Feasibility of MR-tagging to quantify spinal cord motion in degenerative cervical myelopathy.

BACKGROUND

The aim of this study was to investigate the feasibility of MR-tagging for direct visualization and quantification of pathologically altered spinal-cord motion in patients with cervical spinal stenosis and compare it to the standard approach of phase contrast (PC) imaging.

METHODS

In this prospective study, sagittal sections (22 cm field of view) of the cervical spine of nine patients with mono-segmental spinal-canal stenosis were imaged in different heart phases after selective pre-saturation of tissue magnetization in an axially oriented tag-stripe pattern (MR-tagging). Video loops of images acquired in different heart phases were viewed to directly observe and compare head-feet (HF) displacement at the level of the stenosis. The maximum HF displacement of MR-tags in the cord was quantitatively assessed and compared to that derived from integration of PC velocity data.

RESULTS

Regional MR-tag displacement in the spinal cord could successfully be observed in all patients (4 females, 5 males, mean age 57 ± 7 years). Maximum displacement data derived from tagging at the stenosis level correlated excellently (R2 = 0.84) with matched measurements from PC imaging.

CONCLUSION

Without complex post-processing, MR-tag imaging provides an intuitive direct visualization and quantification of pathologically altered spinal-cord motion at the level of cervical stenosis offering a faster alternative to PC imaging in clinical routine.