Visualization of the greater and lesser occipital nerves on three-dimensional double-echo steady-state with water excitation sequence.

PURPOSE

To investigate the ability of three-dimensional double-echo steady-state with water excitation sequence (3D-DESS-WE) in detecting the greater occipital nerve (GON) and the lesser occipital nerve (LON).

MATERIALS AND METHODS

We retrospectively reviewed 66 consecutive patients who underwent magnetic resonance imaging, including 3D-DESS-WE. Two readers evaluated the detectability [0 (poor) to 3 (excellent)] and thickness of the GON and LON. We calculated the average evaluation scores and interobserver variability for the detectability of the GON and LON. We also calculated the average nerve thickness for each of the two readers and the interobserver reproducibility for the thickness of the GON and LON. The interobserver variability was calculated using a weighted kappa analysis and the intraclass correlation coefficient (ICC) was used to evaluate the interobserver reproducibility of the nerve thickness.

RESULTS

The respective average score, interobserver variability, thickness and interobserver reproducibility were 3.00, excellent (κ = 1.00), 1.07 ± 0.12 mm, and almost perfect (ICC = 0.82) for the GON and 1.81, good (κ = 0.73), 0.84 ± 0.11 mm, and substantial (ICC = 0.78) for the LON. The GON was significantly thicker than the LON (p < 0.001).

CONCLUSION

The 3D-DESS-WE demonstrated excellent visualization of the GON and relatively good visualization of the LON.