This medical schematic diagram illustrates four pre-clinical spinal cord injury (SCI) models in axial cross-section, highlighting damaged regions (translucent red overlay), motor tracts (opaque red), and sensory tracts (blue). 1. Cord Hemisection Model: Shows damage isolated to one lateral half of the spinal cord, characteristic of Brown-Séquard syndrome, affecting both motor and sensory tracts on the ipsilateral side. 2. Cord Transection Model: Depicts complete injury across the entire cord diameter, resulting in total disruption of all motor and sensory pathways. 3. Dorsal Column Crush Model: Features localized damage concentrated in the posterior (dorsal) funiculus, primarily affecting ascending sensory tracts. 4. Weight Drop Contusion Model: Displays a diffuse, central injury zone impacting the grey matter and surrounding white matter tracts, simulating clinical traumatic contusion. The diagram serves as an educational tool for comparing injury patterns across experimental models used in neurotrauma research and their resulting impact on anatomical tracts.

This diagnostic image consists of two axial T2-weighted magnetic resonance imaging (MRI) slices of the cervical spine, labeled at the C5-C6 and C6-C7 levels. The images demonstrate significant right paracentral disc herniation at both levels, resulting in pronounced hemicord compression. At the C5-C6 level, the herniated disc material is seen extruding into the spinal canal, causing asymmetric flattening and displacement of the spinal cord toward the left. Similar pathological findings are observed at the C6-C7 level, though the compression at C5-C6 appears more severe. The vertebral bodies and surrounding soft tissues show signs of degenerative spondylosis. The visual evidence of unilateral cord compression is a classic radiological correlate for Brown-Séquard syndrome, illustrating the mechanical etiology of ipsilateral motor loss and contralateral sensory deficits. This material is suitable for intermediate to advanced medical learners focusing on neuroradiology, orthopedics, or neurology.

This diagnostic image is an axial T2-weighted MRI of the cervical spine at the C4-C5 level. The scan demonstrates a significant right paracentral disc herniation protruding into the spinal canal. The herniated disc material causes focal mass effect on the right side of the spinal cord, resulting in evident hemicord compression and distortion of the cord's normal elliptical contour. Despite the mechanical compression, the signal intensity within the spinal cord remains relatively uniform, with no definitive T2 hyperintensity to suggest acute myelomalacia or cord edema at this level. The vertebral body and posterior elements are visualized, though anatomical detail is slightly limited by image graininess. This clinical finding correlates with Brown-Séquard Syndrome, characterized by ipsilateral motor deficits and contralateral sensory loss due to unilateral cord compression. This image serves as a key educational example of how a focal disc protrusion can cause significant mechanical deformation of the spinal cord and lead to specific neurological deficits.