Posterior Anterior Annulus Fibrosus Research Articles

Quantitative magnetic resonance spectroscopy and imaging analysis of the lipid content in the psoas major and its association with intervertebral disc degeneration: a cross-sectional study

Aim: It is shown that the diminished function of the psoas major is mainly associated with increased lipid content; nonetheless, whether the fat content of the psoas major is associated with intervertebral disc degeneration (IVDD) is still under study. It is hypothesized that IVDD is correlated with the lipid content of the psoas major and that IVDD can be comprehensively investigated using quantitative magnetic resonance imaging (MRI). Consequently, this study aimed to analyse the association between the psoas major extramyocellular lipid (EMCL) and intramyocellular lipid (IMCL) content and disc degeneration quantified using MRI T2 mapping in patients with chronic low back pain (CLBP). Methods: In this study, 20 men and 23 women (mean age, 63.1 years ± 2.6 years) underwent magnetic resonance spectroscopy (MRS). The psoas major IMCL and EMCL content of patients was analysed. T2 values of the anterior annulus fibrosus (AF), nucleus pulposus (NP), and posterior AF were evaluated using MRI T2 mapping. Multiple linear regression analysis was used to determine the possible correlations of the psoas major EMCL and IMCL content with the T2 values of the anterior AF, NP, and posterior AF. Results: The EMCL content and T2 values of the anterior AF were significantly and negatively correlated [standardised partial regression coefficient (β) = −0.60, P < 0.01]. There were no significant correlations between the EMCL content and T2 values of the NP (β = −0.16, P = 0.30) or posterior AF (β = −0.14, P = 0.49) or between the IMCL content and T2 values of the anterior AF (β = −0.04, P = 0.82), NP (β = 0.05, P = 0.73), or posterior AF (β = −0.11, P = 0.58). Conclusions: The EMCL content and T2 values of the anterior AF were correlated. Conversely, the IMCL content and T2 values were not correlated.

Patterns of Intervertebral Disk Alteration in Asymptomatic Elite Rowers: A T2* MRI Mapping Study.

Background:Repetitive loading of the back puts elite rowers at risk for acute and chronic back injuries.Hypothesis:That asymptomatic elite rowers would demonstrate characteristic intervertebral disk (IVD) alterations on T2* magnetic resonance imaging (MRI) mapping compared with asymptomatic nonrowers.Study Design:Cross-sectional study; Level of evidence, 3.Methods:This study included 20 asymptomatic elite rowers (mean age, 23.4 ± 3.03 years; 9 women, 11 men) studied at 2 different times, once before (t 1) and once after (t 2) the competition phase. MRI including T2* mapping was performed on a 3-T scanner. The authors derived normative T2* data from a previous study on 40 asymptomatic volunteers (20 men, 20 women) who were not competitive rowers; based on complete T2* data sets, 37 controls were included. T2* values were compared between groups in 4 lumbar IVDs, and midsagittal T2* values were compared in 5 zones: anterior annulus fibrosus (AF), anterior nucleus pulposus (NP), central NP, posterior NP, and posterior AF. The Pfirrmann grade was used for morphological assessment of disk degeneration. Statistical analysis was conducted using the Mann-Whitney U test, Wilcoxon matched-pairs test, and Spearman rank correlation coefficient.Results:Lower T2* values were noted in the rower group compared with the controls (37.08 ± 33.63 vs 45.59 ± 35.73 ms, respectively; P < .001). The intersegmental comparison revealed lower mean T2* values among rowers (P ≤ .027 for all). The interzonal comparison indicated significantly lower mean T2* values for the rowers in all zones except for the anterior NP (P ≤ .008 for all). Lower mean T2* values were observed for the rowers at t 1 versus t 2 (39.25 ± 36.19 vs 43.97 ± 38.67 ms, respectively; P = .008). The authors noted a higher level of IVD damage according to Pfirrmann assessment in the rower cohort (P < .001); the Pfirrmann grade distributions of rowers versus controls, respectively, were as follows: 51.3% versus 73.7% (grade 1), 20.5% versus 19.5% (grade 2), 21.8% versus 6.8% (grade 3), 5.1% versus 0% (grade 4), and 1.3% versus 0% (grade 5). The authors also noted a correlation between low T2* and high Pfirrmann grade at t 1 (r =–0.48; P < .001) and t 2 (r =–0.71; P < .001).Conclusion:The cohort of elite rowers revealed more degenerative IVD changes compared with controls. The T2* values suggest that repetitive loading of the spine has demonstrable short-term and possibly permanent effects on the lumbar IVD.

Association between lumbar segmental mobility and intervertebral disc degeneration quantified by magnetic resonance imaging T2 mapping

BackgroundThe relation between segmental mobility and degree of lumbar degenerative change is still unknown. This cross-sectional study aimed to elucidate the association between intervertebral disc degeneration (IVDD) and segmental mobility in chronic low back pain using magnetic resonance imaging (MRI) T2 mapping. MethodsSubjects comprised 60 patients (29 men, 31 women; mean age, 61.8 ± 1.9 years; range, 41–79 years). T2 values of the anterior annulus fibrosus (AF), the nucleus pulposus (NP) and the posterior AF were evaluated with MRI T2 mapping. Facet joint degeneration was divided into 4 grades using MRI. We analyzed the correlation between segmental mobility and T2 values of anterior AF, NP and posterior AF using multiple linear regression analysis adjusted for age and facet joint degeneration. ResultsThe standardized partial regression coefficient of the anterior AF, NP and posterior AF T2 values were 0.125 (p=0.72), 0.499 (p<0.01) and –0.026 (p=0.11), respectively, for the L1-2 level; 0.102 (p=0.27), 0.395 (p<0.01) and –0.094 (p=0.20), respectively, for the L2-3 level; 0.108 (p=0.38), 0.415 (p<0.01) and –0.050 (p=0.51), respectively, for the L3-4 level; 0.124 (p=0.09), 0.396 (p<0.01) and 0.025 (p=0.73), respectively, for the L4-5 level; and 0.011 (p=0.89), 0.443 (p<0.01) and 0.030 (p=0.72), respectively, for the L5-S level. There was a significantly positive correlation between segmental mobility and the T2 values of NP at L1–L2, L2–L3, L3–L4, L4–L5, and L5–S1. No significant correlations arose between segmental mobility and the T2 values of the anterior AF and the posterior AF at L1–L2, L2–L3, L3–L4, L4–L5, and L5–S1. ConclusionCharacterization of the relationship between NP degeneration and lumbar segmental mobility may enhance our ability to evaluate the changes seen in kinematics of functional spinal unit.

Relevance between Schmorl's Node and Lumbar Intervertebral Disc Degeneration Quantified with Magnetic Resonance Imaging T2 Mapping in Chronic Low Back Pain.

Study DesignCross-sectional study.PurposeThe purpose of this study was to elucidate the relevance among Schmorl’s node (SN), chronic low back pain (CLBP), and intervertebral disc degeneration (IVDD) with the use of magnetic resonance imaging T2 mapping.Overview of LiteratureSN may be combined with CLBP and/or IVDD; however, their relationship has not been determined to date.MethodsA total of 105 subjects were included (48 men and 57 women; mean age, 63.2±2.7 years; range, 22–84 years). We analyzed five functional spinal unit levels (L1–S1) and evaluated the T2 values of the anterior annulus fibrosus (AF), nucleus pulposus, and posterior AF. We compared the low back pain (LBP) Visual Analog Scale (VAS) scores and the T2 values in each decade with or without SN.ResultsThere were no remarkable differences in SN prevalence rate regarding age decade or gender. SNs were more prevalent in the upper 2 levels (70.3%). LBP VAS scores with and without SN were 64.7±4.3 mm and 61.9±2.8 mm, respectively, with no significant differences between the groups (p=0.62). The T2 values of anterior AF with SN were significantly lower than those without SN in patients in their 50s, 60s, 70s, and 80s (p<0.01).Conclusions SN presence is not itself a risk factor for CLBP; however, it indicates IVDD of the anterior AF in subjects with SN who are ≥50 years old.

Association between Spinopelvic Alignment and Lumbar Intervertebral Disc Degeneration Quantified with Magnetic Resonance Imaging T2 Mapping in Patients with Chronic Low Back Pain.

Introduction Although intervertebral disc degeneration (IVDD) and spinopelvic malalignment are likely key structural features of spinal degeneration and chronic low back pain (CLBP), the correlation analysis has not been fully conducted. This cross-sectional quantitative magnetic resonance imaging (MRI) T2 mapping study aimed to elucidate the association between IVDD and spinopelvic alignment in CLBP patients. Methods The subjects included 45 CLBP patients (19 men and 26 women; mean age, 63.8 ± 2.0 years; range, 41-79 years). The T2 values of the anterior annulus fibrosus (AF), the nucleus pulposus (NP), and the posterior AF were evaluated using MRI T2 mapping. We compared the possible correlations of spinopelvic parameters with T2 values of anterior AF, NP, and posterior AF using Pearson's correlation coefficient analysis. T2 values in these regions were classified into upper (L1-L2 and L2-L3), middle (L3-L4), and lower (L4-L5 and L5-S1) disc levels, and we analyzed the correlations with spinopelvic parameters. Results There were significant correlations of the anterior AF T2 values with lumbar lordosis (r = 0.51, p < 0.01), sacral slope (r = 0.43, p < 0.01), sagittal vertical axis (r = −0.40, p < 0.01), and pelvic tilt (r = −0.33, p < 0.01). In all lumbar levels, T2 values of anterior AF had significantly positive correlation with LL and significantly negative correlation with SVA. In lower disc level, T2 values of anterior AF had significantly positive correlation with SS and significantly negative correlation with PT. T2 values of NP and posterior AF had no significant correlations with spinopelvic parameters in all lumbar disc levels. Conclusions In summary, this study indicated that the anterior AF degeneration is associated with hypolordosis of the lumbar spine, anterior translation of the body trunk, and posterior inclination of the pelvis in CLBP. Anterior AF degeneration in all lumbar disc levels was associated with hypolordosis of the lumbar spine and anterior translation of the body trunk. Anterior AF degeneration in lower disc level was associated with posterior inclination of the pelvis.

T2* Mapping of the Adult Intervertebral Lumbar Disc: Normative Data and Analysis of Diurnal Effects.

In this prospective study, we sought to establish normative data for T2* analysis of lumbar intervertebral discs (IVDs). Further, potential diurnal effects regarding T2* relaxometry of the lower spine were examined. Lumbar IVDs of young, healthy, adult men (n = 20) and women (n = 20; mean age = 24.5 ± 2.9 years) were assessed. Magnetic resonance imaging including T2* mapping was performed on a 3-T scanner. Mid-sagittal T2* values were obtained in five regions: anterior annulus fibrosus (AF), anterior nucleus pulposus (NP), central NP, posterior NP, and posterior AF. Zonal and segmental differences, as well as diurnal variations between the T2* analysis in the morning and the evening and effects of unloading, were analyzed. Discs with signs of degeneration on morphological images or imaging artifacts were excluded. We noted a zonal and segmental T2* distribution with high values in the NP, low T2* values in the AF and a T2* increase towards the caudal NP. We observed no diurnal differences between the mean T2* values in the morning and in the evening (p = 0.748). The effect of unloading the spine was low (maximum T2* difference between four measurements = 13.6 ms; significant difference noted only between the 0 and 15-min measurement). The T2* values obtained in this study will serve as normative values for future T2* measurements. There are no diurnal influences, and we suggest that unloading of the spine has no demonstrable effect after 30 min on the T2* results. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1956-1962, 2019.

Multifidus Muscles Lipid Content Is Associated with Intervertebral Disc Degeneration: A Quantitative Magnetic Resonance Imaging Study.

Study DesignCross-sectional study.PurposeTo determine the association between fatty degeneration of the multifidus muscle (Mm) and intervertebral disc degeneration (IVDD) using quantitative magnetic resonance imaging (MRI).Overview of LiteratureFew studies have reported on quantitative MRI analysis of the relation between the Mm and IVDD.MethodsThe subjects with chronic low back pain comprised 45 patients (19 males, 26 females; mean age, 63.8±2.0 years; range, 41–79 years). We analyzed the intramyocellular lipids (IMCL) and extramyocellular lipids (EMCL) of the Mm using magnetic resonance spectroscopy. The T2 values of the anterior annulus fibrosus (AF), nucleus pulposus (NP), and posterior AF were evaluated using MRI T2 mapping. We compared the possible correlations of IMCL and EMCL of the Mm with the T2 values of anterior AF, NP, and posterior AF.ResultsThere was a significant negative correlation between IMCL and T2 values of the anterior AF (r=−0.65, p<0.01). There were no significant correlations between the IMCL and T2 values of NP (r=−0.16, p=0.30) and posterior AF (r=0.07, p=0.62). There were no significant correlations between the EMCL and T2 values of the anterior AF (r=−0.11, p=0.46), NP (r=0.15, p=0.32), and posterior AF (r=0.07, p=0.66). After adjustment for age and sex using multiple linear regression analysis, there was a significant negative correlation between the IMCL and T2 values of anterior AF (standardized partial regression coefficient=−0.65, p<0.01).ConclusionsThe results indicated that IMCL of the Mm might be accompanied with anterior AF degeneration. Therapeutic exercises using IMCL of the Mm as evaluation index might have the potential to identify novel targets for the treatment and prevention of IVDD.

Friday, September 28, 2018 1:00 PM–2:30 PM abstracts: a new look at imaging: 203. Analysis of chronic low back pain with magnetic resonance imaging T2 mapping of lumbar intervertebral disc

Friday, September 28, 2018 1:00 PM–2:30 PM abstracts: a new look at imaging: 203. Analysis of chronic low back pain with magnetic resonance imaging T2 mapping of lumbar intervertebral disc

Evaluation of Water Content in Lumbar Intervertebral Discs and Facet Joints Before and After Physiological Loading Using T2 Mapping MRI.

T2 mapping was used to quantify the water content of lumbar spine intervertebral discs (IVDs) and facet joints before and after physiological loading. The aim of this study was to clarify the interaction between lumbar spine IVD and facet joints as load-bearing structures by measuring the water content of their matrix after physiological loading using T2 mapping magnetic resonance imaging (MRI). To date, few reports have functionally evaluated lumbar spine IVD and facet joints, and their interaction in vivo. T2 mapping may help detect changes in the water content of IVD and articular cartilage of facet joints before and after physiological loading, thereby enabling the evaluation of changes in interacted water retention between IVD and facet joints. Twenty asymptomatic volunteers (10 female and 10 male volunteers; mean age, 19.3 years; age range, 19-20 years) underwent MRI before and after physiological loading such as lumbar flexion, extension, and rotation. Each IVD from L1/2 to L5/S1 was sliced at center of the disc space, and the T2 value was measured at the nucleus pulposus (NP), anterior annulus fibrosus (AF), posterior AF, and bilateral facet joints. In the NP, T2 values significantly decreased after exercise at every lumbar spinal level. In the anterior AF, there were no significant differences in T2 values at any level. In the posterior AF, T2 values significantly increased only at L4/5. In the bilateral facet joints, T2 values significantly decreased after exercise at every level. There was a significant decrease in the water content of facet joints and the NP at every lumbar spinal level after dynamic loading by physical lumbar exercise. These changes appear to play an important and interactional role in the maintenance of the interstitial matrix in the IVD NP and cartilage in the facet joint. 3.

Quantitative evaluation of lumbar intervertebral disc degeneration by axial T2* mapping.

To quantitatively evaluate the clinical value and demonstrate the potential benefits of biochemical axial T2∗ mapping-based grading of early stages of degenerative disc disease (DDD) using 3.0-T magnetic resonance imaging (MRI) in a clinical setting.Fifty patients with low back pain and 20 healthy volunteers (control) underwent standard MRI protocols including axial T2∗ mapping. All the intervertebral discs (IVDs) were classified morphologically. Lumbar IVDs were graded using Pfirrmann score (I to IV). The T2∗ values of the anterior annulus fibrosus (AF), posterior AF, and nucleus pulposus (NP) of each lumbar IVD were measured. The differences between groups were analyzed regarding specific T2∗ pattern at different regions of interest.The T2∗ values of the NP and posterior AF in the patient group were significantly lower than those in the control group (P < .01). The T2∗ value of the anterior AF was not significantly different between the patients and the controls (P > .05). The mean T2∗values of the lumbar IVD in the patient group were significantly lower, especially the posterior AF, followed by the NP, and finally, the anterior AF. In the anterior AF, comparison of grade I with grade III and grade I with grade IV showed statistically significant differences (P = .07 and P = .08, respectively). Similarly, in the NP, comparison of grade I with grade III, grade I with grade IV, grade II with grade III, and grade II with grade IV showed statistically significant differences (P < .001). In the posterior AF, comparison of grade II with grade IV showed a statistically significant difference (P = .032). T2∗ values decreased linearly with increasing degeneration based on the Pfirrmann scoring system (ρ < −0.5, P < .001).Changes in the T2∗ value can signify early degenerative IVD diseases. Hence, T2∗ mapping can be used as a diagnostic tool for quantitative assessment of IVD degeneration.

Axial loading during MRI influences T2-mapping values of lumbar discs: a feasibility study on patients with low back pain.

To investigate whether axial loading of the spine during MRI (alMRI) instantaneously induces changes in biochemical disc features as reflected by altered quantitative T2 values in patients with chronic low back pain (LBP). T2 mapping was performed on 11 LBP patients (54 lumbar discs) during the conventional unloaded MRI and subsequent alMRI. Each disc was divided into five volumetric regions of interests (ROIs), anterior annulus fibrosus (AF) (ROI 1), the interface anterior AF-nucleus pulposus (NP) (ROI 2), NP (ROI 3), the interface NP-posterior AF (ROI 4), and the posterior AF (ROI 5). The mean T2 values for each ROI were compared between MRI and alMRI and correlated with degeneration grade (Pfirrmann), disc angle, and disc level. With alMRI, T2 values increased significantly in the whole disc as well as in various parts of the disc with an increase in ROI 1-3 and a decrease in ROI 5. The changes in T2 values correlated to degeneration grade, changes in disc angle, and lumbar level. alMRI instantaneously induces T2-value changes in lumbar discs and is, thus, a feasible method to reveal dynamic, biochemical disc features in patients with chronic LBP.

T1rho and T2 mapping of lumbar intervertebral disc: Correlation with degeneration and morphologic changes in different disc regions

PurposeTo assess regional variations of T1rho (T1ρ) and T2 rates within lumbar intervertebral discs and to evaluate the correlation of T1ρ and T2 rates in different disc regions with Pfirrmann grades of degeneration and morphologic changes. Materials and methodsWe retrospectively evaluated 105 lumbar discs in 22 subjects who were examined at 3.0-T MRI. T1ρ and T2 relaxation rates (1/T1ρ and 1/T2) were measured in five segmented regions of discs: anterior annulus fibrosus (AF), anterior junction, nucleus pulposus (NP), posterior junction, and posterior AF. Disc degeneration was graded using 5-level Pfirrmann grading system and morphologic change was categorized into five groups (normal, bulging, annular fissure, protrusion, and extrusion). Regional differences of T1ρ and T2 rates and correlation with degeneration and morphologic changes were statistically analyzed. ResultsMost of the five segmented regions showed statistically different T1ρ and T2 rates from each other. T1ρ and T2 relaxation rates were positively associated with Pfirrmann grades of degeneration and morphologic changes, with different strength of relation in each region. T2 rates in the posterior junction showed the strongest correlation with degeneration (r=0.810) and T2 rates in the anterior junction showed the highest association with morphologic changes (r=0.621). ConclusionsRegional variations of T1ρ and T2 rates within discs and different strength of relation with degeneration and morphologic changes should be taken into account when evaluating lumbar discs.

Analysis of chronic low back pain with magnetic resonance imaging T2 mapping of lumbar intervertebral disc

BackgroundMagnetic resonance imaging (MRI) T2 mapping utilizes the T2 values for quantification of moisturecontent and collagen sequence breakdown. Recently, attempts at quantification of lumbar disc degeneration through MRI T2 mapping have been reported. We conducted an analysis of the relationship between T2 values of degenerated intervertebral discs (IVD) and chronic low back pain (CLBP). MethodsThe subjects who had CLBP comprised 28 patients (15 male, 13 female; mean age 48.9 ± 9.6 years; range 22–60 years). All subjects underwent MRI and filled out the low back pain visual analog scale (VAS) and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ). The disc was divided into the anterior annulus fibrosus (AF), the nucleus pulposus (NP), and the posterior AF, and each T2 value was measured. This study involved 25 asymptomatic control participants matched with the CLBP group subjects for gender and age (13 male, 12 female; mean age 43.8 ± 14.5 years; range 23–60 years). These subjects had no low back pain, and constituted the control group. ResultsT2 values for IVD tended to be lower in the CLBP group than in the control group, and these values were significantly different within the posterior AF. The correlation coefficients between the VAS scores and T2 values of anterior AF, NP and posterior AF were r = 0.30,−0.15 and −0.50. The correlation coefficient between the JOABPEQ scores (low back pain) and T2 values of anterior AF, NP and posterior AF were r = −0.0041, 0.11 and 0.42.Similarly, the JOABPEQ scores (lumbar function) were r = −0.22, −0.12 and 0.57. ConclusionsThe results indicated a correlation between posterior AF degeneration and CLBP. This study suggeststhat MRI T2 mapping could be used as a quantitative method for diagnosing discogenic pain.

Age- and degeneration-related variations in cell density and glycosaminoglycan content in the human cervical intervertebral disc and its endplates.

The first aim of this study was to quantify cell density in cervical intervertebral discs (IVDs) and endplates of varying age and degeneration grade. The second aim was to analyze glycosaminoglycan (GAG) content in cervical IVDs and their endplates. Sixty cervical IVDs were excised from 30 human cadavers, not later than 24 hours post-mortem. Each sample underwent sectioning. Half of each sample underwent GAG content analysis using the dimethylmethylene blue binding assay. The other half underwent histological processing, histological degeneration grading, and cell density assessment using the Abercrombie method. The nucleus pulposus (NP) (4218 ± 417 cells/mm³) had significantly higher cell density than the anterior annulus fibrosus (AF) (3283 ± 438 cells/mm³; p < 0.0001), and similar cell density (4464 ± 551 cells/mm³; p = 0.36) to the posterior AF. Cell density was similar throughout the different regions of the endplate. The NP (619 ± 178 µg/mg dry weight) had a significantly higher GAG content than both the anterior (428 ± 199 µg/mg dry weight; p < 0.0001) and posterior AF (524 ± 218 µg/mg dry weight; p < 0.0001). In conclusion, this study introduces detailed 3D maps of cervical IVD and endplate cell density and GAG content. Furthermore, it shows that cervical IVDs and their endplates only slightly differ, in terms of cell density and GAG content, from lumbar IVDs.

Accelerated T1rho relaxation quantification in intervertebral disc using limited spin-lock times.

T1rho relaxation measurement has the potential to identify early biochemical changes in the intervertebral disc. Traditionally, multiple spin-lock times (SLT), often ~5 SLTs, are used to ensure the accuracy and robustness of T1rho mapping. It will be advantageous to use fewer SLT points if comparable accuracy of T1rho mapping can be achieved. In this study, the feasibility of using 3 SLT points to measure intervertebral disc T1rho relaxation time is explored. The lumbar spine of 12 subjects (age range: 30-75 years, disc =60) were studied on 3-T MRI. For T1rho measurement, a rotary echo spin-lock pulse was implemented in a 3D balanced fast field echo (b-FFE) sequence. Spin-lock frequency was set as 500 Hz and the SLTs of 1, 10, 20, 40, and 60 ms were acquired. T1rho maps were generated by fitting each pixel's intensity as a function of SLT using a non-negative least-square fitting algorithm. Images were analysed in the mid-sagittal section. T1rho maps were re-constructed using all 5 SLT points of 1, 10, 20, 40, and 60 ms, and three SLT points of 1, 20, and 60 ms respectively. ROIs included nucleus pulposus (NP), anterior annulus fibrosus (AF) and posterior annulus fibrosus. Values of anterior AF and posterior AF were averaged as the value for AF. Agreement of T1rho measurements using different SLT points was assessed using intra-class correlation coefficient (ICC) on absolute agreement as well as Bland and Altman plot. There was no significant difference for T1rho values by 5-SLT measurement and 3-SLT measurement in both NP (P=0.63) and AF (P=0.31). The ICC for 5-SLT T1rho measurement vs. 3-SLT T1rho measurement was 0.991 and 0.981 respectively for NP and AF T1rho time. The Bland and Altman plots for the comparison showed a mean difference of 3.14 and 1.83 for NP and AF respectively. Polling the T1rho values for NP and AF in 60 discs together, the ICC for 5-SLT T1rho measurement vs. 3-SLT T1rho measurement was 0.993, and the Bland and Altman analysis showed a mean difference of 2.56. This study suggests that adopting 3 SLTs of 1, 20, and 60 ms can be an acceptable alternative for the disc T1rho measurement.

Clinical investigation of high-intensity zone in anterior annulus fibrosus of lumbar disc: compared with high-intensity zone in posterior annulus fibrosus

To explore the prevalence, distribution and clinical significance of high-intensity zone (HIZ) in anterior annulus fibrosus (AF) in comparison with HIZ in posterior AF of lumbar disc. According to the diagnosis and location of HIZ, 610 lumbar magnetic resonance images with entire clinical materials were divided into control group (without HIZ), anterior AF group (HIZ), posterior AF group (HIZ) and anterior & posterior (AP) AF group (HIZ). The incidence of HIZ was summarized. The clinical data, such as male/female ratio, age, and body weight, prevalence of low back pain (LBP) and distribution of HIZ, were compared and analyzed between the groups. Three hundred and fifteen cases shown no HIZ (51.6%), 95 cases presented HIZ in anterior AF (15.6%, 119 discs), 159 cases presented HIZ in posterior AF (26.1%, 189 discs) and 41 cases presented HIZs in both anterior and posterior AF (6.7%, 96 discs). There was significant difference between the prevalence of HIZ in anterior AF and that in posterior AF (P < 0.01). The male/female ratio and body weight of each groups showed no difference (P > 0.05), and the age was proved to be statistically different between four groups (P < 0.01, control group < posterior AF group < AP AF group < anterior AF group). HIZs in anterior AF often occurred at L(1,2)-L(4,5), whereas, they usually developed at L(3,4)-L(5)S(1) in posterior AF. The incidence of LBP in control group, anterior AF group, posterior AF group, AP AF group were 40.0%, 52.6%, 55.4% and 65.8%, respectively. The LBP prevalence of control group was lower than that of other three groups (P < 0.05), and the prevalence of last three groups showed no difference (P > 0.05). Compared with HIZ in posterior AF, the HIZ in anterior AF of lumbar disc has a lower prevalence, often develops in elder patients and in upper motion segments. It also indicates an obvious relation to LBP as the former.