That MRI may not be as safe as you think

When you find yourself in need of imaging, a lot of doctors and patients — myself included, as you’ll likely recall — prefer MRI scans. That’s because the radiation risks with MRI are a whole lot lower than CT scans.

But unfortunately, nothing comes for free — and as it turns out, the benefits of MRI have their own cost.

This unfortunate news comes down from the Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA). (Yes, another European institution, which should surprise no one.)

The PRAC stands behind evidence showing that gadolinium — a heavy metal that is also a common MRI contrast agent — deposits into brain tissues as a result of these routine procedures.

In fact, their review found gadolinium accumulations in the brain months after injection with gadolinium contrast agents. This is something I never knew about — though it’s not exactly surprising.

I can attest to the fact that gadolinium often shows up when I test for heavy metals in my patients — even years after they’ve had contrast MRIs. Which, frankly, makes these findings all the more concerning.

So I’m definitely going to think twice before ordering MRIs with contrast in the future. Who needs a heavy metal accumulating anywhere in your body… let alone your brain?

Granted, there aren’t any reports of disease related to gadolinium deposits in the brain… yet. But the PRAC recommends suspending the use of its least stable forms, out of an abundance of caution.

And I have to say, it’s beyond refreshing to hear someone talking some sense for a change.

Some key factors to note: there are two types gadolinium-based contrast agents, boasting either “linear” or “macrocyclic” structures. Research shows that the linear agents are the less stable of the two, making them more likely to release gadolinium into the body.

Therefore, the PRAC advises that gadoxetic acid and gadobenic acid — two linear forms of this contrast agent — be used only for liver scans and in instances where it’s absolutely critical for diagnosis. Gadopentetic acid, meanwhile, should be reserved for joint scans — and only because the concentration of gadolinium in these injections is low.

The use of all other linear agents should be suspended, according to the PRAC. While safer macrocyclic gadolinium agents (which include gadobutrol, gadoteric acid, and gadoteridol) can still be used with caution — i.e. in the lowest doses possible to get the necessary images.

I do realize this is a lot of medical terminology — and I’m not expecting you to be able to rattle off a complete list of contrast agents at your next doctor’s appointment.

But if you need to get an MRI for any reason in the future (and it’s likely you will, as they’re very common, especially in women for routine breast imaging), I encourage you to write this information down or print it out. Take it with you to your appointment and make sure these agents are being used (or not being used, as the case may be) in accordance with the above precautions.

Once again, the IV contrast agents of concern are linear agents — gadobenic acid, gadodiamide, gadopentetic acid (except in the case of joint scans), and gadoversetamide.

Awareness of this risk is particularly important should you require multiple contrast MRIs. Four or more appears to lead to the highest gadolinium retention in the brain. And routine MRI scans are common practice in the management of conditions like MS or cancer. And even if you don’t have one of these conditions yourself, you likely know someone who does.

If so, be sure to share this information. Because as usual, the FDA has assumed a different position from their European counterpart.

Based on the results of a single two-year study, they claim there is no evidence that gadolinium retention in the brain following MRIs cause adverse events. So they’re not taking any steps to restrict its use.

Hardly a shocker, when you consider that the FDA always errs on the side of industry — not the side of public health and well-being. Unfortunately, this is the sad reality. But it’s one you need to keep in mind the next time your doctor tells you “it’s just a test.”