ABSTRACT

At present, due to advances in neuroradiological imaging techniques, computer-aided MRI measurements can be conducted on personal computers. In this way, we performed measurements of lumbar MR images digitally to obtain the lumbar spinal canal diameter in sagittal and axial MR cross-sections, in order to acquire a standard national value for a Turkish population. Our study included a group of 200 patients (105 female, 95 male) who applied to our outpatient clinic with lower back pain.

We divided the patients into three groups: the first group were those under the age of 40 (109 people), the second group were those between the ages of 41 and 60 (64 people) and the third group were those over the age of 61 (27 people). Measurements of the canal diameter were made at the following locations: axial cross-section measurements from the facet joint level, front–rear diameter and left–right diameter measurements from the level where the canal was broadest, and sagittal cross-section measurements from the cross-sections where the vertebral canal was broadest. When the sagittal cross-section measurements were performed, the range was taken from the exact middle of the corpus to the farthest middle point of the lamina by taking the dural sac as the border. Height and width measurements of the corpus were made from the middle points. At the axial cross-section, the canal inner area was measured.

The largest canal diameter was 15.1 mm, obtained from the sagittal cross-section of the lumbar first spine (sL1), whilst the smallest value was 12.8 mm from the sagittal cross-section of the lumbar fourth spine (sL4). In all patients, while the average canal diameter decreased from sL1 to sL3, in sL4 and sL5 a diameter increase was observed. When comparison was done by age, the canal diameter from sL1 to sL4 was inversely proportional to age.

The values for the canal diameter of the lumbar spine and the corpus height vary with age, gender and the level of measurement.