Magnetic Resonance Imaging based Determination of Conus Medullaris Position in Adults

The position of the conus medullaris was determined in 289 patients without obvious spine or cord pathology using midsagittal Magnetic Resonance (MR) images of the lumbosacral spine. In all patients, lumbosacral X-ray was evaluated for transitional vertebra to avoid misidentification of vertebrae on MR images. The mean location of the conus tip was at L1 upper third, ranging from T12 upper third to L2 middle third. The position was slightly higher in males than in females. Presence of transitional vertebra or degenerative joint disease did not have significant effect on the position of the conus.