Can you tell me the difference between a lumbar puncture and a myelogram?

Injection of dye: They both involve a needle being placed into the spinal canal. In a lp, cerebrospinal fluid is removed from the canal, while in a myelogram a dye is injected into the canal. This dye allows very clear imaging of the spinal cord and nerve roots.

The difference is : That a lumbar puncture is a spinal tap to obtain fluid and measurements of the cerebral spinal fluid while a myelogram is the same procedure but then a contrast material or "dye" is then injected to outline the spinal cord for imaging with x-rays or radiographs and usually followed by a ct scan.

See below: A LP involves withdrawing cerebrospinal fluid for study. A myelogram involves injecting a special dye for evaluation of spinal pathology. The placement and location of the needle are the same for both procedures.