Canal-to-body ratio of Torg and Pavlov

Last revised by Henry Knipe on 22 Feb 2023

The canal-to-body ratio of Torg and Pavlov is a method of evaluating the degree of cervical canal stenosis on lateral cervical spine radiographs.

This ratio is variously referred to as the Torg ratio 3, the Pavlov ratio 3,4, the Torg-Pavlov ratio 5, or the canal-to-body ratio 3.

This method uses the ratio of the diameter of the cervical canal to the width of the cervical vertebral body on a lateral cervical spine radiograph.

A ratio of <0.8 is taken as an indication of cervical stenosis 1.

The standard method of evaluating cervical canal stenosis was historically the sagittal diameter in millimeters, using various cut-offs 1. In two articles published in 1986 and 1987 1,2 American orthopedic surgeon Joseph Torg (fl. 2018) and American radiologist Helene Pavlov (fl. 2018) et al. introduced the ratio method in order to reduce inter- and intraobserver error caused by variance in magnification and landmarking.

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