Today on the Doc On The Run Podcast, we’re talking about MRI Essentials for Runners, T1 versus T2 Images.
If you’re a runner who got injured and you’re calling me for a second opinion and you have an MRI, I’ll bet that you’ve already tried to look at it and you have no idea what you’re looking at. You have no idea what to do with the hundred-plus images that you got on your MRI and you’re not even sure where to start.
Well, in this series on reading your own MRIs on the MRI Essentials for Runners, I’m going to try to tell you some of the simple things that you need to understand when you’re getting an MRI or you’re looking at your own MRI, trying to figure out what was in the report that you received, and it’s really simple.
When you get an MRI, when we’re talking about this thing called T1 versus T2 images, they’re very different and it’s very obvious they’re different when you start to look at them. It doesn’t really matter what T1 is, and it doesn’t matter what T2 means. All you need to know is that on one set of images, the pictures of your foot look a lot like an x-ray. The bones are white and the soft tissue is dark. That’s just like an x-ray. That’s the T1 images and what those do is they show you anatomic detail really well.
So if you actually look at your MRI, you open one of them up, you’ll be able to see all kinds of detail. You’ll see the little wavy lines in the bone that we call trabeculation. They’re like little ridges of bone. You’ll be able to see the collagen septa, which is like the bands of collagen that hold the fat pad in place underneath your heel. You’ll see these little globules of fat. You see lots of really interesting detail. They’re very clear images.
The T2 images are actually in the exact same position as those. So when you look at the what we call sagittal images, it look like they’re a side view. Well, you’ll have a set of side view sagittal images that are bones are white, another one where the bones are black. The ones where the bones are black are the T2 images.
Why do you need both? Well, it’s really simple. One of them, the T1 images, show you anatomic detail really clearly. However, they don’t really show you where the trouble is all the time and sometimes it’s hard to figure out where the trouble is. Keep in mind your radiologist who reads this MRI is sitting in a dark room someplace, maybe in your own town, maybe in India. You have no idea, but the radiologist is alone in a dark room looking at your images on a computer screen trying to figure out what’s wrong with you. The T2 images make it really easy for the radiologist or for you, for that matter, to find the trouble quickly.
How do you do that? Well, it’s simple. When you think about this in terms of how an MRI works without all of the stuff about the magnet and protons flipping and all this other scientific stuff you don’t really care about, I’ll make it really simple for you. The MRI creates an image based on the amount of water content in the tissues. Okay, so where is there lots of water? Blood. So if you see a blood vessel in cross-section, it will be bright white on the T2 images where those bones are black.
Why are the bones black? Because there’s not a lot of water in there. It’s mostly bone marrow inside the bone, which is mostly fat. Fat, of course, is mostly oil, which is why many, many years ago, like lamps, street lamps used to be powered by whale oil being burned, right? It’s oil, it’s fat, it’s not water. It’s the opposite of water. So those are dark, and where there’s water, it’s white.
When you get a thing like a stress fracture, what you see is that one of those bones that is normally dark turns bright white. That gives you an indication to the radiologist that something’s going on in that bone like a stress fracture. Or if you have a peroneal tendon injury, you have the tendon, which is mostly collagen, not a lot of water, but it might be surrounded by tons of inflammatory fluid which, of course, is mostly water and mostly white on the T2 images. So that actually helps you or the radiologist find the trouble.
So when you get the T2 images and you start scanning through those, you just look for really bright white spots and then try to figure out what structure that is. If you do that, you get on track a lot faster.
Also, if you got an MRI and they took a little marker, sometimes it’s a vitamin E capsule, but they basically tape it to your foot, right where you’re supposed to have the most pain, that also you can see on the MRI, this little thing on the outside of your foot, and that gives the radiologist a clue where to start looking first. So you can look for that, too.
But I’ve got some examples. Some of these things I’m talking about here on the podcast are going to be in the video version. We’ll also have those pasted in on the show notes page under the podcast tab at docontherun.com, so you can see those a little better.
But those things should help you see the differences between T1 and T2 images. Then when you find the trouble on the T2 image, you just go to the exact same slice on the T1 images, again, where the bones are white and you can see a little more detail to see if you see a crack in the bone or a tear in the tendon or something like that. But hopefully, this will help you understand a little bit more about what you’re looking at and what you’re looking for when you’re reviewing your own MRI as an injured runner.
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