MR imaging of acute transverse myelitis and AIDS myelopathy

Area of Science:

• Neurology
• Radiology
• Immunology

Background:

• Acute transverse myelitis (ATM) is a recognized neurological disorder with an unclear cause.
• Limited magnetic resonance imaging (MRI) data exists for ATM, with conflicting reports on spinal cord signal intensity.
• Understanding MRI characteristics is crucial for diagnosing and differentiating myelopathies.

Purpose of the Study:

• To describe MRI findings in five cases of ATM.
• To investigate the utility of long repetition time (TR) sequences in visualizing spinal cord abnormalities in ATM.
• To compare MRI findings in ATM with those in acquired immunodeficiency syndrome (AIDS) myelopathy.

Main Methods:

• Retrospective analysis of five ATM cases using MRI.
• Focus on signal intensity changes on long TR sequences.
• Inclusion of one AIDS myelopathy case for comparison.

Main Results:

• All five ATM cases showed increased spinal cord signal intensity on long TR MRI sequences.
• Abnormal signal extended over at least six spinal segments in four cases.
• Cord expansion was observed in two cases with normal myelograms.
• A case of AIDS myelopathy presented with similar high signal intensity.

Conclusions:

• Diffuse increase in spinal cord signal intensity on long TR MRI sequences is characteristic of ATM.
• MRI findings in ATM can be extensive, sometimes exceeding clinical sensory levels.
• Both ATM and AIDS myelopathy should be considered in the differential diagnosis for diffuse spinal cord signal abnormalities on MRI.