and throat (ENT) region, as muscle tissue, nervous tissue, white adipose tissue, stromal tissue, parotid gland, and tumorous tissue of five patients. The measured behavior of adipose corresponds well with the literature, which sustains the applied method. It is shown that muscle is well supplied with blood as it features the same characteristic peaks at 430 and 555 nm in the absorption curve. The parameter <inline-formula>μs'</inline-formula> decreases for all tissue types above 570 nm. The accuracy is adequate for the purposes of providing μa and <inline-formula>μs'</inline-formula> of different human tissue types as muscle, fat, nerve, or gland tissue, which are embedded in large complex structures such as in the ENT area. It becomes possible for the first time to present reasonable results for the optical behavior of human soft tissue located in the ENT area and in the near-UV, visual, and near-infrared areas.

Keywords: Monte Carlo simulation; absorption coefficient; optical properties; parotidectomy; scattering coefficient.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / diagnostic imaging
  • Aged
  • Aged, 80 and over
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Middle Aged
  • Monte Carlo Method
  • Nerve Tissue / diagnostic imaging
  • Optical Imaging / methods*
  • Parotid Gland* / diagnostic imaging
  • Parotid Gland* / surgery
  • Parotid Neoplasms* / diagnostic imaging
  • Parotid Neoplasms* / surgery
  • Scattering, Radiation