0:00

So here is a young woman who's come in with flank

0:04

pain, and we have a contrast-enhanced CT scan.

0:06

We're going to see that the liver and the spleen

0:08

look pretty good, and so does the pancreas. Coming

0:12

down, we see no evidence of bowel obstruction, but

0:15

coming back up, we can see in that retroperitoneal

0:17

location that we have asymmetry of the kidneys.

0:21

Demonstrating this kind of striated or

0:24

tiger-striped appearance of the left kidney.

0:27

This patient has left-sided flank pain.

0:29

Let's look on the coronals, 'cause I've always

0:31

said kidney's on coronals, so I'm going to stand

0:34

by my word, and you'll see that the left kidney.

0:37

Is a bit enlarged comparatively to the right kidney.

0:40

You'll also have this very heterogeneous

0:42

enhancement pattern with these just little gray

0:45

stripes throughout the entire kidney, looking like

0:46

tiger stripes, and a bit of perinephric stranding.

0:49

See all that?

0:49

Just slight inflammation around the kidney.

0:52

This would be a classic appearance of pyelonephritis

0:56

of the left kidney with that heterogeneous enhancement

0:59

secondary to basically bacteria within the tubules,

1:04

causing that heterogeneous excretion of contrast.

1:07

We always say that pyelonephritis is a clinical

1:10

diagnosis, but I have to say in most ERs anymore,

1:13

where there is a very fast time to imaging.

1:18

Frequently we are catching pyelonephritis on imaging.

1:21

Also, I think in medical school, we believe that

1:23

patients come in being like, oh, I have burning

1:25

urine, and I have flank pain, and they have that

1:28

classic history, but in reality, it can be.

1:31

Much more subtle, like maybe only minimal

1:34

urinary tract symptoms or none at all,

1:36

and they may still have pyelonephritis.

1:39

So we do see this on CT scan.

1:41

It's a good reason that we can see this

1:42

better with contrast, obviously, than on a

1:44

non-contrast, where you may only have some

1:46

renal enlargement and a bit of stranding.

1:48

It's a diagnosis that can be made.

1:50

Obviously, we would prefer to do that clinically

1:52

and not expose patients to radiation, but I think

1:54

in reality, um, these cases aren't as slam-dunk

1:58

clinically as we were taught back in those times.

2:01

So this is a patient who has renal enlargement,

2:04

heterogeneous attenuation with that.

2:06

Tiger-striped, or if you are a radiologist, we're

2:09

going to use the words striated nephrogram, that

2:12

comes back from the old days of IVPs, which none of us

2:15

have done, and perinephric stranding, all in keeping

2:18

with pyelonephritis or a urinary tract infection,

2:22

which has gone from the bladder and ascended.

2:24

Into the kidney itself.

2:26

I don't see any evidence of a renal abscess here.

2:30

Nothing that looks drainable or anything like this.

2:33

This would be a normal, non-complicated,

2:35

left-sided pyelonephritis.