0:02

Hello, and welcome to Noon Conferences hosted by MRI Online.

0:06

In response to changes happening around the world and

0:10

the canceling of in-person events, we have decided to

0:12

provide free noon conferences to radiologists worldwide.

0:16

Today we are joined for a lecture from Dr. Manjiri Dighe,

0:23

who is a board-certified radiologist and director

0:25

of ultrasound at UW Medical Center at

0:28

and a UW professor of radiology.

0:30

Dr. Dighe is an expert, expert in OB ultrasound and

0:34

placental imaging, in addition to thyroid elastography.

0:38

A reminder that there will be a Q&A session

0:40

at the end of the lecture, so please use the Q&A

0:42

feature to ask your questions, and we will

0:44

get to as many as we can before our time is up.

0:47

That being said, thank you for joining us today.

0:49

I'll let you take it from here.

0:52

Thank you very much for that kind introduction.

0:54

Um, so, as mentioned, my topic for the lecture

0:58

today is role of MRI in abdominal pelvic emergencies.

1:04

So acute abdomen or pelvic pain is the

1:07

most common reason for an ER visit.

1:10

If you look at the data from Medicare beneficiaries,

1:13

and this is courtesy of Drano from Emory, and this is

1:16

data from 2016, um, you can see that basically the number of

1:20

exams, the number of patients who have presented per acute,

1:24

has progressively increased.

1:27

Um, so, and in 2018, the national Hospital

1:32

Ambulatory Survey from greater than 10 million

1:35

cases, uh, that presented for non-traumatic pain.

1:39

And if you look at the number of ER visits, acute abdomen

1:42

is about 7 to 10% of these visits within the ER.

1:46

So we have a big population that comes in for

1:49

this indication within the emergency room.

1:54

When you look at the number of exams that

1:57

are done for MRI per, um, for this, this is

2:02

Medicare data, and you progressively through, um.

2:07

The number of MRIs that are done in an outpatient

2:09

and inpatient, uh, outpatient and office setting,

2:12

obviously, uh, quite a bit.

2:16

Um, inpatients also, we do quite a bit of MRIs,

2:19

but the number of MRIs that we do for abdominal

2:22

pain, or abdominal MRIs when patients can come into

2:24

the ER, that's a small fraction, but it's been

2:27

increasing progressively throughout the years.

2:31

So, um, you know, ultrasound and CT are the dominant exams.

2:35

If you look at the number of, you know, the

2:36

number of patients coming in, about 22% of

2:39

those undergo CT imaging for abdominal pain.

2:42

Why MRI then in acute symptoms?

2:44

Well, there are some, uh, uh, some advantages.

2:48

So the pros are, you know, there is no ionizing radiation.

2:51

As you can understand, some young patients or

2:53

patients who get repeated exams, and pregnant

2:55

patients, no ionizing radiation is very beneficial.

2:58

It does a very good contrast resolution, and

3:01

you avoid contrast in some patients who have

3:03

either allergic reaction to, you know, severe

3:06

allergic reaction, or have bad renal function.

3:09

Um, it's, it's of the ultimate modality, right?

3:12

I mean, you do, many times you do ultrasound,

3:14

sometimes you do CT, and eventually you go to MR because

3:18

that's sort of the final modality, uh, of imaging.

3:21

And then, uh, if we can get it done, you'll get a more

3:23

rapid diagnosis, and we're able to treat patients as well.

3:26

But there are some.

3:27

Disadvantages as well, because it's a much costlier

3:30

exam than getting an ultrasound or a CT done.

3:33

You don't have, uh, MRI availability, you know,

3:36

especially like, uh, MRI technicians, technologists,

3:39

they don't necessarily staff 24 hours a day.

3:41

These are lengthy exams, you know, and ultrasound can be

3:44

done probably in 20 minutes or so.

3:47

CT is probably less than that, maybe even just 15

3:49

minutes, but MR takes an hour or so to be done.

3:53

You have to think about the, um, implants

3:55

that are placed in some patients.

3:57

And, uh, some of these patients

3:58

need careful monitoring as well.

4:00

So all those, uh, factors come into play.

4:02

And then, um, you know, it's, it's, it's difficult in some

4:07

patients who require immediate diagnosis in an ER setting.

4:10

Many patients can't wait for an hour or two to

4:13

get the exam and then come to the diagnosis.

4:16

So as far as our experience is concerned, um, we primarily

4:20

use MR or abdominal pelvic MR in the emergency department

4:24

in patients who are pregnant, and we have a concern

4:26

for, uh, appendicitis or any other acute pathology.

4:30

Uh, and then second-line test for

4:32

everyone else after a CT or MR is done.

4:36

We use MRI when patients have contrast or renal

4:40

issues, and then young patients as well, because we

4:43

want to avoid the radiation exposure for these patients.

4:47

It is important to remember that the, um, the

4:50

protocols should be tailored to the clinical condition.

4:53

Sometimes you may, you may need those additional sequences,

4:56

or you may need a different, um, uh, sequence altogether,

5:00

uh, when you're trying to look for specific things.

5:02

Um, so you can have two types of protocols.

5:04

You can have free-breathing protocols

5:06

or breath-hold protocols, uh, or sequences.

5:09

Um, at UW what we do is we have,

5:12

we acquire all three planes.

5:15

Our primary plane is, of course, axial, where we get

5:18

quite a few of these sequences.

5:21

Uh, and then we get coronal and

5:23

sagittal additional planes as well.

5:26

Uh, in our patients, we have contrast as

5:30

an option on our protocol because, obviously,

5:33

in pregnant patients we wouldn't give contrast.

5:35

Um, and then it depends on the clinical indication

5:38

as to whether we're giving contrast or not.

5:40

If you do give contrast, we get at least

5:42

axial and coronal images, uh, sequences.

5:47

So what are these different sequences that we use?

5:49

So primarily the sequence, um, the T2

5:52

single-shot sequence is sort of the workhorse.

5:55

These are free-breathing.

5:56

They give excellent in-plane spatial resolution.

5:59

We get some T2 fat-sat images as well because,

6:02

obviously, if you want to see fluid

6:04

better, especially like around the appendix,

6:06

if there's any amount of edema, T2 fat-sat does help there.

6:10

Um, we get some balanced FFE images, and those

6:13

help with vascular structures because you can look

6:15

at them, um, without giving actual IV contrast.

6:18

So they're pseudo, um,

6:20

to look at vascular structures.

6:23

As such, we always get diffusion-weighted images.

6:26

Diffusion-weighted images help in detecting blood

6:29

products or material.

6:33

And then the gradient images help with

6:36

detecting fat or free air in these patients as well.

6:39

So that's why we make sure that we

6:42

get these different sequences.

6:45

Now contrast, as I said, can be used

6:47

depending on the clinical indication.

6:49

Uh, we don't use it in pregnant patients

6:51

because it crosses the placenta

6:54

and gets accumulated in amniotic fluid.

6:56

But we do use it in other

6:57

indications in nonpregnant patients.

7:01

As I said, it crosses the placenta, and the gadolinium

7:09

free ion is toxic, and it stays in the amniotic fluid.

7:11

Um, besides, we really don't

7:13

have good controlled studies to know if it

7:16

is really that harmful or not to the fetus.

7:20

So to be cautious, we avoid giving contrast,

7:22

um, gadolinium in pregnant patients.

7:23

So in pregnant patients, we've used it mainly for

7:25

appendicitis, looking for adnexal pathology, um,

7:29

or if, uh, we've even used it in patients where

7:32

we suspect that they might have intra-abdominal

7:33

pathology, like bowel-related issues other than

7:36

appendicitis, pancreatitis, and even renal pathology.

7:40

So, for example, this particular patient

7:41

has had pancreatitis, and you can see the,

7:44

um, pancreas has some fluid around it.

7:47

Um, her lipase levels were elevated, and then, um.

7:57

So MR, um, has high sensitivity and

8:00

specificity in pregnancy, almost 80 to 90%.

8:03

And if you look at the ACR recommendations,

8:05

ultrasound is obviously recommended

8:07

as a first-line exam, but then after that

8:10

you have MR as a second-line modality.

8:13

Um, it is also important to understand that MR can

8:16

actually give you alternatives if the appendix is.

8:21

Um, if everything is, you know, you see the appendix

8:24

looks beautiful, as can be seen in this particular

8:26

patient who had appendicitis, and you can see an appendix

8:28

in this patient, in the image on the top right.

8:31

Um, uh, but if the patient does not have

8:35

appendicitis, you can always look

8:38

at the surrounding structures, the ovary,

8:40

and see if there's another diagnosis which, um,

8:43

has caused pain in this particular patient.

8:47

You know, there's always concern about MR exposure

8:49

during pregnancy and, um, outcomes in the kids.

8:54

This particular paper in JAMA, um, was a large study

8:57

that was done, uh, this was published in 2016, and

9:01

they wanted to evaluate what's the long-term safety

9:03

after exposure to MRI in the first trimester, um, of

9:06

pregnancy, and then gadolinium anywhere during the pregnancy.

9:10

And they, um, they did this, um, you know, this was

9:13

done in Canada because they have universal healthcare.

9:15

They could get this information from their database.

9:18

Uh, and what they found was, um, uh, basically,

9:23

they had 1.4 million deliveries, so quite a lot of

9:25

deliveries. Out of those, they had about, um, 1,737

9:31

patients had MRI, so about four per thousand pregnancies.

9:35

Um, they found that the first-trimester MRIs were not

9:37

associated with anomalies or neoplasms.

9:42

Gadolinium did increase the risk of stillbirth,

9:45

neonatal death, um, inflammatory skin conditions,

9:48

and that's the reason why we don't give gadolinium.

9:50

But MRI is safe even if it's performed

9:53

in the first trimester of pregnancy.

9:56

Now, how about acute abdominal and pelvic pain?

9:59

You know, does MRI really help, and especially since

10:02

ultrasound is so easily available and it can be done

10:05

within the emergency department itself, how does MRI help?

10:08

So this particular study, um, in abdominal imaging.

10:11

At 40 patients, they found that, um, you know,

10:15

in 19 out of the 40 patients, uh, MRI was normal

10:19

and unremarkable, and 21 out of the 40

10:22

patients, they could come to a correct diagnosis.

10:25

Um, so MRI was helpful as an adjunct to be, uh,

10:28

um, to ultrasound in their particular population.

10:32

Important.

10:33

They found all pathology in these patients as well.

10:36

When looking for appendicitis, did not see appendicitis.

10:43

Same ultrasound.

10:50

This particular paper, um, uh, uh, had 29

10:54

patients, and again, they looked at the same thing.

10:56

MRI.

10:56

How useful is it?

10:58

And again, you can see a theme over here

10:59

that, you know, they had 29 patients.

11:02

It was just one patient who had

11:03

torsion that wasn't detected by MRI.

11:06

Prospectively or retrospectively, we had 12 patients out of

11:10

those that were, um, normal and unremarkable, but then they

11:13

could find this host of other, um, conditions, uh, and,

11:17

and other diagnoses on MRI, um, uh, which then helped the

11:21

patients, you know, with these different diagnoses.

11:25

What about children?

11:26

Should we do MRI in children?

11:28

Well, that depends on the age of children.

11:30

So small children, you cannot explain

11:32

to them that they need to be still.

11:34

Uh, you know, they can't even show

11:36

where they have their discomfort, et cetera.

11:38

So, in small children, because it can

11:40

depict all the organs, that is an advantage.

11:43

And as long as the children can, you know, be, be, um,

11:46

um, non-sedated or stay still.

11:50

Um, of course, the disadvantage is that sometimes you have

11:53

to give, um, sedation to these small children for MRI.

11:57

So looking at, you know, acute appendicitis,

12:00

yes, ultrasound is the initial modality.

12:02

MRI is the preferred second-line modality, and it

12:05

does have very high sensitivity and specificity.

12:08

Specificity, but also very high negative predictive

12:11

value, which is really important because if

12:12

you can show that the appendix is normal,

12:15

then, and, and of course, give other diagnoses.

12:18

That is really helpful.

12:19

Um, appendicitis happens in about

12:21

one in 800 to one in 1,500 pregnancies.

12:24

Um, women are less likely to have appendicitis

12:26

during pregnancy, but the clinical

12:28

diagnosis is really challenging because

12:31

one, they can have abdominal

12:33

discomfort from the pregnancy itself.

12:35

You can have mild leukocytosis due to the pregnancy

12:37

itself, so that doesn't really help in assessing.

12:40

And then appendix, it moves up as the uterus

12:43

grows; the appendix does move up in the abdomen.

12:46

Now appendicitis is associated with fetal

12:50

loss seen in about 1.6% of patients who

12:53

have just acute appendicitis, but that increases

12:56

to 35% when they have perforated appendicitis.

12:59

So it's important for us to make the diagnosis

13:02

and give early treatment of these patients.

13:06

When you look at the ACR appropriateness

13:08

criteria for acute pelvic pain in patients

13:11

who have positive pregnancy tests.

13:14

MRI is the second-line modality before

13:17

CT, so that's important to remember.

13:19

You know, we need to do ultrasound first.

13:22

If the ultrasound doesn't help, then MRI would be indicated.

13:26

So this is an example.

13:27

Um, how, what does the appendix look like?

13:29

So it is a, you know, similar features, tubular blind-

13:33

ending structure arising from the cecum. Size cutoff,

13:37

you can talk about that, six millimeters or

13:38

less, because there's some controversy whether

13:40

we should be using the size cutoff or not.

13:42

But this is an example, you know, patient is pregnant.

13:45

Um, the endometrium and, you know, the, the, um,

13:49

and the appendix are sort of pushed around,

13:51

and in her case they have been pushed posteriorly.

13:54

We can see the appendix, um, on these

13:55

images, and that looks completely normal.

13:58

I don't see any fluid or fat around this patient.

14:01

So this is what happens.

14:04

In pregnancy, as the uterus sort of rises up from the

14:08

pelvis, it pushes the appendix and the cecum further up.

14:12

And if you look at, you know, even by

14:15

five months, it's out of the pelvis.

14:17

It's in sort of mid abdomen, you know, and then

14:20

eight months, it's sort of mid to upper abdomen.

14:22

So this is an example you see.

14:24

Um.

14:28

Cecum and the appendix are seen now,

14:31

but they're pushed by the uterus that

14:33

gets, that sort of rises out of the pelvis.

14:37

So as I mentioned, you know, if you look, if you

14:39

see a dilated appendix that has fluid or fat around

14:42

it, you may see appendicoliths in it.

14:47

And of course, because, um.

14:51

And, and that is what you look for.

14:54

Now, marked contrast enhancement.

14:56

We don't give contrast to pregnant patients.

14:57

And so we wouldn't see that in this

14:58

work, in, in, in, uh, pregnant patients.

15:01

Now, diameter should be interpreted with

15:04

caution, or you don't need to perform it at all.

15:06

You know, you can eyeball the measurements,

15:09

but actually look for surrounding features,

15:12

other features that can help in the diagnosis.

15:14

So there's, there's, there's, the, the

15:16

new thinking is that you don't really.

15:18

Be skeptical about the measurement.

15:20

What if it's three, you know, what if it's three

15:22

or four millimeters, four millimeters, and still

15:24

has fluid around it and inflammation around it?

15:27

Or what if it's eight millimeters?

15:28

It doesn't have anything, so it, so just keep that in mind.

15:33

So this is another case, patient you can clearly see.

15:35

I mean, in this patient, you know, I, I, uh, um,

15:38

the calipers say that it's about one centimeter

15:40

in size, but on the, um, T2-weighted images, uh,

15:44

axial, uh, and the FANTA images, you can clearly

15:47

see that there's fluid around this appendix.

15:49

Um, there's fat stranding and fluid around this, and the, uh,

15:53

T2 fat-sat actually emphasizes the periappendiceal inflammation.

15:56

So that, um, tells us that this patient has

15:59

appendicitis, you know, regardless

16:01

of whatever the size it may be at.

16:04

What about perforated appendicitis?

16:06

We're looking for those periappendiceal fluid collections.

16:08

Um, uh, what you would have is you

16:11

could potentially have air as well.

16:12

If it's a small amount, that's difficult to detect, but,

16:15

you know, um, uh, you are also looking for mesenteric edema.

16:19

So in this particular patient, coronal

16:20

images, um, there's fluid in the right lower

16:23

quadrant, but if you look at the surrounding.

16:26

There's, uh, heterogeneity, some, um, fluid within

16:29

the mesentery and fluid collection seen within this

16:32

mesentery in the patient who had appendicitis.

16:37

So, um, in terms of diagnostic performance,

16:40

this was a meta-analysis that was done in 2016.

16:43

We had 12 studies, and they found that the sensitivity and

16:46

specificity was about 95% for MR in appendicitis.

16:53

In terms of children, um, you know, it's, uh.

16:56

Uh, Hryhorczuk, in his article in 2008, recommended that if

17:00

ultrasound especially has uncertain results or,

17:03

um, uh, an atypical presentation, um, then we can do MR,

17:08

uh, in these patients.

17:09

In older children,

17:09

neuro don't need sedation.

17:10

I mean, they can stay still.

17:12

Um, you can counsel them, you can talk to them.

17:14

You don't need oral IV contrast as well.

17:16

No radiation.

17:17

And so in his, uh, uh, study, um, they found

17:21

that the appendix was seen in all cases, and

17:23

appendicitis was shown in one hundred percent

17:25

of the cases that had a positive diagnosis.

17:27

So this is a 12-year-old boy with right quadrant

17:30

pain and a history of Crohn’s disease.

17:33

Um, but when you look at the appendix, you can see

17:36

that there’s periappendiceal inflammation, some fluid,

17:38

fat stranding, and the axial, uh, fat-sat images

17:41

actually show you that inflammation quite well.

17:44

So this patient had, um, in addition to his history

17:47

of Crohn’s disease, acute appendicitis as well.

17:51

This was an 11-year-old boy who came in with fever,

17:55

and, um, you know, the T2-weighted

17:58

images, axial and coronal, show you the

18:01

inflammation in the right lower quadrant.

18:03

It’s a little difficult to pick out the appendix

18:04

in this particular patient, um, because of the

18:07

amount of inflammation and fluid collection with

18:09

fat stranding seen. Um, this patient did get contrast.

18:13

And on contrast, you can see that

18:14

there’s some fluid collection.

18:16

So this, um, was most consistent

18:18

with perforated appendicitis.

18:22

Now, in terms of bowel pathology, uh, we

18:24

mainly use it for, um, in addition to

18:27

appendicitis, inflammatory bowel disease.

18:29

But we’ve seen other cases like, um,

18:31

small bowel obstruction or masses as well.

18:34

They can be seen incidentally when you’re

18:35

actually looking for these other findings.

18:38

So this is a patient who is 45 years old, has known,

18:41

um, ulcerative colitis, came in with acute abdominal pain.

18:44

We decided to do MR, and you can easily see

18:50

that there’s inflammation in the sigmoid colon,

18:56

um, seen in these images with inflammation seen

19:03

well. So MRI is really helpful and is helpful

19:07

in follow-up with these patients as well.

19:09

This is a patient who was 37 years old.

19:12

She’s pregnant, so she was in the first trimester.

19:14

You can see the uterus on here.

19:16

And, um, uh, there was a question about, you

19:19

know, she had a history of Crohn’s, so there’s

19:21

a question about whether her Crohn’s disease

19:23

was acting up or what exactly was going on.

19:25

So we decided to do an MR without contrast, and you could

19:28

see that the bowel loops are quite dilated in this patient.

19:31

But more importantly, you could actually

19:32

follow the bowel loops all the way to

19:34

the, uh, ileostomy site in the right.

19:37

And the, um, the transition point was at the

19:40

ileostomy site, um, because of her Crohn’s disease.

19:44

And so we could give them this information without

19:46

actually subjecting the patient who is seeking.

19:50

With acute colitis, um, uh, nonpregnant patients or patients

19:54

who, uh, you know, uh, uh, typically seen in older patients.

19:58

So we obviously do CT most often, but in some

20:01

cases you might, uh, get an MR done for these

20:04

patients, and especially if they have, you know,

20:06

when they have multiple episodes and complications.

20:09

Um.

20:10

On imaging, you look for those diverticula, which are seen as

20:13

hyperintense outpouchings, or you look for, um, concentric or

20:17

focal, uh, thickening in these patients, and you look for

20:20

the inflammation and then complications from this as well.

20:24

This was a patient who presented

20:26

with, um, he’s 76 years old.

20:27

He had gall carcinoma.

20:29

MR was done because this patient had high

20:31

creatinine, could not get, um, a CT done.

20:34

And so we decided to do an MR, and you can easily

20:37

see that this patient does have diverticulitis; there’s

20:39

fluid around the colon with wall thickening seen as

20:43

well, and there was enhancement seen

20:45

post-contrast, um, within this segment of bowel.

20:49

And this was consistent with, um, diverticulitis.

20:52

So you can see this diverticulitis, which

20:54

is inflamed, um, has fluid around it.

20:56

So this can help in diagnosis in

20:59

these patients who cannot get CTs done.

21:04

Now Crohn’s disease, uh, as we know, is an

21:06

inflammatory lesion in the gastrointestinal

21:08

tract, mostly in the terminal ileum and colon.

21:10

Um, you have transmural lesions in addition

21:14

to stenosis, fistula, and abscess formation.

21:17

And these are some of the imaging features

21:19

that are seen, where you have segmental mural enhancement

21:23

and edema.

21:24

If you do, um, diffusion-weighted imaging, you

21:26

would have restricted diffusion in that segment.

21:28

And then you look for other findings like mesenteric edema and

21:31

inflammation and complications with stricture formation.

21:35

So this is a patient who, um, so this is a patient who

21:37

has Crohn’s disease, and you can see typical findings.

21:40

You have these engorged.

21:44

Adjacent to the cecum and the

21:46

ileum in the right lower quadrant.

21:47

And then on post-contrast, so pre-

21:49

contrast and then post-contrast images.

21:51

You can see the, uh, increased giving the

21:55

comb sign, but also the inflammation and

21:57

the wall with enhancement and thickening.

21:59

And then on the lower panels you can see

22:02

the, uh, ADC map and the diffusion images.

22:05

We do diffusion at high b-value.

22:07

And you can see that this.

22:10

Segment, along with the high, uh, signal intensity

22:12

seen on the diffusion, uh, the DWI images.

22:16

So that can help in, um, pinpointing the, uh, uh, location

22:20

of, you know, the inflammation of inflamed bowel.

22:24

But more importantly, in patients, in children, when

22:26

they have IBD, because it has a relapsing course, you

22:29

need repeated imaging and you need, um, uh, because

22:33

these are kids, it's best if you avoid any radiation.

22:36

And so between the ages of 10 to 20 years, um, and even

22:39

in some of the older patients, we prefer to do MRI.

22:43

In these patients rather than doing a CT.

22:45

So this is a 16-year-old, um, and you

22:50

clearly see these features of ulcerative.

22:56

All these features seen.

22:57

Uh, so in this patient, we opted, you know, we, this was,

23:01

uh, patients with Crohn’s disease, and so we opted follow-

23:04

up even, um, uh, when the patient presented again with

23:07

abdominal pain with MRI, because one, we had the, uh,

23:10

baseline MRI that showed the changes and we could easily

23:13

compare them, um, the, the previous and the follow-up MRI,

23:17

and you can see the changes and give them information about

23:20

the activity of the disease, whether it's still the same or

23:25

what's going on?

23:26

Um, you can, and, and so we prefer to do young kids.

23:29

Um, do MRI even in an acute setting.

23:33

Now, uh, moving on to the biliary system.

23:35

Ultrasound is always a first-line modality.

23:38

Um, but MRI can be used in some cases and,

23:40

um, we've used it even for evaluation of

23:43

polyps and obviously for bile duct obstruction.

23:46

So, um, this particular pregnant patient,

23:49

um, you can see the stones really well.

23:50

So in this patient you can see that

23:52

there's biliary dilatation on the.

23:53

Upper, um, upper panel, uh, the intrahepatic

23:57

dilatation, the common bile duct is dilated and

23:59

you could follow it right up to the, um, uh,

24:02

uh, insertion of the CBD into the duodenum.

24:05

You see a filling defect, which is magnified

24:07

on the image lower, um, lower down, and

24:09

you can see a small stone obstructing.

24:12

So.

24:14

Biliary system.

24:15

You know, sometimes ultrasound, it’s a

24:17

firsthand modality, but sometimes the visualization

24:19

of the bile ducts is obstructed because of the duodenum and gas.

24:23

And so in these patients, MRCP is excellent, similar

24:26

to ERCP in terms of, um, the findings and the resolution.

24:30

And, um, you can get all these

24:33

images that show the exact location of the stone.

24:36

Um, now one thing to remember is that, you know, we

24:39

always get thin, thin, thin slice thickness

24:43

images in these patients because some of the thick slabs

24:45

can obscure small stones, so just be careful that if

24:48

you're interpreting it, always make sure that you have

24:50

thin sliced images through the biliary system

24:54

as well, so that you can pick up those small stones.

24:58

Uh, cholecystitis.

24:59

The imaging findings would be similar

25:01

to what we see on CT, wall thickening.

25:04

Um, uh, there's hyperemia, pericholecystic fluid, and then you

25:08

may see some, uh, hyperemia in the adjacent liver as well.

25:12

So this patient has had a gallstone, uh, seen on the

25:15

T2 image, um, that is distended, has wall thickening.

25:20

The T2 fat-sat shows some of

25:22

the cystic duct edema, like cystic fluid.

25:26

And then post-contrast, you can see that there's,

25:28

um, enhancement in the gallbladder wall, but also the

25:32

liver in the middle panel shows that there's some

25:34

hyperenhancement in the liver as well, which, uh,

25:38

because of hyperemia around, we call that a focus.

25:42

So this patient is 68 years old,

25:45

had right upper quadrant pain, and the

25:46

ultrasound was indeterminate for cholecystitis.

25:49

So we decided to, um, do an MRI.

25:51

On MRI.

25:52

You can see that there's biliary dilatation.

25:54

The patient did have multiple stones.

25:56

And then, um, if you look at the cystic duct, um, you

26:00

can see that there's compression of the cystic duct, uh,

26:02

the common duct by the stones in the gallbladder.

26:06

Um, and so we could give a diagnosis that this was, um,

26:09

Mirizzi syndrome because of the gallstones in

26:13

the neck of the gallbladder that are compressing on the bile duct.

26:17

In terms of renal disease, um, uh, or renal

26:22

disease or urinary pathology is the most non-obstetric

26:25

cause of acute, uh, pain and most often

26:29

is what we find, um, but can have infection as well.

26:32

Uh, it is important to remember that

26:34

patients can have necrosis, so keep that in

26:37

mind, uh, when evaluating these patients.

26:40

Now, um.

26:42

If you see on MR, then the obstruction is distal

26:45

to the segment two month and be very suspicious.

26:47

It most likely suggests an obstructive

26:49

process and not physiologic hydronephrosis.

26:52

And you're looking for stones, which

26:53

appear as hypointense filling defects.

26:56

Um, you can have other changes in the kidney,

26:58

uh, from the back-pressure changes like enlargement.

27:02

Edema and fluid, uh, pyelonephritis makes the kidneys

27:05

look heterogeneous, and you can see the changes on T2-

27:09

weighted images, as well as, as well as the perfusion images.

27:12

And then you look for complications as well.

27:15

So this was a patient, um, a 36-year-old pregnant

27:17

patient with right flank pain.

27:20

You can see that the left kidney does

27:22

not have any hydronephrosis, right?

27:23

The right kidney has.

27:26

And, uh, you know, we, this could be

27:29

from physiologic hydronephrosis as well.

27:31

So, um, uh, but on careful review of her images,

27:35

you can see that the ureter is dilated, and there

27:37

was actually a filling defect within the ureter.

27:39

And this patient had a stone, which is causing her symptoms.

27:43

This was a 64-year-old who had bacteremia

27:45

and suspicion of some intra-abdominal pathology.

27:49

Um, and on.

27:51

The ultrasound was negative, uh, and, and

27:54

decided to do an MR because of creatinine issues.

27:57

And you can see that the, uh, kidneys, especially

28:00

the right one, you can see some areas of high

28:04

intensity on the T2-weighted images within the kidney.

28:07

And then, uh, post-contrast, you could again

28:10

see the heterogeneity within this right kidney.

28:12

And then look at the ADC maps

28:14

and the diffusion-weighted images.

28:16

You can actually see some bright areas on the

28:18

diffusion-weighted images.

28:20

These are switched.

28:21

And then the ADC map showed some restriction, but

28:24

this patient had, um, pyelonephritis related to

28:27

his, um, you know, uh, giving him this bacteremia.

28:31

So we could give this diagnosis on MR.

28:33

Um, this was a pregnant patient who came

28:36

in with acute right upper quadrant pain.

28:37

And so we did an MR. And what we found was this patient

28:40

had a wedge-shaped area of low, uh, signal intensity in her

28:45

right kidney, and she actually had an occluded branch.

28:48

So we postulated that this right kidney lesion

28:51

was a renal infarction, acute renal infarction,

28:54

giving the patient, um, pain, uh, because

28:56

she had, she was throwing emboli basically.

29:00

Can help with other diagnosis as well.

29:02

This is a 17-year-old who came in with acute abdominal pain.

29:05

She had this large mass, so her uterus is seen anteriorly.

29:09

She had a large mass behind her uterus.

29:11

We're not really sure as to

29:12

where this thing was coming from.

29:13

Um, there's a little bit of fluid within the endometrium.

29:16

Um, and, you know, we thought we saw

29:19

potentially the right, uh, ovary.

29:22

Um, we could not do a transvaginal exam because of her age.

29:25

But we decided to do an MRI, and on MRI you can see that,

29:29

you know, this particular, here's the uterus, there's a notch

29:32

mass in the, uh, pelvis, has some cystic changes within it.

29:36

Um, has some, he, uh, on the T1-weighted images.

29:40

Uh, there were some areas of hemorrhage within this mass.

29:42

And, um.

29:44

When we gave contrast, you know, one of the differentials

29:46

that we had was, is this an obstructed horn that this

29:49

patient has, because she's young, you know, is she,

29:52

is this related to obstruction in one of the horns?

29:55

But when we gave contrast, there was no

29:57

enhancement in this particular structure at all,

29:59

um, compared to the uterus, which did enhance.

30:02

And then more importantly, when we go back to this

30:04

T2-weighted images, coronal T2-weighted image,

30:07

you can see that this particular structure here.

30:09

Um, there's, there's a fallopian tube attached to it,

30:12

and that fallopian tube is, um, the right fallopian tube.

30:16

And then on the coronal T2-weighted image on the second one,

30:19

you can actually see that the left ovary is pretty high.

30:22

It's located up, uh, uh, uh, above the iliac bone.

30:25

So this actually was a patient who had torsion,

30:28

which we could diagnose on MRI, and we could not

30:31

diagnose on ultrasound because of the confusing

30:33

findings, um, that we had when we had this.

30:36

Overall look at the pelvis and the

30:38

structures and the good resolution.

30:41

This is an intraop picture showing the twisted

30:43

pedicle and the large mass that they took out.

30:46

Um, uh, which we did not know what it turned

30:48

out to be because it was quite necrotic and

30:50

hemorrhagic, um, but it was a case of torsion.

30:54

This was a 36-year-old with fever and lower abdominal pain.

30:57

She had a CT done, which showed, um, the

31:00

cystic structure in the right adnexa, uh,

31:03

and then you could see the ovary adjacent to it.

31:05

Um, she had, because she had a history of fever, we suspected

31:09

that this may, you know, it's a, it's a common thing.

31:12

ER sends patients, and they always send patients to

31:15

see OB-GYN when they have abdominal pelvic pain.

31:17

Uh, but we recommended, uh, ultrasound was done, and

31:20

then we recommended an MR, and you can see that there

31:23

was, um, this patient had a tubo-ovarian abscess bilaterally,

31:27

and, you know, some of this was within the tube, some

31:30

of it was just the ovary with inflammation in it.

31:33

So, um, MR gives really good resolution

31:36

when it comes to, uh, pelvic masses.

31:38

And it's very helpful, uh, to give you the

31:40

diagnosis, uh, and to plan the treatment.

31:44

This was a 3-year-old who had,

31:46

uh, trauma, um, to the left leg.

31:49

She fell from some height, and she had trauma

31:52

to her left leg, and she had some mild abdominal pain.

31:55

Um, but, uh, so CT wasn't that remarkable.

31:58

So we decided to do an MR, and actually on MR

32:01

you can see that she had a liver laceration.

32:05

She also had adrenal hemorrhage, uh, which was

32:08

not seen on the CT; the adrenal hemorrhage was

32:10

seen on the CT, but not the liver laceration.

32:13

And so, uh, MR was really helpful in this patient.

32:17

So then we come to the question about,

32:19

you know, when should we not use MRI?

32:21

So, um, if a pregnant patient needs

32:24

contrast, we shouldn't be using MRI.

32:26

In those cases, we should be doing CT with contrast.

32:29

Iodinated

32:30

contrast is safe in pregnant patients, um, especially second

32:34

trimester, and you could do low-dose CT and give contrast

32:37

as well in these cases, you know, low-dose CT

32:41

and IV contrast in these patients, um, when you

32:43

need much better spatial resolution, um, or when the

32:47

patients are unable to hold still, as you can imagine,

32:50

because it takes a long time to acquire the images.

32:53

You need patients to be, uh, still; CT is much faster.

32:56

Obviously ultrasound can be, uh,

32:58

easy, you know, useful as well.

33:00

In some of those patients, when you have

33:01

intensive care patients, you cannot have

33:04

them sitting in the MR scanner for an hour or

33:06

so because, obviously, they need to be monitored.

33:08

In those cases, you would then, um,

33:10

look for other options, ultrasound or CT.

33:14

So, in conclusion, MRI is very useful in acute situations

33:18

and specific situations, and I've listed those over here.

33:21

Um, but there are also situations in which MRI

33:23

should not be used, and, uh, we talked about those.

33:26

Uh, so, so it's up to us to sort of look at the clinical

33:31

situation, look at the indication, and try to figure

33:33

out, you know, is, would MR be helpful in these patients?

33:36

Um.

33:37

At our institution, we, um, have an MRI tech until 11 at night.

33:42

We don't have someone overnight, but, uh, we

33:44

do call in, uh, MRI techs, uh, at night, um,

33:48

if need be and for these specific conditions.

33:51

And, um, we get those MRIs done if need be.

33:54

Um, but again, not every institution is the same.

33:57

Some institutions have overnight specs.

33:59

Some institutions don't have that availability.

34:01

But if you do, um, this is a good,

34:03

uh, solution in some, some patients.

34:07

Thank you very much.

34:10

All right.

34:10

Thank you so much, Dr. Dighe.

34:12

Um, it looks like we do have one

34:15

question in the Q&A feature.

34:19

Yeah.

34:19

So, um, the question asked was, do you have any

34:22

experience in using ASL in the abdomen pelvis to

34:25

identify hyperperfusion as a surrogate for inflammation?

34:30

So that's an excellent question.

34:31

We, um, are experimenting with that.

34:34

Um.

34:35

Right now, um, not in our acute abdomen patients,

34:37

as you can imagine that these patients do

34:39

come in at, you know, odd hours in the night,

34:42

and we're not here to monitor those exams.

34:44

Um, but we are, uh, you know, we're trying these, um, the

34:47

ASL sequence in, um, other, uh, applications, um,

34:53

to see if we can sort of produce a robust enough

34:55

sequence, which can then be transferred to the acute.

34:58

So currently I don't have

35:00

Um,

35:00

the experience with the ASL sequence.

35:03

Um, but I'm hoping that, you know, as our MR division sort

35:06

of builds up experience, we can start using it in some of

35:09

these patients, some of acute abdomen patients as well.

35:13

Great.

35:14

I'll give people just one more minute here.

35:16

I can start to read our closing call, and we can

35:18

do one final check for questions before we go.

35:22

Uh, looks like we did have another question pop

35:25

in while I was reading the closing call here.

35:28

Are you able to see that, Dr. Dighe?

35:31

So, um, the question was, um, uh, can you give

35:34

us more details about inflammatory bowel disease?

35:37

So, uh, with inflammatory bowel disease, what we

35:40

do is, um, we all, our patients with IBD, uh, we've

35:45

actually moved away from CT enterography toward MR

35:48

enterography, uh, in an acute situation.

35:51

We don't necessarily have the patients

35:53

drink all that contrast, but, um.

35:56

You know, especially when you have pregnant patients or

35:58

overnight cases, uh, if the patients can take the contrast,

36:02

we give them the, um, oral contrast because that way

36:05

you can get good distension of the bowel loops and, um,

36:08

um, you know, then, then we do, uh, uh, a routine protocol.

36:12

We do get some sequences.

36:14

We get one sequence, which is a cine sequence,

36:16

so you can actually see the peristalsis in the bowel.

36:19

And then we get predominantly T2-weighted images,

36:22

mostly, um, in either the axial or coronal plane.

36:25

Uh, we also give contrast to patients, if we can get,

36:28

if they can get it.

36:30

And then, as I mentioned, we do

36:31

diffusion-weighted images as well.

36:34

Um, uh, so, so, um.

36:38

It's sort of, it's a protocol now.

36:40

We use it very commonly.

36:42

Our gastroenterology, uh, physicians like MR

36:46

enterography much more, and we, we like it because

36:49

it gives us so much, uh, better contrast resolution

36:52

and, uh, details than what you get on CT as well.

36:55

So, hopefully I've, uh, answered your question.

36:59

One question was, uh, why was contrast MRI done in

37:02

patients with gallbladder cancer with elevated creatinine?

37:05

Um, so that patient had gallbladder

37:07

cancer and diverticulitis.

37:09

Uh, we did not know that the patient had diverticulitis.

37:12

The patient came in with abdominal

37:13

pain, could not get, uh, CT done.

37:16

So as a matter of fact, we were thinking

37:18

maybe it was, you know, the, we do have.

37:20

We actually have an MRI abdomen pelvis as

37:23

a staging protocol as well, a staging exam.

37:26

Uh, we use it in place of our, um, we use it in place

37:31

of our, uh, CT abdomen pelvis for staging, uh, diseases.

37:34

And that patient, uh, we did not

37:37

know the patient had diverticulitis.

37:38

We suspected we wanted to get staging

37:40

done and see, uh, you know, what's going on.

37:43

And we incidentally found the diverticulitis.

37:45

So we gave contrast because we were looking at.

37:47

You know, the patient could.

37:48

So protocol for giving contrast

37:50

for MRI, we go up to a GFR of 15.

37:53

So we have a very low threshold in terms

37:55

of giving contrast for MRI, um, for CT.

37:58

Our, uh, uh, threshold is less than 60.

38:02

Um, you know, we have to give, um,

38:04

uh, hydration, et cetera, et cetera.

38:05

So we just prefer to go to MRI if that is the case.

38:08

So that's the reason why we did MRI in

38:10

that patient and gave contrast as well.

38:15

Um, there is one in the chat that says,

38:18

how long does MRI appendicitis, but I,

38:22

I'm not sure if that makes sense to you.

38:25

Maybe.

38:25

How so?

38:25

How long does it take to do an MRI, right?

38:29

Right.

38:30

I think that's what this person is asking, is how long

38:32

does it take to do the MRI protocol for appendicitis?

38:35

I mean, if the patient is cooperative and

38:37

everything goes well, we can do the exam

38:39

within 20 minutes, at the most 30 minutes.

38:42

Because what we like to do is get three-plane T2-

38:44

weighted images, get a, uh, a T1-weighted

38:47

sequence, um, and then we get, uh, diffusion images as well.

38:51

You know, each of those, um, especially the T2 single-

38:54

shot images, take about three or four minutes at the most.

38:57

Uh, usually because they're quick,

38:59

we can get them done within a few

39:01

seconds, free-breathing.

39:03

Um, uh, so it doesn't, doesn't take

39:06

as long to do it without contrast.

39:08

It's just the, um, you know, the whole process of

39:11

getting the technologist in, getting the patient

39:13

on in the MR scanner, et cetera, that takes longer.

39:16

So it is a, and we are trying to decrease the

39:19

amount of time that, you know,

39:21

uh, uh, for the exams as well.

39:23

So, at one point when we used to take about, uh,

39:26

45 minutes to an hour, we've gone down to about 30

39:29

minutes to 20 minutes for doing these, um, MRI exams.

39:35

Okay.

39:36

I think that is all the questions.

39:39

Um, so thank you again so much, Dr. Dighe, and, um, thank you

39:43

again to our audience, um, for an excellent conference.

39:48

Thank you.

39:48

Well, thank

39:49

you very much for the invitation.

39:50

I enjoyed giving this talk.

39:51

And if people have, uh, any further questions,

39:54

they can, um, send me an email at my email,

39:57

which is just my last name at uw dot edu.

40:01

So on behalf of MRI Online, I would like to thank

40:04

you, Dr. Dighe, for an excellent lecture today.

40:07

And thank you to all of our audience for

40:10

participating in this Noon Conference with MRI Online.

40:15

Uh, coming up next week, we're going to have a

40:17

Noon Conference on Thursday, November 4th, uh,

40:21

from Dr. Dave SSO on the temporomandibular joint.

40:25

Uh, you can register for that at MRI Online.

40:28

Thank you.