m2ABQ-a proposed refinement of the modified algorithm-based qualitative classification of osteoporotic vertebral fractures.

Currently, there is no reproducible, widely accepted gold standard to classify osteoporotic vertebral body fractures (OVFs). The purpose of this study is to refine a method with clear rules to classify OVFs for machine learning purposes. The method was found to have moderate interobserver agreement that improved with training. INTRODUCTION: The current methods to classify osteoporotic vertebral body fractures are considered ambiguous; there is no reproducible, accepted gold standard. The purpose of this study is to refine classification methodology by introducing clear, unambiguous rules and a refined flowchart to allow consistent classification of osteoporotic vertebral body fractures. METHODS: We developed a set of rules and refinements that we called m2ABQ to classify vertebrae into five categories. A fracture-enriched database of thoracic and lumbar spine radiographs of patients 65 years of age and older was retrospectively obtained from clinical institutional radiology records using natural language processing. Five raters independently classified each vertebral body using the m2ABQ system. After each annotation round, consensus sessions that included all raters were held to discuss and finalize a consensus annotation for each vertebral body where individual raters' evaluations differed. This process led to further refinement and development of the rules. RESULTS: Each annotation round showed increase in Fleiss kappa both for presence vs absence of fracture 0.62 (0.56-0.68) to 0.70 (0.65-0.75), as well as for the whole m2ABQ scale 0.29 (0.25-0.33) to 0.54 (0.51-0.58). CONCLUSION: The m2ABQ system demonstrates moderate interobserver agreement and practical feasibility for classifying osteoporotic vertebral body fractures. Future studies to compare the method to existing studies are warranted, as well as further development of its use in machine learning purposes.

Osteoporosis identification among previously undiagnosed individuals with vertebral fractures.

Because osteoporosis is under-recognized in patients with vertebral fractures, we evaluated characteristics associated with osteoporosis identification. Most patients with vertebral fractures did not receive evaluation or treatment for osteoporosis. Black, younger, and male participants were particularly unlikely to have had recognized osteoporosis, which could increase their risk of negative outcomes. INTRODUCTION: Vertebral fractures may be identified on imaging but fail to prompt evaluation for osteoporosis. Our objective was to evaluate characteristics associated with clinical osteoporosis recognition in patients who had vertebral fractures detected on their thoracolumbar spine imaging reports. METHODS: We prospectively identified individuals who received imaging of the lower spine at primary care clinics in 4 large healthcare systems who were eligible for osteoporosis screening and lacked indications of osteoporosis diagnoses or treatments in the prior year. We evaluated characteristics of participants with identified vertebral fractures that were associated with recognition of osteoporosis (diagnosis code in the health record; receipt of bone mineral density scans; and/or prescriptions for anti-osteoporotic medications). We used mixed models to estimate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs). RESULTS: A total of 114,005 participants (47% female; mean age 65 (interquartile range: 57-72) years) were evaluated. Of the 8579 (7%) participants with vertebral fractures identified, 3784 (44%) had recognition of osteoporosis within the subsequent year. In adjusted regressions, Black participants (OR (95% CI): 0.74 (0.57, 0.97)), younger participants (age 50-60: 0.48 (0.42, 0.54); age 61-64: 0.70 (0.60, 0.81)), and males (0.39 (0.35, 0.43)) were less likely to have recognized osteoporosis compared to white participants, adults aged 65 + years, or females. CONCLUSION: Individuals with identified vertebral fractures commonly did not have recognition of osteoporosis within a year, particularly those who were younger, Black, or male. Providers and healthcare systems should consider efforts to improve evaluation of osteoporosis in patients with vertebral fractures.

Lumbar Spinal Stenosis Severity by CT or MRI Does Not Predict Response to Epidural Corticosteroid versus Lidocaine Injections.

BACKGROUND AND PURPOSE: Epidural steroid injections may offer little-to-no short-term benefit in the overall population of patients with symptomatic spinal stenosis compared with lidocaine alone. We investigated whether imaging could identify subgroups of patients who might benefit most. MATERIALS AND METHODS: A secondary analysis of the Lumbar Epidural Steroid Injections for Spinal Stenosis prospective, double-blind trial was performed, and patients were randomized to receive an epidural injection of lidocaine with or without corticosteroids. Patients (n = 350) were evaluated for qualitative and quantitative MR imaging or CT measures of lumbar spinal stenosis. The primary clinical end points were the Roland-Morris Disability Questionnaire and the leg pain numeric rating scale at 3 weeks following injection. ANCOVA was used to assess the significance of interaction terms between imaging measures of spinal stenosis and injectate type on clinical improvement. RESULTS: There was no difference in the improvement of disability or leg pain scores at 3 weeks between patients injected with epidural lidocaine alone compared with corticosteroid and lidocaine when accounting for the primary imaging measures of qualitative spinal stenosis assessment (interaction coefficients for disability score, -0.1; 95% CI, -1.3 to 1.2; P = .90; and for the leg pain score, 0.1; 95% CI, -0.6 to 0.8; P = .81) or the quantitative minimum thecal sac cross-sectional area (interaction coefficients for disability score, 0.01; 95% CI, -0.01 to 0.03; P = .40; and for the leg pain score, 0.01; 95% CI, -0.01 to 0.03; P = .33). CONCLUSIONS: Imaging measures of spinal stenosis are not associated with differential clinical responses following epidural corticosteroid injection.

Prospective Comparison of Changes in Lumbar Spine MRI Findings over Time between Individuals with Acute Low Back Pain and Controls: An Exploratory Study.

BACKGROUND AND PURPOSE: The clinical importance of lumbar MR imaging findings is unclear. This study was an exploratory investigation of whether lumbar spine MR imaging findings change more commonly during a 12-week period in individuals with acute low back pain compared with pain-free controls. MATERIALS AND METHODS: Twenty individuals with recent-onset low back pain and 10 pain-free controls were recruited into an exploratory prospective cohort study. All participants had a lumbar spine MR imaging at baseline and repeat MR imaging scans at 1, 2, 6, and 12 weeks. The proportion of individuals who had MR imaging findings that changed during the 12-week period was compared with the same proportion in the controls. RESULTS: In 85% of subjects, we identified a change in at least 1 MR imaging finding during the 12 weeks; however, the proportion was similar in the controls (80%). A change in disc herniation, annular fissure, and nerve root compromise was reported more than twice as commonly in the subjects as in controls (65% versus 30%, 25% versus 10%, and 15% versus 0%, respectively). Caution is required in interpreting these findings due to wide confidence intervals, including no statistical difference. For all other MR imaging findings, the proportions of subjects and controls in whom MR imaging findings were reported to change during 12 weeks were similar. CONCLUSIONS: Changes in MR imaging findings were observed in a similar proportion of the low back pain and control groups, except for herniations, annular fissures, and nerve root compromise, which were twice as common in subjects with low back pain.

Test-Retest and Interreader Reproducibility of Semiautomated Atlas-Based Analysis of Diffusion Tensor Imaging Data in Acute Cervical Spine Trauma in Adult Patients.

BACKGROUND AND PURPOSE: DTI is a tool for microstructural spinal cord injury evaluation. This study evaluated the reproducibility of a semiautomated segmentation algorithm of spinal cord DTI. MATERIALS AND METHODS: Forty-two consecutive patients undergoing acute trauma cervical spine MR imaging underwent 2 axial DTI scans in addition to their clinical scan. The datasets were put through a semiautomated probabilistic segmentation algorithm that selected white matter, gray matter, and 24 individual white matter tracts. Regional and white matter tract volume, fractional anisotropy, and mean diffusivity values were calculated. Two readers performed the nonautomated steps to evaluate interreader reproducibility. The coefficient of variation and intraclass correlation coefficient were used to assess test-retest and interreader reproducibility. RESULTS: Of 42 patients, 30 had useable data. Test-retest reproducibility of fractional anisotropy was high for white matter as a whole (coefficient of variation, 3.8%; intraclass correlation coefficient, 0.93). Test-retest coefficient-of-variation ranged from 8.0%-18.2% and intraclass correlation coefficients from 0.47-0.80 across individual white matter tracts. Mean diffusivity metrics also had high test-retest reproducibility (white matter: coefficient-of-variation, 5.6%; intraclass correlation coefficient, 0.86) with coefficients of variation from 11.6%-18.3% and intraclass correlation coefficients from 0.57-0.74 across individual tracts, with better agreement for larger tracts. The coefficients of variation of fractional anisotropy and mean diffusivity both had significant negative relationships with white matter volume (26%-27% decrease for each doubling of white matter volume, P < .01). CONCLUSIONS: DTI spinal cord segmentation is reproducible in the setting of acute spine trauma, specifically for larger white matter tracts and total white or gray matter.

MRI Findings of Disc Degeneration are More Prevalent in Adults with Low Back Pain than in Asymptomatic Controls: A Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Imaging features of spine degeneration are common in symptomatic and asymptomatic individuals. We compared the prevalence of MR imaging features of lumbar spine degeneration in adults 50 years of age and younger with and without self-reported low back pain. MATERIALS AND METHODS: We performed a meta-analysis of studies reporting the prevalence of degenerative lumbar spine MR imaging findings in asymptomatic and symptomatic adults 50 years of age or younger. Symptomatic individuals had axial low back pain with or without radicular symptoms. Two reviewers evaluated each article for the following outcomes: disc bulge, disc degeneration, disc extrusion, disc protrusion, annular fissures, Modic 1 changes, any Modic changes, central canal stenosis, spondylolisthesis, and spondylolysis. The meta-analysis was performed by using a random-effects model. RESULTS: An initial search yielded 280 unique studies. Fourteen (5.0%) met the inclusion criteria (3097 individuals; 1193, 38.6%, asymptomatic; 1904, 61.4%, symptomatic). Imaging findings with a higher prevalence in symptomatic individuals 50 years of age or younger included disc bulge (OR, 7.54; 95% CI, 1.28-44.56; P = .03), spondylolysis (OR, 5.06; 95% CI, 1.65-15.53; P < .01), disc extrusion (OR, 4.38; 95% CI, 1.98-9.68; P < .01), Modic 1 changes (OR, 4.01; 95% CI, 1.10-14.55; P = .04), disc protrusion (OR, 2.65; 95% CI, 1.52-4.62; P < .01), and disc degeneration (OR, 2.24; 95% CI, 1.21-4.15, P = .01). Imaging findings not associated with low back pain included any Modic change (OR, 1.62; 95% CI, 0.48-5.41, P = .43), central canal stenosis (OR, 20.58; 95% CI, 0.05-798.77; P = .32), high-intensity zone (OR = 2.10; 95% CI, 0.73-6.02; P = .17), annular fissures (OR = 1.79; 95% CI, 0.97-3.31; P = .06), and spondylolisthesis (OR = 1.59; 95% CI, 0.78-3.24; P = .20). CONCLUSIONS: Meta-analysis demonstrates that MR imaging evidence of disc bulge, degeneration, extrusion, protrusion, Modic 1 changes, and spondylolysis are more prevalent in adults 50 years of age or younger with back pain compared with asymptomatic individuals.

Systematic literature review of imaging features of spinal degeneration in asymptomatic populations.

BACKGROUND AND PURPOSE: Degenerative changes are commonly found in spine imaging but often occur in pain-free individuals as well as those with back pain. We sought to estimate the prevalence, by age, of common degenerative spine conditions by performing a systematic review studying the prevalence of spine degeneration on imaging in asymptomatic individuals. MATERIALS AND METHODS: We performed a systematic review of articles reporting the prevalence of imaging findings (CT or MR imaging) in asymptomatic individuals from published English literature through April 2014. Two reviewers evaluated each manuscript. We selected age groupings by decade (20, 30, 40, 50, 60, 70, 80 years), determining age-specific prevalence estimates. For each imaging finding, we fit a generalized linear mixed-effects model for the age-specific prevalence estimate clustering in the study, adjusting for the midpoint of the reported age interval. RESULTS: Thirty-three articles reporting imaging findings for 3110 asymptomatic individuals met our study inclusion criteria. The prevalence of disk degeneration in asymptomatic individuals increased from 37% of 20-year-old individuals to 96% of 80-year-old individuals. Disk bulge prevalence increased from 30% of those 20 years of age to 84% of those 80 years of age. Disk protrusion prevalence increased from 29% of those 20 years of age to 43% of those 80 years of age. The prevalence of annular fissure increased from 19% of those 20 years of age to 29% of those 80 years of age. CONCLUSIONS: Imaging findings of spine degeneration are present in high proportions of asymptomatic individuals, increasing with age. Many imaging-based degenerative features are likely part of normal aging and unassociated with pain. These imaging findings must be interpreted in the context of the patient's clinical condition.

[Cement augmentation for osteoporotic compression fractures]. / Zementaugmentation bei osteoporotischen Wirbelkompressionsfrakturen.

High-quality evidence has raised significant questions on the widespread use of vertebroplasty in the treatment of osteopenic vertebral insufficiency fractures. Further research is shifting the burden of proof on procedures such as balloon kyphoplasty and other interventions. New prospective clinical trials may need to consider including sham arms to enhance their relevance.

Baseline pain and disability in the Investigational Vertebroplasty Efficacy and Safety Trial.

BACKGROUND AND PURPOSE: Multiple case series of vertebroplasty outcomes have been published, though no large, placebo controlled trial has yet been performed. Our aim was to report baseline characteristics for the Investigational Vertebroplasty Efficacy and Safety Trial (INVEST), a randomized blinded controlled study of vertebroplasty. MATERIALS AND METHODS: We compared baseline demographics, pain scores, and scores on the modified Roland-Morris Disability Scale (RMDS), a back pain-specific metric, between 2 groups. One group included subjects enrolled at the lead INVEST site (n = 27 to date). The second group consisted of eligible patients seen concurrently at the lead INVEST site, who declined enrollment (n = 70). Comparisons were made by using 2-sample t tests. RESULTS: Mean ages were similar between groups, averaging approximately 74 years among study participants and 77 years among nonenrolled eligible patients (P = .17). Approximately 75% of subjects were female in both groups. RMDS scores of enrolled patients at the lead site (18.0 +/- 4.2) were not statistically different from those of eligible nonenrolled patients at the lead site (18.6 +/- 3.6, P = .49). Pain scores in the enrolled subjects were measured as "average intensity over the prior 24 hours" with mean scores of 7.6 +/- 2.1 among enrolled patients at the lead site. Pain scores in eligible nonenrolled patients were measured as "pain at rest," with mean score of 3.4 +/- 3.3, and "pain with activity," with mean score of 8.5 +/- 2.0. CONCLUSIONS: Patient demographics among subjects enrolled in the INVEST are similar to those in a cohort of eligible nonenrolled patients. Back pain-specific disability was similar between subjects enrolled in the INVEST study and eligible nonenrolled patients at the lead site.

A systematic literature review of magnetic resonance spectroscopy for the characterization of brain tumors.

BACKGROUND AND PURPOSE: Proton MR spectroscopy ((1)H-MR spectroscopy) is a potentially useful adjunct to anatomic MR imaging in the characterization of brain tumors. We performed an updated systematic review of the evidence. METHODS: We employed a standardized search strategy to find studies published during 2002-2004. We reviewed studies measuring diagnostic accuracy and diagnostic, therapeutic, or health impact of (1)H-MR spectroscopy. We abstracted information on study design, (1)H-MR spectroscopy technique, and methodologic quality. We categorized studies into 5 subgroups: (1) metastasis versus high-grade tumor; (2) high-versus low-grade tumor; (3) recurrent tumor versus radiation necrosis; (4) tumor extent; and (5) tumor versus non-neoplastic lesion. RESULTS: We identified 26 studies evaluating diagnostic performance, diagnostic impact, or therapeutic impact. No articles evaluated patient health or cost-effectiveness. Methodologic quality was mixed; most used histopathology as the reference standard but did not specify blinded interpretation of histopathology. One large study demonstrated a statistically significant increase in diagnostic accuracy for indeterminate brain lesions from 55%, based on MR imaging, to 71% after analysis of (1)H-MR spectroscopy. Several studies have found that (1)H-MR spectroscopy is highly accurate for distinguishing high- and low-grade gliomas, though the incremental benefit of (1)H-MR spectroscopy in this setting is less clear. Interpretation for the other clinical subgroups is limited by the small number of studies. CONCLUSION: The current evidence on the accuracy of (1)H-MR spectroscopy in the characterization of brain tumors is promising. However, additional high-quality studies are needed to convince policy makers. We present guidelines to help focus future research in this area.

A multicenter in vivo proton-MRS study of HIV-associated dementia and its relationship to age.

OBJECTIVE: Differences in diagnostic criteria and methods have led to mixed results regarding the metabolite pattern of HIV-associated brain injury in relation to neurocognitive impairment. Therefore, a multicenter MRS consortium was formed to evaluate the neurometabolites in HIV patients with or without cognitive impairment. METHODS: Proton magnetic resonance spectroscopy (MRS) at short-echo time (30 ms) was assessed in the frontal white matter, basal ganglia, and parietal cortex of 100 HIV patients [61 with AIDS dementia complex (ADC) and 39 neuroasymptomatic (NAS)] and 37 seronegative (SN) controls. RESULTS: Compared to SN, NAS had higher glial marker myoinositol-to-creatine ratio (MI/Cr) in the white matter (multivariate analyses, adjusted P=0.001), while ADC showed further increased MI/Cr in the white matter and basal ganglia (both P<0.001), and increased choline compounds (Cho)/Cr in white matter (P=0.04) and basal ganglia (P<0.001). Compared to NAS, ADC showed a reduction in the neuronal marker N-acetyl compound (NA)/Cr in the frontal white matter (P=0.007). CSF, but not plasma, viral load correlated with MI/Cr and Cho/Cr in white matter and NAA/Cr in parietal cortex. HIV infection and aging had additive effects on Cho/Cr and MI/Cr in the basal ganglia and white matter. CONCLUSIONS: The results suggest that glial activation occurs during the NAS stages of HIV infection, whereas further inflammatory activity in the basal ganglia and neuronal injury in the white matter is associated with the development of cognitive impairment. Aging may further exacerbate brain metabolites associated with inflammation in HIV patient and thereby increase the risk for cognitive impairment.

MR nerve imaging in a prospective cohort of patients with suspected carpal tunnel syndrome.

OBJECTIVES: To evaluate the reliability and diagnostic accuracy of high-resolution MRI of the median nerve in a prospectively assembled cohort of subjects with clinically suspected carpal tunnel syndrome (CTS). METHODS: The authors prospectively identified 120 subjects with clinically suspected CTS from five Seattle-area clinics. All subjects completed a hand-pain diagram and underwent a standardized nerve conduction study (NCS). The reference standard for determining CTS status was a classic or probable hand pain diagram and NCS with a difference >0.3 ms between the 8-cm median and ulnar peak latencies. Readers graded multiple imaging parameters of the MRI on four-point scales. The authors also performed quantitative measurements of both the median nerve and carpal tunnel cross-sectional areas. NCS and MRI were interpreted without knowledge of the other study or the hand pain diagram. RESULTS: Intrareader reliability was substantial to near perfect (kappa = 0.76 to 0.88). Interreader agreement was lower but still substantial (kappa = 0.60 to 0.67). Sensitivity of MRI was greatest for the overall impression of the images (96%) followed by increased median nerve signal (91%); however, specificities were low (33 to 38%). The length of abnormal signal on T2-weighted images was significantly correlated with nerve conduction latency, and median nerve area was larger at the distal radioulnar joint (15.8 vs 11.8 mm(2)) in patients with CTS. A logistic regression model combining these two MR variables had a receiver operating characteristic area under the curve of 0.85. CONCLUSIONS: The reliability of MRI is high but the diagnostic accuracy is only moderate compared with a research-definition reference standard.

Diagnosis of carpal tunnel syndrome: electrodiagnostic and magnetic resonance imaging evaluation.

In clinically diagnosed CTS without symptoms or signs to suggest other disorders that can mimic CTS, it is unclear whether performing nerve conduction studies are cost-effective. An outcome study to determine whether nerve conduction studies are necessary for the diagnosis may help to clarify this issue. Even less evidence exists regarding the cost-effectiveness of imaging for CTS. MR imaging reliably depicts normal carpal tunnel anatomic details, including the median and ulnar nerves as well as their intraneural fascicular structure. It can also identify pathologic nerve compression and mass lesions that compress nerves such as ganglion cysts. Currently, MR imaging is probably most commonly used to image patients with ambiguous electrodiagnostic studies and clinical examinations. In the near future, MR diffusion-weighted imaging should be possible for peripheral nerves. As is the case with brain imaging, diffusion-weighted imaging of peripheral nerves is likely to be the most sensitive imaging modality for the detection of early nerve dysfunction. Electrodiagnostic studies are likely to remain the pivotal diagnostic examination in patients with suspected CTS for the foreseeable future. With advances in software and hardware, however, high-resolution MR imaging of peripheral nerves should become faster, less expensive, and probably more accurate, possibly paving the way for an expanded role in the diagnosis of this common syndrome.

Treatment with tissue plasminogen activator and inpatient mortality rates for patients with ischemic stroke treated in community hospitals.

BACKGROUND AND PURPOSE: Most analyses of intravenous tissue plasminogen activator (IV tPA) use for acute stroke in routine practice have been limited by sample size and generally restricted to patients treated in large academic medical facilities. In the present study, we sought to estimate among community hospitals the use of IV tPA and to identify factors associated with the use of IV tPA and inpatient mortality. METHODS: We evaluated a retrospective cohort of 23 058 patients with ischemic stroke from 137 community hospitals. RESULTS: Three hundred sixty-two (1.6%) patients were treated with IV tPA, and 9.9% of those patients died during the hospitalization period. In 35.0% of the hospitals, no patients were treated with IV tPA, whereas 14.6% of hospitals treated approximately 3.0% with IV tPA. After control for multiple factors, younger patients, more severely ill patients (OR 2.02, 95% CI 1.36 to 3.01), and patients treated in rural hospitals (OR 1.80, 95% CI 0.99 to 3.26) were more likely to receive IV tPA, whereas black patients were less likely (OR 0.54, 95% CI 0.31 to 0.95). There also was a trend showing that women were less likely to receive IV tPA (OR 0.84, 95% CI 0.69 to 1.03). Factors associated with an increased odds of inpatient mortality included receipt of IV tPA among men (OR 2.81, 95% CI 1.72 to 4.58) and increased age. Black patients were 27% less likely to die during hospitalization (95% CI 0.60 to 0.90). CONCLUSIONS: In this large, retrospective evaluation of community hospital practice, the use IV tPA and inpatient mortality rates among IV tPA-treated patients were consistent with those of other studies. The likelihood of receiving IV tPA varies by race, age, disease severity, and possibly gender. These factors may influence mortality rates.

Inpatient costs, length of stay, and mortality for cerebrovascular events in community hospitals.

BACKGROUND: Accurate estimates of inpatient cost, length of stay (LOS), and mortality are necessary for the development of economic models to estimate the cost-effectiveness of stroke-related treatments. Estimates based on data from academic institutions may not be generalizable to community hospitals. In this study, the authors estimated inpatient costs, LOS, and in-hospital mortality for patients with subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), ischemic cerebral infarction (ICI), and TIA who were treated in community hospitals. METHODS: The authors selected patients using International Classification of Diseases-9-Clinical Modification primary diagnosis codes from the HBSI EXPLORE database. They analyzed patient-level data and inpatient costs, derived from detailed utilization data, for all patients admitted to 137 community hospitals in 1998. Multivariate statistical techniques were used to examine patient-, hospital-, and outcome-related factors associated with inpatient costs. RESULTS: Patients with SAH incurred the highest average cost ($23,777, n = 1,124), followed by patients with ICH ($10,241, n = 3,139), ICI ($5,837, n = 18,740), and TIA ($3,350, n = 7,861). Patient subgroups ranked in the same order for average LOS at 11.5 days for SAH, 7.5 days for ICH, 5.9 days for ICI, and 3.4 days for TIA. Almost one third of patients with SAH (29.0%) and ICH (33.1%) died during hospitalization, whereas 7.0% with ICI and 0.2% with TIA died. For each event, as patient age increased, average costs consistently decreased. Also, average costs were higher among patients treated in community teaching hospitals compared to community nonteaching hospitals for each cerebrovascular event (10 to 29%). CONCLUSIONS: Inpatient costs, LOS, and mortality for patients with cerebrovascular disease are dependent on patient and hospital characteristics.

Imaging of lumbar intervertebral disk degeneration and aging, excluding disk herniations.

With the advent of CT and MR imaging, physicians have been able to complement their clinical diagnosis of the cause of low back pain with a detailed in vivo image of the structure and soft tissues of the spine. At the same time, there has been an increasing realization that information about morphology alone is not enough to make a definitive diagnosis. Proponents of diskography claim that, through pain provocation, it can provide the specificity missing from the purely morphologic information that CT and MR imaging provide. The specificity of diskography, however, is far from clear.