0:00

Okay. Here we have another contrast-enhanced

0:03

CT scan in a patient with flank pain.

0:05

As we come down, you can see that

0:07

the liver here is homogeneous.

0:09

The gallbladder looks good, spleen is okay.

0:12

Once you get to the spleen, find your pancreas.

0:14

Pancreas coming over okay.

0:15

9 00:00:16,710 --> 00:00:18,210 But we have a big hot mess

0:18

here in the right upper quadrant

0:20

retroperitoneal, and you can see a ton

0:23

of fluid around this right kidney, which

0:25

is asymmetric to the contralateral side.

0:27

But I'd like you to note that the kidneys

0:29

are enhancing symmetrically, so it's odd

0:31

that there's a lot of fluid around the kidney

0:33

and the kidneys are enhancing symmetrically.

0:35

So I'm going to try to look for the cause of

0:38

this, um, situation and I'm going to look for a

0:41

renal stone that's causing this hydronephrosis.

0:43

See how there's dilatation of that renal pelvis there?

0:46

We're going to follow it down.

0:47

This would be a common location for that obstructing

0:50

renal stone in the proximal ureteropelvic

0:52

junction, but we don't find anything there.

0:53

Still following that little ureter,

0:55

but it's kind of dilated, so it's in play.

0:57

Look at the contralateral ureter,

0:58

it's probably one of these tiny dots over there,

1:01

so we're going to keep on extending down.

1:04

Down slowly.

1:06

You want to even use

1:07

smaller thickness images if you have them.

1:10

I usually like a 2.5 because some

1:12

stones are just millimeters in size.

1:15

And as we come on over the iliac vasculature,

1:19

we are going to hit a very dense renal calculus.

1:22

So that is an obstructing renal calculus

1:24

within this ureter. Coming down, you

1:27

can see the decompressed ureter.

1:28

Nothing distal to that.

1:30

And the bladder looks okay.

1:32

No stones there.

1:34

Now, here's a patient with an obstructing renal calculus

1:37

with some, a little bit of hydro, but no delayed nephrogram

1:40

and a lot of perinephric fluid in that perirenal space.

1:44

Like it's pretty impressive.

1:46

So we have to think to ourselves, how are

1:49

these kidneys enhancing symmetrically?

1:50

Why isn't that delayed?

1:51

Right?

1:52

And that would be because the pressure here has

1:55

been released and allowed for excretion of contrast.

1:58

What has happened here?

2:00

There are opportunities to pass a

2:02

stone that will release your pressure.

2:04

Maybe this is a passed stone, not in our case.

2:06

We found the stones.

2:07

We know that's not the case.

2:08

The other option, and we're going to go on the

2:10

delayed images, is we're taking a couple minutes

2:12

later, is that you're going to see a lot of

2:15

that very dense urine contrast in the urine

2:19

actually extravasate outside of the kidney and

2:23

be in a perinephric location causing a urinoma.

2:26

This is related to a forniceal rupture.

2:29

Let me see if I can window this just a tiny bit

2:31

for us so we can try to watch that contrast.

2:34

See this large volume of contrast,

2:36

it's coming all the way into where the

2:39

papilla comes into the collecting system.

2:42

That is called the fornix of the urinary collecting

2:45

system, and that's a relative weak spot in that system.

2:50

So,

2:51

this is an obstructing renal calculus

2:54

with a urinoma caused by forniceal rupture.

2:58

That would be an indication for our urology

3:00

colleagues to stent this patient right away

3:03

in order to bypass this obstruction and allow

3:06

the urine to flow into the stent, into the

3:08

ureter, and not accumulate around the kidney.