Can multi-positional magnetic resonance imaging be used to evaluate angular parameters in cervical spine? A comparison of multi-positional MRI to dynamic plain radiograph

Utility of a 2D kinematic HASTE sequence in magnetic resonance imaging assessment of adjacent segment degeneration following anterior cervical discectomy and fusion

OBJECTIVES

To evaluate a dynamic half-Fourier acquired single turbo spin echo (HASTE) sequence following anterior cervical discectomy and fusion (ACDF) at the junctional level for adjacent segment degeneration comparing dynamic listhesis to radiographs and assessing dynamic cord contact and deformity during flexion-extension METHODS: Patients with ACDF referred for cervical spine MRI underwent a kinematic flexion-extension sagittal 2D HASTE sequence in addition to routine sequences. Images were independently reviewed by three radiologists for static/dynamic listhesis, and compared to flexion-extension radiographs. Blinded assessment of the HASTE sequence was performed for cord contact/deformity between neutral, flexion, and extension, to evaluate concordance between readers and inter-modality agreement. Inter-reader agreement for dynamic listhesis and impingement grade and inter-modality agreement for dynamic listhesis on MRI and radiographs was assessed using the kappa coefficient and percentage concordance.

RESULTS

A total of 28 patients, mean age 60.2 years, were included. Mean HASTE acquisition time was 42 s. 14.3% demonstrated high grade dynamic stenosis (> grade 4) at the adjacent segment. There was substantial agreement for dynamic cord impingement with 70.2% concordance (kappa = 0.62). Concordance across readers for dynamic listhesis using HASTE was 81.0% (68/84) (kappa = 0.16) compared with 71.4% (60/84) (kappa = 0.40) for radiographs. Inter-modality agreement between flexion-extension radiographs and MRI assessment for dynamic listhesis across the readers was moderate (kappa = 0.41; 95% confidence interval: 0.16 to 0.67).

CONCLUSIONS

A sagittal flexion-extension HASTE cine sequence provides substantial agreement between readers for dynamic cord deformity and moderate agreement between radiographs and MRI for dynamic listhesis.

CLINICAL RELEVANCE STATEMENT

Degeneration of the adjacent segment with instability and myelopathy is one of the most common causes of pain and neurological deterioration requiring re-operation following cervical fusion surgery.

KEY POINTS

• A real-time kinematic 2D sagittal HASTE flexion-extension sequence can be used to assess for dynamic listhesis, cervical cord, contact and deformity. • The additional kinematic cine sequence was well tolerated and the mean acquisition time for the 2D HASTE sequence was 42 s (range 31-44 s). • A sagittal flexion-extension HASTE cine sequence provides substantial agreement between readers for dynamic cord deformity and moderate agreement between radiographs and MRI for dynamic listhesis.

Correlation and reliability of cervical sagittal alignment parameters between plain radiographs and multipositional MRI images

STUDY DESIGN

A retrospective study.

OBJECTIVES

To assess the validity and reliability of cervical sagittal alignment parameters from multipositional magnetic resonance imaging (MRI) and dynamic cervical radiography.

SETTING

Hospital in Suzhou, China.

METHODS

Patients who underwent both multipositional MRI and dynamic plain radiography of the cervical spine within a 2-week interval between January 2013 and October 2021 were retrospectively enrolled in this study. The C2-7 angle, C2-7 cervical sagittal vertical axis (C2-7 SVA), T1 slope (T1S), cervical tilt, cranial tilt, and K-line tilt were measured in three different positions (neutral, flexion, and extension) with multipositional MRI and dynamic radiography. Inter- and intraobserver reliabilities were assessed by intraclass correlation coefficients (ICCs). Pearson correlation coefficients were used for statistical analyses.

RESULTS

A total of 65 (30 males and 35 females) patients with a mean age of 53.4 years (range 23-69 years) were retrospectively enrolled in this study. Significant positive correlations were noted regarding all parameters between the plain radiographs and multipositional MRI images. Inter- and intraobserver reliabilities were excellent for all cervical sagittal alignment parameters measured in the two imaging modalities. All cervical sagittal parameters had significant positive correlations with those from multipositional MRI in all three positions (p < 0.05). Pearson correlation coefficients demonstrated moderate and strong correlations between the two examinations.

CONCLUSIONS

Cervical sagittal alignment parameters measured on multipositional MRI could reliably substitute for those measured on plain radiographs. Multipositional MRI is a valuable, radiation-free alternative for diagnostic evaluation in degenerative cervical diseases.

The Assessment of Dynamic Spinal Cord Impingement by Kinematic Magnetic Resonance Imaging in Patients with Traumatic Central Cord Syndrome

Background

There are few reports describing the imaging features of traumatic central cord syndrome (TCCS) in kinematic magnetic resonance imaging (kMRI) scans. The current study aimed to assess and characterize dynamic spinal cord impingement (DSCI) using kMRI and evaluate the risk factors for poor outcomes in patients with TCCS after surgery.

Methods

This retrospective study included 63 patients with TCCS who underwent surgery in the authors' hospital. The American Spinal Injury Association impairment scale grade and Japanese Orthopedic Association (JOA) score were collected preoperatively and at the final follow-up to assess neurological function. Patients were divided into two groups based on the JOA score (> or <50%), and clinical and radiographic evaluations were compared. The metrics examined included age at the time of surgery, gender, type of trauma, the interval from injury to surgery, surgical approach, pathological signs, range of motion, DSCI and the length of intramedullary hyperintensity signal (LIHS).

Results

There were statistical differences in the LIHS, DSCI and preoperative JOA score between good (JOA >50%; n = 50) and poor (JOA <50%, n =13) recovery patient groups (P<0.05). Logistic regression, with poor outcomes as the dependent variable, suggested independent risk associations with preoperative JOA score (P<0.05), DSCI (P<0.05) and LIHS (P<0.05).

Conclusion

kMRI can be effective for decision-making in the treatment of TCCS. The lower preoperative JOA score, longer high signal cord and higher dynamic spinal cord impingement were risk factors for poor outcomes in patients with TCCS after surgery.

Clinical feasibility of 2D dynamic sagittal HASTE flexion-extension imaging of the cervical spine for the assessment of spondylolisthesis and cervical cord impingement

PURPOSE

To assess the utility of a 2D dynamic HASTE sequence in assessment of cervical spine flexion-extension, specifically (1) comparing dynamic spondylolisthesis to radiographs and (2) assessing dynamic contact upon or deformity of the cord.

METHODS

Patients with a dynamic flexion-extension sagittal 2D HASTE sequence in addition to routine cervical spine sequences were identified. Static and dynamic listhesis was first determined on flexion-extension radiographs reviewed in consensus. Blinded assessment of the dynamic HASTE sequence was independently performed by 2 radiologists for (1) listhesis and translation during flexion-extension and (2) dynamic spinal cord impingement (cord contact or deformity between neutral, flexion and extension).

RESULTS

32 scans in 32 patients (9 males, 23 females) met inclusion criteria acquired on 1.5 T (n = 15) and 3 T (n = 17) scanners. The mean acquisition time was 51.8 s (range 20-95 seconds). Dynamic translation was seen in 14 patients on flexion-extension radiographs compared to 12 (reader 1) and 13 (reader 2) patients on HASTE, with 90.6 % agreement (K = 0.83; p = 0.789). In all cases dynamic listhesis was ≤3 mm translation with one patient showing dynamic listhesis in the range 4-6 mm. Four cases (13 %) demonstrated deformity of the cord between flexion-extension, not present in the neutral position. For cord impingement there was strong inter-reader agreement (K = 0.93) and the paired sample Wilcoxon signed rank test found no significant difference between the impingement scores of the two readers (p = 0.787).

CONCLUSIONS

A sagittal dynamic flexion-extension HASTE sequence provides a rapid addition to standard MRI cervical spine protocols, which may useful for assessment of dynamic spondylolisthesis and cord deformity.

Occipitocervical measurements: correlation and consistency between multi-positional magnetic resonance imaging and dynamic radiographs

PURPOSE

To evaluate the reliability and validity of the multi-positional magnetic resonance imaging in measuring occipitocervical parameters using the standard cervical dynamic radiographs as a reference.

METHODS

Patients were included if they underwent both dynamic radiograph and cervical multi-positional MRI within a 2-week interval from January 2013 to December 2016. Twelve occipitocervical parameters were measured on both image modalities in all positions (neutral, flexion and extension): Posterior Atlanto-Dental Interval, Anterior Atlanto-Dental Interval (AADI), Dens-to-McRae distance, Dens-to-McGregor distance, Occipito-atlantal Cobb angle (C01 angle), Occipito-axis Cobb angle (C02 Cobb angle), Atlas-axis Cobb angle (C12 angle), Redlund-Johnell, Modified Ranawat, Clivus canal angle, Occiput inclination, and Occiput cervical distance. Pearson correlation and linear regression analysis were used to evaluate the correlation of both modalities for each parameter. A p value of < 0.05 was considered statistically significant.

RESULTS

Cervical images of 70 patients were measured and analyzed. There was a significant positive correlation between dynamic X-ray and multi-positional MRI for all parameters (p < 0.05) except AADI. Dens-to-McGregor distance and Redlund-Johnell parameter demonstrated a very strong correlation in the neutral position (r = 0.72, r = 0.79 respectively) and moderate to very strong correlation(r > 0.4) for Modified Ranawat, Clivus canal angle, C02 Cobb angle and C02 distance in all neck position. The intra-class correlation (ICC) of intra- and inter-observer showed good to excellent reliability, and ICCs were 0.67-0.98.

CONCLUSIONS

Multi-positional MRI can be a reliable imaging option for diagnosis of occipitocervical instability or basilar invagination compared to standard dynamic radiographs.

Review of Radiological Parameters, Imaging Characteristics, and Their Effect on Optimal Treatment Approaches and Surgical Outcomes for Cervical Ossification of the Posterior Longitudinal Ligament

Determining the optimal surgical method for cervical ossification of the posterior longitudinal ligament (OPLL) is challenging. The surgical indication should be made based on not only radiological findings, but also the patient’s age, preoperative neurological findings, social background, activities of daily life, and the presence or absence of comorbid diseases. Anterior resection for OPLL with or without wide corpectomy and fusion, posterior decompression with or without relatively long fusion, or anterior and posterior combined surgery may be considered. When evaluating the clinical condition of patients with cervical OPLL before surgery, various radiological parameters should be carefully considered, including the number of spinal segments involved, the cervical alignment or tilt angle, the relationship between OPLL and the C2–7 line (termed the “K-line”), the occupying ratio of OPLL, and the involvement of dural ossification. The objective of this article is to review the radiological parameters in current use for deciding upon the optimal surgical strategy and for predicting surgical outcomes, focusing on cervical OPLL.

The most appropriate cervical vertebra for the measurement of occipitocervical inclination parameter: a validation study of C3, C4, and C5 levels using multi-positional magnetic resonance imaging

PURPOSE

To evaluate which cervical level is the most appropriate level to measure occipitocervical inclination (OCI).

METHODS

Sixty-two patients with multi-positional MRI: 24 males and 38 females, who had cervical lordosis and had a disk degeneration grade of 3 or less were included. We measured patient's OCI at C3, C4, and C5, occipitocervical angle (OCA), occipitocervical distance (OCD), C2-7 angle, and cervical sagittal vertical axis (cSVA) in neutral, flexion, and extension position. The correlation between OCI and OCA, OCD, C2-7 angle, and cSVA on each cervical level in all three positions was tested using Pearson's correlation coefficient test. The difference between OCIs at each cervical level was tested by Wilcoxon signed-rank test. p value of less than 0.05 was set as a statistically significant level.

RESULTS

C5 OCI showed statistically significant correlation with OCA, OCD, C2-7 angle, and cSVA in all three positions (p < 0.05, r = 0.214-0.525). C3 OCI in flexion (p = 0.393, r = 0.081) and C4 OCI in neutral and flexion (neutral p = 0.275, r 0.104; flexion p = 0.987, r = 0.002) did not show significant correlation with C2-7 angle. There was a statistically significant difference between C3, C4, and C5 OCIs in neutral and extension position (p < 0.05). At the same time, OCI showed statistically strong correlation between adjacent cervical levels (p < 0.001, r = 0.627-0.822).

CONCLUSION

C5 cervical level is the most appropriate level for OCI measurement. OCI should be measured at the same cervical level at all time. C4 OCI can reliably substitute C5 OCI in case C5 which is invisible on radiographic image. These slides can be retrieved under Electronic Supplementary Material.