0:00

I do not recommend using MRI scanning for the primary

0:04

evaluation of ductal stones because they may be quite small,

0:08

and the dark signal intensity on all the pulse sequences

0:11

can be very confusing.

0:13

Here, however,

0:14

is a patient who has a pretty clearly obstructing stone in

0:19

the left Wharton's duct, the left submandibular duct.

0:22

And, in addition,

0:23

a more proximal stone here towards the gland itself

0:27

with dilatation of the duct and sialodochoectasia.

0:32

So this is submandibular and sialodocholithiasis.

0:37

This is a case that was provided to me by

0:40

Ruth Eliahou from the Hadassah Hospital.

0:45

And you can see in these examples of both sialography,

0:50

as well as ultrasound, that there are..

0:54

you can identify the flow void

0:57

within the ductal system of a calculus.

1:00

You can identify it also in the ultrasound evaluation

1:06

with proximal ductal dilatation,

1:07

and then the calcification.

1:09

On CT scan,

1:10

which we're most comfortable with,

1:12

here is a tiny stone, as you would imagine,

1:16

in the floor of the mouth, on either side of the frenulum.

1:18

This is right at the ductal orifice of the submandibular duct.

1:23

No real ductal dilatation.

1:24

The submandibular gland looks pretty good.

1:27

However, when you look at the superficial portion

1:30

of the submandibular duct

1:32

you do see that there is internal ductal dilatation sialectasia,

1:36

as well as some overlying inflammation

1:40

of the platysma muscle.

1:46

I've shown multiple examples of submandibular glandular

1:50

calcifications and ductal stones because, as I said,

1:54

there's about a 4:1 ratio between the submandibular

1:57

gland and the parotid gland for calculi.

2:00

Here are, however, a few examples of parotid sialolithiasis

2:05

or Parotid Sialodocholithiasis

2:08

Here we have a stone in the duct with a mark of the enlarged

2:12

and enhancing parotid gland compared

2:15

to the contralateral parotid gland.

2:17

Here we have an MR showing a stone in the duct of the

2:23

parotid gland, Stensen's duct, with some

2:25

proximal dilatation of the duct.

2:28

Here we have a similar example of a duct in the

2:34

Stensen's duct with associated dilatation of the main duct,

2:38

as well as the internal ducts within the parotid gland.

2:41

Note, again, the enlargement

2:42

and the degree of enhancement on

2:44

the left side compared to the right

2:46

side because of the sialadenitis.

2:50

This is a reconstruction of thin section imaging

2:53

showing the calcification within the ductal system

2:56

of the parotid gland.

2:58

Now, this is effectively our MR sialography

3:02

similar to the MR cholangiopancreatography

3:06

in which we're using a thin section high resolution

3:09

T2-weighted scan,

3:10

akin to the cyst imaging.

3:13

And it allows us to see the

3:15

ductal system quite nicely.

3:17

Finally, we have one which shows the marked dilatation

3:21

of the duct, secondary to a calcification that is

3:24

very close to the parotid duct,

3:27

the Stensen's duct orifice.

3:28

But you also see the amount of enhancement

3:31

in the ductal wall.

3:32

So this is sialodochitis.

3:34

We have cellulitis of the subcutaneous tissue,

3:38

as well as sialadenitis.

3:40

Compare the enhancement of the parotid gland

3:44

compared to the normal parotid gland.

3:47

So, when you think about parotitis,

3:50

sialodochitis, and sialo...

3:54

can be a source of the parotid inflammation itself.

3:59

Lots of great examples of the use of non-contrast CT,

4:03

MR sialography,

4:06

and post-contrast CT scan for demonstrating stones,

4:10

as well as the inflammation that can occur secondary

4:13

to the stones. Remember that on CT scans,

4:16

best to do this with both non-contrast

4:19

followed by contrast-enhanced scan

4:21

so you don't confuse a small blood vessel,

4:25

for example here, for a stone in the duct.