Although the mechanisms are not clearly explained, blood flow may play an important role in mediating skeletal adaptation. Most techniques currently available to measure blood flow in bone are time-consuming and require destruction of the tissue whereas laser Doppler technology offers a less invasive method. The current series of studies investigated the effectiveness of laser Doppler perfusion imaging (LDI) for measuring perfusion in cortical bone. Preliminary pilot studies were conducted to determine the feasibility of using LDI on bone, as well as assessment of bone optical properties and flow characteristics.

Results indicated that LDI effectively measured blood flow in cortical bone and detected physiologically induced changes in perfusion. A significant positive correlation was found between microsphere-determined flow and LDI output (r = 0.58, p < 0.05). Repeatability of consecutive LDI perfusion measurements was within 5%. Red and near infrared wavelengths were significantly correlated suggesting the two wavelengths measured perfusion in the same region. Red and near infrared lasers were measuring blood flow up to 0.8 mm and 0.9 mm, respectively, into the tissue.

This study characterized LDI for measuring perfusion in bone and correlated flow measured by LDI to standardized microsphere-determined flow. The ability to profile heterogeneous structure and sequential changes in blood flow in bone suggests this method has the potential for investigating the role of blood flow in bone metabolism, healing, and remodeling.