Table 2.

Subjective evaluation of image quality.

Score	Image Quality	Artifacts	Structures	Nerve Roots
1	Unacceptable	Severe artifact, obvious distortion	Heterogeneous, cannot be distinguished	Heterogeneous, cannot be distinguished
2	Worse than moderate,	Obvious artifact, mild distortion	Worse than moderate, Distinguishable but obscured	Worse than moderate, Distinguishable but obscured
3	Moderate	Moderate	Moderate	Moderate
4	Above moderate	Little artifact without obvious distortion	Mild heterogeneous, Blurry edged	Mild heterogeneous, Blurry edged
5	Excellent	No artifact	Homogeneous Clear and sharp edged	Homogeneous Clear and sharp edged