Near-infrared spectroscopy for structural bone assessment: A POTENTIAL POINT-OF-CARE TOOL

Abstract

Aims Disorders of bone integrity carry a high global disease burden, frequently requiring inter-vention, but there is a paucity of methods capable of noninvasive real-time assessment. Here we show that miniaturized handheld near-infrared spectroscopy (NIRS) scans, operated via a smartphone, can assess structural human bone properties in under three seconds. Methods A hand-held NIR spectrometer was used to scan bone samples from 20 patients and predict: bone volume fraction (BV/TV); and trabecular (Tb) and cortical (Ct) thickness (Th), porosity (Po), and spacing (Sp). Results NIRS scans on both the inner (trabecular) surface or outer (cortical) surface accurately identi-fied variations in bone collagen, water, mineral, and fat content, which then accurately predict-ed bone volume fraction (BV/TV, inner R2 = 0.91, outer R2 = 0.83), thickness (Tb.Th, inner R2 = 0.9, outer R2 = 0.79), and cortical thickness (Ct.Th, inner and outer both R2 = 0.90). NIRS scans also had 100% classification accuracy in grading the quartile of bone thickness and quality. Conclusion We believe this is a fundamental step forward in creating an instrument capable of intraop-erative real-time use.