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Diffusion-weighted imaging of spinal cord lesions: characteristic findings, differential diagnoses and imaging pitfalls 2012

General Spine

Toshio, Moritani, MD, PhD
Sami, Shibai, MD, Non ASSR Member
Aaron, Berg, MD, Non ASSR Member
John, Kim, MD, Non ASSR Member

Poster

Purpose

Acute paraplegia can result from ischemia/infarction, spinal cord compression, inflammation, infection, or tumor. The poor prognosis of spinal cord lesions is often related to treatment delay, so that early diagnosis is essential. DWI techniques can help in making these diagnoses. Here we demonstrate characteristic findings and differential diagnoses of spinal cord lesions using diffusion-weighted imaging (DWI), focusing on imaging pitfalls and limitations of this technique.

Methods & Materials

We reviewed conventional MRI and DWI findings in 83patients with spinal cord lesions, which included spinal cord ischemia/infarction (arterial and venous), demyelinating diseases (multiple sclerosis, ADEM), transverse myelitis, sarcoidosis, viral myelitis, acute cord injury, cord contusion, spinal cord hemorrhage, compression myelopathy/myelomalacia, syrinx, presyrinx state, subacute combined degeneration, spinal cord abscess, tuberculosis and various neoplasms. In our institution, DWI has been performed in routine spine MRI sequences on 1.5 and 3 T scanners from 2006. Spin-echo type echo-planar DWI with parallel imaging and the ADC maps (b=0, 1000 sec/mm2) was used. In some cases, RESOLVE (readout segmentation of long echo-trains) or HASTE (half-Fourier acquisition single-shot turbo spin echo) DWI were used as a comparison.

Results

DWI hyperintensities associated with decreased ADC values were observed in spinal cord ischemia/infarction, acute demyelination, acute cord injury, spinal cord abscess/pus collection, and hypercellular neoplasm. DWI iso or hyperintensities with various increased ADC values were observed in compression myelopathy/myelomalacia, syrinx, presyrinx state, subacute or chronic demyelination, idiopathic transverse myelitis, sarcoidosis, viral myelitis, and subacute combined degeneration. DWI signals of hemorrhage were variable depending on the age of hemorrhage. We observed that RESOLVE DWI can help reduce the image distortion, especially with the 3T scanners, often by improving spatial resolution.

Conclusion

DWI is useful in the differential diagnosis of spinal cord lesions. Specific DWI intensity and ADC values are associated with particular disease processes and allow the radiologist to narrow the differential diagnosis of spinal cord lesions.

References/Financial Disclosures

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