0:00

Okay, so imaging of pyelonephritis on

0:04

CT, definitely better with contrast.

0:05

I don't think you can really make the diagnosis

0:07

without contrast, except for to infer it secondary

0:10

to renal enlargement, some minor stranding.

0:12

I always look at the kidneys again on

0:13

coronal to determine the different sides.

0:15

I like to see a homogeneous, um, symmetric

0:17

enhancement where, in this case, you would

0:19

see that there's enlargement of the kidney.

0:22

There is, um, some perinephric stranding here, some just

0:25

gentle perinephric stranding or fluid accumulating

0:28

in the setting of inflammation and this

0:30

striated nephrogram. This striated

0:32

nephrogram is the classic for the pyelonephritis.

0:36

We would wanna look for this heterogeneous gray

0:39

appearance, this tiger stripe going radially

0:41

through from the cortex to the medullary cavity.

0:45

This is caused by that, that swollen edematous,

0:48

bacterial-filled tubules in the kidneys.

0:52

So that's a classic appearance of pyelonephritis.

0:54

You may wanna look at this on ultrasound as well.

0:57

Here is a patient who's had an ultrasound

1:00

of the right kidney, and you can see that

1:03

it is pretty subtle, but there's a bit of

1:05

heterogeneity to that renal echotexture.

1:07

I think better when I show you the still image. This is

1:10

the sagittal image, and you can see that very echogenic

1:13

bands of renal parenchyma comparatively

1:16

to the more homogeneous appearance of

1:19

the kidney on the contralateral side.

1:21

So this is right-sided, very

1:23

subtle pyelonephritis in a patient.

1:26

I mean, I've made this diagnosis a number of times.

1:27

Frequently, the clinicians will ask

1:29

me like, oh, should I get a CT scan?

1:30

And I'm like, well, no.

1:31

I mean, I diagnosed it, like, I'm good.

1:34

But you know, I always look for

1:35

any kind of fluid collections.

1:36

Try to be a hero.

1:37

Look at your

1:38

renal parenchyma.

1:39

See if you see some subtle echogenicity that

1:41

can be seen in the setting of pyelonephritis.

1:45

This is a different patient.

1:46

This is a patient who's gone on to renal abscess.

1:48

These don't happen all that often for

1:50

how many cases of pyelonephritis we have.

1:52

I think mostly because most of our cases of

1:54

pyelonephritis are in pretty young patients,

1:57

predominantly women who, um, are treated

2:00

for their urinary tract infections at

2:01

a pretty early stage because, you know,

2:03

urinary tract infections are the worst.

2:04

So they come in, and they get treated early.

2:06

Patients with renal abscesses tend to

2:08

be diabetic patients most frequently,

2:10

and here is a large renal abscess.

2:13

You can even look at this image and

2:14

imagine that if it were a scratch-and-sniff

2:16

image, you'd want no part of it, right?

2:18

It even smells bad in the black and white here, and

2:21

here we have the loculated fluid collections, kind of

2:24

exophytic to the kidneys, lots of inflammation.

2:27

This would be a large,

2:29

thick-walled, loculated renal abscess that is going to

2:33

be for your friends in interventional radiology,

2:36

likely, should they be the heroes they are.

2:39

So this is a dreaded complication of pyelonephritis.

2:42

It's not that common for how many cases

2:45

of pyelonephritis we see a year, but you

2:46

always wanna make sure you don't have an

2:48

abscess or a developing abscess as well.