Anteroposterior diameter of the vertebral canal in cervical region: Comparison of anatomical, computed tomographic, and plain film measurements

The purpose was to compare the computed tomographic and plain film measurem ents with those of anatomical specimens to determine the antero-posterior d iameter of the spinal canal in cervical region. Antero-posterior diameters of 75 cervical vertebral canals (15 sets of C3-C7) were measured anatomical ly at two different levels. Computed tomographic and plain film measurement s were also obtained at the corresponding levels. Considering anatomical me asurements as the gold standard, plain film and computed tomographic measur ements were statistically compared. Interobserver and intraobserver differe nces were also evaluated. At the uppermost pedicle levels, there was no sta tistically significant difference between plain films and anatomical measur ements, a good correlation. However, at lowermost pedicle level there was a statistically significant difference between plain films and anatomical me asurements but not between tomographic and anatomical measurements. Our res ults suggest that plain films can accurately estimate cervical spinal canal mid-sagittal diameter at the uppermost pedicle level and be used as a firs t step examination for the evaluation of cervical spinal stenoses. Clin. An at. 14:15-18, 2001. (C) 2001 Wiley-Liss, Inc.