Clin Orthop Surg.  2015 Dec;7(4):465-469. 10.4055/cios.2015.7.4.465.

Significance of Intramedullary High Signal Intensity on Magnetic Resonance Imaging in Patients with Cervical Ossification of the Posterior Longitudinal Ligament

• Choi BW
• Hum TW

• KMID: 2360260
• DOI: http://doi.org/10.4055/cios.2015.7.4.465

Abstract

BACKGROUND
The purpose of this study was to analyze the relation between intramedullary high signal intensity (IMHS) on magnetic resonance imaging (MRI), radiographic parameters, and clinical symptoms in cervical ossification of the posterior longitudinal ligament (OPLL) patients.
METHODS
Two hundred forty-one patients, who underwent simple radiography, computed tomography (CT), and MRI were included in the present study. As radiographic parameters, the OPLL occupying ratio and occupying area were measured on CT images. Dynamic factors were assessed by measuring cervical range of motion (ROM) on simple radiographs. Visual analog scale (VAS) for neck and arm pain, and Japanese Orthopaedic Association (JOA) scores were evaluated for clinical analysis. The differences in radiographic and clinical findings were assessed between patients with IMHS on T2-weighted MRI findings (group A) and patients without IMHS (group B).
RESULTS
Eighty-one patients were assigned to group A and 160 patients to group B. The occupying ratios were found to be higher in group A than in group B on both sagittal and axial views (p < 0.01). Group A also showed a higher area occupying ratio (p < 0.01). The length and area of underlying spinal canal on the sagittal and cross-sectional planes were lower in group A than in group B (p < 0.01). No significant difference in ROM was observed (p = 0.63). On the clinical findings, group A had a lower JOA score (p < 0.001), and no intergroup differences in VAS scores were observed.
CONCLUSIONS
In cervical OPLL cases, IMHS on MRI was associated with manifestation of myelopathic symptom. Occupying ratio was associated with high signal intensity on MRI, whereas no association was found with ROM. Occurrence of high signal intensity increased inversely with the length and area of underlying spinal canal.

Keyword

Ossification of posterior longitudinal ligament; Cervical spine; Intramedullary high signal change; Magnetic resonance imaging

MeSH Terms

Adult
Aged
Cervical Vertebrae/*pathology
Female
Humans
Magnetic Resonance Imaging/*classification
Male
Middle Aged
Neck Pain
Ossification of Posterior Longitudinal Ligament/*classification/*pathology
Pain Measurement

Figure

• 

  Fig. 1 Radiological evaluations. (A) Sagittal occupying ratio: (b-a)/b. a: sagittal space available for cord, b: sagittal canal length. (B) Axial occupying ratio: (d-c)/d. c: axial space available for cord, d: axial canal length. (C) Area occupying ratio: f/e. e: area of spinal canal, f: area of ossification of posterior longitudinal ligament. (D) Range of motion (yellow line: endplate of C2 and C7).

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