Articles from Spine

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Linn, Jennifer ; Birkenmaier, Christof ; Hoffmann, Ralf T.; Reiser, Maximilian ; Baur-Melnyk, Andrea
The Intravertebral Cleft in Acute Osteoporotic Fractures: Fluid in Magnetic Resonance Imaging-Vacuum in Computed Tomography?
Spine. 34(2):E88-E93, January 15, 2009.
Abstract
Study Design. The study consisted of a retrospective and a prospective study part.Objective. We aimed to investigate the nature of the intravertebral vacuum clefts (IVC) in computed tomography (CT) in acute osteoporotic vertebral fractures in correlation with magnetic resonance imaging (MRI).Summary of Background Data. IVC and intravertebral fluid accumulations have been shown to be indicative of benign vertebral fractures in CT and MRI, respectively.Methods. Twenty-eight patients (30 osteoporotic fractures) associated with intravertebral vacuum in CT in whom MRI of the spine was performed were retrospectively analyzed. Moreover, we prospectively performed MRI examinations in 12 consecutive patients with 13 osteoporotic fractures with an intravertebral vacuum in CT. T1-w SE, STIR, and 5 repetitive T2-w TSE studies were performed (1.5 Tesla system, Siemens). Two experienced readers assessed the examinations in consensus with regard to the occurrence and location of the intravertebral and intradiscal vacuum on CT and the corresponding signal alterations in MRI.Results. Twenty-seven (90%) of the retrospectively analyzed fractures with intravertebral vacuum in CT showed a fluid like signal in the location of the vacuum in MRI. In the prospective group, a small fluid-like signal was initially present on T2-weighted sequences in 11 of 13 fractures (84.6%). During the repeated T2-weighted measurements, the fluid occurred or increased markedly in all cases. An intradiscal fluid was present either initially and/or during the course of the examination in 46% of the prospective cases and in 50% of the retrospectively evaluated fractures.Conclusion. The occurrence of the fluid in MRI within intravertebral clefts is a dynamic process, which is dependent on the position of the patient and is presumably secondary to the extension momentum in the supine position. This may be due to the negative pressure in the horizontal position in which the fracture site is distracted. intravertebral.


Samdani, Amer F. ; Fayssoux, Reginald S. ; Asghar, Jahangir ; McCarthy, James J. et al
Chronic Spinal Cord Injury in the Pediatric Population: Does Magnetic Resonance Imaging Correlate With the International Standards for Neurological Classification of Spinal Cord Injury Examination?
Spine. 34(1):74-81, January 1, 2009.
Abstract
Study Design. Prognostic, retrospective case series.Objective. This study is part of a larger investigation to develop and validate a standardized and reliable method to evaluate and classify the neurologic consequence of spinal cord injury (SCI) in children. Such an instrument may also find use in the evaluation of patients with concomitant brain injury and/or cognitive impairment. We examined the relationship between the International Standards for Neurologic Classification of Spinal Cord Injury (ISCSCI) examination and magnetic resonance imaging (MRI) findings in a pediatric SCI population.Summary of Background Data. Recently, the reliability of the ISCSCI in young children with SCI who are unable to cognitively engage in the examination has been called into question. This has important implications as appropriate classification of these patients is necessary for prognostication, follow-up care, and appropriate placement into clinical trials.Methods. Our longitudinal pediatric SCI database was reviewed for children with chronic SCI (>6 months), ISCSCI examinations performed by experienced testers, and adequate MRIs of the spine. ISCSCI results were correlated with MRI findings. Twenty-six subjects were identified.Results. Overall, good to excellent relationships between ISCSCI neurologic level (NL) and MRI level of injury were found [Kendall [tau] correlation coefficient 0.90

Lehman, Ronald A. Jr ; Helgeson, Melvin D. ; Keeler, Kathryn A. et al
Comparison of Magnetic Resonance Imaging and Computed Tomography in Predicting Facet Arthrosis in the Cervical Spine
Spine. 34(1):65-68, January 1, 2009.
Abstract
Study Design. Retrospective review.Objective. To determine the ability of magnetic resonance imaging (MRI) and computed tomography (CT) to predict the presence of cervical facet arthrosis.Summary of Background Data. In the Food and Drug Administration Investigational Device Exemption trials of cervical disc arthroplasty (CDA), the presence of facet arthrosis on CT was a contraindication to the insertion of a CDA. Most surgeons routinely obtain an MRI, but not necessarily a CT before performing surgery in the cervical spine. We sought to determine if the MRI alone is adequate to assess for the presence of facet arthrosis.Methods. Three experienced spine surgeons retrospectively evaluated CT scans and MRIs of the same patients, obtained within 30 days of each other in a blinded, random fashion. Reviewers graded each of the MRI and CT scan as normal or abnormal on 3 separate occasions and if the facet was abnormal, each reviewer graded the degree of arthrosis. The radiologist's evaluation for each study was compared with our results.Results. Of 594 facets analyzed, 43.1% were categorized as normal on CT, and of those, MRI concordance was only 63.7% with moderate/substantial intermethod agreement. Furthermore, MRI was concordant only 15.9% of the time in patients with ankylosed facet joints on CT. CT inter-rater reliability showed substantial agreement for diagnoses of both normal and ankylosis and fair agreement for lesser degrees of facet arthrosis. MRI inter-rater reliability showed fair/moderate agreement in normal and ankylosed segments and only slight agreement with lesser degrees of facet arthrosis. CT intrarater reliability showed substantial agreement in normal or ankylosed joints, but only fair agreement for all other categories; MRI showed only fair agreement.Conclusion. The ability of MRI to adequately determine the presence or amount of facet arthrosis is not reliable. Additionally, for abnormal facets, MRI was not reliable in adequately determining the degree of arthrosis. Our data suggest that computed tomography remains necessary in diagnosing facet arthrosis before CDA.