Workup of the Child with Urinary Tract Infection - SD

Introduction and Learning Objectives

Good evening.
I'm Henrietta TLAs Rosenberg.
I'm the director of pediatric radiology
at the Mount Sinai Medical Center in New York City
where I'm professor of radiology at the Mount Sinai School
of Medicine and I'm very pleased to have the opportunity
to speak with you now on the workup
of urinary tract infection in infants and children.

Urinary tract infection is a very common problem
in infants and children.
The learning objectives of this lecture are
to identify the various causes of urinary tract infection in
pediatric patients to describe the imaging findings in upper
and lower urinary tract infection
and to describe an appropriate algorithm for workup
of urinary tract infection in various age groups.

Bear in mind that pediatric patients are not small adults
and we have to approach them quite differently than we would
with the older patients.
It is not always easy to get their cooperation
and it's extremely important
to provide a child friendly environment.
We're often cajoling them, entertaining them
with game boys, DVDs, toys.
We even bribed them with lollipops,
but one has to have a lot of patience, understanding,
and lots of love to try to get the cooperation
that we need in order to use ultrasound
to get the most information to help determine
the etiology for the child's symptoms.

Presentation of Urinary Tract Infection in Children

The younger babies tend to present with fever,
foul smelling, urine, and irritability.
While the older children may actually articulate the fact
that they have a abdominal
or pelvic pain, back pain,
they may describe nausea and vomiting.
They may also present with urgency, frequency,
dysuria, hematuria.
At times, children
who are trained will suddenly develop incontinence and resis
and there are others who come in with failure to thrive.

Diagnosis of Urinary Tract Infection

In order to make the diagnosis of urinary tract infection,
one must have a properly collected specimen in the child
who does not have urinary control,
a catheterized specimen is necessary and at times,
but very rarely it's necessary to get a SRA pubic aspiration
if the urethra cannot be cannulated.
In the patients who do have urinary control,
a clean catch midstream is sufficient
and if one finds over a hundred thousand
colony count in this type of specimen, the diagnosis
of urinary tract infection can be made from a cath specimen.
Over 10,000 colony count is sufficient
and in a supra pubic specimen,
any bacteria is diagnostic.

Early diagnosis of urinary tract infection is important so
that treatment can be instituted quickly in the attempt
to prevent renal damage.

Predisposing Factors for Urinary Tract Infection

There are several predisposing factors.
The virulence of the infecting bacterial organism is
important, particularly p fimbria e coli adheres
to the urothelial cells.
The bacteria secretes endotoxins which can cross the mucosa
and go into the muscle of the ureter resulting in paralysis
and ureteral.
Peristalsis is remarkably decreased
when there's slow flow in the peripheral ureters,
the adherent bacteria are not washed away
and there is an increased risk of ascent
and reflux of bacteria into the upper tracts.

Some uncommon organisms can predispose
to urinary tract infection, things like Klebsiella, proteus,
pseudomonas enterobacter.
If there are compromised host natural immune defenses
or if the feces are colonized by virulent bacteria,
there may be a higher chance of urinary tract infection.
Little girls are infected more often than boys due
to the ease of introital contamination.
In boys who are uncircumcised,
there is a 10 times the incidences
of urinary tract infection than in those
who are circumcised.
In patients who have reflux urinary tract obstruction
or cannot empty their bladder properly,
they have a higher chance
of developing urinary tract infection.

Imaging Modalities for Urinary Tract Infection

There are multiple imaging modalities available for children
with urinary tract infection at the time of diagnosis,
as well as follow up ultrasound is the modality of choice
to begin the evaluation
and in many institutions, VCUG voiding, cysto ethnography
is the next step.
Some institutions use nucleus cystogram at times one needs
to use renal scans.
Expiratory urography is very rarely used
and for problem cases we may resort to CT and MRI.

Ultrasound Examination of the Bladder

It's important to examine the bladder in the beginning
of the examination so that one can assess
the capacity, the wall, the distal ureters,
and then all ultimately measure the post void.
Many children will empty their bladder as we come near them
to scan them and so if
that happens you can just give them a bottle or a drink
and by the time you're done examining the kidneys,
the bladder should have refilled.

Ultrasound Examination of the Kidneys

As for the kidneys, we can look at the size, the contour,
look for scarring, examine the echo texture,
and so far as the collecting systems,
we can generally see the distal
UUs if they are dilated.
By using decubitus positions, we can attempt
to see the ureters between the pelvis
and the distal end of the ureters.
They are much more easily seen when they are dilated
and in fact when they're not, we have very little chance
of seeing them with ultrasound
because of the surrounding bowel gas.

And then we need to look at the urethral area
and of course to look for anomalies
always include the bladder
and bear in mind that when the bladder is full
that the collecting systems can have physiological fullness.
So it's important to examine the collecting systems prior to
voiding and then
after voiding when they will decompress in the
normal situation.

Bladder Capacity Equations

Now as to bladder capacity, there are two equations
that can be used in the patients
who are less than a year old.
If you take their weight in kilos
and multiply it by seven, that's an estimate of
what the normal bladder capacity would be.
If the children are older than one year,
the age plus two times 30 will give the bladder
capacity in ccs.
As a rule of thumb, babies within the first few months
of life will have a bladder capacity of approximately 30
to 50 ccs
and it increases over the years until by 10 years.
The bladder capacity will be approximately 300 to 400 ccs.

Always examine the wall, look to see if it's smooth,
if it's thicker than it should be,
and always look for the trigone,
which we can see here on the right and here on the left,
and we can confirm that with Cala Doppler to see the jets.

Ultrasound of the Urethra

The urethra can be easily seen
by using a supra pubic approach
and angling down into the inferior aspect of the pelvis.
In a little boy will see some of the prostate
around the urethra
and in the transverse view of the bladder,
we can see this very slender bow tie hypo coic area
that represents the seminal vesicles.

Remember that we can watch patients
as they void even though we're using ultrasound.
Here we can see the urethra is a mound of tissue inferiorly
and posteriorly
and during the process of voiding, we see
that this area opens.
Likewise, we can do the same in a male
by using a linear probe right over the penis
and have the patient void into a urinal
and the urethra will dis stand up
and can be examined accordingly.

Ultrasound of the Uterus in Girls

Remember to look at the uterus when you have a little girl
baby because it's important to know what the length is,
the configuration and the endometrial stripe
as it differs in various age groups In the newborn,
the uterus is a rather prominent structure measuring
approximately 3.5 centimeters in length
with the cervix being quite
prominent compared to the fundus.
So the fundus to cervix ratio is about one to two.
It's not unusual for the endometrial stripe to be thick
and also it's not unusual
to find fluid within the endometrial canal.

In the pre-pubertal uterus,
the uterus is actually smaller than in the newborn due
to the decrease in the hormone level.
Once the neonatal period is over
and the length is generally from about 2.5
to three centimeters, it's a flat structure
and there's a one to one ratio of the fundus to the cervix.
If the endometrial stripe is seen,
it's generally a very slender structure
and we should always look for the vaginal stripe as well.
And here's the urethra.

In a mature female, the uterus is longer
and will measure somewhere around five to eight centimeters
with the fundus prominent compared to the cervix
and the endometrial stripe varying, depending upon the time
of the menstrual cycle, it's important
to determine if an infection is an upper
urinary tract infection or lower urinary tract infection.

Determining Upper vs Lower Urinary Tract Infection

So as we look at the kidneys, we're gonna look for size,
we're gonna look for the contour,
the parenchymal echogenicity scarring,
and also for the collecting systems.

Be aware that in the newborn baby the echogenicity
of the kidneys differs from
what we see in older children and adults.
The cortex of the kidney is iso coic with the adjacent liver
and spleen and there is accentuation
of the medullary pyramids.
There isn't a lot of fat in the young baby's kidney,
so we see a very faint renal sinus echo
and a very faint white line around the kidney
representing the perinephric fat During the next three
to six months, the echogenicity of the cortex decreases
compared to the liver and spleen,
but there should be definition
of the cortico Medullary junctions know the appearance
of the infant adrenal glands
so it won't be confused with the kidney.
The infant adrenal has a hypoechoic to almost
koic cortex with a bright
linear medullary stroma.

Remember that some babies will have loation of their kidneys
and this may persist into childhood.
This is fetal loation.
Others may have a very prominent mid lateral portion
of the kidney, particularly on the left side
that has been described as a drama dairy hump.
Always look for the medullary pyramid within that so
that you will know that that is normal renal parenchyma
and don't confuse the ranunculus with a scar.
The ranunculus is this little line
that you see going from the periphery of the kidney
to the renal pelvis.
That is actually fibro fatty tissue that forms
during intrauterine life as the two
uls are fusing
and this is known also as the junctional parenchymal defect.
It's easier to see on the right side
and it's easy to differentiate from a scar if you know
what its normal appearance looks like.
Remember with a scar there will be decrease in the tissue in
the periphery of the kidney.
That doesn't occur with the junctional parenchymal defect.

Have a chart that you keep near where you read so
that you can look at renal size and assess growth.
When you see children coming back
with urinary tract infection follow-up exams, it's essential
to be sure that you know whether
or not the kidneys are growing properly.
And the chart that we used that was published in a JR in
1984 by Rosenbaum etal has the lower limits of normal,
the upper limits of normal that are very helpful in terms
of looking for signs of compensatory hypertrophy
or inappropriate growth.

Now there are some disadvantages of ultrasound
in acute pye of nephritis.
It is not as sensitive as other modalities.
We obviously can't assess qual quantitatively renal
function, although when we see normal looking parenchyma we
can qualitatively hypothesize that
that kidney should have normal function.
We may miss tiny cortical scars.
We may miss ureteral stones in the absence of hydronephrosis
and we may miss fungal infection in the absence
of hydronephrosis and fluid outlining a fungus ball.

Voiding Cystourethrogram (VCUG) Procedure

Just a few words about the VCUG voiding, cysto urethrogram.
A preliminary KUB
or a saved spot film is obtained just
to get an idea about the bowel gas pattern, anything
to suggest a mass, anything to suggest calcifications
or bony abnormalities
that might indicate a neurogenic problem.
The bladder is catheterized using a sterile technique
or if the patient has a very tight fibrosis,
a blind catheterization will be done.
After cleansing the external genitalia, keep a note of the
what the bladder capacity is
and also assess the wall for thickness and contour.
One must get filling films and voiding films
and look for reflux as well as graded.
Look at the urethra
and also post void in boys, we like to get the
urethra imaged with the catheter in place as well
as afterwards without, and we do two cycles
because reflux may not happen in every cycle
that we look at.

Remember that there is some little girls who will come in
with labial adhesions
and it may be impossible to catheterize them.
Premarin cream is used to lice the adhesions
and this may in fact be the cause
of their urinary tract infection.

So here's the preliminary S scout film, the AP view
of the distended bladder, the oblique view,
the oblique view during voiding
and then the post void for residual.

Now voiding films are important
because some children only reflux during voiding.
Remember that reflux and ipsilateral obstruction may coexist
so that there could be a ureteral
pelvic junction obstruction.
There may be a primary mega ureter,
posterior urethral valves
and at the same time the patients may have reflux.

Grading of Vesicoureteral Reflux

Reflux is generally treated with a prophylactic low dose
of antibiotics.
The International Reflux Study classification is applied
as we do VCU GS when it's only into the ureter.
It's grade one when the reflux goes all the way up into the
collecting system but there's no dilatation
that's grade two.
With grade three there is mild
to moderate dilatation of the ureter.
There's some tortuosity, there's slight blunting
of the CAEs With grade four there is, I'm sorry,
with grade three there is moderate mild
to moderate dilatation of the ureter and the pelvis
and their slight CAE blunting with grade four.
There is moderate dilatation of the collecting system
and there's tortuosity of the ureter with blunting
of the CAEs
with grade five there's marked tortuosity marked dilatation
and there are no papillary impressions on the CAEs so
that they appear convex reflux tends
to occur in families
and so the siblings are generally screened.

There is usually an underlying anatomic cause in the girls
because of an abnormal insertion of the distal ureter.
At the ureteral vesicle junction it's postulated
that in girls there is a steeper angle
so there is less bladder musculature surrounding the ureter
to function as a sphincter.
As the little girls grow, this abnormal angle
of insertion diminishes.
It's not unusual for girls to have spontaneous resolution
of their reflux by the time they're five years of age.
This phenomenon does not occur in boys due to the presence
of the prostate gland.

Secondary reflux can develop when there is a diverticulum
at the ureteral vesicle junction.
A hutch diverticulum in patients with dysfunctional voiding
who have neurogenic bladder
or have problems with the bladder sphincter dys syner
vesco ureteral reflux can be suspected on ultrasound.
In this patient who had dilatation of the renal pelvis
as well as the proximal ureter, it was clear
that the ureter was quite dilated
and that there was a gaping ureteral vesicle junction
and one can also look at the peristalsis of the ureter
to determine which direction it's going in.

At times vesicle ureteral reflux will be suspected
because there are changes in the size
of the intrarenal collecting system
as one is watching holding the probe stable in a
particular position.
Here we see some dilatation
of the pelvic hee system Within seconds it looked
like it was normal.
This patient had a grade three reflux
and had a normal urethra always compare the
size of the kidneys.
They really shouldn't be more than approximately five
to eight millimeters different.
And here you can see the right one is small,
the left one is a normal size
and on the right side there is grade four reflux
and you can see
that there is quite a small right sided kidney compared
with the normal left side.

Just to look at the VCUG for various grades of reflux,
here it is just into the ureter.
Here we see the reflux into the entire collecting system
but no dilatation, a little hutch diverticulum associated
with grade two reflux.
Here we see some tortuosity
and fullness of the ureters with some fullness of the
CAEs in grade three
with grade four there's more tortuosity in dilatation
but still some maintenance of the CAE concavities.
There's also some intrarenal reflux here
and with grade five this marked tortuosity of the ureter.

Nuclear Cystography

Now there are institutions who do nucleus cystography
and there's a lot of controversy about
whether to do it or not.
It's believed to be a lower radiation dose to the patient
but using digital fluoroscopy we can keep our study down
to a very short number of seconds
but this is sometimes done as the first study in girls
with nucleus cystography grade one Vesco
ureteral reflux may be missed.
We can't grade it According
to the International reflux study
and it's difficult
to assess the bladder sphincter dysinger.
It is useful to screen siblings of children with reflux
and there are centers where ultrasound is being used
to look for reflux.

Just another example of asymetry
of the kidneys in this patient who had a nucleus cystogram
as the bladder filled there was bilateral reflux a little
bit worse on the left than the right.
Looking from a posterior approach patient voided,
we could see that during the voiding phase the left
collecting system became more dilated
and more filled with radiopharmaceutical.
And finally, as the bladder emptied there was still a little
bit of residual in this left collecting system which
correlates well with this very small kidney.

In this particular child there was marked dilatation
of the pelvic hee system.
There was preservation
of the cortico medullary differentiation.
The ureter could be traced
and in fact we could see a lot of two and fro peristalsis
and coming down toward the bladder we could see the
distal ureter.
VCUG demonstrated that there was no reflux
during the filling phase.
But as the patient was voiding, it became apparent
that there was a large amount of reflux
into a very dilated collecting system
and this is the post void film
where there is still residual in this collecting system.

Treatment and Management of Urinary Tract Infection and Reflux

Okay, now early treatment is meant
to eradicate the urinary tract infection
and to prevent recurrences.
Long-term suppressive medication
with antibiotics is often used until four to five years
or until the vesco ureteral reflux ceases.
It's often sufficient for low grades of reflux.
Some children may require anti-reflux surgery in the form
of reimplantation when there is grade five reflux.
And then there is a technique of using
endoscopic intravesical injection of a small amount
of material into the bladder wall
behind the submucosal ureteral tunnel so
that reflux can be prevented.

There's a very nice article in radiology published
by Harriet Paul Thiel from Boston Children's Hospital
who talked about this endoscopic treatment
of vesco ureteral reflux with autologous chondrocytes
and they showed that the prior
to the chondrocyte injection
that there was quite a gaping ureteral orifice and,
after the injection it's a very tiny area.
This is a case that's from Mount Sinai where we saw mounds
of the chondrocytes.
After the injections looking quite
round and appropriate.
Dr. Paul Thiel pointed out
that there are times when there is a double mound rather
than a single mound that is round on follow-up
and the absence of the chondrocyte mound
or the presence of a multi lobe mound contour is associated
with persistent reflux.
The mean mound volume decreases over time
and there can be treatment induced
hydronephrosis which is uncommon
and is usually self-limited.

Upper Tract Anomalies

Now the upper tract anomalies include ureteral,
pelvic junction obstruction, ureteral duplication,
ureteral obstruction,
and ureteral vesicle junction obstruction
with A UPJ we're going to see that there is dilatation
of the CAEs, the in fibula
and all of these communicate with this very large pelvis.
Here's another one.
There is marked thinning of the parenchyma
around these dilated CAEs
and there's no cortico medullary differentiation
implying a nephropathy.
The pelvis of this kidney was gigantic.
It came all the way down to the pelvis as we can see
in relationship to the bladder.

Now if the ultrasound shows hydronephrosis
but the VCUG is normal, then the renal function has
to be assessed and in this situation
nu nuclear renal scans are indicated
and Lasix washout is assessed in the form
of a diuretic renogram
and this is helpful in quantifying renal function.
In the normal situation we'll see the peak
and then the progressive rapid decrease
in the radiopharmaceutical.
In the case of obstruction, that doesn't happen
and actually the reverse happens
but there are some that are indeterminate
because of extreme dilution of the radiopharmaceutical
or poor renal function.

Here's an example of a patient who had dilatation
of the collecting system within the upper pole of the kidney
and had the cystic structure that appeared
to be occupying the lower portion of the kidney.
On an IVP it was apparent that there was filling in
of this cystic mass with the aqueous contrast
and was deviating the ureter medially
pre Lasix from a posterior view showed
that there was delayed filling of this
structure in relationship to the upper pole of the kidney.
After Lasix there was clearing of the
radiopharmaceutical from the normal portion of the kidney
and then there was delayed excretion into this
ureter pelvic junction up obstruction in the region
of the lower pity of a duplicated kidney.

Magnetic Resonance Urography

Now Mr Urography has been called the
questionable future gold standard in pediatric urogenital
imaging because of the fact that the function as well
as the anatomy can be very well assessed using this.
However young children require heavy sedation
or anesthesia to have MRI.
It is not as available
and it is certainly a lot more expensive
and should be reserved for patients who have
a problem that can't be solved with ultrasound.

Duplicated Collecting System

Then there are children who come in
with urinary tract infection where we find
that there's a duplicated collecting system.
Here we can see dilatation of the upper pole
collecting system, very little parenchyma if any.
The lower pole has mild dilatation
of the intrarenal collecting system.
There is cortico medullary differentiation
that looks appropriate
and as we follow this down we can see
that the dilated ureter is actually inserting at the level
of the bladder neck.
So this is an ectopic urease seal in little girls it can be
anywhere from within the bladder
to the bladder neck to the vagina.
In fact, if it's not obstructed the little girls may present
when it's in the vagina with constant
wedding in little boys.
If there is an insertion into the posterior urethra,
it's still inside the external sphincter
and they do not have the same problems
with constant wetness.

Some of the girls who have an obstructed ureteral
that is terminating in the vagina may actually present
with an introital mass that's bulging.
Another one simulating a simple cyst in the kidney
with a normal parenchyma in the lower pole,
although there's none in the upper pole
and some fullness of the lower pole collecting system.
As we look at the additional images, here's the bladder.
This is the continuation of a ureter
that arose in the region of this large cyst
and was actually a duplication cyst that terminated
in the bladder as a large ureter seal.
The fullness of the lower portion
of this duplex kidney is most likely
because of pressure from this dilated ureter,
although there certainly is a higher incidence
of reflux into the lower pole of a duplex system.

Here's another example of a patient with a duplex system
who had a very thin parenchyma around the lower poly moiety.
The appearance on the VCUG was that of a drooping lily
because of the fact that there is an upper pole here
that is associated
with this dilated uh collecting system superiorly
and this was a grade five reflux.

Primary Megaureter

Primary mega ureter is due to an Ady
distal segment of the ureter.
It's more common in boys than girls
and it's frequently bilateral.
There's usually a holdup of the radiopharmaceutical
if it's examined pre and post Lasix.
Many of these will spontaneously regress
and surgery is usually reserved for patients
who have moderately severe obstruction if they're failing
to thrive, if they have urinary tract infection
that doesn't respond to treatment
or they are experiencing pain.

Here's an example of a patient
with A-V-C-U-G done for a UTI.
There's an indentation on the side
of the bladder which turns out to be the distal
ureter on the left side
and this patient also had nephropathy as evidenced
by increased echogenicity
with no cortico medullary
differentiation in the left kidney.
And here's the dilatation
of the intrarenal collecting system, the proximal ureter,
very tortuous dilated ureter which terminated
as a narrowed segment right at the end
of the ureter inferiorly consistent
with a ureteral vesicle junction obstruction.

Posterior Urethral Valves and Other Male Conditions

And then there are little boys who come in
with a tight fibrosis that may be the cause
of the urinary tract infection.
Others have neurogenic bladder, they may have bladder
or urethral diverticular fistula, posterior urethral valves
or anterior urethral valves.
Posterior urethral valves are more common
than the anterior type.
They are obstructing folds
of tissue in the posterior urethra.
They can cause an obstructive neuropathy.
They may also be associated with renal dysplasia.
The bladder wall is usually thick and trabeculated
and there is dilatation of the posterior urethra
and vesco ureteral reflux.

Clinically they may have a urinary tract infection.
They may present with a distended bladder so it appears
to be a lower abdominal mass.
They may have a poor urinary stream,
they may be incontinent.
They may develop a oma because of obstruction to the kidneys
and fractures of the nesses of the caly.
They may also present with urinary ascites as a baby
and very rarely bladder perforation can occur in this baby.

With bilateral grade five reflux we could see the dilatation
of the posterior urethra
and this is the dilatation
of the collecting system inside the kidney.
On one side it looked exactly the same on the other very
bright echogenicity in the parenchyma of the kidney.
That is consistent
with renal dysplasia from long-term obstruction.
You can actually scan the penis to look
for the anterior urethral valve in the sense
that you'll see the diverticulum
that is actually arising in the region of the abnormal fold.

Pyonephrosis and Infections

Py necrosis can be shown with ultrasound
by demonstrating echogenic material within the collecting
system in the presence of bacterial or fungal infection.
However other material can look echogenic such
as protein or blood in the presence of a large
fungus ball in this kidney.
Hydronephrosis helped to outline the fungal infection
and here's a fluid debris level within the
dilated collecting system.

Very increased echogenicity
and no cortico medullary differentiation in this tiny baby
with a ureter rope pelvic junction obstruction.
P nephrosis in a duplex kidney is an example of
what looks like a mass
behind the bladder we see a very dilated,
somewhat tortuous ureter on the left side
and here's a fluid debris level.
The ureter was followed superiorly,
there's another fluid debris level
and we could see that it terminated in the upper pole region
of this otherwise unremarkable appearing kidney.
So this was py nephrosis complicating an ectopic ureter seal
that actually terminated at the bladder.
Neck stones are rare in children.
They can be the underlying cause
of a urinary tract infection.
So we need to do a thorough search for stones,
especially if there is urinary tract obstruction
and difficulty voiding.
We try to reserve CT for patients with negative sonograms
where there's a high suspicion of calculate this patient had
pain and infection, had fullness
of the intrarenal collecting system fullness
of the distal ureter,
a little bright echogenicity in the distal ureter
above the trigone and here we can see a little shadow
and a twinkle artifact to confirm
that this is an obstructing stone.

Don't forget to look at the urethra.
Any child who comes in with dysuria
where there may be a problem
with a stone lodged in the urethra
ultrasound can be very helpful.
This was done through a step off.
We see the base of the penis, the shaft, the glands
of the penis and there's a large stone
that is sitting right in the fossa navicular.

Pyelonephritis

Now pilon nephritis usually results from an ascending
infection or reflux could
develop from hematogenous spread
and the symptoms in the children
who can express themselves are usually flank pain
associated with fever.
They may have nausea, urine, vomiting and malaise.
Babies may present with fever and irritability
and foul smelling urine.

Well it may be totally normal on the ultrasound,
however there may be subtle findings.
The kidney could be large,
there could be decrease in the
cortico medullary differentiation.
There may be focal parenchymal abnormalities,
decreased color doppler in an area
of focal parenchymal inflammation
and there may be thickening of the renal collecting system
that is more than 0.8 millimeter.

In this patient there was swelling of the upper pole
of the kidney, little bit of increased echogenicity.
Here there's an actual rounded area of brighter echogenicity
that correlated with this DMSA study to show a lack
of uptake and this is a non-specific finding
and must be followed about a month later to be sure
that it resolves.
And also to look for scarring
and also to be sure that it's not something that's related
to a neoplasm.

Some children will develop abscesses in the area
where they've had a focal inflammatory infectious process
and so if symptomatology doesn't regress
and the urine culture remains positive,
repeat ultrasound should be done sooner to look
for development of an abscess.
Nuclear medicine may show a focal defect may show patchiness
throughout the entire kidney.
With ultrasound, we may see an area
that looks unusually bright as we see here
and here there's no doppler flow.

Okay, here we see in the article by Robin
that there is mild thickening of the wall
of the renal pelvis, both in this longitudinal view as well
as this transverse view.

Chronic Pyelonephritis

Chronic pyelonephritis.
We may actually be able
to see differences in the contour of the kidney.
This is a patient with a duplex kidney
who had reflux into the lower pole
and there's tremendous thinning of the renal parenchyma.

We did not do CT
and MRI routinely in patients with urinary tract infection,
although there are many findings that can be helpful,
particularly when assessing for abscess
and perinephric collections.
We reserve it for those patients in whom we can't assess
things as completely as we need to with sonography.

Here's an example with sonography of a perinephric abscess.
Here's an example of CT evaluation of a kidney
that was enlarged in this patient with pyelonephritis.
This is small area of
decreased attenuation which is not enhancing on the
post contrast images.
Another image on a patient who had an infection
where there is actually a rind of tissue around the kidney,
which is a lot better seen
with the CT in this perinephric collection.

Cystitis

Now most females who have urinary tract infection
have cystitis
and their symptomatology usually includes dysuria,
lower abdominal or pelvic pain, urgency, new onset
of urinary incontinence frequency, strong foul smelling,
urine hesitancy and hematuria.

With ultrasound, the bladder may be entirely normal when the
child has cystitis.
There are some patients who will present
with bladder wall thickening, could be focal,
it could be diffuse, and particularly with a viral cystitis
or a hemorrhagic cystitis, the bladder wall can be thickened
with viral cystitis.
The bladder wall may actually have characteristics
that are suggestive of rhabdomyosarcoma
and history will differentiate cystitis from a tumor.
The ultrasound findings will typically resolve within two
weeks after the patient presents.

Here's an example of one of the many faces
of cystitis sono graphically.
There's lobulated wall thickening in this patient
who was treated with Cytoxan for a bone marrow transplant.
There was continuing problems with cystitis, thickening
of the wall septations within the bladder lumen
and with color doppler there is hyper vascularity throughout
the bladder wall.

Sometimes the bladder wall will
develop a polypoid appearance as we see here
with this patient who had hemorrhagic cystitis this
thickening of the wall.
Other patients may actually develop bullous cystitis
that also can be demonstrated with sonography.

Sometimes the bladder wall will look like there is a
constriction and be highly suspicious for a mass.
But on ultrasound we see something
that looks very suspicious as well.
But as the bladder fills we see that the size
of this so-called mass actually gets longer
and more slender
and that centrally we can see the lumen of the bladder.
No tumor would do that.
And then just about two weeks later these findings have
completely resolved.

Conditions Mimicking Cystitis

Now some conditions can mimic cystitis.
Neurogenic bladder can have a thick wall
that looks irregular.
There may be a racal diverticulum bladder wall diverticulum.
Sometimes focal bladder wall thickening develops in the
presence of an indwelling catheter with prostatitis.
There can be some symptomatology that is confusing
with cystitis and at times a tumor may have some
similar characteristics.

Neurogenic bladder in this patient demonstrates thickening
of the wall looking very much like cystitis,
but this patient could not empty their bladder.
Here we see the little outpouching from the bladder wall in
this patient with a neurogenic bladder
and these are little divert bilaterally in this patient
with spina bifida.
At first these look like cysts behind the bladder,
but as we angle the probe we see that this is the neck
of a diverticulum and the patient had several.

Approach to Imaging in Pediatric Patients with Urinary Tract Infection

So in closing, I would like
to just spend a few minutes on talking about how we
approach the children and when we scan them so that all
of the things that we've talked about during this lecture
will have the best chance to be demonstrated
and that the children will be appropriately followed so
that they will have the least risk
of damage to their kidneys.

So in the children who are less than five years of age
with a first urinary tract infection,
females will have an ultrasound.
They usually have A-V-C-U-G or a nucleus cystogram,
and the males will have an ultrasound and A-V-C-U-G.
The reason in the males that we like to do the VCUG is
that they need to have the urethra examined carefully
for various things that can cause urinary tract infection
and obstruction, particularly posterior urethral valves,
any type of diverticulum or stricture.
At times we will use nucle renal scanning or ct,
but it is only reserved for cases in which the ultrasound
and the studies for reflux are not conclusive.

Now in patients who are older than five years,
when they present with a urinary tract infection,
they have an ultrasound.
If the ultrasound is normal, no further imaging is done.
If the ultrasound is abnormal, then A-V-C-U-G is done.
And if they have a void function,
VCUG may be done as well.

In patients who are already adolescents who present
for the first time with a urinary tract infection that has
occurred two to three times in 12 to 18 months,
sonography is usually performed at that time.

Now, in terms of monitoring the children
who have been diagnosed with urinary tract infection
and who have vesco ureteral reflux,
they will have an annual VCUG
or NU nuclear VCUG as well as an annual ultrasound,
the VCUG to see whether the grade of reflux has increased,
decreased, or the reflux has resolved.
And the annual ultrasound is very helpful in looking for
progressive appropriate growth of the kidneys, signs
of hydro ureteral nephrosis
to determine if it is, I'm gonna fix that.
And the annual ultrasound is used
to assess renal growth progression
or regression of hydro terone necrosis
and to examine for scars.
And of course the pediatricians
and urologists will follow the children
with urine cultures as well.

So I thank you very much for listening to this
and I hope this information that I presented will be helpful
to you as you examine the pediatric patients
who present with urinary tract infection.
Thank you.