0:01

So when I start reading a pet ct,

0:04

I usually follow the same systematic approach

0:09

to make sure that I essentially don't forget anything

0:12

and I review all the organs that need to be reviewed.

0:16

I always start looking at the mip.

0:20

MIP is uh, an image that gives you a lot

0:23

of information about the study itself.

0:26

In this case, what I go through my mind is, first,

0:31

do I recognize the distribution

0:33

and does this match

0:35

with the intended tracer?

0:39

And obviously this doesn't happen often,

0:42

but sometimes there have been cases where

0:46

the administer tracer is wrong.

0:50

So in this case, I see that the distribution matches

0:54

with FDG, which was the intended tracer.

0:57

I also evaluate the distribution of the tracer

1:02

if it's normal or abnormal

1:04

like we have reviewed in other videos.

1:08

And then I get a sense of where the abnormality are.

1:14

Now, obviously this is only for cases

1:18

where the uptake is greater than expected.

1:23

In the meep I would be missing areas that are foric

1:27

and so that's a caveat of that.

1:30

But I, I like to start looking at this case with the meep

1:34

and uh, see where the distribution

1:37

of disease is, uh, grossly.

1:40

And then I start with the hit.

1:43

I manually change the contrast

1:46

because the,

1:47

the brain has physiologically intense trace

1:49

uptake in the cortex.

1:51

And in order to appreciate the differences, I have

1:53

to change the color scale and now I can see the differences.

1:57

So I scroll all the way from the top to the bottom

2:01

of the brain and

2:02

and see areas looking at the pit only areas

2:06

that are normal versus abnormal uptake.

2:12

After I have reviewed the pit, I will move on

2:15

to the CT series.

2:17

Some things are obvious on the CT

2:18

but are not obvious on the pit,

2:20

and you want to be able to provide an interpretation

2:23

for both scenarios.

2:25

Obviously in a pit viewer you can change the contrast

2:30

the same way you would do on uh, regular ct.

2:34

Once I have finished with the brain, I go back

2:37

to my default uh, color scale on the pit,

2:40

which is the zero to five.

2:42

And then I will scroll through

2:45

and try to identify on the pit images alone areas that are

2:49

not physiologic uptake.

2:53

Once I have done that, I move on again to the CT

2:57

and if I identify something,

2:59

I always use the fused images for anatomical correlation

3:03

and triangulation of the findings.

3:06

I don't read of the fused PET CT image

3:09

because things overlap

3:11

and if there's intense uptake in my obscure the CT findings.

3:16

So it is very important that

3:17

whenever you're reading at a pit ct,

3:20

you look at the pit image only and then the CT image alone

3:25

and then you can use your fusion

3:29

for more correlation.

3:32

Moving on to the chest, I would go through the same

3:36

systematic approach of PET and ct.

3:40

Here it is important

3:41

to obviously not only look at the CT on a soft tissue

3:45

window, but also will change to lung window as you go

3:50

through your organ.

3:53

I continue on the soft tissue window until the end

3:57

and then I do lungs just to keep it consistent

4:00

and not have to go back and forth.

4:02

In this case, we see that there's an area

4:05

of focal intense tracer uptake in the region

4:08

of the upper mediastinum and we can triangulate better

4:12

and see on the ct.

4:13

And this corresponds to an adenopathy.

4:17

You can scroll down

4:19

and in this case we see

4:21

that there's intense uptake in the posterior

4:25

or middle mediastinum that localizes to the SFAs.

4:29

Sometimes the axials are not enough

4:32

and it's important to always go back

4:34

and forth between your axial views

4:36

and your sagittal and coronal views.

4:39

Each viewer will have different options.

4:42

For instance, in this case we see that the uptake is linear

4:47

and it localizes to the esophagus

4:49

and this was consistent with esophageal malignancy.

4:54

The sagittal view allows us to see the extent

4:58

of the FDG uptake along the esophagus

5:01

better than we would appreciate on the axial images alone.

5:05

So once we have gone through the mein structures

5:11

and you know you have reviewed your medicinal organs,

5:15

vascular and nonvascular, the adenopathy, I switch

5:20

to lungs and again, I review the pit alone

5:24

and then the CT separately.

5:28

Same strategy is used for the remainder part

5:32

of the body, the abdomen and pelvis.

5:36

Always look at the pit first and then the CT

5:39

and then correlate with your fusion.

5:43

I personally do the bones at the end as then I can

5:47

change my scale

5:50

and just look at the entire skeleton on its

5:55

own or the skeleton.

5:57

I like to change my display

5:59

and this is totally a personal choice,

6:02

but I change it in a way that I'm able to see

6:07

the most surface of the body that I can like this.

6:12

For the spine, I like to see that the

6:17

uptake is homogeneous throughout the vertebral body.

6:21

I think this view helps me identify areas

6:24

where the uptake might be focal

6:27

and I can identify smaller lesions that go in

6:31

from the top to the bottom.

6:32

On axial view alone, obviously I use the meep

6:37

to see specific areas of uptake that are abnormal, uh,

6:41

like in the lesser counter on the right

6:45

or the left femur.

6:48

And once I have identified that you can change your view

6:52

and for instance, in this case it correlates

6:55

with a lytic lesion that is intensely VG Avid.

6:59

Same on the other side.

7:01

These were, these are ous metastatic lesions.

7:07

So once I have reviewed the entire body, I have gone

7:10

through all the organs

7:12

and I've changed the windows respectively, I will go back

7:17

to my MIP to make sure that

7:20

I have reviewed everything.

7:24

This is particularly important in cases where

7:27

the disease is very extensive

7:30

and we may have identified the majority

7:34

of disease, but maybe we have not reviewed all of it.

7:39

So the meep gives me another chance to make sure

7:42

that I have discussed all the areas

7:45

of abnormal trace uptake in the body.

7:49

The other thing is to always look at the edges of the film.

7:53

You know, these are like common areas where radiologists,

7:56

uh, miss things and the me here helps me particularly

8:01

on the edges

8:04

and specifically on the extremities, you know,

8:07

because if there was a lesion very distally on the leg,

8:11

maybe I would have not scrolled all the way down

8:15

on my axial view.

8:16

But this meat image allows me to make sure

8:21

that I review everything including those ages.

8:24

So this is my personal approach.

8:27

I'm sure that you will develop your own system

8:30

and, uh, I hope this, uh, is useful for you

8:32

and gives you ideas.