COMPUTER-ASSISTED MEASUREMENT OF LUMBAR SPINE RADIOGRAPHS

Rationale and Objectives. The authors evaluated a method for obtaining reproducible, reliable measurements from standard lumbar spine radiog raphs for determining the degree of spondylolisthesis, vertebral body height, intervertebral disk space height, disk space angle, and degree of vertebral body wedging. Materials and Methods. Four to six easily defined points were identified on each vertebral body on antero-poster ior and lateral plain radiographs of the lumbosacral spine of patients . From these points, the degree of spondylolisthesis, the vertebral bo dy height, the intervertebral disk space height, the disk space angle, and the degree of vertebral body wedging were easily calculated by us ing well-known geometric relationships. This method requires the use o f a personal computer and a standard spreadsheet programs but does not require the use of any other specialized radiographic equipment, comp uter hardware, or custom software. Results. Calculations of intra- and interobserver variability for the measurement of spondylolisthesis, d isk space height, disk space angle, and vertebral body height measurem ents showed that the technique is extremely reproducible. Conclusion. This technique may prove useful in the prospective evaluation of poten tial candidates for lumbar spinal stenosis surgery.