The pathogenesis and clinical significance of a high-intensity zone (HIZ) of lumbar intervertebral disc on MR imaging in the patient with discogenic low back pain

Recently, the presence of a high-intensity zone (HIZ) within the posterior annulus seen on T2-weighted MRI has aroused great interest and even controversy among many investigators, particularly on whether the HIZ was closely associated with a concordant pain response on awake discography. The study attempted to interpret the correlation between the presence of the HIZ on MRI and awake discography, as well as its characteristic pathology. Fifty two patients with low back pain without disc herniation underwent MRI and discography successively. Each disc with HIZ was correlated for an association between the presence of a HIZ and the grading of annular disruption and a concordant pain response. Eleven specimens of lumbar intervertebral discs which contain HIZ in the posterior annulus from 11 patients with discogenic low back pain were harvested for histologic examination to interpret the histologic basis of a nociceptive response during posterior lumbar interbody fusion (PLIF). The study found that in all of 142 discograms in 52 patients, 17 presented HIZ. All 17 discs with HIZ showed painful reproduction and abnormal morphology with annular tears extending either well into or through the outer third of the annulus fibrosus. The consecutive sagittal slices through the HIZ lesion showed that a notable histologic feature of the formation of vascularized granulation tissue in the outer region of the annulus fibrosus. The current study suggests that the HIZ of the lumbar disc on MRI in the patient with low back pain could be considered as a reliable marker of painful outer anular disruption.     

In vitro measurement of pressure in intervertebral discs and annulus fibrosus with and without annular tears during discography

BACKGROUND CONTEXT: Discogram studies have shown that pain reproduction correlates with the extent of annular disruption. However, it has not been assessed if pressure changes in the annulus fibrosus vary incrementally with intradiscal pressure. PURPOSE: To determine the relationship between intradiscal pressure and outer annular pressure during discography in intervertebral discs with and without annular tears. STUDY DESIGN: Intradiscal and periannular pressures were measured simultaneously in vitro during intradiscal injection in porcine cadaver spines. METHODS: Twenty fresh porcine cadaver lumbar spines with intervening discs were tested. Intradiscal and periannular pressures were measured simultaneously using two pressure sensors during intradiscal contrast injection. The tip of a 25-gauge needle connected with a pressure manometer was placed in the center of the nucleus pulposus. A second pressure transducer was located at the outer third of the annulus fibrosus. Needle and transducer locations were confirmed by fluoroscopy. To compare the intact and torn annulus fibrosus, annular disruptions were created with a 20-gauge needle and confirmed by fluoroscopy. RESULTS: During intradiscal injections of discs with an intact annulus, annulus fibrosus pressure remained low and a sharp increase in intradiscal pressure was observed. Significantly higher pressures were noted in the outer annulus in discs with annular tears (p<.01). Mean pressures at the central nucleus pulposus, the outer third of intact annuli and torn annuli were 93.4+/-40.9 psi, 14.8+/-1.9 psi and 85.7+/-24.8 psi, respectively. CONCLUSIONS: Volumetric injection of intervertebral discs with a torn annulus fibrosis during discography may increase intra-annular pressure similar to the increase in pressure that may occur during spinal loading activities. This effect may not occur in discs with an intact annulus fibrosus.     

腰椎间盘MRI高信号区的组织病理学特点和临床意义

目的研究椎间盘源性下腰痛患者腰椎间盘纤维环后方MRI高信号区的组织病理学特征及其临床意义。方法对52例经保守治疗无效、CT片显示无腰椎间盘突出的下腰痛患者行腰椎MR检查及腰椎间盘造影术。男39例,女13例;平均年龄38.8岁。选择纤维环后方出现高信号区的部分病例行腰椎后路椎间盘切除、椎体间融合、椎弓根螺钉内固定术,术中收集包括高信号区部位的椎间盘。对标本行矢状面连续组织学切片,光镜下观察高信号区椎间盘组织的组织病理学结构,并分析其临床意义。结果在行腰椎间盘造影的52例142个椎间盘中,17例17个椎间盘显示高信号区,且在椎间盘造影过程中全部呈现2或3级的纤维环破裂和疼痛复制反应。敏感性和特异性均为100%。高信号区与纤维环破裂程度分级呈正相关,说明纤维环破裂程度分级越高,越易出现高信号区(R=0.462,P<0.01)。共收集11例患者11个椎间盘,组织学研究发现对应高信号区的椎间盘组织表现为沿纤维环裂隙形成的不同程度的血管化肉芽组织,有成熟的瘢痕化胶原组织。结论症状性下腰痛患者的腰椎MRI上有椎间盘高信号区,可以作为椎间盘源性下腰痛诊断的重要征象。     

腰椎间盘MRI高信号区在诊断椎间盘源性下腰痛中的意义

目的:探讨腰椎间盘MRI高信号区(HIZ)在诊断椎间盘源性下腰痛中的作用。方法:对52例经保守治疗无效、CT影像上无腰椎间盘突出的下腰痛患者行腰椎MRI检查和腰椎间盘造影术,分析腰椎间盘MRI高信号区与腰椎间盘造影诱发的下腰痛之间的关系。结果:在行腰椎间盘造影的142个椎间盘中,共有38个椎间盘呈现疼痛复制反应,其中17个椎间盘显示高信号区。这17个有高信号区的椎间盘在椎间盘造影过程中全部呈现2～3级的纤维环破裂和疼痛复制反应。结论:无椎间盘突出的下腰痛患者在腰椎MRI上存在椎间盘内高信号区,可表明该椎间盘是产生腰痛的破裂椎间盘。     

Pathophysiology,diagnosis, and treatment of discogenic low back pain

Discogenic low back pain is a serious medical and social problem, and accounts for 26%-42% of the patients with chronic low back pain. Recent studies found that the pathologic features of discs obtained from the patients with discogenic low back pain were the formation of the zones of vascularized granulation tissue, with extensive innervation in fissures extending from the outer part of the annulus into the nucleus pulposus. Studies suggested that the degeneration of the painful disc might originate from the injury and subsequent repair of annulus fibrosus. Growth factors such as basic fibroblast growth factor, transforming growth factor β1, and connective tissue growth factor, macrophages and mast cells might play a key role in the repair of the injured annulus fibrosus and subsequent disc degeneration. Although there exist controversies about the role of discography as a diagnostic test, provocation discography still is the only available means by which to identify a painful disc. A recent study has classified discogenic low back pain into two types that were annular disruption-induced low back pain and internal endplate disruption-induced low back pain, which have been fully supported by clinical and theoretical bases. Current treatment options for discogenic back pain range from medicinal anti-inflammation strategy to invasive procedures including spine fusion and recently spinal arthroplasty. However, these treatments are limited to relieving symptoms, with no attempt to restore the disc’s structure. Recently, there has been a growing interest in developing strategies that aim to repair or regenerate the degenerated disc biologically.     

Side of symptomatic annular tear and site of low back pain: is there a correlation?

STUDY DESIGN: A retrospective chart review. OBJECTIVES: To report the correlation between the side of a concordantly painful, post-discography computer tomography (CT) visualized, annular tear, and the side of a patients' low back pain. SUMMARY OF BACKGROUND DATA: An annular fissure extending from the nucleus to the outer one-third of the annulus is thought to be the nociceptive source stimulated during provocative lumbar discography. To our knowledge, there are no studies that have attempted to delineate whether the side of the annular tear correlates with the side of the patient pain. METHODS: One hundred and one post-discography CT scans, performed on patients with single level, concordantly painful, and fissured discs identified during lumbar discography, were randomly obtained from the archived and current files of the Penn Spine Center's film library. These were reviewed by both the lead author and a spine radiologist, both of who were blinded to the side of the patients pain, to determine which scans demonstrated clearly definable tears extending to the outer one-third of the annulus. Statistical analysis via the exact method was used to determine the correlation between the side of the patients tear and the side of the patients pain. RESULTS: Forty post-discography CT scans met the inclusion criteria. There was a random correlation between the side of the patients concordantly painful annular tear and the side of the patients pain. CONCLUSIONS: The results of this study raise several questions regarding the embryologic development of the intervertebral disc and its somite, neurologic transmission of discogenic pain, distribution of chemical inflammagens, validity of discography, technique of ESI, and technique and validity of IDET.     

MRI and discography of annular tears and intervertebral disc degeneration. A prospective clinical comparison.

We attempted to correlate the findings of MRI and discography in patients with low back pain, examining 108 lumbar intervertebral discs in 33 consecutive patients. MRI results were assessed from the intensity and shape of the signal obtained from the central part of the disc. Discography was classified according to the pattern of contrast material, the pressure accepted and the pain reproduced. All discs which were abnormal on MRI had altered patterns on discography, but 18 of the 60 discs with normal MRI had abnormal discograms. Of 39 asymptomatic discs, 33 had normal MRI signals and 24 had normal discograms. None of the 15 discs showing severe degeneration on MRI sustained high levels of intradiscal pressure, but only six of the 60 discs giving normal MRI had low pressure. With current techniques, discography is more accurate than MRI for the detection of annular pathology: a normal MRI does not exclude significant changes in the peripheral structure of the intervertebral disc which can produce low back pain.     

Provocative discography in volunteer subjects with mild persistent low back pain.

BACKGROUND CONTEXT: Whether discographic injections would be positive in subjects with benign persistent "backache" who are not seeking treatment is unknown. This information is important, because benign backache undoubtedly co-exists in patients with chronic low back pain (CLBP) illness that is not discogenicin origin. If these subjects had a high rate of positive discography, the high background incidence of common backache would allow many positive tests in patients in whom discogenic processes were unrelated to their severe CLBP illness. Conversely, if subjects with benign low back pain rarely if ever had significant concordant pain reproduction on disc injections, the basic tenet of discographic diagnosis would be strengthened. PURPOSE: To compare, using a strict experimental design, the relative pain and concordancy response to provocative discography in subjects with clinically insignificant "backache" and clinical subjects with CLBP illness considering surgical treatment. STUDY DESIGN: Comparison of experimental disc injections in subjects with persistent mild backache and those with chronic low back pain (CLBP) illness. PATIENT SAMPLE: Twenty-five subjects with mild persistent low back pain (LBP) were recruited for an experimental discography study. Subjects were recruited from a clinical study of patients having had cervical spine surgery. Inclusion criteria required that subjects not be receiving or seeking medical treatment for LBP, be taking no medications for backache, have no activity restrictions because of LBP, and have normal psychometric scores. To more closely approximate the pain behavior in CLBP illness, 50% (12) of the "backache" group were recruited with a chronic painful condition (neck/shoulder) unrelated to the low back. CLBP subjects, patients coming to discography for consideration of surgical treatment, were used as control subjects. OUTCOME MEASURES: Results of discography were determined using the criteria of Walsh et al.: pain response of 3 or greater, two or more pain behaviors, a negative "control" discographic injection, and a similar or exact concordancy rating. METHODS: Discography was performed on experimental subjects and control patients. Experienced raters, who were blinded to control versus experimental status of the subjects, scored the magnetic resonance image, discogram, psychometric tests and discography videotapes of the subjects' pain behavior. RESULTS: Thirteen of 25 volunteer subjects had pain rated as "bad" or worse with disc injection. There were 12 painful and fully concordant disc injections in 9 of these 25 "backache" subjects (36%). These injections met all the Walsh et al. criteria for a positive diagnosis of discogenic pain. All positive discs had annular disruption to or through the outer annulus. Of the 9 subjects with positive discograms, 3 had no chronic pain states and 6 did. All subjects with positive injections had negative control discs. In comparison, in 52 subjects with CLBP illness 38 (73%) had at least one positive disc injection. CONCLUSIONS: In a group of volunteer subjects with persistent "backache," 36% were found to have significant pain on disc injection, which is reported to be concordant with their usual pain. The presence of positive concordant pain responses and negative control discs in 33% of subjects without CLBP illness seriously challenges the specificity of provocative discography in identifying a clinically relevant spinal pathology.     

Cytokine evaluation in individuals with low back pain using discographic lavage

Background contextThe pathophysiology underlying degenerative disc disease and its implication in painful syndromes remain unclear. However, spine magnetic resonance imaging (MRI) can demonstrate changes in disc water content and the annulus; provocative discography purportedly identifies degenerate discs causing serious low back pain; and biochemical assays have identified local inflammatory markers. No study to date has correlated pain on disc injection during discography evaluation with relevant MRI findings and biochemical markers.PurposeThe purpose of this study was to correlate concordant pain on during discography to biochemical markers obtained by disc lavage and MRI findings.Study designThis is a Phase 1 Diagnostic Test Assessment Cohort Study (Sackett and Haynes).Patient sampleThe patient sample included 21 symptomatic patients with suspected discogenic pain and three Phase 1 control subjects.Outcome measuresThe outcome measures included discography pain scores, MRI degenerative grades, and immunoreactivity to various inflammatory cytokine concentrations present in disc lavage samples.MethodsTwenty-one symptomatic patients with lumbar degenerative disc disease and three control subjects underwent discography, MRI, and biochemical analysis of disc lavage fluid. Lumbar MRI was scored for Pfirrmann grading of the lumbar discs, and annular disruption was identified by nuclear disc lavage. Disc lavage samples were analyzed for biochemical markers by high-sensitivity immunoassay.ResultsEighty-three discs from 24 patients were studied: 67 discs from 21 patients with axial back pain (suspected discogenic pain group) and 16 discs from 3 scoliosis patients without back pain (Phase 1 control subjects). Among the biochemical markers surveyed, interferon gamma (IFN-γ) immunoreactivity was most consistently identified in patients with axial back pain. Discs with annular disruption and concordant pain reproduction at a visual analog scale of 7 to 10/10 had greater IFN-γ immunoreactivity than those without this finding (p=.003); however, at least some IFN-γ immunoreactivity was found in all but one disc in the symptomatic group.ConclusionsAmong the potential inflammatory markers tested in this Phase 1 study, IFN-γ immunoreactivity was most commonly elevated in discogram “positive” discs but absent in asymptomatic controls. However, this marker was also frequently elevated in degenerative but “negative” discography discs. From these findings, Phase 2 and Phase 3 validity studies are reasonable to pursue. Phase 4 utility studies may be performed concurrently to assess this method's predictive value in outcome studies.     

Experimental disc degeneration due to endplate injury

The aim of this study was to create an experimental model of disc degeneration that closely mimicked human disc degeneration. In six domestic pigs, an L4 cranial endplate perforation into the nucleus pulposus was made. Three months postoperatively, compressive testing was performed on the L2-L4 motion segments, and intradiscal pressure was measured in the intervening discs. Histochemical and morphologic examinations were made on the excised degenerated and adjacent discs. A significant reduction in water content was observed in the outer anterior annulus of the degenerated disc. In the nucleus, the proteoglycan content was significantly reduced, as well as the cellularity, although not significantly. The nucleus lost its gel-like structure and was discolored, and there was delamination of annular layers. Intradiscal pressure in the nucleus was significantly lower in the degenerated disc. In conclusion, experimental degeneration of the intervertebral disc induced by endplate penetration resembled human disc degeneration, as exemplified by biochemical and structural changes.     

An analysis of radiating pain at lumbar discography

This study aimed to identify the morphological abnormalities of the intervertebral disc, as demonstrated by lumbar discography, that are associated with pain radiation to the hip, groin, buttock or lower limb. We carried out a retrospective review of 99 consecutive lumbar discogram reports. The association of disc degeneration, annular tears (partial or full thickness) and the level of disc injected was determined with respect to the presence and pattern of radiating pain. A total of 260 discs were injected, of which 179 were considered abnormal. Posterior annular tears were demonstrated in 84 discs, anterior annular tears in 15 discs and 45 discs had both anterior and posterior tears. A significant association was identified between isolated posterior tears and the production of concordant radiating pain (P = 0.0041). No difference was identified between partial thickness posterior tears and full thickness posterior tears associated with leak of contrast medium, with regard to radiating pain. Similarly, there was no significant association between disc level injected and the pattern of pain radiation. The results indicate that pain experienced in the buttock, hip, groin or lower limb can arise from the posterior annulus of the intervertebral disc without direct involvement of the nerve root. Received: 29 November 1997 Revised: 20 March 1998 Accepted: 6 April 1998     

椎间盘源性腰痛的分型

目的 介绍一种新的椎间盘源性腰痛的分型方法 ,以更好地指导临床诊断和治疗.方法通过回顾性分析386例慢性腰痛患者的椎间盘造影术中X线荧光影像和术后CT扫描片,结合术中患者有无一致性疼痛复制反应,将椎间盘源性腰痛进行分型.结果386例腰痛患者共行1056个椎间盘的腰椎间盘造影术,共有192例患者(49.7%)的226个椎间盘(21.4%)出现疼痛复制反应.192例出现疼痛复制反应的患者中,由于纤维环破裂(internal disc disruption,IDD)160例,由于终板破裂(internal end-plate disruption,IED)32例,分别占83.3%和16.7%.应用修正的Dallas CT椎间盘造影分级方法评估IDD患者纤维环放射状撕裂程度,应用术中荧光X线影像结合术后CT扫描评估IED患者终板放射状破裂程度.IDD患者纤维环破裂分级越高,椎间盘造影时一致性疼痛比例越大(r=-0.604,P=0.000).IED患者终板破裂程度越大,椎间盘造影时一致性疼痛比例越大(r=0.683,P=0.000).结论 根据临床研究结果,我们将椎间盘源性腰痛分为两种类型,由IDD引起的腰痛和由IED引起的腰痛.临床上这两种类型的椎间盘源性腰痛都要通过腰椎间盘造影术确诊,诊断过程、放射状撕裂方式和疼痛反应方式完全一致,表明其为一种科学、合理的分型方法.     

腰椎间盘造影一致性疼痛反应和纤维环破裂程度的相关性研究

目的: 研究椎间盘源性下腰痛病人纤维环破裂程度和腰椎间盘造影一致性疼痛之间的关系。方法: 105例慢性下腰痛且无椎间盘突出的病人, 行腰椎间盘造影术。询问造影时病人疼痛反应, 分析造影后的X线片和造影后的CT片, 比较纤维环破裂程度与腰椎间盘造影一致性疼痛之间的相关性。结果: 105例病人中的 285个造影的腰椎间盘中, 67个腰椎间盘诱发一致性疼痛反应, 且全部呈现 2级以上的纤维环破裂。纤维环破裂分级越高, 椎间盘造影时一致性疼痛比例越大, 两者之间有显著的正相关性。结论: 椎间盘造影诱发的一致性疼痛反应比例和纤维环外层破裂程度呈正相关, 研究结果表明纤维环外层撕裂是疼痛复制的起源部位。     

The stress lumbar discogram

Stress discography is that done during the time in which the subject's pain is present at a significant level of intensity. This prospective study examines the findings in 200 patients who were evaluated for low-back pain. A standardized injection technique was used and the contrast pattern within the disc was studied radiographically and with CT scanning. Pain response was recorded. Familiar low-back pain was reproduced in all cases, and familiar leg pain in 46% of cases. Of 549 discs studied, 319 reproduced familiar pain, an average of 1.6 discs per patient. Pain reproduction occurred in 69% of the L5 discs, 62% of the L4 discs, and 25% of the L3 discs. Internal disc disruption was present in 302 discs, but extruded annular material was found in only 19. Stress discography is a useful diagnostic study in evaluating patients with low-back pain.     

Lumbar discography followed by computed tomography. Refining the diagnosis of low-back pain

Two hundred fifty patients with low-back pain who underwent lumbar discography followed by computed tomography (CT) are the subject of this prospective study. In 93% of the patients, these combined imaging techniques provided additional useful diagnostic information that affected patient management and the selection of treatment alternatives. Lumbar discography followed by CT proved valuable in determining the significance of equivocal or multiple level abnormalities, determining the type of disc herniation, defining surgical options, and evaluating the previously operated spine. In 94% of patients who had surgery, CT-discography correctly predicted the type of disc herniation as protruded, extruded, sequestrated, or internally disrupted. Computed tomography-discography may be more sensitive that magnetic resonance imaging (MRI) in the early stages of disc degeneration because 18 of 177 discs with a normal T2-weighted image were discographically abnormal and the CT-discogram revealed annular tears or radial fissuring. The radiographic morphology of the normal herniated and degenerative lumbar discs shown by CT-discography gives unique insight into the pathogenesis of disc degeneration. The complications that followed the 750 discograms were one case of urticaria and one disc space infection. Even with the availability of high resolution CT and MRI, lumbar discography remains the only pain provocation challenge to the lumbar disc.     

椎间盘源性下腰痛的发病机制

目的探讨椎间盘源性下腰痛的发病机制。方法收集腰椎后路切除的17例椎间盘源性下腰痛患者的19个经腰椎间盘造影术证实的疼痛腰椎间盘;同时收集12个在MRI T2加权像上信号强度明显减弱、无腰痛症状的生理老化椎间盘和10个正常对照椎间盘,行组织学检查和P物质、神经丝蛋白和血管活性肠肽的免疫组织化学染色检查。结果椎间盘源性下腰痛患者的疼痛椎间盘在组织学上的显著特征表现为,一条从髓核至纤维环外层的血管化肉芽组织条带区,其间伴有1个或多个裂隙;肉芽组织条带区与椎间盘造影术后CT上显示的纤维环裂隙一致,肉芽组织之外的纤维环结构基本正常。生理老化椎间盘和正常对照椎间盘表现为与年龄相关的改变。免疫组织化学染色显示,疼痛椎间盘中P物质、神经丝蛋白和血管活性肠肽3种神经肽阳性神经纤维分布数量和比例,较正常对照椎间盘和生理老化椎间盘明显增多;神经纤维主要沿伴有裂隙的肉芽组织条带区分布;疼痛椎间盘髓核中可见P物质和神经丝蛋白的阳性神经纤维分布。结论椎间盘后方神经分布广泛的肉芽组织条带区是椎间盘造影术疼痛和椎间盘源性下腰痛的起源部位。肉芽组织条带可能起源于椎间盘的创伤修复过程。生理老化椎间盘和疼痛椎间盘的差异是后者形成组织学上的肉芽组织条带区。     

CT引导下腰椎间盘造影的临床应用

目的探讨CT引导下椎间盘造影的临床应用价值。方法回顾性分析55例慢性腰痛或腰腿痛患者的CT引导下椎间盘造影表现及临床资料,依据对比剂在椎间盘内、外的弥散范围,对椎间盘破裂、椎间盘退行性变及椎间盘退行性变合并椎间盘破裂进行分级。结果 55例中,2例穿刺失败,53例造影成功。造影椎间盘132个;根据达拉斯CT椎间盘造影评价法,51个椎间盘形态正常,81个椎间盘形态异常。阳性椎间盘73个,其中椎间盘纤维环撕裂30个,包括Ⅰ级3个、Ⅱ级15个、Ⅲ级12个,椎间盘纤维环退行性变24个,包括Ⅰ级2个、Ⅱ级12个、Ⅲ级10个,椎间盘退行性变并合椎间盘破裂19个。CT引导下椎间盘造影同时可激发再现原有腰痛或腰腿痛,证实腰痛或腰腿痛的病因。结论依据CT引导下椎间盘造影表现可准确对椎间盘退行性变和破裂程度及椎间盘退行性变合并破裂进行分级,有助于临床诊断和治疗。     

化学性神经根炎

目的研究分析疼痛椎间盘的纤维环破裂与患者下肢放射痛的关系,进而探讨是否存在化学性神经根炎这一临床病理现象.方法临床收集42例单节段椎间盘源性下腰痛伴单侧或双侧下肢放射痛患者,男27例,女15例;年龄19～52岁,平均34.9岁;症状持续至少6个月,平均3年4个月.通过椎间盘造影和其后的CT扫描,分析纤维环撕裂方向与下肢放射痛侧别的关系;行肌电图和运动神经传导速度检查,分析有无神经根损伤,以及其与下肢放射痛的关系.结果腰椎间盘造影时,所有患者显示单水平纤维环破裂且呈现一致性疼痛复制反应,纤维环撕裂方向与下肢放射痛的侧别有显著的正相关性.42例肌电图检查提示神经根损害者32例（76%）.23例单侧下肢放射痛者中17例（74%）存在神经根损害,均为同侧;19例双侧下肢放射痛者中有15例（79%）存在神经根损害.症状侧腓总神经和胫神经运动传导速度较正常侧减慢,差异有统计学意义.结论疼痛椎间盘产生的炎性化学物质通过纤维环全层撕裂漏出并作用于相邻神经根引起神经根损害,可能是化学性神经根炎产生的基本病理生理学机制.     

Magnetic resonance imaging in the diagnosis of disc degeneration: correlation with discography

One hundred and one disc levels in 36 patients with low-back pain were studied with magnetic resonance imaging (MRI) (T2-weighted) sagittal images and conventional roentgenographic discography to detect early disc degeneration. Thirty-nine discs also were evaluated after discography with roentgenographic CT MRI findings were compared with discography results. MRI was 99% accurate in predicting normality or abnormality as determined by discography. Changes in disc signal on MRI accurately reflected the presence or absence of degenerative changes seen on discography in patients with low-back pain. Clinically, MRI is a useful technique for detecting early disc degeneration and for assessing the affected disc level and adjacent levels in patients with low-back pain and spondylolithesis.