A myelography is a radiographic imaging procedure to visualize the spinal canal, the spinal cord, cerebrospinal fluid (CSF), intervertebral disks and nerve roots. A special contrast agent (dye) is injected through a needle into the subarachnoid space of the spinal canal. A myelogram provides a very detailed picture of the spinal cord and spinal column. A fluoroscopy displays the bones and the fluid-filled space of the spine also in motion. An additional computerized tomography (CT or CAT) scan helps to differentiate the spinal conditions better. The indications include disc herniation, spinal stenosis, tumor, and vertebral fracture.

See also Myeloscintigraphy, Fluoroscopic System, Hounsfield Unit, Bone Densitometry, Nonionic Contrast Agents.

Omnipaque is a low-osmolar, nonionic, contrast medium with a broad range of indications, for example intravascular diagnostic procedures such as coronary angiography, spinal cord imaging, and body cavity procedures including shoulder and knee joints. Omnipaque is approved for use in adults and children, and is available in a wide variety of packagings.

See also Nonionic Contrast Agents.

Digital images can be manipulated for evaluation in various ways. Post-processing includes: Subtraction, addition, rotation, inversion, multiplanar reconstruction (MPR), maximum intensity projection (MIP), etc.
Subtraction is particularly useful in contrast enhanced examinations. The pre contrast images are subtracted from the images after an injection of contrast agents (sometimes also called dye) for better tumor detection. See also Contrast Enhanced Computed Tomography, Digital Subtraction Angiography and Active Zone.

Radiopaque materials are not penetrable by radiation or impede x-rays. Radiopaque substances appear white on radiographic images.

See also Contrast Agents.

See Contrast Agents and Dye.