An image processing method for spine kinematics-preliminary studies

The measurement of spinal segmental movement is essential to the understanding of the pathomechanics of spinal injuries and other mechanical disorders both in research and clinical medicine. Unfortunately, this is difficult to do accurately without the use of invasive and laborious procedures. The image processing method described in this paper provides a possible avenue for overcoming these limitations by using rapid computerized analysis of low-dose motion radiographs. X-ray images of lumbar vertebrae from an image intensifier were digitized using an image processing system. These images were derived both from a calibration model and human subjects and were used to estimate the accuracy and reproducibility of segmental angular position and rotation measurements obtained by image processing. The results of both inter- and intraobserver studies were encouraging. Further research is necessary to develop the system for measuring these and other kinematic parameters in vivo and to assess the possibility of adding a measure of automation to the system.