Spatially offset Raman spectroscopy for in vivo bone strength prediction

Abstract

Bone strength is a worldwide health concern. Although multiple techniques have been developed to evaluate bone quality, there are still gaps to be filled. Here we report a non-invasive approach for the prediction of bone strength in vivo using spatially offset Raman spectroscopy. Raman spectra were acquired transcutaneously from the tibiae of mice from 4 to 23 weeks old and subsequently on the exposed bones. Partial least squares regression was applied to generate predictions of the areal bone mineral density (aBMD), volumetric bone mineralization density (vBMD), and maximum torque (MT) of each tibia as quantified by dual-energy X-ray absorptiometry, microCT imaging, and biomechanical tests, respectively. Significant correlations were observed between Raman spectral predictions and the reference values in all three categories. To our knowledge, this is the first demonstration of Raman spectroscopy predicting a biomechanical bone parameter (MT) in vivo with an uncertainty much smaller than the spread in the reference values.

Non-invasive In Vivo Imaging of Cancer Using Surface-Enhanced Spatially Offset Raman Spectroscopy (SESORS)

“…Currently, the majority of commercially available Raman spectrometers are based on such conventional spectroscopy systems. Such approach is limited with regards to depth penetration of the incident light in diffusely scattering media such as tissue beyond a few millimeters, thus making it extremely difficult to detect tumors at clinically relevant depths 30, 31.…”

Raman Spectroscopy: Guiding Light for the Extracellular Matrix

“…Raman techniques for bone assessment range from microscopy of bone tissue to fiber-optic and computed tomographic (CT) reconstruction approaches (Demers et al, 2012, 2015; Shu et al, 2018). A variety of applications have been reported, ranging from diagnostics of age-related bone loss (Donnelly et al, 2010), osteogenesis imperfecta (Imbert et al, 2014), osteoporosis, and the effect of therapeutic agents (Gamsjaeger et al, 2011, 2013; Olejnik et al, 2014).…”

“…A variety of applications have been reported, ranging from diagnostics of age-related bone loss (Donnelly et al, 2010), osteogenesis imperfecta (Imbert et al, 2014), osteoporosis, and the effect of therapeutic agents (Gamsjaeger et al, 2011, 2013; Olejnik et al, 2014). As an example of recent fiber-optic techniques, Shu et al developed a spatial offset Raman spectroscopy (SORS) approach in order to non-invasively measure the bone signal in vivo from rodents (Shu et al, 2018). The SORS concept is based on diffuse light scattering and the principle that Raman scattered photons originating deep from the tissue can be detected as spatially offset from the excitation light while the shallow Raman photons can be detected closer to the excitation light (Matousek et al, 2005; Matousek and Stone, 2016).…”

Highly Efficient Spatially Offset Raman Spectroscopy to Profile Molecular Composition in Bone

“…It has already been proposed as a method with the potential for in-situ transcutaneous characterization of bones (passing through several millimetres of soft tissue in chicken and humans [18]) as well as in exploring osteogenesis imperfecta with a mouse model (where SORS was shown to be more sensitive than conventional Raman spectroscopy [19]). Finally, the technique has also been used to predict bone mineralization and strength [20].…”