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41 is a 37-year-old woman status post,

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a fall on 7 4 21 with thumb pain.

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Um, I've got it. 41. It's

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Up, it's up, It's not up.

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There we go. So we're gonna start out with kind

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of a standard resolution image,

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and then I'll refer back to one of my favorite cases.

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And when I'm looking at a thumb,

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especially when there's been a history of a fall, let's,

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let's get them three up and see if I can get them upright.

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I usually like to have my coronals lined up in a

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row, and let's do that.

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And this is a standard 1.5 Tesla system with a hand coil.

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I'll show you some microscopy coil imaging in a moment.

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Um, and I'm gonna blow it up a little bit.

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The proton density, fat suppression on the left,

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the T one spin echo in the middle, more of a, a bone,

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uh, evaluator, and then a gradient echo on the far right.

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And, and I really like gradient echo imaging when you have

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additive gradient echo technique, um, such

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as additive gradient, echo, merge medic, and MFFE,

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because you have this very robust signal, it allows me

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to get between 0.8 and 1.2 millimeters per slice.

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So as we, as we scroll through, you have to kind

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of figure out where you are.

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Are you palmar? Are you dorsal?

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And, uh, one way to tell, right, you know, if you're dealing

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with a ental lesion is as soon as you see this, uh,

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yo-yo on a string or lollipop, you know that your dorsal,

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because that's where the lesions occur.

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Another way to tell is to find the sesamoids right away.

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And then, you know, you're, you're in a palmar position.

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And when you're reading in a busy practice, you know,

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if you don't have to cross reference back

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and forth, it's helpful.

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And then here's, here's another potential pitfall,

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which I'll show you in a very magnified thumb,

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perhaps the biggest thumb of all time an NFL quarterback,

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but this is not him.

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This structure right here could easily be misconstrued

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for a floppy ulnar collateral ligament, when in fact, it is

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the adductor pon osis.

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The transverse segment kind of sucked in, uh,

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filling a vacuum or a space where the UCL once was.

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So you can get tripped up

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by this if you're not a little bit experienced.

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And then where is the UCL? Um, but draw it.

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I'm gonna draw the pons,

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which is normally sitting in a more oblique orientation,

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and there's a little notch right here,

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and it's through the, through the hole in that notch.

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The UCL will tear and retract,

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and then it'll poke through this hole.

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It'll come out into the screen dorsally,

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and it will give you this funny looking

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lollipop in the axial projection, which

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makes the diagnosis right away.

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Now, when I scroll them together, the T one not as helpful

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for that, but helpful for the bone.

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The gradient echo helpful

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for assessing the articular cartilage.

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And you also appreciate

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that the proximal phalanx is starting

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to fall a little bit radially, that

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that's not an artifact or a coincidence.

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This offset is real.

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And there's one other finding

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that hasn't been discussed much, and,

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and I, unfortunately I don't see it in this case,

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but in, in almost all high grade ucls, I see a little bit

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of sagging of the metacarpal, uh, of the thumb,

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uh, because the, the, um, UCL is a secondary restraint.

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So when you lose that, you're always gonna get a little bit

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of offset, not as much as you get, uh, as if you have a, a,

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uh, plant or a plate tear.

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Let me show you my, my giant thumb.

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Let's see if I can get to come up. Here's my giant thumb.

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And I think, uh, Christine will recognize this as one

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of the largest thumbs of all time.

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Um, here is the metacarpal proximal phalanx.

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And, and the, the reader misinterpreted.

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I'm showing you the key image,

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but the reader, who was a fellow at the time misinterpreted

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this structure right here.

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This one which is running distal, the proximal as the UCL,

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when in fact it's not.

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It's the torn collapsed abductor pons

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that used to sit like this.

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And another sign that I find helpful for a entner lesion is

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what I call the X sign, not for Twitter, uh,

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but for the X that this makes.

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If you look at the big fat collateral ligament,

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which is here, and the adductor of pon miosis,

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which is here, they make this crisscross phenomenon.

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And when you see that, that's also very

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helpful for the entner lesion.

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And now let's go back again

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and let's look at the axial projection one more time

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and see the location of that yo-yo, on a string

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or lollipop sign, here's the lollipop sign.

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There's the base of the lollipop.

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There's where you lick the lollipop right there.

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And it's almost always in the exact same spot.

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So if you're new to a finger, MRI

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and you're trying to stru, you're struggling

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with a stent lesion, this is the place to look dorsal

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and, and lateral.

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And you'll find this little structure right here.

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And, and that's the tip off to the diagnosis.

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Uh, Christine, any comments on this one?

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No, I think that's great. I,

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I like your gradient sequence, um, Steve,

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because when you're looking at that coronal,

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I think it really makes the alignment change.

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Those subtle alignment changes

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that you're talking about really stand out.

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So it's, that's nice. I like that.

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Thank you. Thank you. It's very, it's a little bit

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of an echo, but it's very amenable to, um, uh,

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to high resolution imaging with fields of view of six,

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eight, and 10 because of how re robust the signal is.

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Let's move on to the next one.