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Updated: Mar 8, 2026
Diffusion Tensor Magnetic Resonance Imaging in Chronic Spinal Cord Compression
Published on: May 7, 2019
Manganese-enhanced MRI Offers Correlation with Severity of Spinal Cord Injury in Experimental Models
Nikolay L Martirosyan1, Gregory H Turner2, Jason Kaufman3
1Departments of Neurosurgery, Barrow Neurological Institute St. Joseph's Hospital and Medical Center Phoenix, Arizona,USA.
Background:
Spinal cord injuries (SCI) are clinically challenging, because neural regeneration after cord damage is unknown. In SCI animal models, regeneration is evaluated histologically, requiring animal sacrifice. Noninvasive techniques are needed to detect longitudinal SCI changes.
Objective:
To compare manganese-enhanced magnetic resonance imaging (MRI [MEMRI]) in hemisection and transection of SCI rat models with diffusion tensor imaging (DTI) and histology.
Methods:
Rats underwent T9 spinal cord transection (n=6), hemisection (n=6), or laminectomy without SCI (controls, n=6). One-half of each group received lateral ventricle MnCl2 injections 24 hours later. Conventional DTI or T1-weighted MRI was performed 84 hours post-surgery. MEMRI signal intensity ratio above and below the SCI level was calculated. Fractional anisotropy (FA) measurements were taken 1 cm rostral to the SCI. The percentage of FA change was calculated 10 mm rostral to the SCI epicenter, between FA at the dorsal column lesion normalized to a lateral area without FA change. Myelin load (percentage difference) among groups was analyzed by histology.
Results:
In transection and hemisection groups, mean MEMRI ratios were 0.62 and 0.87, respectively, versus 0.99 in controls (P<0.001 and P<0.001, respectively); mean FA decreases were 67.5% and 40.1%, respectively, compared with a 6.1% increase in controls (P=0.002 and P=0.019, respectively). Mean myelin load decreased by 38.8% (transection) and 51.8% (hemisection) compared to controls (99.1%) (P<0.001 and P<0.001, respectively). Pearson's correlation coefficients were -0.94 for MEMRI ratio and FA changes and 0.87 for MEMRI and myelin load.
Conclusion:
MEMERI results correlated to SCI severity measured by FA and myelin load. MEMRI is a useful noninvasive tool to assess neuronal damage after SCI.
Insights
Manganese-enhanced MRI (MEMRI) effectively assesses spinal cord injury (SCI) severity. This noninvasive technique correlates with diffusion tensor imaging and histology, offering a new tool for evaluating neuronal damage.
Area of Science:
- Neuroscience
- Radiology
- Biomedical Engineering
Background:
- Spinal cord injuries (SCI) present significant clinical challenges due to limited neural regeneration.
- Current methods for evaluating SCI in animal models require invasive histological analysis.
- There is a critical need for noninvasive techniques to monitor longitudinal changes after SCI.
Purpose of the Study:
- To compare manganese-enhanced magnetic resonance imaging (MEMRI) with diffusion tensor imaging (DTI) and histology for assessing SCI.
- To evaluate MEMRI's efficacy in rat models of spinal cord transection and hemisection.
Main Methods:
- Rats underwent spinal cord transection, hemisection, or laminectomy (control).
- Manganese chloride (MnCl2) was administered via lateral ventricle injection.
- T1-weighted MRI, DTI, and histology were used to measure MEMRI signal intensity, fractional anisotropy (FA), and myelin load.
Main Results:
- MEMRI ratios were significantly lower in transection (0.62) and hemisection (0.87) groups compared to controls (0.99).
- Fractional anisotropy (FA) decreased significantly in both SCI groups, correlating with MEMRI findings.
- Histological analysis revealed substantial myelin load reduction in SCI groups, also correlating with MEMRI and FA.
Conclusions:
- MEMRI results strongly correlate with SCI severity, as measured by FA and myelin load.
- Manganese-enhanced MRI serves as a valuable noninvasive tool for assessing neuronal damage following spinal cord injury.
