The Relation Between Annular Disruption on Computed Tomography Scan and Pressure-Controlled Diskography

Associations between Vertebral Localized Contrast Changes and Adjacent Annular Fissures in Patients with Low Back Pain: A Radiomics Approach

Low back pain (LBP) is multifactorial and associated with various spinal tissue changes, including intervertebral disc fissures, vertebral pathology, and damaged endplates. However, current radiological markers lack specificity and individualized diagnostic capability, and the interactions between the various markers are not fully clear. Radiomics, a data-driven analysis of radiological images, offers a promising approach to improve evaluation and deepen the understanding of spinal changes related to LBP. This study investigated possible associations between vertebral changes and annular fissures using radiomics. A dataset of 61 LBP patients who underwent conventional magnetic resonance imaging followed by discography was analyzed. Radiomics features were extracted from segmented vertebrae and carefully reduced to identify the most relevant features associated with annular fissures. The results revealed three important texture features that display concentrated high-intensity gray levels, extensive regions with elevated gray levels, and localized areas with reduced gray levels within the vertebrae. These features highlight patterns within vertebrae that conventional classification systems cannot reflect on distinguishing between vertebrae adjacent to an intervertebral disc with or without an annular fissure. As such, the present study reveals associations that contribute to the understanding of pathophysiology and may provide improved diagnostics of LBP.

MRI ‐based measurement of in vivo disc mechanics in a young population due to flexion, extension, and diurnal loading

Background

Intervertebral disc degeneration is often implicated in low back pain; however, discs with structural degeneration often do not cause pain. It may be that disc mechanics can provide better diagnosis and identification of the pain source. In cadaveric testing, the degenerated disc has altered mechanics, but in vivo, disc mechanics remain unknown. To measure in vivo disc mechanics, noninvasive methods must be developed to apply and measure physiological deformations.

Aim

Thus, this study aimed to develop methods to measure disc mechanical function via noninvasive MRI during flexion and extension and after diurnal loading in a young population. This data will serve as baseline disc mechanics to later compare across ages and in patients.

Materials & Methods

To accomplish this, subjects were imaged in the morning in a reference supine position, in flexion, in extension, and at the end of the day in a supine position. Disc deformations and vertebral motions were used to quantify disc axial strain, changes in wedge angle, and anterior-posterior (A-P) shear displacement. T₂ weighted MRI was also used to evaluate disc degeneration via Pfirrmann grading and T₂ time. All measures were then tested for effect of sex and disc level.

Results

We found that flexion and extension caused level-dependent strains in the anterior and posterior of the disc, changes in wedge angle, and A-P shear displacements. Flexion had higher magnitude changes overall. Diurnal loading did not cause level-dependent strains but did cause small level-dependent changes in wedge angle and A-P shear displacements.

Discussion

Correlations between disc degeneration and mechanics were largest in flexion, likely due to the smaller contribution of the facet joints in this condition.

Conclusion

In summary, this study established methods to measure in vivo disc mechanical function via noninvasive MRI and established a baseline in a young population that may be compared to older subjects and clinical disorders in the future.

Detection of Imperceptible Intervertebral Disc Fissures in Conventional MRI-An AI Strategy for Improved Diagnostics

Annular fissures in the intervertebral discs are believed to be closely related to back pain. However, no sensitive non-invasive method exists to detect annular fissures. This study aimed to propose and test a method capable of detecting the presence and position of annular fissures in conventional magnetic resonance (MR) images non-invasively. The method utilizes textural features calculated from conventional MR images combined with attention mapping and artificial intelligence (AI)-based classification models. As ground truth, reference standard computed tomography (CT) discography was used. One hundred twenty-three intervertebral discs in 43 patients were examined with MR imaging followed by discography and CT. The fissure classification model determined the presence of fissures with 100% sensitivity and 97% specificity. Moreover, the true position of the fissures was correctly determined in 90 (87%) of the analyzed discs. Additionally, the proposed method was significantly more accurate at identifying fissures than the conventional radiological high-intensity zone marker. In conclusion, the findings suggest that the proposed method is a promising diagnostic tool to detect annular fissures of importance for back pain and might aid in clinical practice and allow for new non-invasive research related to the presence and position of individual fissures.

Therapeutic effect of intradiscal pulsed radiofrequency on internal disc disruption: A case report

RATIONALE

Discogenic low back pain often persists despite medication and medical intervention. In this study, intradiscal pulsed radiofrequency (PRF) was performed in a patient with discogenic low back pain who did not respond to oral medication, posterior medial branch block, epidural steroid injection, and percutaneous epidural adhesiolysis.

PATIENT CONCERNS

A 28-year-old woman visited a pain clinic complaining of low back pain that was scored 8 out of 10 on a numerical rating scale. Her pain was present in any position throughout the day and worsened in the sitting position.

DIAGNOSES

Magnetic resonance imaging showed L5-S1 internal discal disruption. Based on the medical history, physical examination, and magnetic resonance imaging, we determined that her pain originated from the L5-S1 disc.

INTERVENTIONS

We performed an intradiscal PRF on the affected disc under C-arm fluoroscopy guidance. PRF was performed at 5 Hz, 20-ms pulse width, and 70 V for 15 minutes while ensuring that the electrode tip temperature was maintained below 42°C.

OUTCOMES

Immediately after the procedure, the patient's pain subsided. At the 1-month follow-up visit, the patient reported complete relief of her low back pain. The Oswestry disability index, which indicates the degree of disability, improved significantly. She also reported that she could sit for long periods because the pain was reduced. No adverse effects from the procedure were found.

LESSONS

Applying intradiscal PRF seems an effective and safe technique for treating discogenic low back pain.

Comparison between pain at discography and morphological disc changes at axial loaded MRI in patients with low back pain

PURPOSE

Discogenic pain is induced by axial load, but there are no studies evaluating the influence of dynamic MRI in relation to provoked pain at discography. The aim of this study was to investigate the relationship between discography-induced pain and morphological disc changes, occurring during axial loaded MRI (alMRI). A secondary aim was to compare and register the frequency of provoked concordant pain at alMRI and discography.

METHODS

41 patients with assumed discogenic pain were investigated with MRI, alMRI and pressure-controlled discography (PCD) (119 discs). Provoked pain at both discography and alMRI was classified as concordant or discordant with daily pain as reference. A concordant discogram required pain intensity ≥5/10 (numerical rating scale) at ≤50 psi and one negative control disc. A concordant provocation at alMRI required pain intensity ≥5/10. The relationship between concordant pain at discography and morphological disc measures (degeneration, height, bulge, angle, area, and circumference) at MRI/alMRI was investigated.

RESULTS

Changes in the morphological appearance occurred in at least one disc level in all patients when loaded and unloaded MRI were compared. However, no significant differences between concordant and discordant discograms in terms of morphological disc features at conventional MRI or alMRI were found. 78 % of the patients reported concordant provoked pain during the alMRI.

CONCLUSIONS

In the majority of patients with low back pain, discography as well as alMRI provoked concordant pain. Loading of the spine, alMRI, revealed however no clinically useful morphological characteristics in the discs with concordant discograms. Alternative or more sensitive diagnostic methods are needed to understand load-induced discogenic pain.

Pressure Increase in Adjacent Discs During Clinical Discography Questions the Methods Validity

STUDY DESIGN

Observational in vivo clinical study.

OBJECTIVE

To investigate whether intradiscal pressure is transferred to adjacent discs during clinical discography in subjects with discogenic pain.

SUMMARY OF BACKGROUND DATA

Despite the introduction of pressure registration in discography, the validity of the method remains controversial. Discography in vivo in anesthetized pigs has shown that the pressure increase during disc injection is transmitted to adjacent discs. If pressure transmission is confirmed in human spines, it could be a potential source of false-positive discography responses.

METHODS

Twenty-five discograms were performed in 9 consecutive patients. A pressure sensor was introduced through a 22-gauge needle into the nucleus pulposus in 2 adjacent discs. Contrast was injected with a manometer (∼0.05 mL/s) into one of the discs, whereas intradiscal pressure was measured simultaneously in both discs. The injection continued until one of the endpoints was reached; concordant pain with an intensity of 5/10 or more, intradiscal pressure of 80 psi (absolute pressure), and/or 3.5-mL contrast volume.

RESULTS

Intradiscal pressure was successfully measured in 22 adjacent discs of which 7 were not filled with contrast and 15 were prefilled from the previous discogram. A mean pressure increase of 13 psi (range, 3-42 psi) was recorded in 55% (12) of the adjacent discs, corresponding to an increase of 62% above baseline. Of discograms inducing pressure transmission, all had Pfirrmann degeneration grade of 3 or more and, of adjacent discs with increased pressure, 75% had degeneration of 3 or more. Maximum pressure in injected discs averaged 35 psi above opening pressure (range, 10-69 psi).

CONCLUSION

Clinical discography induces a pressure increase in adjacent discs. The induced pressure increase was of a clinically relevant magnitude and was evident despite low absolute pressures in the injected disc. Pressure transmission during discography constitutes a potential major source of false-positive responses, questioning the ability of discography to provoke pain at just a single disc level.

LEVEL OF EVIDENCE

1.

In vivo discography in degenerate porcine spines revealed pressure transfer to adjacent discs

STUDY DESIGN

In vivo experimental porcine study.

OBJECTIVE

To investigate if discography induced pressure increase in adjacent degenerate discs.

SUMMARY OF BACKGROUND DATA

Despite refinements in the past 2 decades, the validity of discography is debated. Discography in healthy pigs has shown that the pressure increase during disc injection transmits to adjacent discs, a potential source for false positive responses.

METHODS

Degeneration in 1 lumbar disc was induced in 10 pigs by drilling a hole through the endplate. Intradiscal pressure was recorded using a 0.36-mm fiber-optic pressure transducer inserted into nucleus pulposus through a 22-gauge needle. The pressure was measured simultaneously in 2 adjacent discs during slow (0.03 mL/s) automated contrast injection into 1 of the discs up to 8 bar (116 psi). Ten adjacent discs were prefilled with contrast from previous discogram. A pressure increase 2 psi or more above baseline was defined as increased pressure in adjacent discs. Pressure was recorded until 15 minutes after injection.

RESULTS

A total of 28 discograms were successfully performed. A pressure increase during injection was detected in 57% (16) of the 28 adjacent discs with mean 3.2 psi (1.7-8.2; standard deviation, 1.8), corresponding to a mean increase above baseline of 11%. Of those 16 adjacent discs, 4 were nondegenerate and 12 degenerate, of which 7 were prefilled. Fifteen minutes after injection, 89% of adjacent discs displayed increase in pressure of mean 14% above baseline.

CONCLUSION

Discography induced pressure increase in adjacent discs in a degenerate disc model, something not reported earlier. If present, also in human spine pressure transmission, may be a potential cause for false positive discography responses.

HIZ's relation to axial load and low back pain: investigated with axial loaded MRI and pressure controlled discography

PURPOSE

The aims were to investigate if the detection of high-intensity zones (HIZ) is affected by axial load, and to study the correlation between HIZ and discogenic pain provoked with pressure controlled discography (PCD).

METHODS

41 consecutive patients with chronic low back pain, referred for discography, were included. Each patient underwent PCD, CT, MRI, and axial loaded MRI (alMRI) within 24 h. 35 patients completed all MRI sequences (140 discs). The detection of HIZ was compared between conventional MRI and alMRI. PCD was performed in 119 of the discs examined at MRI. Provoked pain at PCD was classified into four categories (none/unfamiliar/similar/exact), with the patients' daily pain as reference, and correlated with presence of HIZ.

RESULTS

AlMRI did not affect the detection of HIZ compared with conventional MRI. No significant correlation between HIZ and the 4-graded pain response at discography was found (p = 0.34), neither when combining similarly/exactly reproduced pain (p = 0.08). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of HIZ in detecting discs with exactly reproduced pain were 49, 69, 39 and 76 %. When combining similarly/exactly reproduced pain, PPV was higher but still only 70 %.

CONCLUSIONS

The detection of HIZ was not influenced by axial load. With strict PCD, discogenic pain can neither be confirmed when having HIZ (PPV 39 %) nor ruled out in discs without HIZ (NPV 76 %). Larger PCD studies including quantification of HIZ at conventional and alMRI are needed, before any dynamic component affected by axial load can be ruled out completely.

The impact of discography on the surgical decision in patients with chronic low back pain

BACKGROUND CONTEXT

A reduced frequency of discographies might be the result of increasing concern with long-term effects of discography such as disc degeneration. More knowledge is needed in what patient discography is most likely to influence the surgical decision.

PURPOSE

This study was aimed at highlighting how discography affects surgical decisions when performed on one of four different indications in a complicated subgroup of patients with chronic low back pain assumed to be associated with degenerative disc disease (DDD).

STUDY DESIGN

Prospective before-after study to analyze how frequently a prediscography preliminary decision was changed and in what direction by adding information from discography in a subgroup of patients with DDD.

PATIENT SAMPLE

One hundred thirty-eight patients admitted to a spine clinic more than 4 years with the DDD diagnosis (15% of all) were referred for discography because it was considered that medical history, clinical findings, and magnetic resonance imaging (MRI) were insufficient to make a final assessment on whether to propose surgery/recommend against surgery or what segments to operate on.

OUTCOME MEASURES

These were the recorded changes to prediscography preliminary decisions after information was added from discography.

METHODS

Before these patients were referred to provocative discography, the surgeon had to select one of four alternative questions/indications being the reason for the discography and choose what decision would have been made if discography would not have been available. The questions/indications were as follows: surgery decided discography to establish whether to treat adjacent segment as well (n=17); several segments degenerated on MRI, pain likely to be discogenic, discography to evaluate what segments to treat (n=56); uncertainty whether pain is discogenic but one suspected segment on MRI (n=38); uncertainty whether pain is discogenic and several segments degenerated in MRI (n=27); the decision after discography was then compared with the prediscography decision and the changes affected by the result of the discography were analyzed.

RESULTS

Changes were made to the prediscography decision in 71% of the patients in total. When the surgeon was assured that the pain was discogenic, one segment was added or subtracted in 58% of the patients compared with original prediscography decision. When the surgeon was uncertain if pain was discogenic, the final decision changed from surgery to no surgery in 8%, from no surgery to surgery in 42%, and in cases that were planned for surgery prediscography, one segment was added or subtracted in 17% of the patients. The more certain the surgeon was before discography that the patient's pain was indeed discogenic, the fewer changes between surgical treatment and no surgical treatment took place. The more uncertain the surgeon was before discography that the patient's pain was discogenic, the fewer changes in segments to treat took place in patients who went on to surgery. Changes of involved segments were made to all the 27 patients with a preliminary decision for surgical treatment of the L5-S1 segment solely. The corresponding figure for L4-L5 and L4-L5-S1 was 70% and 53%, respectively.

CONCLUSIONS

A high frequency of decisions was altered in this group of surgeons when using discography as an additional examination in patients where uncertainty remains in how to treat after clinical examination, questioning, and MRI.

Structural etiology of chronic low back pain due to motor vehicle collision

OBJECTIVE

To estimate prevalence rates of discogenic, facet, and sacroiliac joint pain, and describe clinical features of chronic low back pain patients whose symptoms were initiated by motor vehicle collisions.

DESIGN

Retrospective chart review.

SETTING

Academic spine center.

PATIENTS

Twenty-seven motor vehicle collision-induced chronic low back pain patients were included after undergoing diagnostic procedures.

INTERVENTIONS

Lumbar provocation discography, dual diagnostic facet joint blocks, and intra-articular sacroiliac joint injections.

METHODS

Enrolled patients underwent diagnostic procedures based on clinical presentation until the pain source was identified. The prevalence of each source of low back pain was estimated. Clinical, categorical, and continuous characteristics within the source groups were calculated with SAS v.9.2 (SAS Institute Inc., Cary, NC).

OUTCOME MEASURES

Etiology and prevalence were analyzed for each diagnosis group.

RESULTS

Of the 27 patients, 15/27 (56%) were diagnosed with discogenic pain, 7/27 (26%) with sacroiliac joint pain, and 5/27 (19%) with facet joint pain. Seventy-eight percent were female. Mean age was 42.5 years (standard deviation = 10.4) with median duration of symptoms of 24 months (interquartile range = 6-48).

CONCLUSIONS

Our study is the first to demonstrate that diagnostic spinal injections can identify particular spinal structures, namely the intervertebral disc, facet joint, and sacroiliac joint, as the specific source of chronic low back pain due to inciting motor vehicle collisions. The most common source of motor vehicle collision-induced chronic low back pain appears to be the disc followed by the sacroiliac and facet joints.

Etiology of chronic low back pain in patients having undergone lumbar fusion

OBJECTIVE

To estimate the prevalence of lumbar internal disc disruption, zygapohyseal joint pain, sacroiliac joint pain, and soft tissue irritation by fusion hardware in post-fusion low back pain patients compared with non-fused patients utilizing diagnostic spinal procedures.

DESIGN

Retrospective chart review.

SETTING

University spine center.

PATIENT SAMPLE

Patients presenting to a community-based, multidisciplinary, academic spine center (65.9% female, mean age 54.4 years, median pain duration 12 months).

INTERVENTIONS

Charts of consecutive low back pain cases completing diagnostic spinal procedures including provocation discography and zygapohyseal joint, sacroiliac joint, and fusion hardware blockade were retrospectively reviewed.

OUTCOME MEASURES

Based on the results of discography and/or diagnostic blockades, subjects were classified with internal disc disruption, zygapohyseal joint pain, sacroiliac joint pain, or fusion hardware related pain.

RESULTS

The diagnoses of 28 fusion cases identified from 170 low back pain patients undergoing diagnostic procedures included 12 with sacroiliac joint pain, seven with internal disc disruption, five with zygapohyseal joint pain, and four due to soft tissue irritation from fusion hardware. No significant differences were noted in zygapohyseal joint mediated pain with and without fusion history. Mean ages of patients were similar with and without fusion history for cases diagnosed as internal disc disruption.

CONCLUSION

In patients' recalcitrant to non-interventional care, the sacroiliac joint is the most likely source of low back pain after lumbar fusion followed by internal disc disruption, zygapohyseal joint pain, and soft tissue irritation due to fusion hardware. Sacroiliac joint pain is more common after fusion, while internal disc disruption is more common in non-fusion patients.

Does the location of low back pain predict its source?

OBJECTIVE

To evaluate the predictive utility of the pattern of low back pain (LBP) in detecting the source of LBP as internal disk disruption (IDD), facet joint pain (FJP), or sacroiliac joint pain (SIJP).

DESIGN

Retrospective chart review.

SETTING

University spine center.

PATIENT SAMPLE

A total of 170 cases from 156 patients presenting with LBP whose low back disorder was definitively diagnosed. The mean age was 54.4 years (SD, 16.2) and median duration of LBP was 12 months (interquartile ranges, 6-32).

METHODS

Charts of consecutive LBP patients who underwent definitive diagnostic spinal procedures including provocation diskography, facet joint blocks, and sacroiliac joint blocks were retrospectively reviewed. Each patient with LBP was queried as to the exact location of their LBP: midline, defined as in-line with the spinous processes, and/or paramidline, defined as lateral to 1 fingerbreadth adjacent to the midline.

OUTCOME MEASURES

In patients with a definitive diagnosis for the source of LBP, the proportion of each diagnosed source of pain was calculated. χ(2) tests were used to identify differences in the percentages of midline and paramidline LBP among the groups of patients testing positive for IDD, FJP, or SIJP. Diagnostic measures of sensitivity, specificity, positive and negative predictive values, diagnostic accuracy, and likelihood ratios of positive and negative tests using the presence/absence of midline and paramidline pain for the diagnosis of IDD, FJP, and SIJP were estimated.

RESULTS

With cases of IDD, significantly greater percentages of patients reported midline LBP (95.8%; χ(2) = 101.4, df = 2, P < .0001) as compared with cases of FJP (15.4%) or SIJP (12.9%). In cases of IDD, significantly lower percentages of patients reported paramidline pain (67.3%; χ(2) = 16.1, df = 2, P = .0003) as compared with cases of FJP (95.0%) or SIJ (96.0%). In cases of IDD, significantly greater percentages of patients reported midline LBP (95.8%; χ(2) = 101.4, df = 2, P < .0001) as compared with cases of FJP (15.4%) or SIJP (12.9%). The specificity of midline LBP for IDD, FJP, and SIJP was 74.8% (95% CI = 65.0%-82.9%), 28.0% (20.1%-37.0%), and 36.0% (28.0%-44.5%), respectively. The negative predictive value of paramidline LBP for IDD, FJP, and SIJP was 29.2% (95% CI = 12.6%-51.1%), 91.7% (73.0%-99.0%), and 95.8% (78.9%-99.9%). The diagnostic accuracy of midline LBP for IDD, FJP, and SIJP was 83.5%, 24.1%, and 31.8%, respectively.

CONCLUSIONS

The presence of midline LBP increases the probability of lumbar IDD and reduces the probability of symptomatic FJ and SIJ dysfunction. The presence of isolated paramidline LBP increases the probability of symptomatic FJ or SIJ but mildly reduces the likelihood of lumbar IDD.

What is the source of chronic low back pain and does age play a role?

OBJECTIVE

The objective of this study was to estimate the prevalence, mean age, and association of prevalence and age of lumbar internal disc disruption (IDD), facet joint pain (FJP), sacroiliac joint pain (SIJP), spinal and pelvic insufficiency fractures, interspinous ligament injury/Baastrup's Disease, and soft tissue irritation by fusion hardware.

DESIGN

The study's design was a retrospective chart review.

SETTING

The study was set in an academic spine center.

PATIENTS

A total of 378 cases from 358 patients were reviewed of which 170 cases from 156 patients who underwent diagnostic procedures were included.

INTERVENTIONS

Discography, dual diagnostic facet joint blocks, intra-articular sacroiliac joint injections, anesthetic injections of painful interspinous ligaments/opposing spinous processes/posterior fusion hardware, or percutaneous augmentation were performed.

OUTCOME MEASURES

Prevalence and age were analyzed for each diagnosis group.

METHODS

Patients with recalcitrant low back pain underwent diagnostic procedures based on their clinical presentation until the pain source was identified.

RESULTS

The prevalence of internal disc disruption, facet joint pain and sacroiliac joint pain was 42%, 31%, and 18%, respectively. Patients with internal disc disruption were significantly younger than those with facet joint pain or sacroiliac joint pain. Increased age was associated with a decreased probability of internal disc disruption and increased probabilities of facet joint pain and sacroiliac joint pain as the source of low back pain until approximately age 70.

CONCLUSION

Our data confirm the intervertebral disc as the most common etiology of chronic low back pain in adults. Based on our sample, the younger the patient, the more likely low back pain is discogenic in origin. Facetogenic or sacroiliac joint pain is more likely in older patients.

The transfer of disc pressure to adjacent discs in discography: a specificity problem?

STUDY DESIGN

In vivo experimental study.

OBJECTIVE

The primary objective of the study was to investigate pressure transmission to adjacent discs during discography. A secondary objective was to quantify the transmitted pressure, both in contrast injected and noninjected porcine intervertebral discs.

SUMMARY OF BACKGROUND DATA

Discography is used to before surgery identify painful discs. A pain response during discography that is concordant with the patient's experienced back pain is regarded as an indication that the injected disc is the source of pain. However, the sensitivity and specificity of discography are matters of debate. Pressure-controlled discographies have been reported to reduce the number of false-positive discs using low pressure criteria. Preliminary data indicated a transfer of pressure from an injected to an adjacent disc during discography. Pressure transmission in vivo during lumbar discography, not reported before might, if clinically present, contribute to a false-positive diagnosis.

METHODS

Thirty-six lumbar discs in 9 adolescent pigs were investigated. Intradiscal pressure was recorded during contrast injection, using a 0.36/0.25 mm fiber-optic pressure transducer inserted into the nucleus pulposus via a 22 G needle. The pressure was measured simultaneously in 2 adjacent discs during contrast injection into 1 of the discs at pressures up to 8 bar. Transmitted pressure was recorded both in noninjected discs and in discs that were prefilled with contrast.

RESULTS

Thirty-three discs were successfully examined. During contrast injection, there was an intradiscal pressure rise in the adjacent disc with a median value of 16.0% (range, 3.2-37.0) over baseline pressure. There was no significant difference in pressure increase between the noninjected and prefilled discs (P < 0.68).

CONCLUSION

Discography of porcine discs induces a pressure increase in adjacent discs. A similar pressure transfer during human clinical discography might elicit false-positive pain reactions.

Clinical diagnosis for discogenic low back pain

Discogenic lower back pain (DLBP) is the most common type of chronic lower back pain (LBP), accounting for 39% of cases, compared to 30% of cases due to disc herniation, and even lower prevalence rates for other causes, such as zygapophysial joint pain. Only a small proportion (approximately 20%) of LBP cases can be attributed with reasonable certainty to a pathologic or anatomical entity. Thus, diagnosing the cause of LBP represents the biggest challenge for doctors in this field. In this review, we summarize the process of obtaining a clinical diagnosis of DLBP and discuss the potential for serum-based diagnosis in the near future. The use of serum biomarkers to diagnose DLBP is likely to increase the ease of diagnosis as well as produce more accurate and reproducible results.

Lumbar discography

Lumbar discography has generally proven to be a safe diagnostic tool for the evaluation and potential treatment planning of presumed discogenic pain, but it has not been wholeheartedly embraced by the radiologic and surgical community because of doubts as to its safety, accuracy, and relevance to patient outcome. There have been some conflicting reports on the relative merits and limitations of the procedure in the diagnosis and treatment planning of low back pain and radiculopathy; further studies are needed to determine with certainty whether discography is in fact able to localize the precise discs of clinical significance and accurately predict those patients who will respond well to surgery and those who will not.

Technology Insight: imaging of low back pain

Chronic low back pain is a common condition that has significant economic consequences for affected patients and their communities. Despite the prevailing view that an anatomic diagnosis is often impossible, an origin for the pain can frequently be found if current diagnostic techniques are fully used. Such techniques include a mixture of noninvasive and invasive imaging. Prevalence data suggest that the intervertebral disc is one of the most common sources of back pain, accounting for around 40% of cases. The pathologic basis for discogenic low back pain might be full-thickness radial tears of the annulus fibrosus. Unfortunately, only MRI can image the internal morphology of the disc, and both CT and MRI lack the necessary specificity to validate this hypothesis. Many so-called radiographic abnormalities seen on CT and MRI are commonly encountered in asymptomatic individuals. Invasive techniques such as joint injections, nerve blocks and provocative discography can show the connection between an abnormal image and the source of low back pain, but do have notable related risks. The development of a noninvasive, low-risk technique that can show this connection is desirable.