0:00

Dr. P here.

0:01

3 00:00:02,100 --> 00:00:05,650 I've got a 53-year-old female with unguis

0:05

incarnatus, also known as onychocryptosis,

0:11

also known by the common name of ingrown toenail.

0:14

She's got pain and swelling of the great toe.

0:16

It's been going on for

0:18

6 months, no prior

0:20

intervention, no prior surgery.

0:22

On the far left, we've got a T1

0:24

spin echo, fat-weighted image.

0:26

In the middle, a T2 fat-suppressed

0:28

image, and on the far right,

0:30

a proton density fat-suppressed image.

0:32

Let's scroll, and the great toe's

0:37

distal aspect has completely erased.

0:41

It's disappeared.

0:42

Now, there's a companion case with

0:44

this, another osteomyelitis,

0:46

a stubbed toe osteomyelitis in a child.

0:49

In which most of the wipeout

0:52

occurred in the medullary space.

0:54

That's uncommon.

0:55

This is the more typical scenario where

0:58

you have trouble even finding any cortex.

1:00

Maybe a little bit back here

1:01

on the T1-weighted image.

1:03

Now the way to approach these osteomyelitis

1:05

cases is you look at the most heavily water-

1:08

weighted sequence, which is right here,

1:10

and then there's another pretty good one right here.

1:13

And if you don't see any edema

1:15

at all, then you can essentially exclude

1:18

the diagnosis of osteomyelitis.

1:20

You're done with osteo.

1:22

However, if you have edema on the water-weighted

1:25

image, that does not mean you have osteomyelitis.

1:28

You've got to go back to the T1-weighted

1:29

image and look for erasure of medullary and

1:33

cortical bone, which we have here in spades.

1:36

It's rather profound, especially on

1:39

this water-weighted sequence, too.

1:40

But the T1-weighted image is the specifier.

1:43

That's the one that puts the

1:45

hammer down on osteomyelitis.

1:48

Let's look at a few other projections.

1:51

Let's take the T1-weighted, T2-weighted,

1:54

and proton density images in the short

1:56

axis view and look at what this osteo is

1:59

doing from the top down on the cortex.

2:01

It's just destroying the cortex.

2:04

That's not cortex; that's reactive change in

2:08

bone that's just being crunched and eaten away.

2:12

The long axis images, I think,

2:16

are similarly revelatory.

2:19

Here is the water-weighted image.

2:21

The entire toe is edematous,

2:23

but look at the T1-weighted image.

2:24

I mean, where is the cortex?

2:26

There's cortex on this side,

2:27

there's a little bit of cortex here.

2:29

Gone, gone, all the way around

2:31

to the top, and gone at the base.

2:34

So what are your other jobs in deciding the

2:38

report appearance, especially the conclusion,

2:42

for the clinician in a case like this?

2:44

You want to say where the osteo is.

2:46

You want to say how far back it goes.

2:48

You want to say whether it crosses the joint.

2:50

This is part of your checklist.

2:52

You want to say whether you see air or gas.

2:55

A plain film can be helpful there.

2:57

Is there a fluid collection to drain and get

2:59

some bugs, like an abscess or a microabscess?

3:02

Is there a sinus tract?

3:04

Is there an abscess inside the bone?

3:08

Does it cross the joint?

3:09

Is there septic arthritis?

3:11

Does it involve the adjacent bone?

3:13

And if it does, how far proximally does it go?

3:17

So you can prepare for an amputation.

3:20

This is aggressive, penetrating,

3:23

infiltrative, osteomyelitis of the great toe.

3:27

Dr. P out.