An experimentally validated simple standardized method for making precise measurements of the spinal canal directly from the video display of a CT scanner is described. Using this method, normal values for anteroposterior diameter, interpediculate distance, and cross-sectional area of the lumbar spinal canal have been determined in a series of 60 adults. A careful study of canal configuration combined with the prudent use of the normal values should allow the CT diagnosis of lumbar spinal stenosis to be made with a high level of confidence.

Image-guided surgery is an effective tool for the achievement of correct screw placement in C1-C2 transarticular screw fixation procedures. The procedure remains technically demanding.

Fenestration of the extracranial course of the vertebral artery is a developmental or congenital anomaly. A review of the literature demonstrated that this is apparently only a coincidental finding and has no pathologic significance.

No abstract

No abstract