Assessment Of Lumbar Intervertebral Disc Degeneration By MRS, T2Map And DWI

Objective:To assess the value of MR T2 relaxation times ,MRS and ADC to evaluate the lumbar intervertebral disc degeneration.Materials and Methods:MRS,T2map and DWI of the lumbar spine disc were performed in 40 patients in the L1-S1 region. A control standard for disk MRS values was obtained by using a small cylindric water tube that was taped to each participant's back in L3 region. All of discs were visually graded using the Pfirrmann grading scale by two independent observers(10 years experience in MR imaging of the spine) blind read, 177discs of agreement between the two readers were selected. By using software that was available on the MR imager, axial ADC maps,T2 maps and area of water peak(water tube an discs)were created and transferred to an imaging workstation. ADC values and T2 relaxation times were recorded for each disk. The ratio (MRS_RATIO) of disk area of water peak to watertube area of water peak was calculated for each disk. Comparison of 177 discs ADC values, T2 relaxation times and MRS_RATIO was performed at different anatomic levels and different Pfirrmann grades.Results:1 Comparison of disc MRS_RATIO, T2 relaxation times and ADC values in different Pfirrmann grade at the same anatomic level(L1-S1).1.1 For every anatomic level disc,MRS_RATIO showed no statistically significant difference in different Pfirrmann grades.1.2 For every anatomic level disc, T2 relaxation times showed statistically significant difference in all Pfirrmann grades,expect in the Pfirrmann gradeâ…£andâ… ,â…£a ndâ…¢at L2-3 level.1.3 At the L1-2 level disc, ADC values showed no statistically significant difference in all Pfirrmann grades; At the L2-3 level disc, ADC values showed statistically significant difference in the Pfirrmann gradeâ… andâ…¡,â…¢andâ…£; At the L3-4 level disc, ADC values showed significant differences in the Pfirrmann gradeâ… andâ…¡,â…¢andâ…£; At the L4-5 level disc, ADC values showed significant differences in the Pfirrmann gradeâ… andâ…¢,â… andâ…£,â…¡andâ…£. At the L5-S1 level disc, ADC values showed significant differences in the Pfirrmann gradeâ…¡andâ…£.2 Comparison of disc ADC values, MRS_RATIO and T2 relaxation times at different anatomic level (L1-S1) in the same Pfirrmann grade.2.1 In every Pfirrmann grade disc, ADC values and T2 relaxation times showed no significant differences at different anatomic levels.2.2 In the Pfirrmann grade 2 disc, MRS_RATIO showed significant differences at L4-5 and L1-2, L4-5 and L2-3, L5-S1 and L1-2, L5-S1 and L2-3; In the Pfirrmann grade three disc, MRS_RATIO showed significant differences at L5-S1 and L1-2, L2-3 , L3-4.3.1 At all anatomic level disc, ADC values and T2 relaxation times showed evidently significant differences(p<0.05) in different Pfirrmann grades.3.2 At all anatomic level disc, MRS_RATIO showed no significant differences(p>0.05) in different Pfirrmann grades. Conclusion:1 In summary, the most significant findings of the study were that show statistical significtion between decreasing in ADC values and T2 relaxation times with increasing Pfirrmann grade in lumbar intervertebral disc. The results of our study support the feasibility of quantitatively assessing lumbar intervertebral disc degeneration.2 The grade of lumbar intervertebral disc degeneration can not be showed by MRS_RATIO.