Dynamic measurement of bone blood perfusion with modified laser Doppler imaging

Although the mechanisms are not clearly defined, blood flow may play an imp ortant role in moderating skeletal adaptation. Most techniques currently av ailable to measure blood now in bone are time-consuming and require destruc tion of the tissue, but laser Doppler technology offers a less invasive met hod. The present study assessed whether laser Doppler perfusion imaging cou ld detect: changes in perfusion in cortical bone. By use of modified laser Doppler perfusion imaging with an adjustable, incorporated, near infrared-l aser gain photodetection system, perfusion of blood in the mid-diaphyseal t ibial cortex of New Zealand White rabbits (n = 5) was measured before, duri ng, and after occlusion of the femoral artery. During occlusion, perfusion decreased 69% compared with control levels; removal of the arterial clip ca used flux values to return to near normal. Laser Doppler perfusion imaging provides a two-dimensional image related to blood flow, and the results of this pilot study suggest that it may be an effective technique for imaging in vivo dynamic changes in perfusion in cortical bone.