0:01

Here are the standard pulse sequences

0:03

that we use for spinal imaging,

0:06

whether it be for intradural intramedullary

0:09

lesions or for intradural extramedullary lesions.

0:13

Here is our T1-weighed sagittal scan.

0:16

Here, the T2-weighed sagittal scan.

0:19

This is the STIR imaging, which as I described for you,

0:22

causes fat suppression,

0:24

which you see on the T2-weighted scan,

0:26

the fat is bright, but with STIR imaging,

0:29

the fat is dark.

0:30

This is a post-gadolinium T1-weighted scan

0:33

that we also use typically in the sagittal

0:36

plane. In the axial plane,

0:38

we're usually relying on T2-weighted axial

0:41

scans. This is the gradient echo scan,

0:44

which is generally reserved for the cervical

0:46

spine and not used in thoracic

0:49

or lumbar spine imaging.

0:51

And this is an example of the postgad

0:53

axial scan. In this case, we either don't have very

0:57

good fat suppression,

0:58

or it was done without fat suppression.

1:00

What we'd like to do is to nail the high

1:02

signal intensity of the fat here with a

1:05

suppressor pulse and cause it to be dark,

1:08

which allows the background to be even darker.

1:11

And therefore,

1:11

enhancing lesions are going to show up more

1:14

readily in that dark black background.

1:16

So these are the standard pulse sequences that

1:19

are employed for imaging of the spine

1:22

for intradural extramedullary.

1:24

You'll notice that this patient has an intradural

1:28

intramedullary lesion in the spinal cord.

1:31

These are those additional sequences

1:33

that we use in certain occasions.

1:35

What you're seeing on the left are the DWI

1:38

scans, which are used generally for cord

1:42

infarcts and not for intradural extramedullary

1:45

lesions. And on the right hand side,

1:47

we have the MRA of the spine.

1:50

MRA of the spinal cord is very difficult to perform.

1:54

It's usually done in a dynamic mode so that

1:57

you're looking at both the arterial phase,

2:00

as well as the venous phase.

2:02

And then we reconstruct it in a maximum

2:05

intensity projection reconstruction,

2:07

which you're seeing to the right.

2:09

So these are, again, infrequently used,

2:11

but in that certain occasion where you're

2:13

looking for a vascular malformation of the

2:16

spinal canal, you will employ the MRA dynamic technique.