MR neurography visualizes peripheral nerves and plexuses using specialized MRI sequences and post-processing, while black blood imaging of the brain employs techniques to suppress flowing blood signal, enhancing the depiction of vessel walls and brain parenchyma.

MR Neurography Technique

• MR neurography utilizes high-resolution, fat-suppressed T2-weighted and STIR sequences to maximize contrast between nerves (which appear hyperintense in pathology) and surrounding tissues.
• 3D isotropic imaging and multiplanar reconstruction are often used, especially for complex nerve or plexus anatomy.
• Techniques like diffusion-weighted imaging (DWI) and tractography (using DTI) provide additional information on nerve structure and pathology, aiding in localization of lesions, entrapment, and traumatic injuries.
• Commonly applied to brachial and lumbosacral plexus, peripheral nerves, and facial nerve mapping.

Black Blood Imaging of the Brain

• Black blood imaging refers to MRI sequences designed to null or suppress the signal from flowing blood, rendering vessels (arteries and veins) dark.
• This is achieved by using double inversion recovery (DIR) or "black blood" spin echo pulse sequences.
• The technique increases conspicuity of vessel wall structures and adjacent brain parenchyma, making it valuable for detecting vasculitis, vessel wall thickening, dissection, atherosclerotic plaques, and subtle parenchymal lesions adjacent to vessels.
• Black blood imaging is widely used in intracranial vessel wall imaging and in cardiovascular MRI to evaluate aortic and peripheral vessel pathology.