Transdermal Technique Checks Bone Quality

BETHESDA, MD. — Among the many novel technologies cropping up to help analyze bone quality noninvasively, near-infrared spectroscopy may eventually prove to be quite useful, according to results from a preliminary study.

In an investigation that involved mice as subjects, the near-infrared spectroscopy technique has been shown to detect differences in mineralization of those with and without a mutation that models type III osteogenesis imperfecta, Guiyang Li, Ph.D., reported at a meeting on bone quality.

Dual x-ray absorptiometry scans are limited in that they cannot obtain “information on molecular structure of bone and its primary components—hydroxyapatite mineral and collagen,” explained Dr. Li, of the musculoskeletal imaging and spectroscopy laboratory at the Hospital for Special Surgery in New York.

Near-infrared spectroscopy can penetrate millimeters to centimeters through the skin—farther than its close cousin, mid-infrared spectroscopy, which can only penetrate about 10 μm into skin, Dr. Li noted.

Mid-infrared spectroscopy has stronger absorbance bands than near infrared.

The relatively low intensity of near infrared absorbance necessitates the use of special modeling methods to analyze the resulting spectrum, he explained at the meeting, which was sponsored by the National Institute of Arthritis and Musculoskeletal and Skin Diseases. The meeting was cosponsored by the American Society for Bone and Mineral Research.