A practical MRI grading system for cervical foraminal stenosis based on oblique sagittal images

Radiology Reports Do Not Accurately Portray the Severity of Cervical Neural Foraminal Stenosis

STUDY DESIGN

Retrospective study.

OBJECTIVE

(1) To compare cervical magnetic resonance imaging (MRI) radiology reports to a validated grading system for cervical foraminal stenosis (FS) and (2) to evaluate whether the severity of cervical neural FS on MRI correlates to motor weakness or patient-reported outcomes.

BACKGROUND

Radiology reports of cervical spine MRI are often reviewed to assess the degree of neural FS. However, research looking at the association between these reports and objective MRI findings, as well as clinical symptoms, is lacking.

PATIENTS AND METHODS

We retrospectively identified all adult patients undergoing primary 1 or 2-level anterior cervical discectomy and fusion at a single academic center for an indication of cervical radiculopathy. Preoperative MRI was assessed for neural FS severity using the grading system described by Kim and colleagues for each level of fusion, as well as adjacent levels. Neural FS severity was recorded from diagnostic radiologist MRI reports. Motor weakness was defined as an examination grade <4/5 on the final preoperative encounter. Regression analysis was conducted to evaluate whether the degree of FS by either classification was related to patient-reported outcome measure severity.

RESULTS

A total of 283 patients were included in the study, and 998 total levels were assessed. There were significant differences between the MRI grading system and the assessment by radio-logists ( P < 0.001). In levels with moderate stenosis, 28.9% were classified as having no stenosis by radiology. In levels with severe stenosis, 29.7% were classified as having mild-moderate stenosis or less. Motor weakness was found similarly often in levels of moderate or severe stenosis (6.9% and 9.2%, respectively). On regression analysis, no associations were found between baseline patient-reported outcome measures and stenosis severity assessed by radiologists or MRI grading systems.

CONCLUSION

Radiology reports on the severity of cervical neural FS are not consistent with a validated MRI grading system. These radiology reports underestimated the severity of neural foraminal compression and may be inappropriate when used for clinical decision-making.

LEVEL OF EVIDENCE

Level III.

Super-resolution Deep Learning Reconstruction Cervical Spine 1.5T MRI: Improved Interobserver Agreement in Evaluations of Neuroforaminal Stenosis Compared to Conventional Deep Learning Reconstruction

The aim of this study was to investigate whether super-resolution deep learning reconstruction (SR-DLR) is superior to conventional deep learning reconstruction (DLR) with respect to interobserver agreement in the evaluation of neuroforaminal stenosis using 1.5T cervical spine MRI. This retrospective study included 39 patients who underwent 1.5T cervical spine MRI. T2-weighted sagittal images were reconstructed with SR-DLR and DLR. Three blinded radiologists independently evaluated the images in terms of the degree of neuroforaminal stenosis, depictions of the vertebrae, spinal cord and neural foramina, sharpness, noise, artefacts and diagnostic acceptability. In quantitative image analyses, a fourth radiologist evaluated the signal-to-noise ratio (SNR) by placing a circular or ovoid region of interest on the spinal cord, and the edge slope based on a linear region of interest placed across the surface of the spinal cord. Interobserver agreement in the evaluations of neuroforaminal stenosis using SR-DLR and DLR was 0.422-0.571 and 0.410-0.542, respectively. The kappa values between reader 1 vs. reader 2 and reader 2 vs. reader 3 significantly differed. Two of the three readers rated depictions of the spinal cord, sharpness, and diagnostic acceptability as significantly better with SR-DLR than with DLR. Both SNR and edge slope (/mm) were also significantly better with SR-DLR (12.9 and 6031, respectively) than with DLR (11.5 and 3741, respectively) (p < 0.001 for both). In conclusion, compared to DLR, SR-DLR improved interobserver agreement in the evaluations of neuroforaminal stenosis using 1.5T cervical spine MRI.

Preoperative Factors on Loss of Range of Motion after Posterior Cervical Foraminotomy

Background and Objectives: Posterior cervical foraminotomy (PCF) aims to resolve cervical radiculopathy while preserving range of motion (ROM). However, its effectiveness in maintaining ROM is uncertain. This study investigates the changes in ROM after PCF and identifies preoperative factors that influence ROM reduction post surgery. Materials and Methods: This retrospective cohort study included patients treated at our hospital from August 2016 to September 2021. Clinical outcomes were assessed using the visual analog scale (VAS) for neck and arm pain and the neck disability index (NDI). Radiological outcomes included the segmental angle (SA), cervical angle (CA), C2-C7 SVA, Pfirrmann grade, extent of facetectomy, foraminal stenosis, and ROM. Patients were categorized into two groups based on segmental ROM changes: decreased (Group D) and maintained (Group M). Radiological and clinical outcomes were compared between the groups. Univariate and multivariate regression analyses were performed to identify risk factors for ROM loss after PCF. Results: 76 patients were included: 34 in Group D and 42 in Group M, with no demographic differences. Preoperatively, Group D had significantly larger flexion segmental and cervical angles than Group M (segmental, p < 0.001; cervical, p = 0.001). Group D also had a higher Pfirrmann grade (p = 0.014) and more bony bridge formations (p = 0.004). While no significant differences were observed in arm pain VAS and NDI scores, Group D exhibited worse neck pain VAS at the last follow-up (p = 0.03). Univariate linear regression indicated that preoperative segmental ROM (p < 0.001, B = 0.82) and bony bridge formation (p = 0.046, B = 5.33) were significant predictors of ROM loss post PCF. Conclusions: Patients with higher preoperative flexion angles and Pfirrmann grades at the operative level are at an increased risk for ROM loss and neck pain and often exhibit bony bridge formation. Accounting for these factors can improve surgical planning and patient outcomes.

Assessment of image quality and diagnostic accuracy for cervical spondylosis using T2w-STIR sequence with a deep learning-based reconstruction approach

OBJECTIVES

To investigate potential of enhancing image quality, maintaining interobserver consensus, and elevating disease diagnostic efficacy through the implementation of deep learning-based reconstruction (DLR) processing in 3.0 T cervical spine fast magnetic resonance imaging (MRI) images, compared with conventional images.

METHODS

The 3.0 T cervical spine MRI images of 71 volunteers were categorized into two groups: sagittal T2-weighted short T1 inversion recovery without DLR (Sag T2w-STIR) and with DLR (Sag T2w-STIR-DLR). The assessment covered artifacts, perceptual signal-to-noise ratio, clearness of tissue interfaces, fat suppression, overall image quality, and the delineation of spinal cord, vertebrae, discs, dopamine, and joints. Spanning canal stenosis, neural foraminal stenosis, herniated discs, annular fissures, hypertrophy of the ligamentum flavum or vertebral facet joints, and intervertebral disc degeneration were evaluated by three impartial readers.

RESULTS

Sag T2w-STIR-DLR images exhibited markedly superior performance across quality indicators (median = 4 or 5) compared to Sag T2w-STIR sequences (median = 3 or 4) (p < 0.001). No statistically significant differences were observed between the two sequences in terms of diagnosis and grading (p > 0.05). The interobserver agreement for Sag T2w-STIR-DLR images (0.604-0.931) was higher than the other (0.545-0.853), Sag T2w-STIR-DLR (0.747-1.000) demonstrated increased concordance between reader 1 and reader 3 in comparison to Sag T2w-STIR (0.508-1.000). Acquisition time diminished from 364 to 197 s through the DLR scheme.

CONCLUSIONS

Our investigation establishes that 3.0 T fast MRI images subjected to DLR processing present heightened image quality, bolstered diagnostic performance, and reduced scanning durations for cervical spine MRI compared with conventional sequences.

7 T MRI of the Cervical Neuroforamen: Assessment of Nerve Root Compression and Dorsal Root Ganglia in Patients With Radiculopathy

OBJECTIVES

The aim of this study was to assess the diagnostic value of 3-dimensional dual-echo steady-state (DESS) magnetic resonance imaging (MRI) of the cervical spine at 7 T compared with 3 T in patients with cervical radiculopathy.

MATERIALS AND METHODS

Patients diagnosed with cervical radiculopathy were prospectively recruited between March 2020 and January 2023 before undergoing surgical decompression and received 3-dimensional DESS imaging at 3 T and 7 T MRI. Cervical nerve root compression and the dimensions of the dorsal root ganglia were assessed by 2 radiologists independently. Signal intensity, visibility of nerve anatomy, diagnostic confidence, and image artifacts were evaluated with Likert scales. The degree of neuroforaminal stenosis was assessed on standard clinical 3 T scans. Statistics included the analysis of the diagnostic accuracy and interreader reliability. The Wilcoxon signed rank test was used to assess differences between the groups.

RESULTS

Forty-eight patients (mean age, 57 ± 12 years; 22 women) were included in the study with the highest prevalence of severe neuroforaminal stenosis observed at C6 (n = 68) followed by C7 (n = 43). Direct evaluation of nerve root compression showed significantly higher diagnostic confidence and visibility of cervical nerve rootlets, roots, and dorsal root ganglia on 7 T DESS than on 3 T DESS (diagnostic confidence: P = 0.01, visibility: P < 0.01). Assessment of nerve root compression using 7 T DESS allowed more sensitive grading than standard clinical MRI ( P < 0.01) and improved the performance in predicting sensory or motor dysfunction (area under the curve combined: 0.87).

CONCLUSIONS

7 T DESS imaging allows direct assessment of cervical nerve root compression in patients with radiculopathy, with a better prediction of sensory or motor dysfunction than standard clinical MRI. Diagnostic confidence and image quality of 7 T DESS were superior to 3 T DESS.

Morphometric analysis of cervical neuroforaminal dimensions from C2-T1 using computed tomography of 1,000 patients

BACKGROUND

Race and sex differences are not consistently reported in the literature. Fundamentally, anatomical differences of cervical neuroforaminal dimensions (CNFD) amongst these groups would be important to know.

PURPOSE

To establish normative radiographic morphometric measurements of CNFD and uncover the influence of patient sex, race, and ethnicity while also considering anthropometric characteristics.

STUDY DESIGN

Retrospective radiographic morphometric study.

PATIENT SAMPLE

A total of 1,000 patients between 18 and 35 years of age who were free of spinal pathology.

OUTCOME MEASURES

Foraminal height, axial width, and area of cervical neural foramen.

METHODS

Cervical CTs were reviewed to measure CNFD, defined as follows: foraminal height, axial width, and area. Statistical analyses were performed to assess associations between CNFD, and patient height, weight, sex, race, and ethnicity.

RESULTS

CNFD measurements followed a bimodal distribution pattern moving caudally from C2-T1. Irrespective of disc level, cervical CNFD were as follows: left and right widths of 6.6±1.5 and 6.6±1.5 mm, heights of 9.4±2.4 and 9.4±3.2 mm, and areas of 60.0±19.5 and 60.6±20.7 mm2. Left and right foraminal width were highest at C2-C3 and lowest at C3-C4. Left and right foraminal height were highest at C7-T1 and C6-C7, respectively and lowest at C3-C4. Left and right foraminal areas were highest at C2-C3 and lowest at C3-C4. Significant differences were observed for all CNFD measurements across disc levels. CNFD did not vary based on laterality. Significant CNFD differences were observed with respect to patient sex, race, and ethnicity. Male height and area were larger compared to females. In contrast, female foraminal width was larger compared to males. The Asian cohort demonstrated the largest foraminal widths. White and Hispanic patients demonstrated the largest foraminal heights and areas. Black patients demonstrated the smallest foraminal widths, heights, and areas. Patient height and weight were only weakly correlated with CNFD measurements across all levels from C2-T1.

CONCLUSIONS

This study describes 36,000 normative measurements of 12,000 foramina from C2-T1. CNFD measurements vary based on disc level, but not laterality. Contrasting left- versus right-sided neuroforamina of the same level may aid in determining the presence of unilateral stenosis. Patient sex, race, and ethnicity are associated with CNFD, while patient anthropometric factors are weakly correlated with CNFD.

The effectiveness of cervical transforaminal epidural steroid injections for the treatment of cervical radicular pain: A prospective cohort study reporting 12-month outcomes

Objectives

To evaluate the effectiveness of cervical transforaminal epidural steroid injection (CTFESI) for the treatment of unilateral cervical radicular pain.

Design

Single-group prospective cohort study.

Methods

Outcomes included ≥50% reductions in Numeric Rating Scale (NRS) for arm pain, ≥30% Neck Disability Index (NDI-5) improvement, health-related quality of life (EQ-5D), global improvement (PGIC), personal goal achievement (COMBI), Chronic Pain Sleep Index (CPSI), and healthcare utilization at one, three, six, and 12 months. Data analysis included descriptive statistics with the calculations of 95% confidence intervals (CIs), contingency table analysis, and multilevel logistic regression (LR) analysis, including a worst-case (WC) sensitivity analysis in which missing data were treated as treatment failure. Participants who were treated surgically were considered failures in the categorical analyses.

Results

33 consecutively enrolled participants (63.6% females, 51.2 ± 12.2 years of age, BMI 28.3 ± 4.5 kg/m2) were analyzed. Success rates for ≥50% reduction in NRS for arm pain at one, three, six and 12 months were 57.6% (95% CI 40.8-72.8%), 71.9% (95% CI 54.6-84.4%), 64.5% (95% CI 46.9-78.9%), and 64.5% (95% CI 46.9-78.9%). Success rates for ≥30% improvement in NDI-5 were 60.6% (95% CI 43.7-75.3%), 68.8% (95% CI 51.4-82.0%), 61.3% (95% CI 43.8-76.3%), and 71.0% (95% CI 53.4-83.9%). In WC analysis, success rates for ≥50% arm NRS and NDI-5 were 0-4.3% lower between 1 and 12 months. PGIC scores were at least "much improved" or "very much improved," in 48.4-65.6% of participants between 1 and 12 months. 6.1%, 6.1%, and 3.0% had one, two, or three repeat injections, respectively. 18.2% of participants underwent surgery by 12 months. Participants showed significant improvements in arm NRS and NDI-5 after treatment (p < 0.05), multilevel logistic regression models showed no significant decline in improvements across the follow-up time points (p > 0.05).

Conclusion

Statistically significant and clinically meaningful improvements in pain and disability were observed after CTFESI for up to 12 months in individuals with unilateral cervical radicular pain.

The imaging of cervical spondylotic myeloradiculopathy

This review provides a detailed description of the imaging features of cervical spondylotic myelopathy and radiculopathy, with a focus on MRI. Where relevant, we will outline grading systems of vertebral central canal and foraminal stenosis. Whilst post-operative appearances of the cervical spine are outside the scope of this paper, we will touch on imaging features recognised as predictors of clinical outcome and neurological recovery. This paper will serve as a reference for both radiologists and clinicians involved in the care of patients with cervical spondylotic myeloradiculopathy.

Image quality and lesion detectability of deep learning-accelerated T2-weighted Dixon imaging of the cervical spine

OBJECTIVES

To validate the subjective image quality and lesion detectability of deep learning-accelerated Dixon (DL-Dixon) imaging of the cervical spine compared with routine Dixon imaging.

MATERIALS AND METHODS

A total of 50 patients underwent sagittal routine Dixon and DL-Dixon imaging of the cervical spine. Acquisition parameters were compared and non-uniformity (NU) values were calculated. Two radiologists independently assessed the two imaging methods for subjective image quality and lesion detectability. Interreader and intermethod agreements were estimated with weighted kappa values.

RESULTS

Compared with the routine Dixon imaging, the DL-Dixon imaging reduced the acquisition time by 23.76%. The NU value is slightly higher in DL-Dixon imaging (p value: 0.015). DL-Dixon imaging showed superior visibility of all four anatomical structures (spinal cord, disc margin, dorsal root ganglion, and facet joint) for both readers (p value: < 0.001 ~ 0.002). The motion artifact scores were slightly higher in the DL-Dixon images than in routine Dixon images (p value = 0.785). Intermethod agreements were almost perfect for disc herniation, facet osteoarthritis, uncovertebral arthritis, central canal stenosis (κ range: 0.830 ~ 0.980, all p values < 0.001) and substantial to almost perfect for foraminal stenosis (κ = 0.955, 0.705 for each reader). There was an improvement in the interreader agreement of foraminal stenosis by DL-Dixon images, from moderate to substantial agreement.

CONCLUSION

The DLR sequence can substantially decrease the acquisition time of the Dixon sequence with subjective image quality at least as good as the conventional sequence. And no significant differences in lesion detectability were observed between the two sequence types.

Cervical Foraminal Changes in Patients with Intermittent Arm Radiculopathy Studied with a New MRI-Compatible Compression Device

Diagnosing cervical foraminal stenosis with intermittent arm radiculopathy is challenging due to discrepancies between MRI findings and symptoms. This can be attributed to the fact that MRI images are often obtained in a relaxed supine position. This study aims to evaluate the feasibility of the Dynamic MRI Compression System (DMRICS) and to assess possible changes in cervical foramina, with both quantitative measurements and qualitative grading systems, with MRI during a simulated Spurling test. Ten patients (five women and five men, ages 29-45) with previously confirmed cervical foraminal stenosis underwent MRI scans using DMRICS. MRI images were acquired in both relaxed and provoked states. A radiologist assessed 30 foramina (C4-C7) on the symptomatic side in both patient positions. Quantitative and qualitative measures were performed, including the numeric rating scale (NRS) and the Park and Kim grading systems. The provoked state induced concordant neck and arm pain in 9 of 10 patients. Significant shifts in Park and Kim foraminal gradings were noted: 13 of 27 Park gradings and 9 of 27 Kim gradings escalated post provocation. No quantitative changes were observed. This pilot study indicates that the DMRICS device has the potential to improve diagnostic accuracy for cervical radiculopathy, demonstrating induced cervical foraminal changes during a simulated Spurling test while performing MRI.

Posterior cervical foraminotomy versus anterior cervical discectomy for Cervical Brachialgia: the FORVAD RCT

Background

Posterior cervical foraminotomy and anterior cervical discectomy are routinely used operations to treat cervical brachialgia, although definitive evidence supporting superiority of either is lacking.

Objective

The primary objective was to investigate whether or not posterior cervical foraminotomy is superior to anterior cervical discectomy in improving clinical outcome.

Design

This was a Phase III, unblinded, prospective, United Kingdom multicentre, parallel-group, individually randomised controlled superiority trial comparing posterior cervical foraminotomy with anterior cervical discectomy. A rapid qualitative study was conducted during the close-down phase, involving remote semistructured interviews with trial participants and health-care professionals.

Setting

National Health Service trusts.

Participants

Patients with symptomatic unilateral cervical brachialgia for at least 6 weeks.

Interventions

Participants were randomised to receive posterior cervical foraminotomy or anterior cervical discectomy. Allocation was not blinded to participants, medical staff or trial staff. Health-care use from providing the initial surgical intervention to hospital discharge was measured and valued using national cost data.

Main outcome measures

The primary outcome measure was clinical outcome, as measured by patient-reported Neck Disability Index score 52 weeks post operation. Secondary outcome measures included complications, reoperations and restricted American Spinal Injury Association score over 6 weeks post operation, and patient-reported Eating Assessment Tool-10 items, Glasgow-Edinburgh Throat Scale, Voice Handicap Index-10 items, PainDETECT and Numerical Rating Scales for neck and upper-limb pain over 52 weeks post operation.

Results

The target recruitment was 252 participants. Owing to slow accrual, the trial closed after randomising 23 participants from 11 hospitals. The qualitative substudy found that there was support and enthusiasm for the posterior cervical FORaminotomy Versus Anterior cervical Discectomy in the treatment of cervical brachialgia trial and randomised clinical trials in this area. However, clinical equipoise appears to have been an issue for sites and individual surgeons. Randomisation on the day of surgery and processes for screening and approaching participants were also crucial factors in some centres. The median Neck Disability Index scores at baseline (pre surgery) and at 52 weeks was 44.0 (interquartile range 36.0-62.0 weeks) and 25.3 weeks (interquartile range 20.0-42.0 weeks), respectively, in the posterior cervical foraminotomy group (n = 14), and 35.6 weeks (interquartile range 34.0-44.0 weeks) and 45.0 weeks (interquartile range 20.0-57.0 weeks), respectively, in the anterior cervical discectomy group (n = 9). Scores appeared to reduce (i.e. improve) in the posterior cervical foraminotomy group, but not in the anterior cervical discectomy group. The median Eating Assessment Tool-10 items score for swallowing was higher (worse) after anterior cervical discectomy (13.5) than after posterior cervical foraminotomy (0) on day 1, but not at other time points, whereas the median Glasgow-Edinburgh Throat Scale score for globus was higher (worse) after anterior cervical discectomy (15, 7, 6, 6, 2, 2.5) than after posterior cervical foraminotomy (3, 0, 0, 0.5, 0, 0) at all postoperative time points. Five postoperative complications occurred within 6 weeks of surgery, all after anterior cervical discectomy. Neck pain was more severe on day 1 following posterior cervical foraminotomy (Numerical Rating Scale - Neck Pain score 8.5) than at the same time point after anterior cervical discectomy (Numerical Rating Scale - Neck Pain score 7.0). The median health-care costs of providing initial surgical intervention were £2610 for posterior cervical foraminotomy and £4411 for anterior cervical discectomy.

Conclusions

The data suggest that posterior cervical foraminotomy is associated with better outcomes, fewer complications and lower costs, but the trial recruited slowly and closed early. Consequently, the trial is underpowered and definitive conclusions cannot be drawn. Recruitment was impaired by lack of individual equipoise and by concern about randomising on the day of surgery. A large prospective multicentre trial comparing anterior cervical discectomy and posterior cervical foraminotomy in the treatment of cervical brachialgia is still required.

Trial registration

This trial is registered as ISRCTN10133661.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 21. See the NIHR Journals Library website for further project information.

Time for change? Radiologists highly concordant assessing change in stenoses on follow-up cervical spine MRI

OBJECTIVE

There is considerable variability among radiologists when grading spinal canal and foraminal stenosis on MRI. However, to date, studies have not evaluated radiologists' agreement when assessing interval change in cervical spine stenoses. The purpose of this study was to evaluate radiologists' concordance for change in cervical spine stenoses on follow-up MRIs, a major indication for these exams.

METHODS

Initial and follow-up cervical MRIs were retrospectively reviewed by three blinded radiologists. Spinal canal and foramina from C1 through T1 were rated for interval change and concordance between the blinded raters was calculated. The original MRI reports were also reviewed for specific language assessing interval change on the follow-up exams.

RESULTS

40 cervical MRI exams and 40 corresponding MRI follow-ups were assessed. Agreement for interval change in spinal canal and foraminal stenosis was near perfect amongst all readers (kappa values of 0.78-0.94). 97% of the original MRI reports used the standard severity scale. 68% of follow-up MRI reports specifically assessed for change.

DISCUSSION

Blinded radiologists had high agreement when assessing for change in spinal canal and foraminal stenosis on follow-up cervical spine MRIs. Because of inter-rater variability in stenosis grading, reports that do not emphasize change assessment, may imply change that is not truly present. For clarity and consistency in reporting of cervical spine stenoses, change assessment should be emphasized and added to structured reporting templates.

MRI evaluation of foraminal changes in the cervical spine with assistance of a novel compression device

Standard supine Magnetic Resonance Imaging (MRI) does not acquire images in a position where most patients with intermittent arm radiculopathy have symptoms. The aim of this study was to test the feasibility of a new compression device and to evaluate image quality and foraminal properties during a Spurling test under MRI acquisition. Ten asymptomatic individuals were included in the study (6 men and 4 women; age range 27 to 55 years). First, the subjects were positioned in the cervical compression device in a 3 T MRI scanner, and a volume T2 weighted (T2w) sequence was acquired in a relaxed supine position (3 min). Thereafter, the position and compressive forces on the patient's neck (provocation position) were changed by maneuvering the device from the control room, with the aim to simulate a Spurling test, causing a mild foraminal compression, followed by a repeated image acquisition (3 min). A radiologist measured the blinded investigations evaluating cervical lordosis (C3-C7), foraminal area on oblique sagittal images and foraminal cross-distance in the axial plane. A total of three levels (C4-C7) were measured on the right side on each individual. Measurements were compared between the compressed and relaxed state. Reliability tests for inter- and intraclass correlation were performed. The device was feasible to use and well tolerated by all investigated individuals. Images of adequate quality was obtained in all patients. A significant increase (mean 9.4, p = 0.013) in the cervical lordosis and a decreased foraminal cross-distance (mean 32%, p < 0.001) was found, during the simulated Spurling test. The area change on oblique sagittal images did not reach a statistically significant change. The reliability tests on the quantitative measures demonstrated excellent intraobserver reliability and moderate to good interobserver reliability. Applying an individualized provocation test on the cervical spine, which simulates a Spurling test, during MRI acquisition was feasible with the novel device and provided images of satisfactory quality. MRI images acquired with and without compression showed changes in cervical lordosis and foraminal cross distance indicating the possibility of detecting changes of the foraminal properties. As a next step, the method is to be tested on symptomatic patients.

Predictable factors for aggravation of cervical alignment after posterior cervical foraminotomy

OBJECTIVE

This study aimed to investigate the risk factors for aggravation of cervical alignment after posterior cervical foraminotomy (PCF) and to identify their relationships with kyphotic changes in cervical curvature.

METHODS

Ninety-eight patients who underwent PCF for unilateral radiculopathy and received follow-up for more than 2 years were retrospectively reviewed. Segmental Cobb angle (SA), cervical Cobb angle (CA), Pfirrmann grade, foraminal stenosis, and clinical outcomes including neck pain, arm pain, and Neck Disability Index scores were assessed. Radiological and clinical outcomes were compared between groups C (control group with kyphotic change in CA < 5°) and K (kyphotic group with kyphotic change in CA ≥ 5°). Multivariate regression analysis was performed to determine the risk factors for kyphotic change ≥ 5° after PCF.

RESULTS

Group K was significantly older than group C (p = 0.002) and had a higher Pfirrmann grade (p = 0.025). In group K, neck pain had significantly increased at last follow-up (p < 0.001). Multivariate linear regression analysis revealed that kyphotic changes in CA were related to older age (p = 0.016, B = 0.420) and Pfirrmann grade of the operative levels (p = 0.032, B = 4.560). Preoperative hypolordosis was not an independent risk factor for kyphotic changes in CA. Receiver operating characteristic curve analysis showed that the cutoff value for kyphotic changes in patients with CA ≥ 5° was Pfirrmann grade 3.417 (p = 0.008).

CONCLUSIONS

Contrary to previous studies, preoperative hypolordosis was not a risk factor for kyphotic changes in CA after PCF. Older patients with disc degeneration of Pfirrmann grade IV or greater for should be carefully considered.

Deep learning reconstruction for the evaluation of neuroforaminal stenosis using 1.5T cervical spine MRI: comparison with 3T MRI without deep learning reconstruction

PURPOSE

To compare image quality and interobserver agreement in evaluations of neuroforaminal stenosis between 1.5T cervical spine magnetic resonance imaging (MRI) with deep learning reconstruction (DLR) and 3T MRI without DLR.

METHODS

In this prospective study, 21 volunteers (mean age: 42.4 ± 11.9 years; 17 males) underwent cervical spine T2-weighted sagittal 1.5T and 3T MRI on the same day. The 1.5T and 3T MRI data were used to reconstruct images with (1.5T-DLR) and without (3T-nonDLR) DLR, respectively. Regions of interest were marked on the spinal cord to calculate non-uniformity (NU; standard deviation/signal intensity × 100), as an indicator of image noise. Two blinded radiologists evaluated the images in terms of the depiction of structures, artifacts, noise, overall image quality, and neuroforaminal stenosis. The NU value and the subjective image quality scores were compared between 1.5T-DLR and 3T-nonDLR using the Wilcoxon signed-rank test. Interobserver agreement in evaluations of neuroforaminal stenosis for 1.5T-DLR and 3T-nonDLR was evaluated using Cohen's weighted kappa analysis.

RESULTS

The NU value for 1.5T-DLR was 8.4, which was significantly better than that for 3T-nonDLR (10.3; p < 0.001). Subjective image scores were significantly better for 1.5T-DLR than 3T-nonDLR images (p < 0.037). Interobserver agreement (95% confidence intervals) in the evaluations of neuroforaminal stenosis was significantly superior for 1.5T-DLR (0.920 [0.916-0.924]) than 3T-nonDLR (0.894 [0.889-0.898]).

CONCLUSION

By using DLR, image quality and interobserver agreement in evaluations of neuroforaminal stenosis on 1.5T cervical spine MRI could be improved compared to 3T MRI without DLR.

Cervical foraminal stenosis as a risk factor for cervical kyphosis following cervical laminoplasty

BACKGROUND CONTEXT

Cervical laminoplasty (CLP) is an effective spinal cord decompression method for patients with cervical myelopathy. However, cervical kyphosis after CLP may cause insufficient decompression of the spinal cord. Thus, prevention of cervical kyphosis after CLP and identification of its risk factors are essential.

PURPOSE

This study aimed to investigate the relationship between preoperative cervical foraminal stenosis and kyphotic changes after CLP.

STUDY DESIGN

A retrospective study.

PATIENT SAMPLE

We reviewed 108 patients who underwent CLP for cervical myelopathy between May 2014 and May 2019 and who were followed up for at least 24 months.

OUTCOME MEASURES

For clinical assessments, neck pain, arm pain, neck disability index, Japanese Orthopedic Association scores, EuroQol 5-Dimension, and subjective improvement rate reported by the patients were evaluated. For radiologic parameters, C2-7 Cobb lordotic angle (CLA), C2-7 sagittal vertical axis, T1 slope (TS), TS minus CLA (TS-CLA), and cervical range of motion were assessed preoperatively and postoperatively for 24 months. Cervical foraminal stenosis was evaluated by magnetic resonance imaging and computed tomography.

METHODS

The study population was divided into the kyphosis group (n = 25 patients) and the lordosis group (n = 83 patients) according to the CLA at 24 months postoperatively. Preoperative risk factors related to postoperative kyphosis were analyzed. Statistical analyses were performed using independent two-sample t test, Chi-square test, logistic regression analysis, and linear mixed model.

RESULTS

Preoperative foraminal stenosis, CLA, TS, and TS-CLA were significantly different between the kyphosis and lordosis groups. In multivariate logistic regression analysis, foraminal stenosis (odds ratio [OR], 4.471; p = .0242) significantly increased the risk of kyphosis. The probability of developing kyphosis decreased with an increase in the CLA (OR, 0.840; p = .0001), while the probability of developing kyphosis increased with an increase in the TS-CLA (OR, 1.104; p = .0044).

CONCLUSIONS

Preoperative cervical foraminal stenosis is an independent risk factor for cervical kyphosis following CLP. Thus, CLP may not be a suitable surgical option for cervical myelopathy combined with foraminal stenosis.

Limitations of minimally invasive posterior cervical foraminotomy-a decompression method of posteriorly shifting the nerve root-in cases of large anterior osteophytes in cervical radiculopathy: A retrospective multicenter cohort study

BACKGROUND

Posterior cervical foraminotomy against anterior osteophyte is an indirect decompression procedure but less invasive compared to anterior cervical discectomy and fusion. Residual compression to the nerve root may lead to poor surgical outcomes. Although clinical results of posterior cervical foraminotomy for osteophytes are not considered better than those of disk herniation, osteophyte size and the association of the decompression area with poor surgical outcomes remain unclear. This study aimed to identify the limitations of minimally invasive posterior cervical foraminotomy for cervical radiculopathy and discuss the methods to improve surgical outcomes.

METHODS

We analyzed 55 consecutive patients with degenerative cervical radiculopathy who underwent minimally invasive posterior cervical foraminotomy. Minimum postoperative follow-up duration was 1 year. We divided the patients into nonimproved and improved groups. The cutoff value between preoperative and postoperative Neck Disability Index scores was 30% improvement. Preoperative imaging data comprised disk height, local kyphosis, spinal cord compression, anterior osteophytes in the foramen, and anterior osteophytes of >50% of the intervertebral foramen diameter. Postoperative imaging data comprised craniocaudal length and lateral width of decompressed lamina, preserved superior facet width, and area of decompressed lamina.

RESULTS

Fifty-five patients were divided into two groups: nonimproved (n = 19) and improved (n = 36). The presence of osteophytes itself was not significant; however, the presence of osteophytes of >50% of the foramen diameter increased in the nonimproved group (P = 0.004). Mean lateral width and mean area of decompressed lamina after surgery significantly increased in the improved group (P = 0.001, P = 0.03).

CONCLUSION

The presence of anterior osteophytes >50% of the diameter of the foramen led to poor improvement of clinical outcomes in minimally invasive posterior cervical foraminotomy. However, the larger the lateral width and area of the decompressed lamina, the better the surgical outcome.

The value of magnetic resonance imaging and computed tomography in the study of spinal disorders

Computed tomography (CT) and magnetic resonance imaging (MRI) have replaced conventional radiography in the study of many spinal conditions, it is essential to know when these techniques are indicated instead of or as complementary tests to radiography, which findings can be expected in different clinical settings, and their significance in the diagnosis of different spinal conditions. Proper use of CT and MRI in spinal disorders may facilitate diagnosis and management of spinal conditions. An adequate clinical approach, a good understanding of the pathological manifestations demonstrated by these imaging techniques and a comprehensive report based on a universally accepted nomenclature represent the indispensable tools to improve the diagnostic approach and the decision-making process in patients with spinal pain. Several guidelines are available to assist clinicians in ordering appropriate imaging techniques to achieve an accurate diagnosis and to ensure appropriate medical care that meets the efficacy and safety needs of patients. This article reviews the clinical indications of CT and MRI in different pathologic conditions affecting the spine, including congenital, traumatic, degenerative, inflammatory, infectious and tumor disorders, as well as their main imaging features. It is intended to be a pictorial guide to clinicians involved in the diagnosis and treatment of spinal disorders.

A systematic review of validated classification systems for cervical and lumbar spinal foraminal stenosis based on magnetic resonance imaging

PURPOSE

Foraminal stenosis is commonly investigated with radiological methods in patients with radiating pain in extremities. However, there is a lack of consensus regarding the methodology to assess compression of the nerve roots. This systematic review was performed to identify validated classification systems for foraminal stenosis in the lumbar and cervical spine based on magnetic resonance imaging (MRI).

METHODS

A systematic search was conducted according to the PRISMA guidelines. The search included Cochrane, Embase, Medline and PubMed databases going back 30 years and up to September 2021. Three categories of words were used in different variations; foraminal stenosis, MRI and scoring. For inclusion, at least one word from each category had to be present. Articles suggesting classification systems or reporting on their validation were selected for inclusion.

RESULTS

A total of 823 articles were identified and all abstracts were reviewed. Subsequently, a full-text review of 64 articles was performed and finally 14 articles were included. A total of three validated classification systems were found for the cervical and lumbar spine. The remaining 11 articles reported on validation or suggested modifications of the classification systems.

CONCLUSION

The three classification systems demonstrated moderate to good reliability and have all been shown feasible in the clinical setting. There is however a need for further studies testing the validity of these classifications in relation to both clinical findings and to surgical outcome data.

Clinical evaluation versus magnetic resonance imaging findings in patients with radicular arm pain—A pragmatic study

Objectives

Methods

Results

Conclusions

Clinical validity of the smallest oblique sagittal area of the neural foramen in patients with suspected cervical spondylotic radiculopathy

OBJECTIVE

To evaluate the smallest oblique sagittal area of the neural foramen in detecting cervical spondylotic radiculopathy (CSR) and to determine its potential significance for treatment decisions.

METHODS

The subjects of the study were patients with CSR who visited the spine surgery from 2016 to 2019. All patients were compared according to the minimum oblique sagittal area and the cut-off point value, and they were divided into positive and negative parameters. The changes in neck disability index (NDI), Japanese Orthopaedic Association score (JOA), and visual analog scale (VAS) during the two treatment groups from baseline to at least 24 months of follow-up were compared.

RESULTS

In the surgery group, there was no significant difference in symptom improvement between patients with positive and negative parameters. In the non-surgical group, for patients with positive parameters, NDI decreased by 2.35, JOA increased by 0.88, and neck VAS score improved by 0.42. For patients with negative parameters, NDI decreased by 10.32, JOA increased by 2.86 on average, and neck VAS score improved by 2.46 points on average (both p<0.01 on t test).

CONCLUSIONS

Patients with both positive and negative parameters showed significant improvement in their symptoms after surgery, and the smallest oblique sagittal area of the neural foramen seems to be unable to predict the outcome of the surgery. However, in non-surgical patients, symptomatic improvement was more limited in patients with positive parameters than in those with negative parameters. This suggests that patients with positive parameters may be more suitable for surgery and those with negative parameters are more suitable for conservative treatment.

Magnetic resonance imaging in the evaluation of cervical foraminal stenosis: comparison of 3D T2 SPACE with sagittal oblique 2D T2 TSE

OBJECTIVE

The oblique orientation of the cervical neural foramina challenges the implementation of a short MRI protocol with concurrent excellent visualization of the spine. While sagittal oblique T2-weighted sequences permit good evaluation of the cervical neuroforamina, all segments may not be equally well depicted on a single sequence and conspicuity of foraminal stenosis may be limited. 3D T2-weighted sequences can be reformatted in arbitrary planes, including the sagittal oblique. We set out to compare 3D T2w SPACE sequences with sagittal oblique reformations and sagittal oblique 2D T2w TSE sequences for the evaluation of cervical foraminal visibility and stenosis.

MATERIALS AND METHODS

Sixty consecutive patients who underwent MRI of the cervical spine with sagittal oblique 2D T2w TSE and 3D T2w SPACE sequences were included. Image homogeneity of the sequences was evaluated. Imaging sets were assessed for structure visibility and foraminal stenosis by two independent readers. Results of the sequences were compared by Wilcoxon matched-pairs tests. Interreader agreement was evaluated by weighted κ.

RESULTS

Visibility of most structures was rated good to excellent on both sequences (mean visibility scores ≥ 4.5 of 5), though neuroforaminal contents were better seen on sagittal oblique T2w TSE (mean scores 4.1-4.6 vs. 3.1-4.1 on 3D T2w SPACE, p < 0.01). Stenosis grades were comparable between sequences (mean 1.1-2.6 of 4), with slightly higher values for 3D T2w SPACE at some levels (difference ≤ 0.3 points).

CONCLUSION

3D T2w SPACE is comparable with sagittal oblique 2D T2w TSE in the evaluation of cervical neural foramina.

Is the Severity of Cervical Foraminal Stenosis Related to the Severity and Sidedness of Symptoms?

(1) Background: Cervical foraminal stenosis (CFS) is a common cause of axial neck and arm pain. The aim of this study was to determine the relationship between the severity of CFS and clinical symptoms in terms of severity and sidedness. (2) Methods: We retrospectively reviewed 75 consecutive patients with degenerative CFS. We graded 900 foramina from C3–4 to T1–2 using Park’s grading system. We collected visual analogue scale (VAS) and neck disability index (NDI) values from the neck and both arms. We analyzed the relationships with CFS grades and total number. We defined four types of left/right dominance of CFS (none, left-dominant, right-dominant, and both) by comparing left and right sides using total counts and maximal grade of CFS, respectively. We compared arm pain sidedness (no arm pain, left-only, right only, and bilateral) among different left and right CFS dominance types. (3) Results: Mean neck and left and right arm VAS scores were 4.4 ± 2.5, 4.9 ± 1.6, and 4.6 ± 2.0, respectively. The mean total NDI was 16.0 ± 8.0. The CFS grade at C3–4 and total count were correlated with neck VAS. Arm VAS was also correlated with CFS grade and total counts. Total NDI score was not correlated with radiological parameters. The presence and sidedness of arm pain were significantly different between left and right CFS dominance groups divided by total count of grade 2 and 3 CFS. (4) Conclusions: The CFS grade and total count were correlated with neck and arm VAS. Arm pain occurred more frequently on the side with more grade 2 and 3 CFS.

Correlation Between Intravascular Injection Rate, Pain Intensity, and Degree of Cervical Neural Foraminal Stenosis During a Cervical Transforaminal Epidural Block

Purpose

Cervical transforaminal epidural blocks (CTEBs) are useful for the treatment of cervical radicular pain. However, during CTEBs, inadvertent intravascular injection can introduce particulate steroids into the bloodstream, thus leading to serious complications. Moreover, the risk factors associated with intravascular injection during CTEBs have not been identified. Cervical neural foraminal stenosis (CNFS) is a form of neural foraminal narrowing and a common cause of cervical radicular pain. In this study, we aimed to identify whether there is a correlation between the incidence of intravascular injection during CTEB, pain intensity, and the degree of CNFS.

Patients and Methods

A total of 126 patients were recruited. The patients were classified into two subgroups (group M and group S) based on the routine cervical T2-weighted axial magnetic resonance imaging (MRI) findings. Group M (n = 63) consisted of moderate CNFS patients, while group S (n = 63) consisted of severe CNFS patients. The occurrence of intravascular injection during CTEB was established using real-time fluoroscopy. The intravascular injection was determined by the spreading of the contrast medium through the vascular channel during the injection. Additionally, pain intensity was scored using a Numeric Rating Scale (NRS) before the procedure and 1 month after the procedure.

Results

There was no significant difference in the incidence of intravascular injection during CTEB between group M and group S (41.3% vs 39.7%, respectively; p = 0.99) and in the NRS scores before and 1 month after CTEB. However, both groups showed a significant decrease in the NRS scores at 1 month after the procedure compared with that before the procedure.

Conclusion

The degree of CNFS does not affect the incidence of intravascular injection during CTEB. Regardless of whether patients have moderate or severe CNFS, caution should be exercised during CTEB procedures.

A New Parameter, the Smallest Oblique Sagittal Area of the Neural Foramen, as an Index to Diagnose Cervical Neural Foramen Stenosis

OBJECTIVE

The objective was to reconstruct the cervical neural foramen and accurately measure the minimum oblique sagittal area of the neural foramen. Then, a quantitative diagnostic standard for cervical neural foramen stenosis was proposed and its value as an indication for surgery was evaluated.

METHODS

(1) CT data were used to reconstruct the neural foramen using Mimics software, and the minimum area was measured. (2) The optimal cut-off value was determined using a receiver operating characteristic (ROC) curve. (3) Patients who underwent single-segment surgery were divided into 2 groups according to the cut-off value. Then the postoperative neurological function improvement rate was analyzed to identify any significant difference between the 2 groups.

RESULTS

A total of 1056 neural foramens were measured in 132 patients, of which 495 (46.88%) were diagnosed as radiculopathy by clinical neurological examination. The optimal cut-off value determined by the ROC curve was 25.95 mm² (sensitivity 74.1%, specificity 80.9%) and the area under the curve (AUC) was 0.827 (95%CI: 0.803-0.849). There was a significant difference in the neurological function improvement rate between the 2 groups after surgery (P < 0.05). The intraclass correlation coefficient (ICC) was 0.969.

CONCLUSION

Three-dimensional digital simulation reconstruction of CT data is a good measurement method. The optimal cut-off value determined here not only has a certain reference value for the diagnosis of cervical neural foramen bony stenosis, but also helps to select patients suitable for neural foramen decompression and can be used as a reference for surgical indication.

Systematic review of radiological cervical foraminal grading systems

The study design of this paper is systematic review. The purpose of this review is to evaluate the existing radiological grading systems that are used to assess cervical foraminal stenosis. The importance of imaging the cervical spine using CT or MRI in evaluating cervical foraminal stenosis is widely accepted; however, there is no consensus for standardized methodology to assess the compression of the cervical nerve roots. A systematic search of Ovid Medline databases, Embase 1947 to present, Cinahl, Web of Science, Cochrane Library, ISRCTN and WHO international clinical trials was performed for reports of cervical foraminal stenosis published before 01 February 2020. In collaboration with the University of Leeds, a search strategy was developed. A total of 6952 articles were identified with 59 included. Most of the reports involved multiple imaging modalities with standard axial and sagittal imaging used most. The grading themes that came from this systematic review show that the most mature for cervical foraminal stenosis is described by (Kim et al. Korean J Radiol 16:1294, 2015) and (Park et al. Br J Radiol 86:20120515, 2013). Imaging of the cervical nerve root canals is mostly performed using MRI and is reported using subjective terminology. The Park, Kim and Modified Kim systems for classifying the degree of stenosis of the nerve root canal have been described. Clinical application of these scoring systems is limited by their reliance on nonstandard imaging (Park), limited validation against clinical symptoms and surgical outcome data. Oblique fine cut images derived from three dimensional MRI datasets may yield more consistency, better clinical correlation, enhanced surgical decision-making and outcomes.

Cervical Radiculopathy Focus on Characteristics and Differential Diagnosis

Cervical radiculopathy is characterized by neurological dysfunction caused by compression and inflammation of the spinal nerves or nerve roots of the cervical spine. It mainly presents with neck and arm pain, sensory loss, motor dysfunction, and reflex changes according to the dermatomal distribution. The most common causes of cervical radiculopathy are cervical disc herniation and cervical spondylosis. It is important to find the exact symptomatic segment and distinguish between conditions that may mimic certain cervical radicular compression syndromes through meticulous physical examinations and precise reading of radiographs. Non-surgical treatments are recommended as an initial management. Surgery is applicable to patients with intractable or persistent pain despite sufficient conservative management or with severe or progressive neurological deficits. Cervical radiculopathy is treated surgically by anterior and/or posterior approaches. The appropriate choice of surgical treatment should be individualized, considering the patient’s main pathophysiology, specific clinical symptoms and radiographic findings thoroughly.

Spine system changes in soldiers after load carriage training in a plateau environment: a prediction model research

BACKGROUND

Low back pain is the most common spinal disorder among soldiers, and load carriage training (LCT) is considered the main cause. We aimed to investigate changes in the spine system of soldiers after LCT at high altitudes and the change trend of the lumbar spine and surrounding soft tissues under different load conditions.

METHODS

Magnetic resonance imaging scans of the lumbar spines of nine soldiers from plateau troops were collected and processed. We used ImageJ and Surgimap software to analyze changes in the lumbar paraspinal muscles, intervertebral discs (IVDs), intervertebral foramina, and curvature. Furthermore, the multiple linear regression equation for spine injury owing to LCT at high altitudes was established as the mathematical prediction model using SPSS Statistics version 23.0 software.

RESULTS

In the paraspinal muscles, the cross-sectional area (CSA) increased significantly from 9126.4 ± 691.6 mm² to 9862.7 ± 456.4 mm², and the functional CSA (FCSA) increased significantly from 8089.6 ± 707.7 mm² to 8747.9 ± 426.2 mm² after LCT (P < 0.05); however, the FCSA/CSA was not significantly different. Regarding IVD, the total lumbar spine showed a decreasing trend after LCT with a significant difference (P < 0.05). Regarding the lumbar intervertebral foramen, the percentage of the effective intervertebral foraminal area of L₃/₄ significantly decreased from 91.6 ± 2.0 to 88.1% ± 2.9% (P < 0.05). For curvature, the lumbosacral angle after LCT (32.4° ± 6.8°) was significantly higher (P < 0.05) than that before LCT (26.6° ± 5.3°), while the lumbar lordosis angle increased significantly from 24.0° ± 7.1° to 30.6° ± 7.4° (P < 0.05). The linear regression equation of the change rate, △FCSA% = - 0.718 + 23.085 × load weight, was successfully established as a prediction model of spinal injury after LCT at high altitudes.

CONCLUSION

The spinal system encountered increased muscle volume, muscle congestion, tissue edema, IVD compression, decreased effective intervertebral foramen area, and increased lumbar curvature after LCT, which revealed important pathophysiological mechanisms of lumbar spinal disorders in soldiers following short-term and high-load weight training. The injury prediction model of the spinal system confirmed that a load weight < 60% of soldiers' weight cannot cause acute pathological injury after short-term LCT, providing a reference supporting the formulation of the load weight standard for LCT.

The Effect of Oblique Magnetic Resonance Imaging on Surgical Decision Making for Patients Undergoing an Anterior Cervical Discectomy and Fusion for Cervical Radiculopathy

Background

The purpose of this study was to determine if oblique magnetic resonance imaging (MRI) sequences affect the surgical treatment recommendations for patients with cervical radiculopathy.

Methods

In this cohort study consecutive clinical cases of persistent cervical radiculopathy requiring surgical intervention were randomized, blinded, and reviewed by 6 surgeons. Initially each surgeon recommended treatment based on the history, physical examination, and axial, coronal and sagittal preoperative magnetic resonance (MR) images; when reviewing the cases the second time, the surgeons were provided oblique MR images. This entire process was then repeated after 2 months. Change in surgical recommendation, interobserver and intraobserver reliability and the average number of levels fused was determined.

Results

The addition of the oblique images resulted in the surgical recommendation being altered in 49.2% (59/120) of cases; however, the addition of oblique images did not substantially improve the interobserver reliability of the treatment recommendation (κ = .57 versus.57). Similarly, the overall intraobserver reliability using only traditional MRI sequences (κ = .64) was only slightly improved by the addition of oblique images (κ = .66). Lastly, the addition of oblique images did not change the average number of levels fused (traditional MRI = 1.38, oblique MRI = 1.41, P = .53), or the total number of 3-level fusions recommended (6 versus 6, P = 1.00).

Conclusions

The additional oblique images resulted in a change to the surgical plan in almost 50% of cases; however, it had no substantial effect on the reliability of surgical decision making. Further studies are needed to see if this alteration in treatment affects clinical outcomes.

Level of Evidence

3.

Best cut-off point of the cervical facet joint area as a new morphological measurement tool to predict cervical foraminal stenosis

Purpose: One of the main factor of cervical foraminal stenosis (CFS) is the hypertrophic change of the cervical facet joint. In order to analyze the connection between CFS and the facet joint hypertrophy, we devised a new morphological parameter, called the cervical facet joint cross-sectional area (CFJA). The CFJA has not yet been investigated for its association with CFS. We hypothesized that the CFJA is an important morphologic parameter in the diagnosis of CFS.

Patients and methods: All patients over 50 years of age were included. Data regarding the CFJA were collected from 160 subjects with CFS. A total of 162 control individuals underwent cervical spine magnetic resonance imaging (CMRI) as part of a routine medical examination. Axial T2-weighted CMRI images were acquired from all subjects. We used a picture archiving system to analyze the cross-sectional area of the bone margin of the cervical facet joint at the level of the most stenotic cervical spine in the axial plane.

Results: The average CFJA was 109.07±20.91 mm² in the control group, and 126.75±22.59 mm² in the CFS group. The CFS group was found to have significantly higher levels of the CFJA (p<0.001) than the control group. ROC curve estimation was used to verify the validity of the CFJA as a new predictor of CFS. In the CFS group, the best cut off-point was 113.14 mm², with sensitivity =70.6%, specificity =68.6%, and AUC =0.72 (95% CI, 0.66–0.77).

Conclusions: CFJA high values were closely associated with a possibility of CFS. We concluded CFJA is easy to use, fast, and useful new morphological parameter to predict CFS.

Full Endoscopic Key Hole Technique for Cervical Foraminal Stenosis: Is Mere Dorsal Decompression Enough?

OBJECTIVE

To study whether and when mere dorsal decompression is enough in the full endoscopic key hole technique for foraminal stenosis.

METHODS

We retrospectively reviewed a total of 22 patients with cervical foraminal stenosis who underwent full endoscopic key hole mere dorsal decompression in our institute from October 2016 to October 2017.

RESULTS

Preoperative neck disability index, neck visual analog scale score, and arm visual analog scale score were 25.8 ± 0.8, 4.9 ± 0.6, and 7.5 ± 0.5 in the group. Immediate postoperative scores were 6.9 ± 0.9, 1.3 ± 0.9, and 1.4 ± 0.5. Follow-up scores at 3 months (7.0 ± 0.9, 1.9 ± 0.6, and 2.7 ± 0.9), 6 months (7.3 ± 0.9, 2.1 ± 0.9, and 1.9 ± 0.5), and 12 months (7.6 ± 0.5, 2.5 ± 0.8, and 2.1 ± 0.7). The symptoms had improved significantly (P < 0.05). According to the Macnab criteria, 15 patients reported excellent results, 2 reported good results, and 2 reported fair results at the 12-month follow-up.

CONCLUSIONS

Stenosis is mainly caused by dorsal structures; mere dorsal decompression is enough. In both cases, the ventral and dorsal structures contributed to the stenosis. When there is no herniated soft fragment contributing to the stenosis, ventral decompression is not always necessary. If intraoperative exploration detects less tension formed by the ventral abnormal structures, mere dorsal decompression is enough to settle the symptoms.

Sonoelastographic evaluation of the sciatic nerve in patients with unilateral lumbar disc herniation

OBJECTIVE

The aim of this study was to compare strain elastography (SE) and shear wave elastography (SWE) findings of the sciatic nerve in patients with unilateral lumbar disc herniation (LDH) and healthy control subjects.

MATERIALS AND METHODS

The study group included patients with complaints of unilateral sciatica for 3-12 months, with foraminal stenosis due to one level of LDH (L4-L5 or L5-S1). An age- and gender-matched control group was formed of healthy subjects. Evaluations were performed on both the axial and longitudinal planes from the bilateral gluteal region using a 5-9 MHz multifrequency convex probe.

RESULTS

There were 40 patients (20 male, 20 female) with a mean age of 43.1 ± 12.7 years in the study group, and 40 healthy subjects (22 male, 18 female) with a mean age of 42.9 ± 10.7 years in the control group (p > 0.05). The sciatic nerve stiffness assessed on both the axial (12.3 ± 3.7 kPA) and longitudinal (14.3 ± 3.8 kPA) planes of the involved side was significantly higher than non-involved side (axial: 6.8 ± 2.1 and longitudinal: 8.3 ± 2.3 kPA) in the patient group (p < 0.001).

CONCLUSIONS

Patients with unilateral LDH have increased stiffness of the sciatic nerve compared to healthy control subjects. Although the findings in this preliminary study show that shear wave elastography can detect a change in sciatic nerve stiffness in patients with unilateral LDH, larger studies are required to determine the clinical utility of this technique.

Utility of Oblique Sagittal Reformatted and Three-dimensional Surface Reconstruction Computed Tomography in Foraminal Stenosis Decompression

Determining the responsible level of cervical radiculopathy can be difficult. Because asymptomatic findings are common in cervical radiculopathy, diagnoses based on imaging studies can be inaccurate. Therefore, we investigated whether the application of oblique sagittal reformatted computed tomography (oblique sagittal CT) and three-dimensional surface reconstruction CT (3DCT) affects surgical plans for patients with cervical foraminal stenosis and whether it assists diagnosis of foraminal stenosis. Accordingly, four reviewers, with office notes, observed the CT and magnetic resonance imaging (MRI) images of 18 patients undergoing surgical treatment for cervical radiculopathy. After reviewing the MRI and sagittal, coronal, and axial CT images, the reviewers recorded the operation to be performed; they examined oblique sagittal CT and 3DCT images of the same patients and noted any differences from their surgical plans. Consequently, we analyzed these changes in the decompressed foramina in the surgical plan; mean percent change in the plan was 18.1%. Inter-rater reliability improved from κ - 0.194 to κ - 0.240. Therefore, the addition of oblique and 3DCT images improves inter-rater reliability owing to changes in a part of decompressed foramina. The addition of oblique sagittal CT and 3DCT is helpful in evaluating the foramen and planning surgical treatment of cervical radiculopathy.

Coronal oblique orientation of the neural foramen improves cervical spine MRI: A comparison of the sensitivity of different angulations

OBJECTIVE

Angulated projections are used in radiography to show the cervical neural foramen. Imaging the coronal oblique planes in an MRI of the cervical spine should therefore improve visualization of neural foramen pathology. This has to be demonstrated.

PATIENTS AND METHODS

A multi-center investigation of 40 patients with monoradiculopathy and 10 healthy controls was undertaken. T2-weighted sagittal, coronal oblique and axial slices were individually and separately examined by four readers blinded to the diagnosis. The statistical evaluation compared against the clinical gold standard of the neurological diagnosis of a single nerve root irritation or lesion.

RESULTS

The sensitivity/specificity required to detect the relevant neural foramen pathology was 0.47/0.60 for axial, 0.57/0.90 for sagittal and 0.55/0.70 for coronal oblique scans. The readers felt significantly more confident in attributing the cause of pathology using coronal oblique planes. Interreader reliability was moderate to substantial, with the highest values for the sagittal planes (0.39-0.76) and lower values for the transversal and coronal oblique planes (0.15-0.63). Intrareader reliability was substantial, with values between 0.53 and 0.88. Reading the axial planes was significantly more time consuming than reading the other planes.

CONCLUSION

The use of coronal oblique planes in cervical spine MRIs increases sensitivity and confidence in attributing the cause of neural foramen obstruction. They are easy to interpret and demand less reading time than axial planes, and so the inclusion of coronal oblique planes in the workup of cervical spine MRI is recommended, at least when neural foramen pathology is suspected.

Degenerative findings on MRI of the cervical spine: an inter- and intra-rater reliability study

Background

Knowledge about the assessment reliability of common cervical spine changes is a prerequisite for precise and consistent communication about Magnetic Resonance Imaging (MRI) findings. The purpose of this study was to determine the inter- and intra-rater reliability of degenerative findings when assessing cervical spine MRI.

Methods

Fifty cervical spine MRIs from subjects with neck pain were used. A radiologist, a chiropractor and a second-year resident of rheumatology independently assessed kyphosis, disc height, disc contour, vertebral endplate signal changes, spinal canal stenosis, neural foraminal stenosis, and osteoarthritis of the uncovertebral and zygapophyseal joints. An evaluation manual was composed containing classifications and illustrative examples, and ten of the MRIs were evaluated twice followed by consensus meetings to refine the classifications. Next, the three readers independently assessed the full sample. Reliability measures were reported using prevalence estimates and unweighted kappa (Κ) statistics.

Results

The overall inter-rater reliability was substantial (Κ ≥ 0.61) for the majority of variables and moderate only for zygapophyseal osteoarthritis (Κ = 0.56). Intra-rater reliability estimates were higher for all findings.

Conclusions

The present classifications for some of the most common cervical degenerative findings yielded mainly substantial inter-rater reliability estimates and substantial to almost perfect intra-rater reliability estimates. .

Trial registration

Regional Data Protection Agency (J.no. 1-16-02-86-16). The letter of exemption from the Regional Ethical Committee is available from the author on request (case no. 86 / 2017).

Diagnostic Accuracy of Zero-Echo Time MRI for the Evaluation of Cervical Neural Foraminal Stenosis

STUDY DESIGN

A cohort study.

OBJECTIVE

The aim of this study was to evaluate the clinical utility of Zero-Echo-Time (ZTE) magnetic resonance imaging (MRI) for the assessment of cervical neural foraminal stenosis (CNFS) through the comparison of inter-modality [computed tomography (CT) and ZTE-MRI] CNFS grade severity agreements.

SUMMARY OF BACKGROUND DATA

Conventional MRI limited in its ability to provide direct visualization of cortical bone. The highly organized tissue structure of cortical bone results in very short T2 values that preclude acquisition of sufficient signal intensity and positive image contrast. ZTE imaging permits visualization of tissues with very short transverse relaxation times, and is capable of displaying images with CT-like contrast.

METHODS

Thirty-four subjects were recruited from a clinical cohort of patients undergoing standard of care MRI and CT imaging for evaluation of CNFS. Standard of care CT imaging studies were obtained on all subjects within 6 months of their ZTE-MRI acquisition (mean time interval: 25.3 ± 54.1 days; median: 0 days). ZTE-MRI and CT imaging studies were evaluated and severity of CNFS was graded on a scale from 0 to 5 (0 = none; 5 = severe). Weighted-kappa statistics were used to assess agreement between ZTE and CT grades of CNFS on both sides (right and left) of each motion segment. Ordinal logistic mixed-effects regression analyses evaluated the effects of inter-modality position differences (flexion-extension curvature) on inter-modality differences in CNFS grade.

RESULTS

Substantial agreement (κ = 0.72) was found between ZTE- and CT-based grades of CNFS. Significant inter-modality differences in cervical spine curvature were found for all motion segments, except C2-3 and C3-4 (P < 0.05). However, no significant relationship was found between inter-modality differences in curvature, and inter-modality differences in CNFS grade for any motion segment (P = 0.28).

CONCLUSION

Results of the current study suggest that ZTE-MRI is well-suited for the evaluation of CNFS and may have the potential to obviate the need for concurrent CT scans in some cases.

LEVEL OF EVIDENCE

2.

ABCs of the degenerative spine

Degenerative changes in the spine have high medical and socioeconomic significance. Imaging of the degenerative spine is a frequent challenge in radiology. The pathogenesis of this degenerative process represents a biomechanically related continuum of alterations, which can be identified with different imaging modalities. The aim of this article is to review radiological findings involving the intervertebral discs, end plates, bone marrow changes, facet joints and the spinal canal in relation to the pathogenesis of degenerative changes in the spine. Findings are described in association with the clinical symptoms they may cause, with a brief review of the possible treatment options. The article provides an illustrated review on the topic for radiology residents.

TEACHING POINTS

• The adjacent vertebrae, intervertebral disc, ligaments and facet joints constitute a spinal unit. • Degenerative change is a response to insults, such as mechanical or metabolic injury. • Spine degeneration is a biomechanically related continuum of alterations evolving over time.

Comparing the Effectiveness of Sagittal Balance, Foraminal Stenosis, and Preoperative Cord Rotation in Predicting Postoperative C5 Palsy

STUDY DESIGN

Retrospective cohort review.

OBJECTIVE

To determine whether preoperative cord rotation is independently correlated with C5 palsy when analyzed alongside measures of sagittal balance and foraminal stenosis.

SUMMARY OF BACKGROUND DATA

Postoperative C5 palsy is a well-documented complication of cervical procedures with a prevalence of 4%-8%. Recent studies have shown a correlation with preoperative spinal cord rotation. There have been few studies, however, that have examined the role of sagittal balance and foraminal stenosis in the development of C5 palsy.

METHODS

A total of 77 patients who underwent cervical decompression-10 of whom developed C5 palsy-were reviewed. Sagittal balance was assessed using curvature angle and curvature index on radiographs and magnetic resonance image (MRI). Cord rotation was assessed on axial MRI. C4-C5 foraminal stenosis was assessed on sagittal MRI using area measurements and a grading scale. Demographics and information on surgical approach were gathered from chart review. Correlation with C5 palsy was performed by point-biserial, χ, and regression analyses.

RESULTS

Point-biserial analysis indicated that only cord rotation showed significance (P<0.01). There was no statistical significance shown with surgical approach, sex, or age. In addition, changes in sagittal balance did not correlate with presence of C5 palsy. Logistic regression model yielded cord rotation as the only significant independent predictor of C5 palsy. For every degree of axial cord rotation, the likelihood ratio for suffering a C5 palsy was 3.93 (95% confidence interval, 2.01-8.66; P<0.05).

CONCLUSIONS

This supports the independent capability of preoperative cord rotation to predict postoperative C5 palsy. Lack of correlation with measures of neuroforaminal stenosis potentially points to mechanisms other than direct compression as the etiology. In addition, the lack of correlation with postoperative changes in sagittal balance hints that measures of curvature angle and curvature index may not be appropriate to accurately predict this complication.

LEVEL OF EVIDENCE

Level 3.

Comparison of two MR grading systems for correlation between grade of cervical neural foraminal stenosis and clinical manifestations

OBJECTIVE

To compare the reliability of two recently reported MR grading systems of cervical neural foraminal stenosis (CNFS) and their correlation with clinical manifestations.

METHODS

We evaluated 188 patients (male : female = 80 : 108; mean age of 41 years) who visited our institution and underwent oblique sagittal MRI of the cervical spine. Two radiologists evaluated the MRI findings for the presence and grade of CNFS at the narrowest point, with the grading systems (Park, Kim and mKim systems) suggested by Park et al and Kim et al. More than one positive neurologic sign and more than one neurologic clinical symptom was considered a positive neurologic manifestation of each foraminal stenosis. Interobserver agreement between the two readers was analyzed using kappa statistics. Non-parametric correlation analysis (Spearman's correlation) was used to evaluate the correlation coefficients (R) to assess the relationship between CNFS grade and clinical manifestations.

RESULTS

Both the Park and mKim systems demonstrated a relatively high correlation (R = 0.714-0.764) between the CNFS grade and clinical manifestation, while the Kim system yielded a moderate correlation (by Reader 2). The Park and mKim systems demonstrated higher correlation values at the level of C6-7 than C4-5, while the Kim system showed no difference in correlation at the cervical spine level.

CONCLUSION

Both the Park and mKim systems provide a reliable, reproducible CNFS diagnosis, while the Kim system has a slightly inferior reliability. The Park and mKim systems had a similar, relatively high clinical correlation.

ADVANCES IN KNOWLEDGE

Grades 2 and 3 of the Park system and Grade 2 in the Kim and mKim systems exhibited a similar clinical significance. Patients with a grade of 0 (using each system) consistently exhibit negative neurologic manifestation.

Comparison of agreement of cervical spine degenerative pathology findings in magnetic resonance imaging studies

BACKGROUND CONTEXT

Magnetic resonance imaging (MRI) is often used in the evaluation of degenerative conditions of the cervical spine. However, the agreement of interpreting and reporting varying degenerative findings on cervical MRI has not been well assessed.

PURPOSE

This study aimed to compare the inter-rater and intra-rater agreement of MRI findings between common degenerative findings of the cervical spine.

STUDY DESIGN

A retrospective diagnostic study was used as study design.

PATIENT SAMPLE

The sample consisted of 48 patients who underwent routine cervical spine MRI at our institution between January 2011 and June 2012.

OUTCOME MEASURES

Reviewers evaluated each MRI study at each vertebral level for disc hydration, disc space height, central stenosis, foraminal stenosis, end plate changes, spondylolisthesis, and cord signal change.

METHODS

A panel of two orthopedic spine surgeons and four musculoskeletal radiologists independently reviewed 48 sets of T2-weighted axial and sagittal MRI sequences for a series of preselected criteria, and their findings were compared with those of the other panelists to determine inter-rater agreement. Each panelist also re-reviewed the first 10 studies to determine intra-rater agreement. Absolute inter-rater and intra-rater agreements were then calculated and compared for different findings. A modified analysis ignored disagreements between the least severe grades of findings to determine the inter-rater and intra-rater agreements of the most clinically important severity grades.

RESULTS

Absolute inter-rater agreement ranged from 54.6% to 95.0%. Disc hydration (54.6%), central stenosis (72.7%), and foraminal stenosis (73.1%) demonstrated the lowest inter-rater agreement, whereas spondylolisthesis (95.0%) and cord signal change (92.9%) demonstrated the highest agreement. The modified analysis found better inter-rater agreement, ranging from 80.9% to 95.0%. Absolute intra-rater agreement ranged from 74.2% to 94.7%. The modified analysis again found better agreement, ranging from 85.0% to 94.7%. As would be expected, overall intra-rater agreement (81.6%, 95% CI 78.9%-84.3%) was higher than inter-rater agreement (75.7%, 95% CI 74.4%-77.0%). The clinical specialty of the reviewer had no significant impact on inter- or intra-rater agreement.

CONCLUSIONS

MRI findings play an important role in the management of patients with cervical spine conditions. For this reason, consistent descriptions of these findings are essential and physicians should be aware of the relative reliability of these findings. This systematic study developed standardized grading criteria and nomenclature for common clinically significant MRI findings in the cervical spine. Even in this optimized research setting, we found significant ranges in agreement across these MRI findings. In the clinical setting, inter- and intra-rater agreements may be lower, and the range of agreements between findings may be greater. Physicians should be aware of inconsistencies inherent in the interpretation of cervical MRI findings and should be aware that some findings demonstrate lower agreement than others.

A New MRI Grading System for Cervical Foraminal Stenosis Based on Axial T2-Weighted Images

OBJECTIVE

The purpose of this study was to evaluate the reliability of a new magnetic resonance imaging (MRI) grading system for cervical neural foraminal stenosis (NFS).

MATERIALS AND METHODS

Cervical NFS at bilateral C4/5, C5/6, and C6/7 was classified into the following three grades based on the T2-weighted axial images: Grade 0 = absence of NFS, with the narrowest width of the neural foramen greater than the width of the extraforaminal nerve root (EFNR); Grade 1 = the narrowest width of the neural foramen the same or less than (but more than 50% of) the width of the EFNR; Grade 2 = the width of the neural foramen the same or less than 50% of the width of the EFNR. The MRIs of 96 patients who were over 60 years old (M:F = 50:46; mean age 68.4 years; range 61-86 years) were independently analyzed by seven radiologists. Interobserver and intraobserver agreements were analyzed using the percentage agreement, kappa statistics, and intraclass correlation coefficient (ICC).

RESULTS

For the distinction among the three individual grades at all six neural foramina, the ICC ranged from 0.68 to 0.73, indicating fair to good reproducibility. The percentage agreement ranged from 60.2% to 70.6%, and the kappa values (κ = 0.50-0.58) indicated fair to moderate agreement. The percentages of intraobserver agreement ranged from 85.4% to 93.8% (κ = 0.80-0.92), indicating near perfect agreement.

CONCLUSION

The new MRI grading system shows sufficient interobserver and intraobserver agreement to reliably assess cervical NFS.

[Utility of coronal oblique slices in cervical spine MRI: Improved detection of the neuroforamina]

BACKGROUND AND OBJECTIVES

Angulated projections are standard in conventional radiography of the cervical spine, but rarely used in magnetic resonance imaging (MRI). As neuroforaminal pathology plays an important role in the etiology of radicular syndromes and may influence an operative approach, the utility of coronal oblique slices in MRI is explored.

MATERIALS AND METHODS

In a retrospective setting, 25 consecutive patients with neurologically diagnosed cervical monoradiculopathy were identified. T2-weighted sagittal, coronal oblique, and transversal slice orientations were anonymized. Two radiologists and two neurosurgeons independently assessed the cases. Criteria were site, cause, and grading of the neuroforaminal stenosis and the level of confidence on a 100-point visual analog scale (VAS). We computed interrater agreement, sensitivity, and t tests.

RESULTS

Using only one slice orientation, the sensitivity in detecting the relevant neuroforamen was 0.40 for transversal, 0.68 for sagittal, and 0.64 for coronal oblique scans. A combination of the different angulations increased sensitivity and in 4 cases only the coronal oblique scans proved diagnostic. The readers felt significantly more confident in attributing the cause of the pathology on coronal oblique planes (a mean of 72 VAS points, p = 0.0003 vs 58 (sagittal) vs 64 (transversal)). Interrater agreement was significantly better for experienced (kappa 0. 48) than for inexperienced readers (0.32, p = 0.02).

CONCLUSIONS

Adding coronal oblique planes in cervical spine MRI increases sensitivity and confidence in attributing the cause of neuroforaminal pathology. They are regarded as useful by all the readers.

MR imaging of degenerative disc disease

Magnet resonance imaging (MRI) is the most commonly used imaging modality for diagnosis of degenerative disc disease (DDD). Lack of precise observations and documentation of aspects within the complex entity of DDD might partially be the cause of poor correlation of radiographic findings to clinical symptoms. This literature review summarizes the current knowledge on MRI in DDD and outlines the diagnostic limitations. The review further sensitizes the reader toward awareness of potentially untended aspects of DDD and the interaction of DDD and endplate changes. A summary of the available classifications for DDD is provided.

Diagnostic value of oblique magnetic resonance images for evaluating cervical foraminal stenosis

BACKGROUND CONTEXT

The benefits of oblique magnetic resonance imaging (MRI) reformations to assess cervical neural foramina have been reported previously in clinical and cadaveric studies. But there is a paucity of literature investigating intra- and interobserver variabilities for assessing cervical foraminal stenosis using oblique MRI views.

PURPOSE

To determine the value of oblique MRI views compared with axial and sagittal views for assessing foraminal stenosis of the cervical spine using intra- and interobserver variabilities.

STUDY DESIGN

A retrospective study.

PATIENT SAMPLE

Twenty-six patients were included.

OUTCOME MEASURES

Two independent reviewers blindly identified the presence of foraminal stenosis as definite or indeterminate on the sagittal, axial, and oblique views. The assessments using the different views were compared using an independent t test. Intra- and interobserver variabilities were assessed using Kappa analysis.

METHODS

We evaluated the cervical spine MRIs of patients with varying degrees of foraminal stenosis. The mean age of the patients was 60.8 years (range 50-86 years). Male to female ratio was 16:10. The oblique images were obtained by reformatting the scans perpendicular to the long axis of the right and left neural foramina, respectively.

RESULTS

The oblique or axial views had significantly greater confidence rates for determining the presence of foraminal stenosis than the sagittal views (92.3%, 88.1% vs. 58.0%, respectively, p=.000). The oblique view had significantly better intraobserver agreement than the sagittal and axial images. Both the axial and oblique views had significantly better interobserver agreement than the sagittal images.

CONCLUSIONS

Oblique MRI views of the cervical spine significantly reduce the degree of intra- and interobserver variabilities and increase observer confidence in the assessment of foraminal stenosis. Our results suggest that routine use of oblique cervical MRI views might be useful for evaluating cervical foraminal stenosis.