Table 1.

Changes in Enhancement Percentage at Center of Disc and histologic scores of endplate in different age groups in rats

Age group	Discs in L3–L4	Discs in L4–L5	Discs in L5–L6	Discs in L6–S1	Histologic score (0–18)
3-month-old	54.54 ± 5.81	47.69 ± 13.36	48.79 ± 11.45	43.56 ± 12.95	2.67 ± 0.52
6-month-old	44.14 ± 8.35*	44.84 ± 6.21	43.65 ± 9.92	29.26 ± 5.04*	9.50 ± 1.05*,**
9-month-old	40.96 ± 4.57	36.45 ± 6.12	34.29 ± 7.13	25.43 ± 6.85*	14.17 ± 1.72*

Values are expressed as the mean ± SD. Enhancement Percentage = (the maximum signal intensity postenhancement (SImax) − the signal intensity from baseline (SIbase))/SIbase × 100 (L3–L4 represent the intervertebral disc between the third and the fourth lumbar vertebra, and so on)

*P < 0.05 compared with 3-month-old groups

**P < 0.05 the histologic changes for the endplate of 6-month-old compared with 9-month-old group