#859 Difference between MRI vs MRA in runner with ankle injury - DOC

#859 Difference between MRI vs MRA in runner with ankle injury

What’s the difference between an MRI or an MRA when you have an ankle injury and you’re a runner? Well, that’s what we’re talking about today on the Doc On The Run Podcast.



Let’s say you had an ankle injury a long time ago, you rolled your ankle, and you sprained it when you’re out on a trail run, and you got back to activity. And then over time, you got more and more pain in the ankle. Well, your doctor might order an MRI of your ankle, and in some cases, they might actually order something called an MRA instead of I.

What’s the difference? Well, it’s really important to understand this. So, the first thing is the MRI is probably the most commonly performed advanced imaging for a suspected ankle injury, like a ligament tear, a tendon tear, maybe even cartilage damage inside the ankle. When I order an MRA, which is a magnetic resonance arthrogram, that’s different than a standard MRI, which is magnetic resonance imaging.

If you have a normal problem, we think maybe one of your perineal tendons is injured, I would get an MRI. It going to look at the soft tissue well, and it’s going to really evaluate it very cleanly. When we have a suspected injury inside the ankle, where the two surfaces are sitting there, we think that you have a crack in the bone underneath the cartilage and you might actually have a cyst or a sort of hole in the bone right above the cartilage is communicating with the ankle joint that has sort of a hole in it that goes through the cartilage and through the bone,  you definitely want an MRA for that not an MRI.

So, what is it? An MRI is really simple. MRI, we just put you in the scanner, we take an image with using a magnet to create all those images with the computer. MRA the arthrogram part, so “arthro” means joint and gram means image. So, what we do is we actually inject some radio opaque dye into your ankle right before the MRI. And so, it’s still an MRI, but it’s with some radio opaque dye that will show up differently, some contrast material injected into the ankle, so it looks different than the normal fluid.

Why don’t we do that? Really simple. So, the ankle joint is sort of this curved joint because it’s sitting there and you’ve got the talus on the bottom, you have the tibia on top. When you do the MRA and you’ve injected contrast material in there, if there’s a hole in the cartilage and a crack in the bone, all of that fluid instead of just sitting there and looking kind of like an umbrella, well it leaks up and creates a round spot in the bottom of the tibia or in the top of the talus bone underneath the tibia.

If you have that, we know it’s a completely different problem. We then know for sure you’ve got an actual damage to the cartilage, you have a thing called an osteochondral defect, you have a crack in the bone and the joint fluid is seeping back and forth across that. That has to be fixed very differently than if you just have a tendon or ligament tear or some inflammation of the tissue around the ankle. Totally different problem.

Many doctors don’t even think about that because it’s a rare thing when you actually have that problem. But if you do suspect you have that problem, if you get an MRI and you’re not getting better, see someone, get a second opinion, and ask them, “Should I get an MRA? Do you think the arthrogram part of this might be helpful? Because if you don’t figure it out, you’re not going to get better.

If you want to learn more about ankle injuries in runners and consistent pain that happens after these, come join me in the ankle pain masterclass for runners. You can join me for free. It’s at www.docontherun.com/anklepainmasterclass. So, go and check it out and I’ll see you in the training.