Source:
http://imageradiology.blogspot.com/2011/11/diffusion-tensor-imaging-in-spinal-cord.html
Spinal cord injuries result in damage to the myelinated fibers of the spinal cord and/or nerve roots, causing myelopathy. There are various causes of spinal cord injuries, e.g., trauma, tumor, and demyelination. These injuries can cause damage to the central gray matter, involving interneurons and motor neurons. Pathologically, such spinal cord insult can cause Wallerian degenerationeither above or below the level of injury. MRI can detect these changes as increased signal intensity on T2W(T2 weighted) images. However diffusion tensor imaging (DTI) has the potential to detect abnormalities in the spinal cord, even in cases where routine MRI (Magnetic resonance imaging) may be normal.
DTI is being widely used in the brain for various applications. DTI in diffuse axonal injury has been extensively studied. Recently, the feasibility of tensor imaging in the spinal cord has been tested both in the cervical and the lower cords. The clinical application of tensor imaging in spinal cord lesions due to trauma, tumors, and inflammation has shown the usefulness of this technique. DTI has even been able to demonstrate displaced white matter tracts or their involvement by lesions in the cord, thus helping treatment planning and follow-up of cases.
The greatest advantage of tensor imaging is that it can show changes in white matter tracts even in cases where routine imaging is normal. In diffuse axonal injury, where routine CT (Computed tomography) scan and MRI were normal, there was reduction in diffusion anisotropy after 24 h, suggesting axonal injury. Similarly, in demyelinating disease such as multiple sclerosis, reduced FA in the cervical cord has been demonstrated in patients as compared to controls, although routine MRI imaging was normal. Also, it has been well documented that signal changes seen on routine MRI may not correlate with neurological deficits and clinical findings, whereas DTI has been shown to correlate with motor deficits.
In conclusion, DTI in the spinal cord is a feasible technique. It can detect Wallerian degeneration, which is not detected on routine imaging.It correlates well with motor deficits and is a predictor of long-term motor recovery.
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Spinal cord injuries result in damage to the myelinated fibers of the spinal cord and/or nerve roots, causing myelopathy. There are various causes of spinal cord injuries, e.g., trauma, tumor, and demyelination. These injuries can cause damage to the central gray matter, involving interneurons and motor neurons. Pathologically, such spinal cord insult can cause Wallerian degenerationeither above or below the level of injury. MRI can detect these changes as increased signal intensity on T2W(T2 weighted) images. However diffusion tensor imaging (DTI) has the potential to detect abnormalities in the spinal cord, even in cases where routine MRI (Magnetic resonance imaging) may be normal.
DTI is being widely used in the brain for various applications. DTI in diffuse axonal injury has been extensively studied. Recently, the feasibility of tensor imaging in the spinal cord has been tested both in the cervical and the lower cords. The clinical application of tensor imaging in spinal cord lesions due to trauma, tumors, and inflammation has shown the usefulness of this technique. DTI has even been able to demonstrate displaced white matter tracts or their involvement by lesions in the cord, thus helping treatment planning and follow-up of cases.
The greatest advantage of tensor imaging is that it can show changes in white matter tracts even in cases where routine imaging is normal. In diffuse axonal injury, where routine CT (Computed tomography) scan and MRI were normal, there was reduction in diffusion anisotropy after 24 h, suggesting axonal injury. Similarly, in demyelinating disease such as multiple sclerosis, reduced FA in the cervical cord has been demonstrated in patients as compared to controls, although routine MRI imaging was normal. Also, it has been well documented that signal changes seen on routine MRI may not correlate with neurological deficits and clinical findings, whereas DTI has been shown to correlate with motor deficits.
Wallerian degeneration above or below the injury level has also been demonstrated on pathological examination. Buss et al, has shown that there is sequential loss of myelin proteins during Wallerian degeneration after spinal cord injury that can be seen years after injury. Tensor imaging spinal cord contusion has shown evolving changes in the ADC with recovery in ADC values with time suggesting that recovery from spinal cord injury is a dynamic process that goes on for years.
Tensor imaging has the potential to noninvasively identify axonal regeneration after stem cell therapy.In conclusion, DTI in the spinal cord is a feasible technique. It can detect Wallerian degeneration, which is not detected on routine imaging.It correlates well with motor deficits and is a predictor of long-term motor recovery.
READ MORE CLICK THE FOLLOWING LINKS:
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