Torg-Pavlov ratio, (AKA Pavlov ratio, Torg ratio) or so called “Canal Body Ratio” CBR was first described in 1987 by Pavlov et al., it represented the ratio between the sagittal diameter of the spinal canal and the sagittal diameter of the corresponding vertebral body and was first measured on lateral cervical spine X-ray. A ratio of <0.7–0.8 indicated a significant spinal stenosis with high risk of neurological injury 1) 2): the ratio of the AP diameter of the spinal canal at the mid VB level to the VB at the same location. A ratio < 0.8 is sensitive

1)
Pavlov H, Torg JS, Robie B, et al. Cervical Spinal Stenosis: Determination with Vertebral Body Ratio Method. Radiology. 1987; 164:771–775
2)
Torg JS, Naranja RJ, Pavlov H, et al. The Relationship of Developmental Narrowing of the Cervical Spinal Canal to Reversible and Irreversible Injury of the Cervical Spinal Cord in Football Players. J Bone Joint Surg. 1996; 78A:1308–1314