Objective To develop a modified short time inversion recovery (STIR) sequence grading system for lumbar intervertebral disc degeneration based on MRI STIR sequences, and to test the validity and reproducibility of this grading system. Methods A modified 8-level grading system for lumbar intervertebral disc degeneration based on routine sagittal STIR sequences and modified Pfirrmann grading system was developed. Between April 2011 and February 2012, 60 patients with different degrees of lumbar intervertebral disc degeneration were selected as objects of study, including 32 males and 28 females with an average of 50 years (range, 17-85 years). T2 weighted and STIR sequence images were obtained from the lumbar discs of L1, 2-L5, S1 of each object (total, 300 discs). All examinations were analyzed independently by 3 observers and a consensus readout was performed after all data collected. The validity and reproducibility were analyzed by calculating consistent rate and Kappa value. Results According to the grading system, there were 0 grade 1, 83 (27.7%) grade 2, 87 (29.0%) grade 3, 66 (22.0%) grade 4, 31 (10.3%) grade 5, 15 (5.0%) grade 6, 12 (4.0%) grade 7, and 6 (2.0%) grade 8. Intra-observer consistency was b (Kappa value range, 0.822-0.952), and inter-observer consistency was high to b (Kappa value range, 0.749-0.843). According to the consensus analysis, the total consistent rate was 82.7%-92.7% (mean, 85.6%). A difference of one grade occurred in 13.9% and a difference of two or more grades in 0.5% of all the cases. Conclusion Disc degeneration can be graded by using modified STIR sequence grading system, which can improve the accuracy of grading different degrees of lumbar intervertebral disc degeneration.
To detect the cell density, apoptotic incidence and the expressions of Bax and Caspase-3in human lumbar intervertebral discs, so as to further understand the mechanism of human lumbar intervertebral discdegeneration and provide a new idea for biologic treatment of it in future. Methods From May to December in 2006,30 human lumbar intervertebral discs in experimental group(L2 to S1)were surgically collected from 27 patients undergoing posterior lumbar intervertebral discoidectomy and fusion. All the cases were affirmed by MRI and they never experienced discography, collagenolysis of nucleus pulposus and percutaneous laser disc decompression. The control group consisted of 20 human lumbar intervertebral discs(L2 to S1)harvested from 5 young men without spine-related condition immediately after their accidental death. Apoptotic disc cells were detected by TUNEL and histomorphology, and immunohistochemical staining with SP method was performed to examine the expressions of Bax and Caspase-3 in all specimens. Results HE staining disclosed that the average cell density in control group (17.16 ± 1.22)/HP was higher than that in experimental group (12.41 ± 0.95)/HP (P lt; 0.01). However, TUNEL staining observed that the average TUNEL positive incidence in control group (6.97% ± 0.92%) was lower than that in experimental group (12.59% ± 0.95%), (P lt; 0.01). Immunohistochemical staining with SP method showed that the Bax and Caspase-3 positive incidence of nucleus pulposus in control group (11.02% ± 1.18%, 9.01% ± 1.00%) were lower than those in experimental group (19.29% ± 1.18%, 15.07% ± 0.97%), (P lt; 0.01). The results of the average gray scale value of nucleus pulposus in control group were 187.33 ± 7.88 and 185.68 ± 3.26, respectively, with 124.98 ±6.69 and 160.13 ± 4.37 in experimental group. There was significant difference between the two groups (P lt; 0.01). When thetotal 50 specimens in the two groups were analyzed, TUNEL positive incidence showed significant inverse correlations with their respectively corresponding cell densities (r = － 0.88, r = － 0.93, P lt; 0.01). The Bax and Caspase-3 positive incidence of nucleus pulposus showed significant positive correlation with the TUNEL positive incidence of nucleus pulposus (r = 0.83, r = 0.91, P lt; 0.01). Conclusion The decrease of cell density is involved in the development of human lumbar intervertebral disc degeneration. Bax and Caspase-3 might play a role in disc cell apoptosis in nucleus pulposus of human lumbar intervertebral disc.
ObjectiveTo analyze the relationship between the bone mineral density (BMD) and lumbar intervertebral disc degeneration in rhesus macaques by using T1ρ-MRI. MethodsTwenty female rhesus macaques at the age of 10.9 years on average (rang, 4-20 years) were selected. The lumbar intervertebral discs were classified by Pfirrmann grading system and the T1ρ relaxation time (T1ρ value) was examined by using MRI (Philips 1.5 Tesla), and then BMD values of the L4,5 vertebrae and femoral ward's triangle were detected by using Osteocore dual energy X-ray absorptiometry. Finally, the relationship of T1ρ value of the lumbar intervertebral discs and Pfirrmann grading with age, weight, BMD of lumbar vertebrae and femoral ward's triangle was analyzed. ResultsThe BMD values of lumbar vertebrae and femoral ward's triangle were (0.64±0.17) g/cm2 and (0.67±0.19) g/cm2 respectively, showing no significant difference (t=2.893, P=0.128). According to Pfirrmann grading system, there were 7 cases of grade I, 8 cases of grade Ⅱ, and 5 cases of grade Ⅲ at L4,5 intervertebral discs. The T1ρ value of the lumbar intervertebral disc was (104.08±18.65) ms; the T1ρ values of grades I, Ⅱ, and Ⅲ were (121.31±13.44), (104.73±15.01), and (77.41±11.87) ms, respectively. There was a negative correlation between T1ρ value and the age and the BMD of lumbar vertebrae and femoral ward's triangle. There was a positive correlation between Pfirrmann grading and the variables as listed above. Significant negative linear correlation was also observed between T1ρ value and Pfirrmann grading. ConclusionThe T1ρ value is a reliable index when quantifying lumbar intervertebral disc degeneration, and there is a significant positive correlation between BMD and lumbar intervertebral disc degeneration in rhesus macaques.
ObjectiveTo investigate the role of transforming growth factor β1(TGF-β1) and connective tissue growth factor (CTGF) in pathogenesis and progression of human intervertebral disc degeneration by detecting the expressions of these two factors in different degrees of degenerative discs. MethodsThe lumbar intervertebral discs were collected from 33 patients with lumbar disc herniation and 12 patients with lumbar vertebral fracture between November 2012 and April 2013.All samples were observed under the microscope after HE staining,and then were divided into different subgroups according to the degenerative degree.The expressions of TGF-β1 and CTGF were detected by Western blot. ResultsAccording to the pathological features,10 discs were defined as normal discs,10 as mild degenerative discs,9 as moderate degenerative discs,and 16 as severe degenerative discs.The histological observation showed that rounded nucleus pulposus cells with similar size evenly distributed in the cartilage-like matrix,and no hyperplastic collagenous fiber was seen in normal discs;mild degenerative discs characterized by slightly larger nucleus pulposus cells in the matrix,but cells did not decrease,a small quantity of inflammatory cells infiltrated in the matrix,hyperplasia of collagenous fiber was not seen;most of the nucleus pulposus cells became bigger,some showed a bulb form,the number of nucleus pulposus cells was significantly reduced,low grade hyperplasia of collagenous fiber emerged in the matrix,new vessels and inflammatory cells were both found in some specific areas of discs in moderate degenerative discs;there was no nucleus pulposus cells in the matrix of severe degenerative discs,the hyperplasia of collagenous fiber was obvious.The relative expression of TGF-β1 in 3 degeneration discs was significantly higher than that in normal discs (P<0.05),and the expression of TGF-β1 was significantly higher in severe degenerative discs than in moderate and mild degenerative discs (P<0.05),but no significant difference between moderate and mild degenerative discs (P>0.05).The relative expression of CTGF in moderate and severe degeneration discs was significantly higher than that in normal discs (P<0.05);and the expression of CTGF in mild degenerative discs was higher than that in normal discs,but there was no significant difference (P>0.05);and significant difference in CTGF expression was found among 3 degeneration discs (P<0.05). ConclusionThe expressions of TGF-β1 and CTGF are closely related to the degree of human lumbar disc degeneration,these two factors may play an important role in promoting lumbar intervertebral disc degeneration.