0:00

So in addition to obtaining the axial and coronal

0:04

T2-weighted sequences, we also obtain a T2-weighted

0:06

sequence with fat saturation performed utilizing

0:09

fast spin echo, turbo spin echo techniques.

0:12

This can be seen in this example over here.

0:14

We perform these with fat saturation in

0:16

order to provide greater tissue contrast.

0:18

And this sequence actually takes a little bit

0:20

longer to perform than the other T2-weighted

0:22

sequences, resulting in more motion artifact.

0:25

As a result, you often have to do this

0:27

sequence using respiratory gating, so the

0:29

images are obtained at end expiration.

0:31

But we like this sequence because overall, soft

0:33

tissue contrast resolution is much better with this

0:35

sequence compared to our single-shot techniques.

0:39

So how do I use this practically?

0:41

If I see an indeterminate liver lesion, and

0:44

I want to get a sense of what its actual T2

0:46

signal really is, I'm going to be looking at the

0:48

turbo spin echo fat-saturated T2-weighted sequence.

0:51

For example, if the liver lesion has signal that is very

0:55

close to the CSF over here, I'm not going to worry about it.

0:58

Most likely, it's going to be a

0:59

cyst or potentially a hemangioma.

1:02

On the other hand, if the liver lesion has a T2

1:04

weighted imaging appearance that's similar to

1:06

say the spleen, I know that it may be something

1:09

benign, but it could also be something malignant

1:11

and something I need to work up even more.

1:13

In some instances, the turbo spin echo sequence over here

1:16

is replaced by an axial echo-planar imaging sequence.

1:20

The advantage of doing it that way is

1:21

that it can be performed more rapidly,

1:23

providing a similar degree of tissue contrast.