Neuroanatomy Basics Arcot Chandrasekhar M D Ashok Kumar

Neuroanatomy Basics Arcot Chandrasekhar, M. D. Ashok Kumar, M. D. November 5, 2013

MRI Titbits • MRI can provide axial, sagittal and coronal views. • MRI is best for tissue discrimination and is superior to CT. • Look at pre-contrast and post-contrast MRI as a pair. • T 2 wtd MRI: There are many MRI sequences used to visualize specific tissues. • Flair and diffusion wtd images are a few examples. • The best way to distinguish T 1 wtd MRI from T 2 wtd MRI is by the appearance of CSF is bright in T 2 wtd MRI and CSF is dark in T 1 wtd MRI.

Post-contrast sagittal T 1 wtd MRI

• For axial images you need to know the level. • The next set of images are axial sections of brain from top to bottom.

Pre-contrast axial T 1 wtd MRI

Spinal cord anatomy

Pre-contrast sagittal T 1 wtd MRI of cervical spine

Pre-contrast axial T 2 wtd MRI of cervical spine at C 5 -C 6 level

Pre-contrast axial T 1 wtd MRI of thoracic spine

Pre-contrast sagittal T 1 wtd MRI of cervical spine

Pre-contrast sagittal T 1 wtd MRI lumbar spine CSF dark in T 1 wtd image

Sagittal T 2 wtd MRI of lumbar spine CSF bright in T 2 wtd image

CT Titbits • CT provides axial views of the brain and spine. • Computer reconstructed process can provide sagittal view. • Pre-contrast CT is best for evaluation of bone and acute hemorrhage. • Bone and acute blood appear hyperdense. • Post-contrast CT enables visualization of vasculature and abnormal brain tissue. • Normal brain does not enhance with contrast. • CSF is hypodense and dark. • Vertebra are counted down from C 2 or up from S 1.

6 Pre Contrast CT Brain

Normal CT anatomy of cervical spine at the level of C 1 vertebral body