Renal Disease: Technique and Quantification - HD

Introduction and Background

Okay, Paul, thank you very much for the kind invitation.

I was very missed to come to Kings College.

As I've seen a lot of faces here, I know from the papers of the last 15 years of my practice.

It's really great to be here.

In the program, there's nothing written about the hospital.

I'm from the Technical University of Munich, which means there's the technician anyway, that this is the second university.

Yesterday you met my friend Di Cleve.

He's working at Den and working at re the smaller hospital in Munich.

And it was so to say, it became a university after the Munich Air crash.

This is professor Mara, who was our first sur to say, chief consultant there.

He was a surgeon.

And this, because of this air crash, our hospital became university sad thing, but it's got a very good ending.

And they, they're still a closed collaboration between England and our hospital.

Topic Overview: Renal Disease Technique and Quantification

What would I talk about?

My subject was renal disease technique and quantification.

I want to tell you some things about basic stuff, renal disease, introduction, patient positioning.

I want to give you some ideas about nomenclature, about practical aspects and quantification.

I've seen a lot of people here from all over Europe and also from all over the world, and it's really great.

Audience Engagement on Contrast-Enhanced Ultrasound

Who does contrast enhanced ultrasound every day in this room?

This is a thing I was really interested in.

Give me a hand, right, who's gonna start with it now?

Okay, so I think I'm not completely wrong because I want you to give some ideas about practical aspects of which I did wrong in the first place.

Dirk and me, we were the first two stupid guys in Munich starting this method nearly with about 2003.

And people first laughed at us, then they tried to fight us, and now they copy us.

So I think it's really good.

And we are quite happy with this position.

Awareness Training for Ultrasound

First of all, I want to have a little training and a little morning training on your concentration.

So if you perform ultrasound in general, what do you have to think?

You always have to be aware of what you see.

You can only find things that you're looking for.

This is an important thing for ultrasound in general, but also even in contrast enhanced ultrasound.

So look at that.

I just want to exercise your awareness.

Okay, what do you see?

Ducks, right?

Okay, so what is different?

Now you're a duck expert, so what's different here?

Yeah, you can see there's one duck, which is not really a duck.

And so you are aware of the duck, which is not functioning the right way.

So you're duck expert.

So the thing is, same with COS.

You have to learn and you have, especially if you work with a kidney, you have to see several little changes which make you, which decide.

For example, if you have a look at the renal tumor, whether it is a renal tumor has to be taken out by the surgeon, or if not, and you more and more responsible for result and also for the treatment of the patient afterwards, knowledge, you have to really, you only see what you know, you know these pictures, right?

And be a young girl And be an old woman.

Depends whether you are working in medicine for, for example, geriatric or whether you work with in gynecology.

Yeah, it depends how you feel with this picture.

Patient Positioning and Depicting the Kidney

All right, so back to ultrasound, back to the kidney.

First of all, we have to depict the kidney the right way.

So we normally eat this right flank proposition.

Here you can see the kidney is depicted very well.

This is the position and a lot of people just this position, but you have really to turn the transducer for 90 degree and to have this cross-sectional anatomy of the kidney.

This is not normally not so helpful, but if you now turn the transducer in this section, you can really depict even cortical tumors very nicely and think that can be not depicted with b mode.

Ultrasound cannot be depicted with COS if you can't see this size of the kidney.

So we really have to fight for a good B mode picture, and you have to be a skilled ultrasound physician if you work with that method.

Of course, we've got two kidneys, and we have to be aware of the left flank, which is not so easy, in contrary to the right flank.

So in Germany, we have more and more problems with patients, who have got this size right, and how, what should we do with these patients?

Sometimes we're a little bit desperate, but there's always a solution and we have to be reminded to our small and younger patients.

This is one of our youngest patients.

We treat them together with the urology department, and you can see they have this dorsal approach.

We have this dorsal approach as the kidneys can be depicted very well from dorsal, especially in children.

And what's good for children can also be good for bigger children.

And here you can see the dorsal position, which we normally use if we perform renal biopsy, right?

And of course, this also can be used for both kidneys, COS of the kidney.

Kidney Anatomy and CEUS Basics

So if we use contrast enhanced ultrasound in the kidney, we always have to be aware of the kidney anatomy.

The kidney is a big vessel, if you want, right?

This is from our anatomy department, Heidelberg, and you can see the whole kidney is really a big, big vessel and their fine little vessels, which can depicted which cry for ultrasound, right?

And if you use COS on the kidney, yesterday there were some questions concerning the doses.

And it always depends on your machine, of course, but less is more and normally can drop down a little bit the dose from the liver.

I have five different machines from different companies.

For ultra contrast enhanced ultrasound, we normally use the dosage from point A to one R 0.5 milliliter contrast media, which is quite good.

Yes.

This is our ultrasound lab.

This is the room where performed the contrast enhanced ultrasound mainly.

And you can see we are prepared for everything, even for resuscitation.

That's important.

The contradiction, indication is of course the allergy of the patient.

If he says, okay, I nearly died of vu, you won't applicated otherwise.

I'm an internal medicine specialist, was trained gastroenterology, went to nephrology 10 years ago.

Why is that like that?

Because we do all the imaging techniques with contrast enhanced ultrasound first, and we try to avoid CT scans.

MRI scans at their sometimes a problem for the kidney.

And the second thing is we've got a lot of people with thyroid problems in Germany, especially in South Germany where I work.

And it's free.

And this is a big advantage.

The disadvantage of course, time, special training.

That's why we are all here.

And you always have to have a continued education.

You have to have a small group of people where you talk about your video clips to get ahead.

Injection Technique

This is how we con inject the contrast media.

We inject it straight, right?

Don't use that side because even more microbubbles are destroyed.

And we in my department, we always use contrast enhanced ultrasound with two doctors.

One is doing the injection, one is doing, she's the learner, so to see, and she's doing the injection.

And if we've got a problem, we've got always two doctors and I'm doing the contrast enhanced scan, so I can concentrate completely on the machine, on the patient and don't have to handle the contrast media.

So this is a very nice video clip from big contrast firm.

And here you can see the injection of the microbubbles here, the lung passage, so to see.

And then it's going back into the left heart and then the audit stuff.

RK showed some nice video clips yesterday.

And then the kidney is getting started to depict with contrast enhanced ultrasound.

Phases of Enhancement in Kidney CEUS

So the principle, the main principle is a single blood supply of the kidney in contrary, for example, to the liver, where we've got the dual blood supply.

It's mainly done by the kidney artery, but if you scan every day, and as you all know, we've got this weird accessory kidney arteries, and they're sometimes a little bit stupid in my, to my knowledge, something about 10% I would think of of my patients have that.

So you always have to be aware of special contrast funment if you do the ultrasound.

So it's important.

I always have a big report after my exam and I write down what I did.

So if you're talking about COS of the kidney, you have also different phases.

We first have this cortical enhancement phase.

This is just in the first phase after injection, the times can be highly variant because they're highly dependable on where lon placed.

And of course, how is the circulation of the patient?

This is you should keep that in mind.

So just have a look at the organ cortical enhancement phase, medullary enhancement fees.

This is slower than the cotton enhancement, and it's from the outset to the inner parts of the renal me.

And last but not least, the late phase, just like the liver, we've got a loss of intensity in the medullary enhancement and is slowly progressive wash out in the renal cortex.

So once again, this is the renal cortex, and the contrast media is entering the kidney while the renal artery, and it's going to the bertin's columns.

And this is the direction of the contrast media.

Here you can see the microbubbles body particle phase.

Then the metal enhancement phase starts.

So the contrast uptake goes from the out to the inner parts of the middle is normally very short.

And then you've got that picture and the late phase, everything is getting weak, and the whole perfusion is running down a we bit.

Okay?

This is if we destroy the bubbles and we can see the refilling, this is very helpful.

For example, if you've got an infarction or if you want to prove that it's not an artifact, and that things that were previously perfused are not perfused anymore.

Quantification in CEUS

So here again, so what can we do?

Of course we can quantify.

And we've seen we had yesterday some very good lectures about quantifying and even today, V two showed us some things from the guidelines.

And we can, so what we do is quantification.

If you even think about quantification, you have to think about standardization, standardization, standardization, otherwise leave it.

Because if you have a tiny program, which is counting pixels or something like that, you have to make sure that it's counting the right thing.

So you have a patient who is holding the breath or who's breathing very regularly to get a motion condensation, which is really worth the money.

And then you have to have your probe at one place for about two minutes, which is also a physical problem.

And then you produce clips, and you can put these clips together, and then you can mark this.

Royce.

Royce means region of interest, and you could put one of these rights in the renal artery, for example, and one in the renal cortex.

And then you can quantify the times.

And here you get the different contrast behavior in several parts of the kidney.

And as I will show you later on, on the renal transplant, this can be useful.

But at the moment, it's a thing that can be performed, but we all have to learn and we all have to standardize.

And I think there's a big thing for the asom to do, to get comparable curves and comparable analysis for different patients.

I think it's very good if you've got one patient and if you follow one patient, then you can use this method.

And then it's very helpful, for example in mainly in kidney transplant, but sometimes also in normal kidneys.

And you've got different things time to peak.

Yesterday we heard about that.

That means when do we have the peak intensity in a special region of interest?

And then you can see of course here in the renal artery, we've got a stronger and a quicker time to peak than in the renal cortex.

So this is quite helpful sometimes, but this is I think it's quite time consuming, so we really should think whom to quantify.

Normally you do it by your eyes semi-quantitative.

Storing and Reviewing Video Clips

So the main thing for you, if you start with cones enhance ultrasound and all the routine contrast answer ultrasound experts here will know is we have to store and review all video clips.

It's interesting if we perform the contrast enhance exam, and if you have a look on the video clips right after, we always see some things we didn't see in the first time.

So it's really important to review the CUS clips and not to say, okay, everything is okay or not okay, have a second look.

It really will improve your diagnostic outcome is really important.

Presenting Clips at Conferences

And what is also important is not only produce nice pictures and being and doing eminence based contrast enhance ultrasound, which can only be handled by one person in the department.

You have to present the clips at clinical conferences, and you have to show them to the surgeons, to urologist, to the gynecologist who perform surgery right after and who take your clips as a basis for their decision.

And this decision can be a five hours surgery procedure.

So we really have to convince these guys, this our UR urology team, for example, and they want to see these things and why do they believe in a CT scan, like in a religion?

Because they understand ct, they can have a look at it, and they make sure that they're doing the right decision.

So really have to present the ultrasound clips in conferences.

That's work.

But it's worth, in our department, the urologists, for example, say, oh, this is a great guy for contrast enhanced ultrasound, or this is not a good patient.

And they send me the contrast enhanced ultrasound patients, and they even perform surgery on the basis of the contrast enhanced ultrasound pictures only COS.

Practical Aspects of CEUS

Some practical aspects as well.

It's always a problem, the preparation of the contrast and contrast media.

Some guys ask Conrad, I've got problems with my machine or the contrast media doesn't work.

These are especially people who start, they say The contrast media doesn't work with my machine very well.

And this is here a local aspect, yeah, shaken, not stirred.

So if you use contrast enhanced ultrasound, a lot of people, these are the micro bubbles and the sulfur hexa fluorine is in this bottle.

So you really have to produce the bubbles if you shake it.

If you just do it like that, yeah, it's not very helpful, and you will have weak results.

For example, if you have a very bad contrast, think about the application of this contrast, median about the preparation.

So don't do this, don't do it like this.

You really have to shake the battle like that to get nice bubbles.

And if you had a break and the while was just standing around, shake it again to have nice and proper bubbles, and you will have a much better contrast.

Then you always have to be aware of your machine.

This photo took a dirk when we were on the ultrasound Congress, optimize your machine.

You get the technicians, get the experts from the ultrasound companies at your site to optimize your machine and plan the exam.

The problem with contrast and enhance ultrasound, especially on the kidneys, you have to plan the exam.

You can't look everywhere at once, like CT scan.

You have to be really aware of what do I want to see?

Yeah.

And you have to think, okay, now I concentrate on the tumor, then I concentrate on the rest.

Localization of the IV tether, catheter always is use the same position if possible to get an impression.

We normally use that aspect because we've got a lot of nephrology patients with shunts and be aware of the dosage of the contrast media, and you have to find out the right dosage for your machine at tomb.

And of course, be aware of patient related factors, the circulation time, and also if you've got patients with hard ws, with artificial hard ws, you have to have a little high dosage because they and it takes longer till contrast starts.

Comparison to CT and Visual Perfusion Analysis

And just to summarize, the behavior and the kidney, it's as if CT scan is as if you've got a helicopter and you're flying over the football stadium and you have a very good camera depicting everything of your, and you've got two shots, right?

And then you can say, okay, must be a goal with COS.

You have a video camera inside the stadium and you can see what's really going on in real time.

But the problem is you only have parts of the playground.

So you really have to plan which part of the playground will I have a look at.

So be aware of that big difference.

And of course, as a ct, a renal elimination of the contrast agent is sometimes a problem, especially if you've got patients with renal insufficiency.

And always be aware of the function.

CS is a real time imaging method.

It's brilliant.

But be aware of the use of it and how to plan that quantification.

Visual Perfusion Analysis Training

Some visual perfusion analysis training for you.

What do you think of these kidneys?

Most of your experts, so what do you think of that kidney Right out?

What do you think?

Pretty nice, right?

Okay.

What do you think of that kidney patient on the oncology ward?

Acute renal failure.

Yeah, there's something missing.

Big renal function.

What do you think of that kidney?

This is a patient who's got atrial fiber lesion and he's very heavily breathing as you can see here.

What do you think?

Same.

Just the same Real infarction can be easily depicted.

You don't need to mess up the whole kidney with another contrast ct, right?

What's the matter here?

Right?

Hyperperfusion in a real tumor.

So you can quantify quite well with your eyes, so rely on your eyes if you do quantification.

If you do software based quantification, be aware of the limitations.

Conclusion

So I want to conclude, depict the entire kidney that the main thing store and the review is the COS video clips of the exam.

Don't use too much contrast.

That's also important.

And if you do quantification, visual or software base, always write it down and be aware of the diagnosis of the patient.

That's my team.

That's our conference where contrast enhanced ultrasound video clips and CT scans are demonstrated side by side.

This radiology friend where he, we are sitting here, these are the surgeons.

And we always have a look on these tumors together and try to make the right decisions that our surgeons are not surprised if they see the patient in real life in the operation theater.

So thank you very much for the kind of attention.