What is a "CT myelogram"?

A CT myelogram is an imaging study that specifically utilizes computed tomography (CT) in conjunction with contrast material to visualize the spinal cord, nerve roots, and surrounding structures within the spinal canal. During the procedure, a contrast agent is injected into the subarachnoid space, which allows for a clearer distinction between cerebrospinal fluid and the structures of the spinal canal when imaged with CT. This is particularly useful in identifying issues such as herniated disks, spinal stenosis, tumors, or other abnormalities affecting the spinal cord and nerve roots, which may not be adequately visualized with conventional CT or MRI alone.

The other options represent different imaging techniques that do not focus on the specialized function of a CT myelogram, making them less relevant in this context. For instance, a type of MRI for brain imaging is unrelated as it pertains to magnetic resonance imaging rather than a CT-based technique. Similarly, methods for assessing bone density and ultrasound techniques for spinal assessment diverge from the specific applications and mechanisms of a CT myelogram.