In Vivo, Non-Invasive Characterization of Human Bone by Hybrid Broadband (600-1200 nm) Diffuse Optical and Correlation Spectroscopies

PLoS One. 2016 Dec 20;11(12):e0168426. doi: 10.1371/journal.pone.0168426. eCollection 2016.

Abstract

Non-invasive in vivo diffuse optical characterization of human bone opens a new possibility of diagnosing bone related pathologies. We present an in vivo characterization performed on seventeen healthy subjects at six different superficial bone locations: radius distal, radius proximal, ulna distal, ulna proximal, trochanter and calcaneus. A tailored diffuse optical protocol for high penetration depth combined with the rather superficial nature of considered tissues ensured the effective probing of the bone tissue. Measurements were performed using a broadband system for Time-Resolved Diffuse Optical Spectroscopy (TRS) to assess mean absorption and reduced scattering spectra in the 600-1200 nm range and Diffuse Correlation Spectroscopy (DCS) to monitor microvascular blood flow. Significant variations among tissue constituents were found between different locations; with radius distal rich of collagen, suggesting it as a prominent location for bone related measurements, and calcaneus bone having highest blood flow among the body locations being considered. By using TRS and DCS together, we are able to probe the perfusion and oxygen consumption of the tissue without any contrast agents. Therefore, we predict that these methods will be able to evaluate the impairment of the oxygen metabolism of the bone at the point-of-care.

MeSH terms

  • Adult
  • Female
  • Humans
  • Male
  • Middle Aged
  • Oxygen Consumption*
  • Point-of-Care Systems*
  • Radius* / diagnostic imaging
  • Radius* / metabolism
  • Spectrophotometry / instrumentation
  • Spectrophotometry / methods
  • Tomography, Optical Coherence* / instrumentation
  • Tomography, Optical Coherence* / methods
  • Ulna* / diagnostic imaging
  • Ulna* / metabolism

Grants and funding

The research leading to these results has partially received funding from the EC's Seventh Framework Programme under the projects OILTEBIA (grant agreement n. 317526), Fundació CELLEX Barcelona, Obra social “la Caixa” Foundation (LlumMedBcn), “Severo Ochoa” (SEV-2015-0522), LASERLAB-EUROPE IV, Ministerio de Economía y Competitividad del Gobierno de España (grant MTM2015-64465-C2-1-R) and Departament d’Economia i Coneixement de la Generalitat de Catalunya (2014 SGR 464). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.