Interreader reliability for a new classification of lumbar disk disease

Development of a Multivariate Prognostic Model for Pain and Activity Limitation in People With Low Back Disorders Receiving Physiotherapy

OBJECTIVE

To identify predictors for back pain, leg pain, and activity limitation in patients with early persistent low back disorders (LBDs).

DESIGN

Prospective inception cohort study.

SETTING

Primary care private physiotherapy clinics in Melbourne, Australia.

PARTICIPANTS

Individuals (N=300) aged 18-65 years with low back and/or referred leg pain of ≥6 weeks and ≤6 months duration.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Numeric rating scales for back pain and leg pain as well as the Oswestry Disability Scale.

RESULTS

Prognostic factors included sociodemographics, treatment related factors, subjective/physical examination, subgrouping factors, and standardized questionnaires. Univariate analysis followed by generalized estimating equations were used to develop a multivariate prognostic model for back pain, leg pain, and activity limitation. Fifty-eight prognostic factors progressed to the multivariate stage where 15 showed significant (P<.05) associations with at least 1 of the 3 outcomes. There were 5 indicators of positive outcome (2 types of LBD subgroups, paresthesia below waist, walking as an easing factor, and low transversus abdominis tone) and 10 indicators of negative outcome (both parents born overseas, deep leg symptoms, longer sick leave duration, high multifidus tone, clinically determined inflammation, higher back and leg pain severity, lower lifting capacity, lower work capacity, and higher pain drawing percentage coverage). The preliminary model identifying predictors of LBDs explained up to 37% of the variance in outcome.

CONCLUSIONS

This study evaluated a comprehensive range of prognostic factors reflective of both the biomedical and psychosocial domains of LBDs. The preliminary multivariate model requires further validation before being considered for clinical use.

Reliability of standing weight-bearing (0.25T) MR imaging findings and positional changes in the lumbar spine

OBJECTIVE

To test the reliability and absolute agreement of common degenerative findings in standing positional magnetic resonance imaging (pMRI).

METHODS AND MATERIALS

Low back pain patients with and without sciatica were consecutively enrolled to undergo a supine and standing pMRI. Three readers independently evaluated the standing pMRI for herniation, spinal stenosis, spondylolisthesis, HIZ lesions and facet joint effusion. The evaluation included a semi-quantitative grading of spinal stenosis, foraminal stenosis and spinal nerve root compression. The standing pMRI images were evaluated with full access to supine MRI. In case lower grades or the degenerative findings were not present in the supine images, this was reported separately as position-dependent changes. A subsample of 20 pMRI examinations was reevaluated after two months. The reproducibility was assessed by inter- and intra-reader reliability (kappa statistic) and absolute agreement between readers.

RESULTS

Fifty-six patients were included in this study. There was fair-to-substantial inter-reader reliability (κ 0.47 to 0.82) and high absolute agreement (72.3% to 99.1%) for the pMRI findings. The intra-reader assessment showed similar reliability and agreement (κ 0.36 to 0.85; absolute agreement: 62.5% to 98.8%). Positional changes between the supine and standing position showed a fair-to-moderate inter- and intra-reader reliability (κ 0.25 to 0.52; absolute agreement: 97.0% to 99.1).

CONCLUSION

Evaluation of the lumbar spine for degenerative findings by standing pMRI has acceptable reproducibility; however, positional changes from the supine to the standing position as an independent outcome should be interpreted with caution because of lower reliability, which calls for further standardisation.

ACR Appropriateness Criteria Low Back Pain

Most patients presenting with uncomplicated acute low back pain (LBP) and/or radiculopathy do not require imaging. Imaging is considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. It is also considered for those patients presenting with red flags raising suspicion for serious underlying conditions, such as cauda equina syndrome, malignancy, fracture, and infection. Many imaging modalities are available to clinicians and radiologists for evaluating LBP. Application of these modalities depends largely on the working diagnosis, the urgency of the clinical problem, and comorbidities of the patient. When there is concern for fracture of the lumbar spine, multidetector CT is recommended. Those deemed to be interventional candidates, with LBP lasting for > 6 weeks having completed conservative management with persistent radiculopathic symptoms, may seek MRI. Patients with severe or progressive neurologic deficit on presentation and red flags should be evaluated with MRI. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (the RAND/UCLA Appropriateness Method and the Grading of Recommendations Assessment, Development, and Evaluation) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

How should we grade lumbar disc herniation and nerve root compression? A systematic review

BACKGROUND

MRI is the gold standard for evaluating the relationship of disc material to soft tissue and neural structures. However, terminologies used to describe lumbar disc herniation and nerve root compression have always been a source of confusion. A clear understanding of lumbar disc terminology among clinicians, radiologists, and researchers is vital for patient care and future research.

QUESTIONS/PURPOSES

Through a systematic review of the literature, the purpose of this article is to describe lumbar disc terminology and comment on the reliability of various nomenclature systems and their application to clinical practice.

METHODS

PubMed was used for our literature search using the following MeSH headings: "Magnetic Resonance Imaging and Intervertebral Disc Displacement" and "Lumbar Vertebrae" and terms "nomenclature" or "grading" or "classification". Ten papers evaluating lumbar disc herniation/nerve root compression using different grading criteria and providing information regarding intraobserver and interobserver agreement were identified.

RESULTS

To date, the Combined Task Force (CTF) and van Rijn classification systems are the most reliable methods for describing lumbar disc herniation and nerve root compression, respectively. van Rijn dichotomized nerve roots from "definitely no root compression, possibly no root compression, indeterminate root compression, possible root compression, and definite root compression" into no root compression (first three categories) and root compression (last two categories). The CTF classification defines lumbar discs as normal, focal protrusion, broad-based protrusion, or extrusion. The CTF classification system excludes "disc bulges," which is a source of confusion and disagreement among many practitioners. This potentially accounts for its improved reliability compared with other proposed nomenclature systems.

CONCLUSIONS

The main issue in the management of patients with lumbar disc disease and nerve root compression is correlation of imaging findings with clinical presentation and symptomatology to guide treatment and intervention. Although it appears that the most commonly supported nomenclatures have strong interobserver reliability, the classification term "disc bulges" is a source of confusion and disagreement among many practitioners. Additional research should focus on the clinical application of the various nomenclatures.

Lumbar disc nomenclature: version 2.0: recommendations of the combined task forces of the North American Spine Society, the American Society of Spine Radiology, and the American Society of Neuroradiology

STUDY DESIGN

This article comprises a review of the literature pertaining to the normal and pathological lumbar disc and the compilation of a standardized nomenclature.

OBJECTIVE

To provide a resource that promotes a clear understanding of lumbar disc terminology among clinicians, radiologists, and researchers.

SUMMARY OF BACKGROUND DATA

The article "Nomenclature and Classification of Lumbar Disc Pathology. Recommendations of the Combined Task Forces of the North American Spine Society, American Society of Spine Radiology and American Society of Neuroradiology" was published in 2001 in Spine © Lippincott, Williams and Wilkins and formally endorsed by the 3 boards. Its purpose, which it served for well over a decade, was to promote greater clarity and consistency of usage of spine terminology. Since 2001, there has been sufficient evolution in our understanding of the lumbar disc to suggest the need for revision and updating. The document represents the consensus recommendations of the current combined task forces and reflects changes consistent with current concepts in radiological and clinical care.

METHODS

A PubMed search was performed for literature pertaining to the lumbar disc. The task force members individually and collectively reviewed the literature and revised the 2001 document. It was then reviewed by the governing boards of the American Society of Spine Radiology, the American Society of Neuroradiology, and the North American Spine Society. After further revision based on their feedback, the paper was approved for publication.

RESULTS

The article provides a discussion of the recommended diagnostic categories and a glossary of terms pertaining to the lumbar disc, a detailed discussion of the terms and their recommended usage, as well as updated illustrations and literature references.

CONCLUSION

We have revised and updated a document that, since 2001, has provided a widely accepted nomenclature that helps maintain consistency and accuracy in the description of the properties of the normal and abnormal lumbar discs and that serves as a system for classification and reporting built upon that nomenclature.

Lumbar disc nomenclature: version 2.0: Recommendations of the combined task forces of the North American Spine Society, the American Society of Spine Radiology and the American Society of Neuroradiology

BACKGROUND CONTEXT

The paper ''Nomenclature and classification of lumbar disc pathology, recommendations of the combined task forces of the North American Spine Society, the American Society of Spine Radiology and the American Society of Neuroradiology,'' was published in 2001 in Spine (© Lippincott, Williams & Wilkins). It was authored by David Fardon, MD, and Pierre Milette, MD, and formally endorsed by the American Society of Spine Radiology (ASSR), American Society of Neuroradiology (ASNR), and North American Spine Society (NASS). Its purpose was to promote greater clarity and consistency of usage of spinal terminology, and it has served this purpose well for over a decade. Since 2001, there has been sufficient evolution in our understanding of the lumbar disc to suggest the need for revision and updating of the original document. The revised document is presented here, and it represents the consensus recommendations of contemporary combined task forces of the ASSR, ASNR, and NASS. This article reflects changes consistent with current concepts in radiologic and clinical care.

PURPOSE

To provide a resource that promotes a clear understanding of lumbar disc terminology amongst clinicians, radiologists, and researchers. All the concerned need standard terms for the normal and pathologic conditions of lumbar discs that can be used accurately and consistently and thus best serve patients with disc disorders.

STUDY DESIGN

This article comprises a review of the literature.

METHODS

A PubMed search was performed for literature pertaining to the lumbar disc. The task force members individually and collectively reviewed the literature and revised the 2001 document. The revised document was then submitted for review to the governing boards of the ASSR, ASNR, and NASS. After further revision based on the feedback from the governing boards, the article was approved for publication by the governing boards of the three societies, as representative of the consensus recommendations of the societies.

RESULTS

The article provides a discussion of the recommended diagnostic categories pertaining to the lumbar disc: normal; congenital/developmental variation; degeneration; trauma; infection/inflammation; neoplasia; and/or morphologic variant of uncertain significance. The article provides a glossary of terms pertaining to the lumbar disc, a detailed discussion of these terms, and their recommended usage. Terms are described as preferred, nonpreferred, nonstandard, and colloquial. Updated illustrations pictorially portray certain key terms. Literature references that provided the basis for the task force recommendations are included.

CONCLUSIONS

We have revised and updated a document that, since 2001, has provided a widely acceptable nomenclature that helps maintain consistency and accuracy in the description of the anatomic and physiologic properties of the normal and abnormal lumbar disc and that serves as a system for classification and reporting built upon that nomenclature.

Consensus conference on core radiological parameters to describe lumbar stenosis - an initiative for structured reporting

PURPOSE

To define radiological criteria and parameters as a minimum standard in a structured radiological report for patients with lumbar spinal stenosis (LSS) and to identify criteria and parameters for research purposes.

MATERIAL AND METHODS

All available radiological criteria and parameters for LSS were identified using systematic literature reviews and a Delphi survey. We invited to the consensus meeting, and provided data, to 15 internationally renowned experts from different countries. During the meeting, these experts reached consensus in a structured and systematic discussion about a core list of radiological criteria and parameters for standard reporting.

RESULTS

We identified a total of 27 radiological criteria and parameters for LSS. During the meeting, the experts identified five of these as core items for a structured report. For central stenosis, these were "compromise of the central zone" and "relation between fluid and cauda equina". For lateral stenosis, the group agreed that "nerve root compression in the lateral recess" was a core item. For foraminal stenosis, we included "nerve root impingement" and "compromise of the foraminal zone".

CONCLUSION

As a minimum standard, five radiological criteria should be used in a structured radiological report in LSS. Other parameters are well suited for research.

KEY POINTS

The five most important radiological criteria for standard clinical reporting were selected. The five most important quantitative radiological parameters for research purposes were selected. These core criteria could help standardize the communication between health care providers.

Influence of low back pain and prognostic value of MRI in sciatica patients in relation to back pain

BACKGROUND

Patients with sciatica frequently complain about associated back pain. It is not known whether there are prognostic relevant differences in Magnetic Resonance Imaging (MRI) findings between sciatica patients with and without disabling back pain.

METHODS

The study population contained patients with sciatica who underwent a baseline MRI to assess eligibility for a randomized trial designed to compare the efficacy of early surgery with prolonged conservative care for sciatica. Two neuroradiologists and one neurosurgeon independently evaluated all MR images. The MRI readers were blinded to symptom status. The MRI findings were compared between sciatica patients with and without disabling back pain. The presence of disabling back pain at baseline was correlated with perceived recovery at one year.

RESULTS

Of 379 included sciatica patients, 158 (42%) had disabling back pain. Of the patients with both sciatica and disabling back pain 68% did reveal a herniated disc with nerve root compression on MRI, compared to 88% of patients with predominantly sciatica (P<0.001). The existence of disabling back pain in sciatica at baseline was negatively associated with perceived recovery at one year (Odds ratio [OR] 0.32, 95% Confidence Interval 0.18-0.56, P<0.001). Sciatica patients with disabling back pain in absence of nerve root compression on MRI at baseline reported less perceived recovery at one year compared to those with predominantly sciatica and nerve root compression on MRI (50% vs 91%, P<0.001).

CONCLUSION

Sciatica patients with disabling low back pain reported an unfavorable outcome at one-year follow-up compared to those with predominantly sciatica. If additionally a clear herniated disc with nerve root compression on MRI was absent, the results were even worse.

Magnetic resonance imaging interpretation in patients with sciatica who are potential candidates for lumbar disc surgery

Background

Magnetic Resonance Imaging (MRI) is considered the mainstay imaging investigation in patients suspected of lumbar disc herniations. Both imaging and clinical findings determine the final decision of surgery. The objective of this study was to assess MRI observer variation in patients with sciatica who are potential candidates for lumbar disc surgery.

Methods

Patients for this study were potential candidates (n = 395) for lumbar disc surgery who underwent MRI to assess eligibility for a randomized trial. Two neuroradiologists and one neurosurgeon independently evaluated all MRIs. A four point scale was used for both probability of disc herniation and root compression, ranging from definitely present to definitely absent. Multiple characteristics of the degenerated disc herniation were scored. For inter-agreement analysis absolute agreements and kappa coefficients were used. Kappa coefficients were categorized as poor (<0.00), slight (0.00–0.20), fair (0.21–0.40), moderate (0.41–0.60), substantial (0.61–0.80) and excellent (0.81–1.00) agreement.

Results

Excellent agreement was found on the affected disc level (kappa range 0.81–0.86) and the nerve root that most likely caused the sciatic symptoms (kappa range 0.86–0.89). Interobserver agreement was moderate to substantial for the probability of disc herniation (kappa range 0.57–0.77) and the probability of nerve root compression (kappa range 0.42–0.69). Absolute pairwise agreement among the readers ranged from 90–94% regarding the question whether the probability of disc herniation on MRI was above or below 50%. Generally, moderate agreement was observed regarding the characteristics of the symptomatic disc level and of the herniated disc.

Conclusion

The observer variation of MRI interpretation in potential candidates for lumbar disc surgery is satisfactory regarding characteristics most important in decision for surgery. However, there is considerable variation between observers in specific characteristics of the symptomatic disc level and herniated disc.

Magnetic resonance imaging in follow-up assessment of sciatica

BACKGROUND

Magnetic resonance imaging (MRI) is frequently performed during follow-up in patients with known lumbar-disk herniation and persistent symptoms of sciatica. The association between findings on MRI and clinical outcome is controversial.

METHODS

We studied 283 patients in a randomized trial comparing surgery and prolonged conservative care for sciatica and lumbar-disk herniation. Patients underwent MRI at baseline and after 1 year. We used a 4-point scale to assess disk herniation on MRI, ranging from 1 for "definitely present" to 4 for "definitely absent." A favorable clinical outcome was defined as complete or nearly complete disappearance of symptoms at 1 year. We compared proportions of patients with a favorable outcome among those with a definite absence of disk herniation and those with a definite, probable, or possible presence of disk herniation at 1 year. The area under the receiver-operating-characteristic (ROC) curve was used to assess the prognostic accuracy of the 4-point scores regarding a favorable or unfavorable outcome, with 1 indicating perfect discriminatory value and 0.5 or less indicating no discriminatory value.

RESULTS

At 1 year, 84% of the patients reported having a favorable outcome. Disk herniation was visible in 35% with a favorable outcome and in 33% with an unfavorable outcome (P=0.70). A favorable outcome was reported in 85% of patients with disk herniation and 83% without disk herniation (P=0.70). MRI assessment of disk herniation did not distinguish between patients with a favorable outcome and those with an unfavorable outcome (area under ROC curve, 0.48).

CONCLUSIONS

MRI performed at 1-year follow-up in patients who had been treated for sciatica and lumbar-disk herniation did not distinguish between those with a favorable outcome and those with an unfavorable outcome. (Funded by the Netherlands Organization for Health Research and Development and the Hoelen Foundation; Controlled Clinical Trials number, ISRCTN26872154.).

[Standardized terminology for disc disease]

This article reviews the terminology used to describe morphological alterations in the intervertebral discs. Radiologists must be able to communicate information about the type, location, and severity of these alterations to medical and surgical clinicians. It is crucial to use simple, standard, and unified terminology to ensure comprehension not only among radiologists but also with professionals from the different specialties for whom the radiology reports are written (fundamentally traumatologists and neurosurgeons). This terminology will help ensure a more accurate diagnosis and better patient management.

Influence of nomenclature in the interpretation of lumbar disk contour on MR imaging: a comparison of the agreement using the combined task force and the nordic nomenclatures

BACKGROUND AND PURPOSE

The CTF nomenclature had not been tested in clinical practice. The purpose of this study was to compare the reliability and diagnostic confidence in the interpretation of disk contours on lumbar 1.5T MR imaging when using the CTF and the Nordic nomenclatures.

MATERIALS AND METHODS

Five general radiologists from 3 hospitals blindly and independently assessed intravertebral herniations (Schmorl node) and disk contours on the lumbar MR imaging of 53 patients with low back pain, on 4 occasions. Measures were taken to minimize the risk of recall bias. The Nordic nomenclature was used for the first 2 assessments, and the CTF nomenclature, in the remaining 2. Radiologists had not previously used either of the 2 nomenclatures. κ statistics were calculated separately for reports deriving from each nomenclature and were categorized as almost perfect (0.81-1.00), substantial (0.61-0.80), moderate (0.41-0.60), fair (0.21-0.40), slight (0.00-0.20), and poor (<0.00).

RESULTS

Categorization of intra- and interobserver agreement was the same across nomenclatures. Intraobserver reliability was substantial for intravertebral herniations and disk contour abnormalities. Interobserver reliability was moderate for intravertebral herniations and fair to moderate for disk contour.

CONCLUSIONS

In conditions close to clinical practice, regardless of the specific nomenclature used, a standardized nomenclature supports only moderate interobserver agreement. The Nordic nomenclature increases self-confidence in an individual observer's report but is less clear regarding the classification of disks as normal versus bulged.

Potential of magnetic resonance imaging findings to refine case definition for mechanical low back pain in epidemiological studies: a systematic review

STUDY DESIGN

systematic review and meta-analysis.

OBJECTIVE

to assess how confidently low back pain (LBP) can be attributed to abnormalities on magnetic resonance imaging (MRI), and thereby explore the potential value of MRI abnormalities in refining case definition for mechanical LBP in epidemiological research.

SUMMARY OF BACKGROUND DATA

most epidemiological studies of mechanical LBP have defined cases only by reported symptoms, but it is possible that the potency of causes differs depending on whether there is demonstrable underlying spinal pathology.

METHODS

we reviewed the published data on MRI abnormalities, looking for data on the repeatability of their assessment, their prevalence in people free from LBP, and their association with LBP. Where data were sufficient, we calculated a summary estimate of prevalence in people without LBP and a meta-estimate of the odds ratio for the association with LBP. A formula was then applied to estimate the corresponding prevalence rate ratio, assuming 3 possible prevalence rates for LBP in the general population.

RESULTS

data were most extensive for disc protrusion, nerve root displacement or compression, disc degeneration, and high intensity zone, all of which could be assessed repeatedly. All were associated with LBP, meta-estimates of odds ratios ranging from 2.3 (nerve root displacement or compression) to 3.6 (disc protrusion). However, even for disc protrusion, estimates of the corresponding prevalence rate ratios were mostly less than 2.

CONCLUSION

MRI findings of disc protrusion, nerve root displacement or compression, disc degeneration, and high intensity zone are all associated with LBP, but individually, none of these abnormalities provides a strong indication that LBP is attributable to underlying pathology. This limits their value in refining epidemiological case definitions for LBP.

Magnetic resonance imaging interpretation in patients with symptomatic lumbar spine disc herniations: comparison of clinician and radiologist readings

STUDY DESIGN

Retrospective review of imaging data from a clinical trial.

OBJECTIVE

To compare the interpretation of lumbar spine magnetic resonance imaging (MRIs) by clinical spine specialists and radiologists in patients with lumbar disc herniation.

SUMMARY OF BACKGROUND DATA

MRI is the imaging modality of choice for evaluation of the lumbar spine in patients with suspected lumbar disc herniation. Guidelines provide standardization of terms to more consistently describe disc herniation. The extent to which these guidelines are being followed in clinical practice is unknown.

METHODS

We abstracted data from radiology reports from patients with lumbar intervertebral disc herniation enrolled in the Spine Patient Outcomes Research Trial. We evaluated the frequency with which morphology (e.g., protrusions, extrusions, or sequestrations) was reported as per guidelines and when present we compared the morphology ratings to those of clinicians who completed a structured data form as part of the trial. We assessed agreement using percent agreement and the kappa statistic.

RESULTS

There were 396 patients with sufficient data to analyze. Excellent agreement was observed between clinician and radiologist on the presence and level of herniation (93.4%), with 3.3% showing disagreement regarding level, of which a third could be explained by the presence of a transitional vertebra. In 3.3% of the cases in which the clinician reported a herniation (protrusion, extrusion, or sequestration), the radiologist reported no herniation on the MRI.The radiology reports did not clearly describe morphology in 42.2% of cases. In the 214 cases with clear morphologic descriptions, agreement was fair (kappa = 0.24) and the disagreement was asymmetric (Bowker's test of symmetry P < 0.0001) with clinicians more often rating more abnormal morphologic categories. Agreement on axial location of the herniation was excellent (kappa = 0.81). There was disagreement between left or right side in only 3.3% of cases (kappa = 0.93).

CONCLUSION

Radiology reports frequently fail to provide sufficient detail to describe disc herniation morphology. Agreement between MRI readings by clinical spine specialists and radiologists was excellent when comparing herniation vertebral level and location within level, but only fair comparing herniation morphology.

Reliability of magnetic resonance imaging readings for lumbar disc herniation in the Spine Patient Outcomes Research Trial (SPORT)

STUDY DESIGN

Assessment of the reliability of standardized magnetic resonance imaging (MRI) interpretations and measurements.

OBJECTIVE

To determine the intra- and inter-reader reliability of MRI parameters relevant to patients with intervertebral disc herniation (IDH), including disc morphology classification, degree of thecal sac compromise, grading of nerve root impingement, and measurements of cross-sectional area of the spinal canal, thecal sac, and disc fragment.

SUMMARY OF BACKGROUND DATA

MRI is increasingly used to assess patients with sciatica and IDH, but the relationship between specific imaging characteristics and patient outcomes remains uncertain. Although other studies have evaluated the reliability of certain MRI characteristics, comprehensive evaluation of the reliability of readings of herniated disc features on MRI is lacking.

METHODS

Sixty randomly selected MR images from patients with IDH enrolled in the Spine Patient Outcomes Research Trial were each rated according to defined criteria by 4 independent readers (3 radiologists and 1 orthopedic surgeon). Quantitative measurements were performed separately by 2 other radiologists. A sample of 20 MRIs was re-evaluated by each reader at least 1 month later. Agreement for rating data were assessed with kappa statistics using linear weights. Reliability of the quantitative measurements was assessed using intraclass correlation coefficients (ICCs) and summaries of measurement error.

RESULTS

Inter-reader reliability was substantial for disc morphology [overall kappa 0.81 (95% confidence interval (CI): 0.78, 0.85)], moderate for thecal sac compression [overall kappa 0.54 (95% CI: 0.37, 0.68)], and moderate for grading nerve root impingement [overall kappa 0.47 (95% CI: 0.36, 0.56)]. Quantitative measures showed high ICCs of 0.87 to 0.96 for spinal canal and thecal sac cross-sectional areas. Measures of disc fragment area had moderate ICCs of 0.65 to 0.83. Mean absolute differences between measurements ranged from approximately 15% to 20%.

CONCLUSION

Classification of disc morphology showed substantial intra- and inter-reader agreement, whereas thecal sac and nerve root compression showed more moderate reader reliability. Quantitative measures of canal and thecal sac area showed good reliability, whereas measurement of disc fragment area showed more modest reliability.

Multidetector CT in patients suspected of having lumbar disk herniation: comparison of standard-dose and simulated low-dose techniques

PURPOSE

To compare standard-dose and simulated low-dose multidetector computed tomography (CT) in patients suspected of having lumbar disk herniation.

MATERIALS AND METHODS

The institutional review board approved the research protocol with a waiver of patient informed consent. Sixty consecutive patients underwent multidetector CT with four detector rows at 1 mm collimation at 140 kVp, with tube current-time product adapted to body mass index (BMI): 200 (BMI< 22 kg/m(2)), 300 (BMI > or =22 to <30 kg/m(2)), and 400 effective mAs (BMI > or =30 kg/m(2)). Simulated doses at 65%, 50%, 35%, and 20% of the dose were used for acquisition. During two separate sessions, three independent radiologists coded each of three caudal disks as normal, bulging, or herniated and graded canal and foramen compromise. Median numbers of discrepancies between the standard and reduced doses were compared with Friedman and Wilcoxon tests. Agreements within and between readers were evaluated through kappa statistics.

RESULTS

Dose reduction had no effect on a reader's ability to identify bulging disks (P = .128) and left and right foramen compromises (P = .413 and .665, respectively). However, for normal disks (P = .002), herniated disks (P = .004), and canal compromise (P = .002), dose reduction did have a significant effect. For normal disks and canal compromise, a reduction dose effect was not detected at 65% (P = .121 and .250, respectively) but appeared at 50% (P = .004 and .008, respectively). For herniation, a dose reduction effect was detected at 35% (P = .031). Agreements within and between readers ranged from poor to excellent and tended to decrease with dose reduction.

CONCLUSION

For patients suspected of having lumbar disk herniation, tube charge settings could be reduced to 65% of the standard dose adapted to the BMI.

Nomenclature and Standard Reporting Terminology of Intervertebral Disk Herniation

Spine pathology is ubiquitous and is encountered by nearly all medical specialties. The anatomy of the spine is complex, but the language used to describe pathology may be even more complex. Many of the common references differ in their nomenclature used to report intervertebral disk herniation. This article summarizes and relates the standard recommendations for reporting terminology in regard to herniation of the intervertebral disk. This standard reporting terminology may be used with CT or MR imaging and is useful to report the location and size of the disk herniation. Recommendations are to report abnormalities in zones on axial images and in levels on the sagittal and coronal images. The diagnostician must also be aware of the various pitfalls associated with disk herniation to avoid the scenario of surgical intervention at the incorrect spinal level.

The effect of lumbar flexion and extension on disc contour abnormality measured quantitatively on magnetic resonance imaging

STUDY DESIGN

Experimental study with subjects as their own control.

OBJECTIVE

To determine if lumbar disc contour abnormality dimensions, measured quantitatively, differ in flexed, neutral or extended positions.

SUMMARY OF BACKGROUND DATA

MRIs obtained lying supine are used to determine the degree of lumbar disc contour abnormality (bulging or herniation). Variations in positioning are suspected to influence this assessment.

METHODS

Lumbar MR images for 26 male volunteers (24-74 years of age), with or without low back pain, were obtained with the subjects lying in neutral, maximal flexion, and maximal extension positions allowable within a conventional 1.5T MR scanner. Quantitative measures of anterior and posterior disc contour abnormality were obtained for each position.

RESULTS

Statistically significant differences in disc angles were obtained between positions (2-5 degrees) for all levels. Posterior contour abnormality was significantly smaller in flexion and extension than in the neutral position (9.5%-30.1%). Posterior contour abnormality in extension was similar or smaller than in flexion. Anterior contour abnormality was significantly smaller in extension than flexion and smaller in the neutral position than flexion.

CONCLUSION

Spine position should be standardized when assessing disc contour abnormality with MRI. The largest measured disc contour abnormalities when lying supine in a standard MR scanner are observed in the neutral position, as opposed to flexion or extension.

Decision Making in Medicine and Health Care

Decision making is central to health policy and medical practice. Because health outcomes are probabilistic, most decisions are made under conditions of uncertainty. This review considers two classes of decisions in health care: decisions made by providers on behalf of patients, and shared decisions between patients and providers. Considerable evidence suggests wide regional variation exists in services received by patients. Evidence-based guidelines that incorporate quality of life and patient preferences may help address this problem. Systematic cost-effectiveness analysis can be used to improve resource allocation decisions. Shared medical decision making seeks to engage patients and providers in a collaborative process to choose clinical options that reflect patient preferences. Although some evidence indicates patients want an active role in making decisions, other evidence suggests that some patients prefer a passive role. Decision aids hold promise for improving individual decisions, but there are still few systematic evaluations of these aids. Several directions for future research are offered.

Observer variability based on the strength of MR scanners in the assessment of lumbar degenerative disc disease

OBJECT

aim of this study was to analyse the observer variability in the diagnosis and definition of disc pathologies with low and high-field strength MR scanners.

MATERIAL AND METHODS

95 patients with low back pain or radicular pain who were referred from two different centers were included in the study. Fifty-seven patients were scanned with 0.3 T MR (group 1) and 38 patients with 1.5 T (group 2). The intraobserver and interobserver reliability were assessed with the cappa coefficient which was characterised as follows: values less than 0.0 = 'poor' agreement, values 0.01-0.2 = 'slight' agreement beyond chance, 0.21-0.4 = 'fair' agreement, 0.41-0.60 = 'moderate' agreement, 0.61-0.80 = 'substantial' agreement and 0.81-1.00 = 'almost perfect' agreement.

RESULTS

intraobserver agreement in group 1 and group 2 for both readers was 'almost perfect' in differentiating normal and pathological discs; 'substantial-almost perfect' in defining the disc pathologies, 'moderate-substantial' in root compression, and 'moderate-substantial' in spinal stenosis. Interobserver agreement was 'almost perfect' in differentiating normal and pathological discs, 'substantial' in defining disc pathologies, 'moderate' in root compression and 'moderate' in spinal stenosis in the group 1, whereas in group 2, it was 'almost perfect' in differentiating normal and pathological discs, 'almost perfect' in defining disc pathologies, 'slight-substantial' in root compression and 'moderate' in spinal stenosis.

CONCLUSION

in the diagnosis of root compression and spinal stenosis, the intra and interobserver agreements were relatively poor with both high and low-strength field MRIs, indicating a need for more objective criteria. In differentiating normal and pathologic appearance of disc, the interobserver agreement was considerably better with high-field compared to low-field strength MRI. In cases where this definition is important, high-field strength scanners should be preferred.

Imaging of disk disease and degenerative spondylosis of the lumbar spine

Low back pain is a common but poorly understood entity. Features of degeneration depend on which component of the motion segment is predominantly affected, and include disk space narrowing, vacuum phenomenon, disk desiccation, vertebral osteophyte formation, disk herniation, and facet arthrosis, but these features do not necessarily have any relationship to symptoms. Since most episodes of back pain resolve on their own, and most disk herniations spontaneously regress, imaging of low back pain, although widely performed, is probably not necessary in most cases.

The significance of quality of life in health care

This paper compares a traditional biomedical model with an outcomes model for evaluating health care. The traditional model emphasizes diagnosis and disease-specific outcomes. In contrast, the outcomes model emphasizes life expectancy and health-related quality of life. Although the models are similar, they lead to different conclusions with regard to some interventions. For some conditions, diagnosis and treatment may reduce the impact of a particular disease without extending life expectancy or improving quality of life. Older individuals with multiple co-morbidities may not benefit from treatments for a particular disease if competing health problems threaten life or reduce quality of life. In preventive medicine, diagnosis of disease is made more difficult because of ambiguity, uncertainty, lead-time bias, and length bias. In some circumstances, successful diagnosis and treatment may actually reduce life expectancy or overall life quality. Example applications of the outcomes model from clinical policy analysis, individual decision making and shared decision-making are offered. The outcomes model has received little attention in dental health care but may have parallels to applications in other areas of medicine.

Imaging of adults with low back pain in the primary care setting

The evidence for the diagnostic accuracy of the four main imaging modalities used in low back pain (plain radiographs, CT, MR imaging, radionuclide bone scans) is variable in quality and limits the ultimate conclusions regarding the effectiveness and cost-effectiveness of diagnostic strategies. In addition, the frequent finding of abnormalities in normal adults limits the specificity of all of these tests. Nevertheless, MR imaging is likely in most cases to offer the greatest sensitivity and specificity for systemic diseases, and its performance is superior to that of radiographs and comparable with CT and radionuclide bone scans for most conditions causing neurologic compromise.

Low back pain

The communication between radiologists and their surgical colleagues is particularly important in the setting of back pain. This common disorder often does not have a definable cause, even when the imaging findings are abnormal. A shared understanding of the various causes of back pain, the appropriate terminology, and the needs of the surgeon is vital to proper patient treatment. Unfortunately, little standardization in the terminology for and management of back pain syndromes exists. This article elucidates the approaches to problems of back pain used in one clinical setting.

Classification, diagnostic imaging, and imaging characterization of a lumbar herniated disk

The absence of universal nomenclature standardization with respect to the definition of a disk herniation and its different categories, especially regarding type and location, is still a major problem that will only be overcome when major national or international scientific societies join efforts to support a particular scheme. Meanwhile, it is important to realize that the two models that are currently most used are based on a different [figure: see text] perspective. Trying to straddle the two by opposing, for instance, bulging disk and herniation is doomed to failure because this exercise defies formal logic. MR imaging is currently the most accurate noninvasive imaging modality to diagnose a disk herniation and to determine its exact location. The determination of some pathoanatomic characteristics of herniated disks (type and composition) may require the use of CT, diskography, or CT diskography.

Interobserver variability in the detection of cervical-thoracic Hodgkin's disease by computed tomography

PURPOSE

Computed tomography (CT) scans of the neck and chest are obtained at diagnosis of Hodgkin's disease to establish disease extent, plan radiotherapy, and serve as baseline studies for subsequent evaluation of response to therapy. However, differences in interpretation may occur even among experienced radiologists. This study was designed to test the extent of variation among expert radiologists' interpretations and to assess how their interpretations differed from that of the primary (institutional) radiologists.

MATERIALS AND METHODS

Five radiologists independently reviewed randomly selected CT scans of 59 patients enrolled onto two Pediatric Oncology Group Hodgkin's disease treatment protocols. For each patient, 31 potential disease sites were scored as positive, negative, uncertain, or unassessable. Agreement among the reviewers and between the reviewers and the primary readers was analyzed.

RESULTS

For 58% of the sites, at least four of the five reviewers agreed in >/= 80% of the cases. Kappa analysis showed moderate agreement in approximately two thirds of the sites and poor agreement in the remainder. There was moderate agreement between a majority of the expert readers and the primary radiologist reports for approximately one third of the sites, and agreement was poor in two thirds.

CONCLUSION

There are disparities among radiologists' interpretations of cervical-thoracic CT imaging of patients with Hodgkin's disease. This variability may affect patient care and the performance and results of multi-institutional clinical trials. We propose that a standardized method of reporting might improve the consistency of interpretation of CT scans in these patients.

Differentiating lumbar disc protrusions, disc bulges, and discs with normal contour but abnormal signal intensity. Magnetic resonance imaging with discographic correlations

STUDY DESIGN

Independent evaluation by two observers of 132 lumbar discs in 45 patients with chronic low back pain investigated by both magnetic resonance imaging and discography.

OBJECTIVES

To assess some of the fundamental differences between lumbar disc protrusions, disc bulges, and discs with normal contour but abnormal signal intensity on T2-weighted magnetic resonance images.

SUMMARY OF BACKGROUND DATA

Moderate interobserver agreement has been reported when the morphologic terms normal, bulge, protrusion, and extrusion are used. The validity of this nomenclature remains unknown.

METHODS

Discs were evaluated on magnetic resonance images for central and peripheral signal characteristics, height, contour, and nerve root compression. Discograms were classified according to degrees of disc degeneration, disruption, and pain reproduction.

RESULTS

Loss of intervertebral height or abnormal signal intensity on magnetic resonance imagery was significantly associated with disc disruptions extending into or beyond the outer anulus on discograms. All 23 protrusions (100%) and 12 of 15 disc bulges (80%) were associated with Stage 2 or 3 anular disruptions and, in most instances, similar or exact reproduction of pain during disc injection. There was no significant difference between disc protrusions, disc bulges, and discs with normal contour but abnormal signal, with respect to degree of disc degeneration, extent of disruptions, or presence of discogenic pain.

CONCLUSIONS

In patients with chronic low back pain, loss of disc height or abnormal signal intensity is highly predictive of symptomatic tears extending into or beyond the outer anulus. Disc bulges and disc protrusions do not represent discs with significantly different internal architecture, based on the findings of discography, and are no more suggestive of symptomatic tears than discs showing normal contour but decreased height or abnormal signal intensity.