Upper Back (Thoracic Spine) MRI (with contrast)

What it is

Contrast is not what makes a spine MRI able to see a slipped disc — plain images do that perfectly well, which is why the great majority of spine scans involve no injection at all. Gadolinium is added when the question turns from shape to activity. Injected into a vein, it leaks out of vessels wherever the normal barrier between blood and tissue has broken down, which happens around tumor, around infection, and in an inflamed segment of spinal cord. In the thoracic region that matters more than it might elsewhere, because the cord runs through this entire stretch of spine in a canal with very little spare room, and the conditions worth finding here are more often cord and bone-marrow conditions than disc ones. This particular code records that the study was imaged after contrast. Where a plain baseline set was also acquired and read alongside it, the study belongs under the with-and-without code instead, so it is worth checking which one appears on your bill.

Why it is done

• To look for tumor deposits in the thoracic vertebrae, in the coverings of the cord, or within the cord itself, which stand out once dye is on board
• To assess suspected infection in a disc space or the bone around it, where the enhancing area maps how far the infection has spread
• To evaluate inflammation within the cord, as in demyelinating disease, where an active lesion takes up dye and an old one does not
• To follow a lesion already known about, and to judge whether treatment has changed it
• To look at a segment of thoracic spine that has been operated on, where scar tissue takes up dye and recurrent disc material does not

What to expect

Metal and device screening happens before you go near the room. An IV is placed, and most centers check kidney function before gadolinium is given. Imaging is done lying flat inside the tube. The thoracic spine sits directly behind the heart and lungs, so this region moves with every breath and every heartbeat more than the low back does; the sequences are built to cope, and steady, unforced breathing helps. Expect the machine to be loud and hearing protection to be provided, and expect the appointment to run longer than an unenhanced spine study. There is no recovery period once the IV is out.

Questions worth asking

• Check whether the order and the claim agree. If a plain series was also performed, the study should be coded with and without contrast, and the two codes carry different prices.
• Ask how many spinal regions are covered. Cervical, thoracic and lumbar are three separate codes even when scanned back to back in one appointment.
• Ask whether the contrast agent is itemized separately from the scan on the bill.
• If this is a repeat of a scan done elsewhere, ask whether the earlier images can be retrieved for comparison instead of repeating the whole study.
• Ask whether the reading radiologist bills separately from the imaging facility, and confirm that group's network status, not just the building's.