Evaluation of Cervical Myelopathy Using Apparent Diffusion Coefficient Measured by Diffusion-Weighted Imaging

Abstract

Cervical spondylosis is a very common degenerative condition of the spine, found in more than 75% of patients after the age of 65. Progressive cervical myelopathy is caused by chronic segmental compression of the spinal cord due to spondylotic changes.

The most appropriate treatment of the cervical myelopathy is surgical decompression, and the earlier the treatment, the more effective. Since the results of surgical treatment are better in mildly affected patients than in severely affected patients, the diagnosis of cervical spondylotic myelopathy must be made as early as possible and with highly sensitive tools.

Magnetic resonance (MR) imaging with T2 weighting has been reported to have low sensitivity for the detection of cervical myelopathy. Furthermore, the high signal intensity related to cervical myelopathy appears on T2 weighted images only in patients of late clinical stages .

An MR imaging technique that evaluates the translation motion of water molecules in vivo gives the possibility of assessing the spinal cord with diffusion-weighted imaging.

DWI has been used far less frequently in spinal cord because of the inhomogeneous magnetic environment, the small size of the spinal cord, and increased motion in and around the spine. However, once these limitations were overcome DWI is recently used increasing the sensitivity of MR imaging for the depiction of spinal cord changes in patients with clinical symptoms of cervical spondylotic myelopathy.

ADC measured by DWI of the spinal cord can provide objective and reliable indications of the severity of CSM, by evaluating the relationship between ADC values and other clinical factors, An increased ADC value was reported to relate to internal changes in the early stages of chronic spinal cord compression,wi