0:01

If you've been following along with the course,

0:03

you just saw a case of a patient who had multiple

0:06

myeloma with a compression fracture

0:09

of multiple vertebral bodies.

0:12

The distinction between a malignant versus a benign

0:17

osteoporotic compression fracture

0:20

is one that has led to hundreds,

0:24

if not thousands, of publications in the neuroradiology

0:28

and Musculoskeletal radiology literature.

0:31

Distinguishing between these two, in some

0:34

cases when it's classic, is very easy,

0:36

but in some cases is very difficult indeed.

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Let's talk about this problem.

0:43

So here we have a patient who has two vertebral bodies

0:47

that have abnormal signal intensity within them.

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The upper one,

0:51

the L2 vertebral body is compressed and you see that

0:54

there is decrease in the height as opposed to the

0:57

L3 vertebral body. This is four, this is five.

1:00

So are these metastases with compression fractures

1:05

or are these on the basis of osteoporosis?

1:10

This is the issue.

1:12

Some people have advocated using diffusion-weighted

1:15

imaging to identify whether or not a compression

1:19

fracture is from metastatic disease or osteoporosis.

1:24

The theory here is that if there is

1:27

hypercellularity within the bone,

1:30

it would suggest that this is secondary metastases.

1:33

Hypercellularity would result in decreased ADC and

1:38

brighter signal in diffusion-weighted imaging.

1:41

Contrast that to osteoporotic fractures, which

1:44

have less cellular vertebral bodies.

1:47

And this would lead to more vasogenic edema

1:51

and brighter signal intensity on the ADC map.

1:54

So in this case, in particular,

1:56

we have a patient who has a lesion,

2:00

which is showing compression deformity on the

2:04

T2-weighted scan. This is a T1-weighted scan.

2:07

And here on your ADC map of the diffusion-weighted scan,

2:12

we see that it's relatively bright.

2:14

A brighter lesion would imply that

2:17

this is on an osteoporotic basis.

2:20

If it's darker on the ADC secondary to hypercellularity,

2:24

it's going to lead to a diagnosis of metastatic disease.

2:29

Here's another example of a compression fracture.

2:32

This one shows vacuum phenomenon

2:34

air within the vertebral body.

2:36

Vacuum phenomenon air within the vertebral body is

2:39

a marker for a benign compression fracture.

2:42

Here we have a patient who has intermediate bright

2:46

signal intensity in the vertebral body on the T1-weighted

2:50

scan. This higher signal intensity on T1-weighted scan,

2:54

as opposed to complete replacement of

2:56

the T1 signal is a marker for a benign etiology.

3:01

You notice that this patient has compression deformity

3:04

of the superior endplate of the vertebral body,

3:07

but we notice that it's brightened signal intensity.

3:09

Again, brightened signal intensity means that there is normal

3:13

bone marrow fat and therefore this is unlikely to be on

3:16

a basis of neoplasm and is more likely to

3:20

be on an osteoporotic reason.

3:22

Similarly here, this wedged vertebral body has normal signal

3:25

intensity and therefore is more likely

3:28

to be benign osteoporotic in its etiology.

3:31

Here's a diffusion-weighted scan showing that the high

3:36

signal intensity in the vertebral body, on the diffusion

3:40

weighted imaging, is associated with the compression

3:43

deformity and when it's bright on

3:46

DWI and bright on the ADC map,

3:49

it's just that, indeed, the patient has a benign

3:52

osteoporotic compression fracture.

3:54

This is the follow-up on this patient, and this is the imaging

4:00

finding that is most reliable in suggesting

4:04

a benign compression fracture. That is,

4:06

if the signal intensity of the compressed vertebra

4:10

returns to a normal bone marrow,

4:13

bright on T1-weighted scan,

4:15

it suggests that this is a benign etiology since

4:18

neoplastic infiltration would not return to bright.

4:21

So once again,

4:23

a reasonable approach is to do a follow up scan at two

4:27

months in order to determine whether or not the bone

4:30

marrow signal returns to normal,

4:32

that is bright on T1-weighted scan, to suggest a benign etiology.

4:37

That said,

4:37

there are very few clinicians that I've run into,

4:40

at least at Johns Hopkins, that are willing to wait to

4:43

find out the diagnosis in a follow-up scan at

4:46

six weeks to two months.

4:47

And therefore, quite often, we are asked to do biopsies

4:50

of these lesions to determine whether or not they're

4:54

neoplastic or benign in their etiology.

4:56

To summarize, what are the findings of a

5:00

malignant compression fracture on MR? If you have

5:04

convex posterior border of the vertebral body,

5:06

suggesting that it's filled with neoplasm,

5:09

more likely to be malignant.

5:11

Abnormal signal intensity extending into the pedicle or

5:13

the posterior element, or completely replacing the

5:16

vertebral body, more likely to be malignant.

5:19

An epidural mass or encasing epidural mass, or a focal

5:23

paraspinal mass associated with the compression

5:26

fracture, suggest a malignancy. If you see other lesions

5:31

elsewhere in the spine or in the ribs,

5:34

more likely to be metastatic disease. And if there is

5:37

restricted diffusion, more likely to be malignancy.

5:40

Benign features on MR, having low signal intensity linear

5:46

bands, but the majority of the vertebral body

5:49

being bright on T1 suggests benign.

5:53

If you have spared normal bone marrow signal in the

5:56

vertebral body, again, similarly to this linear band,

6:00

that's more likely to be benign.

6:03

If there are multiple compression fractures with high

6:07

normal signal intensity on T1-weighted

6:10

scan, more likely to be benign

6:13

osteoporotic. Return of the normal signal intensity of

6:16

the vertebral body on a follow-up

6:18

scan at six to eight weeks,

6:20

benign etiology. And/or fluid or the air that you saw,

6:26

the vacuum phenomena within the fracture, is more

6:29

likely to suggest benign etiology.