Diffusion tensor imaging (DTI) is a novel magnetic resonance imaging (MRI) technique potentially able to evaluate the microscopic structural organization of white matter fibers.
T2 signal changes in conventional MR images in patients with CSM are associated with poor prognosis after surgery, underscoring the importance of early diagnosis and treatment in this condition. DTI of the cervical spine is a promising novel imaging modality in this group of patients offering increased diagnostic sensitivity as compared to standard MRI and enabling earlier detection of CSM before T2 changes appear on conventional MRI. Diagnostic improvements observed in these preliminary studies with the use of DTI warrant further studies with larger samples designed to evaluate the sensitivity and specificity of DTI in CSM in order to better identify patients at risk of progressive myelopathy.
Individually, the sacrum and coccyx are composed of smaller bones that fuse (grow into a solid bone mass) together by age 30. The sacrum is made up of 5 fused vertebrae, and 3 to 5 small bones fuse to create the coccyx. Both structures are weight-bearing and integral to functions such as walking, standing and sitting.
Diffusion tensor imaging (DTI) is a magnetic resonance technique capable of measuring the magnitude and direction of diffusion of water molecules in various tissues. DTI developed from a technique known as diffusion weighted imaging, which measures the attenuation of MR signals due to diffusion, and was initially used for brain imaging. DTI was formally introduced by Basser et al, and subsequent improvements in this technique have led to the development of DTI as a tool to delineate white matter tracts in the brain.
DTI of the spinal cord in humans was initially inadequate due to the small area of the cord, susceptibility artifacts, as well as cardiac and respiratory motion artifacts. Improvements in scanning protocols have allowed for useable diffusion images of the spinal cord. Spinal cord DTI, initially performed in animals, is now used to evaluate spinal cord disorders in humans. Investigators have shown that DTI is able to detect cord damage in regions of the cord that appear normal on T2W images. Spinal cord DTI, therefore, represents an important advancement in the field of neuroimaging, and its use is being expanded both for prognostication as well as for guiding therapy.