A novel approach to Paget's disease diagnosis and monitoring using near-infrared absorption spectroscopy

ABSTRACT Paget’s disease of bone affects about 1 to 3 percent of people over 40 years of age in the United States. The disease is characterized by an increase in the rate of bone remodeling due to excessive osteoclast activity; therefore patients with Paget’s disease can develop severe bone deformities. Pagetoid bones are large, fragile and prone to fractures. A hallmark of Paget’s disease of bone is a marked increase in vascularization in bones. The fingerprint determinants of vascularization are deoxyhemoglobin (Hb) and oxyhemoglobin (HbO 2 ), which are the key chromophores in the NIR “tissue optical window” from 700nm to 1200nm. We have designed a Bone Optical Analyzer which utilizes optical spectroscopy imaging to non-invasi vely measure the changes of Hb and HbO 2 , thus enabling early diagnosis and monitoring of disease progression in these patients. Using inverse imaging algorithms, based on the diffusion equation, 2D and 3D maps of the bone’s internal structure can be reconstructed. The use of NIR light will allow for repeated studies on patients with Paget’s disease quickly, safely, inexpensively and without the risks associated with standard procedures. The model will be tested on bone tissue phantoms which mimic the scattering properties of human bone. This work will be the foundation for the future use of this device in vivo.