Final answer:
The myelogram involves the injection of contrast media into the spinal subarachnoid space. It is a diagnostic imaging procedure, while the lumbar puncture is performed to sample CSF and is conducted in the lower lumbar region to avoid spinal cord injury.
Step-by-step explanation:
The procedure that involves the injection of contrast media into the spinal subarachnoid space is A. myelogram. A myelogram is a diagnostic imaging test that can detect issues with the spinal cord, nerve roots, and other tissues within the spinal canal. In a myelogram, contrast dye is injected into the spinal column's subarachnoid space, which is the area within the meninges where cerebrospinal fluid (CSF) flows, to enhance the imaging obtained by X-ray or CT scan.
Conversely, a lumbar puncture is performed in the lower lumbar area of the vertebral column because the spinal cord does not extend through the lower lumbar region, allowing a needle to be inserted without the risk of damaging the central tissue of the spinal cord. A lumbar puncture is also used to sample CSF for testing, especially in cases where meningitis is suspected, and treatment such as antibiotics or antiviral drugs may be prescribed based on the test results.