Contrast Enhanced Ultrasound (CEUS) for Pancreas Transplantation: Normal and Pathologic Findings - SD

Introduction

My name is Antonio Sergio Marcino.
I'm from San Paulo, Brazil.
I work as a radiologist at University of Sao Paulo
and at a osteo serial Lebanese.
I will talk a little bit about complications
of pancreas transplants
and the findings with contrast enhanced ultrasound
Contrast enhanced ultrasound
for pancreas transplantations normal
and pathologic findings.

Learning Objectives

My learning objectives are identify the main complications
of pancreas graft and the importance of imaging methods.
Describe the main findings
of pancreas graft in gray scale ultrasound and doppler.
List the patterns
of pancreas graft vascularization in normal grafts
and in those with suspected vascular abnormalities
using contrast enhanced ultrasound and evaluate the role
and the perspectives of contrast.
Enhanced ultrasound for pancreas implantation.

Background on Pancreas Transplantation

As you know, pancreas implantations is the only longstanding
therapeutic option
for maintaining normal glycemia in patients
with diabetic mellitus.
The survival increased at 10% from
1999 to 22, thanks
to better surgical techniques,
more efficient immunosuppression, knowledge of risk factors
and early detection of complications evolution.
In 19 90 66, Kelly
performed the first pancreas transplants at University
of Minnesota in 1990.
It was accepted as a therapeutic modality.
In 2005, more than 23 thousands
of pancreas transplants were performed, most of them
in the USA in Brazil.
There are an increasing number of pancreat transplants.
Here is you can see an illustration about the evolution
of pancreas transplants worldwide since the beginning
of immunosuppression with cyclosporine
and when it was accepted
as a therapeutic modality in 1990
and increase the number around the world.
Up to now there are at least three surgical
techniques to consider the vasculars
drainage, systemic drainage.
The zine suppressions goes to the bladder
and then end rine suppression.
Go to systemic circulation. Some advantage.
Low instance of technical complications.
You can monitor the urine analyzing
that is the early diagnosis of rejection.
Some advantage, recurrent ary tract infection
that can cause graft loss
and in many patients we need to convert
to enteric drainage,
enteric portal drainage advantage that are lower rates
of metabolic and urinary complications.
It's more physiologic
because in this case the endrin aggression such as
insulin go to the liver and that are some disadvantage.
More severe complications.
We can monitor urine amazin
and pancreas venous thrombosis can elu
and can cause portal vein thrombosis.
The enteral and system drainage.
This is the most used technique in many hospitals.
It permits greater and better survival
and lower rates of clinical complications in
post-surgical period.
The advantage of these techniques are
it's technically harder to perform
and we can monitor the urine.
Analyzing the insulin resistance can cause
dyslipidemia in many patients.
Here you can see on the left the
iliac vein and the iliac artery.
The pancreas graft is here
and here is the venous conduct
of the pancreas graft.
Here this is anastomosis of white graft
with iliac artery.
There are two brain one go to the head of the pancreas
and another one go to the body.

Complications of Pancreas Transplants

And the the complications.
There are many complications of pancreas transplants,
pancreatitis, acute rejection, chronical rejection, arterial
or venous thrombosis post transplants, lymph
for proliferative disease, empirical S internal S
and anto leaks.
Some of them such as pancreatitis,
acute rejection, chronic rejection, arterial oros thrombosis
evolves the compromise of micro circulation
of the pancreas graft.
Nowadays more than an imaging method is necessary to,
to evaluate the pancreas grafts
and we have a suspicion of vascular complications.
We need a perfusion assessment evaluation of the graft
and as you know, x-ray ated
and gadolinium containing contrast media are not free
of complications.
This is an angio MRI study
where we can see the pancreas graft here
and an Ontario venous fistula between iliac artery
and the iliac vein.
On the right side, it's a normal kidney graft.
In this computed tomography study,
we can see an larger pancreas graft with uh,
massive pancreatitis with some areas
of necrotic tissue
and some areas with perfusion,
a good perfusion of the pancreas.
Now we can identify a pseudo SM of white graft
here at computed tomography that it was confirmed.
Here on the right
by angiography is study ultrasound.

Ultrasound and Doppler Advantages and Limitations

There are some advantage for ultrasound and doppler.
This is the first line modality.
It's non-invasive, a low cost availability.
It's not the orated contrast median.
It can be performed in a real time and bedside scenario.
Some limitations are the advantage.
Most of them are related to technique.
There there is no capsule of the pancreas
and it can cause poor individualization.
It's placed at intraperitoneal
and sub reposition of intestinal gas
can cause poor individualization too.
On ultrasound, the echo pattern is similar
to different complications such as acute rejection
and acute pancreatitis.
On ultrasound doppler, the resistive
and versatility indexes are in a specific in some
situations and we need a clinical
and laboratory correlation.
Here we can see the iliac vein and the iliac artery of,
and here the pancreas graft.
We can identify with colo doppler, the Y graft
of the pancreas, the venous conduct going
to iliac vein
and with poster doppler we can identify
the arterial conduct
and the resistive indexes.
Posterity indexes the velocities in the main branch
of Y graft.
Here on the left we can see an arm pancreas graft
with hypo coic characteristic.
And here the a dermatosis of iliac artery
on color doppler, we can identify the profusion
of the pancreas in some areas
and the loss of perfusion in the tail.
The intra pancreatic branches can be
identified using a pul doppler
and we can see the velocities, the pulsatility indexes
and the resistive indexes

Contrast-Enhanced Ultrasound

contrasting has to ultrasound it's uh,
intravascular contrast media.
It permits perfusion assessment, micro circulation valuation
in a real time study.
It's safe capable
of detecting low flow in small branches without the
artifacts from Doppler.
Ultrasound contrast enhanced ultrasound
has been working with in kidney transplantation in liver
transplantation, but there are no studies for perfusion.
Assessment of the pancreas graft
for evaluation of pan primitive pancreas pathology
contrasted enhanced ultrasound Has been, uh,
used for in different situations such as
for acute pancreatitis, comparing
with the criteria of baltazar in the diagnosis
of pancreatic tumors
and in the evolution of evaluation
of pathology of the pancreas.
Our main objectives with these studies were
to establish patterns
of graft vascularization in normal grafts
and in both with suspected abnormalities, the role
of contrasting in the evaluation
of pancreatic transplantation
and to compare need for exogenous insulins,
the gold standard of reference
and to compare the findings of gray scale
and contrast enhanced ultrasound material and methods.

Materials and Methods

From November of 24 to September of 26,
we performed 30 examinations in 26 individuals.
One study was excluded due to technical limitations.
We performed the exams
in our a GI 5,000 using post inversion harmonic imaging
and a broadband transducer two
to four megawatts on a gray scale.
We characterized the genicity,
the counters and size of the pancreas with post inversion.
The mechanical index was placed
between 0.252
0.5 in the first studies.
Now we have been working with 0.2
of mechanical index.
The focus was placed at the level of the pancreas
and in the first studies we use it, uh, preferred carbon
base, non labeled contrast enhanced ultrasound.
We injected three ml intravenous bolus manually
followed by 10 millimeter, 10 ml of saline solution.
Now we have been working with uh, 0.8 of
uh, contrasting hazard ultrasound
called definitive.
Here we can see the importance
of post inversion in a normal grade scale valuation
of the pancreas graft.
The pancreas is here.
We'll see the micro bubbles arriving
in a gray scale valuation.
These are the microbubbles on the pancreas
and the importance of post inversion sequence
that we can identify the microbubbles
and the perfusion of the pancreas.
Contrasting hazard ultrasound evaluation,
we studied some parameters such
as elapse time two.
Pancreatic enhancement occurs
after beginning of the injection enhancement pattern
of pancreatic parenchyma during arterial phase
if homogeneous
or a heterogeneous enhancement pattern, degree
of enhancement of pancreatic par arterial phase.
The degree of enhancement of pancreatic graft was done, used
using a direct
and real time comparison between pancreatic enhancement
and enhancement of common or external I electro arters
and classified as intenses moderate minimal
or absent laboratory exams.
The golden standard of graft loss is the necessity
of insulin, the exhaustion insulin
and in some case laboratory exams such as lipi,
amazi and sero keratin can be altered without
compromise of the graft.
Graft function in most patients were submitted
to kidney transplant.
Two. Many results

Results

enhancement pattern in the arterial phase.
In 19 of 29 studies
we have found homogeneous enhancement pattern.
On the left we can see a great case study
of normal pancreas graft
and underwrite the post contrast imaging
of the same study using
contrast enhanced ultrasound.
In nine studies we have found
heterogeneous enhancement pattern.
This is a great scale study of pancreas,
an enlarged pancreas graft with pancreatitis
and pre contrast Series.
And on the right we can see the post contrast
enhancement pattern
and heterogeneous enhancement pattern of the pancreat graft.
In one study, there are no enhancement due
to graft thrombosis.
The graft enhancement, as I said before, real time.
We did a real time comparison between pancreatic enhancement
and enhancement of the common or sternal iliac arteries.
It was classified as intense when you have found an
enhancement of the pancreas graft was similar
to the iliac artery.
On the right on the left we can see the pancreas
with an intense enhancement.
And here the iliac artery on the right
is the drawing of the same study
and we can identify the pancreas graft
and the iliac artery here.
This is a short movie of intense enhancement.
We, we saw the iliac artery here
and the pancreas graft
with an intense enhancement of parenchyma
moderate enhancement when you found lower enhancement
of pancreas graft in comparison to the iliac artery
and an larger pancreas here
with moderate enhancement.
And the iliac artery here on the drawing
is the same aspect of the left.
It's a short movie. We can see the IAC art iliac artery here
and an enlarged pancreas
Here with some pseudocysts
inside the pancreas graft.
And in this case, the patient present, uh, pancreatitis,
minimal enhancement when it identified a few vessels
and minimal enhancement of the pancreas.
Graft on the left is mild pancreas,
a hypo coic aspect of this, this pancreas,
the iliac artery here
and the drawing showing the same situation,
the same findings.
Uh, small pancreas graft with uh,
rear irregular counters
and the iliac artery here in this case
with minimal enhancement there.
There are four cases of these situations, all of them
with chronic rejection.
This is a short video showing the iliac artery here
and the a small pancreas here with
irregular conns, a small size
and hypo coic aspect of it.
This is the case of chronic rejection results.
In summary, genicity
and size were statistically significant
and on a great scale study enhancement pattern
and degree of enhancement were significant too
and we see an increase or a decrease in size.
It's more frequent in patients
with abnormal clinical status.
A heterogeneous enhancement increase the risk
of abnormal clinical status
about 14 times.
It's 14 times higher
and you found a heterogeneous enhancement.
It some parameter parameters
were not significant.
The diagnostic performance of perfusion assessment
of pancreas graft using contrast enhanced ultrasound,
the sensitivity was a hundred percent.
Specificity was 72%
positive value was 36.4% negative.
Predict value was a hundred percent.
And accuracy of this, this test was
75.9%.

Discussion

Discussion based on the re the results that present, um,
presented, uh, we can see that
nowadays we have some limitations
for perfusion characterization
with different image methods such as CT and MRI
and enhanced ultrasound permits.
The assessment of the shadow perfusion
and it can detect low flow as a simple method.
It can be performed in a bedside scenario
in a real time study.
Let me explain a little bit about chronicle rejection.
The definition of chronicle rejection is the gradual
function loss at least two months after transplantation.
The zary component is the first component
third, followed by alteration
of endy component.
The patient presents hyperglycemia episodes
with acute severe rejection episodes in a short period
of time on histology, we can, we can characterize,
characterize concentric thickening of small artery walls,
fibrosis of the ner and atrophy
and ner atrophy.
Chronically rejection is a diagnostic challenge.
There are field descriptions on imaging studies
and in our cases we have found a mouth size
and low enhancement similar to computed tomography study
and maybe contrast.
Ute ultrasound can be used
for a ative profusion analysis.
Baseline exams followed by uh,
some exams in follow up time of pancreas graft

Conclusions

in conclusions enhancement pattern between normal
and abnormal studies were identified.
There are no difference between pathologic situations such
as acute pancreatitis and re rejection.
Gray scale ultrasound allowed to distinguish between normal
and abnormal pancreatic grafts based on e
echogenicity in size.
Contrasting enhance ultrasound also happen to distinguish
between normal and abnormal grafts,
based it on enhancement patterns
and degree of enhancement
during the arterial phase of dissemination.
You are very optimistic with the perspectives
of contrasting enhanced ultrasound.
We can develop an imaging protocol using
gray scale ultrasound, contrasting enhanced ultrasound CT
and MRI with different approaches.
Contrasting enhanced ultrasound can be
studied for a long time.
ATIVE profusion analysis with baseline exams and follow up.
Now it's available some perfusion quantification
softwares for evaluation of the pancreas graft
and maybe gray scale ultrasound
with contrast enhanced ultrasound will avoid
and further imaging studies such as MRI and C.
In some situations.
Here is a perfusion software
where on the left we can see the
contrast enhanced ultrasound arriving at the pancreas graft.
This is the uh, interest area area
and here we can see the uptake
of contrast enhanced ultrasound on the pancreas graft.
Thank you very much.