Paediatric Nuclear Medicine - Higher Education AP diameter of the pelvis on ultrasound and DRF...
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Transcript of Paediatric Nuclear Medicine - Higher Education AP diameter of the pelvis on ultrasound and DRF...
Anita Brink
Nephro –urology: • DMSA Scans
• MAG3 renograms
• Indirect Cystograms
Gastro oesophageal studies “Milkscans”
Oncology topics
The “missing” kidney: • Multicystic dysplastic kidney
• Agenesis
• Ectopic kidneys
• Fused kidney
The “scarred” kidney: • Hypertension
• Urinary tract infections
Probable multicystic dysplastic kidney:
Ultrasound findings: • No or thin cortex
• No communication between cysts
• Ureter not seen
• Bladder normal
DMSA done when baby 6 weeks.
Multicystic dysplastic kidney:
Acute infection- within 10 to 14 days after
onset of symptoms.
To assess for permanent defects – wait at
least 6 months after infection.
The patient has hydro-nephrosis, MAG3
is the agent of choice.
Pelvic kidney/s = MAG3 is better in
theses cases
The new born baby you are seeing had
an antenatal ultrasound that showed
hydronephrosis.
Where do you go from here?
Prenatal hydronephrosis is found in
approximately 0.25% of pregnancies(1).
There is spontaneous resolution in:
50% of cases with mild
15% with moderate and
0% with severe hydronephrosis(2).
1.Helin I, Person P.H. Prenatal diagnosis of urinary tract abnormalities by
ultrasound. Pediatrics, 78:879, 1986.
2.Feldman, D.M. et al: Evaluation and follow-up of fetal hydronephrosis.
J Ultrasound Med, 20: 1065,2001.
A post natal ultrasound is performed to confirm the antenatal findings.
This should not be performed in the first five
days of life unless the antenatal ultrasound is grossly abnormal.
Once hydronephrosis is conformed on
postnatal ultrasound a MAG3 study is
done in all cases.
Timing of MAG3 depends on: 1. The size of the renal pelvis.
2. Thickness of cortex.
3. Renal pelvis intra/ extra renal.
NOT done in the first week of life.
Ideally after 6/52.
Preferably after 3/52.
Only done between 7 and 21 days if
there is severe hydronephrosis – can this
kidney be salvaged?
Differential renal function (DRF) is the
most important information obtained
from the renogram.
The AP diameter of the pelvis on
ultrasound and DRF determine the
treatment and follow-up investigations of
the patient.
1. Infections/Complications.
2. Fall in differential renal function.
3. Increasing AP pelvis (relative
indication).
DRF 50/50%.
AP pelvis Calyceal
dilatation
Baseline
MAG3 at
Follow-up
MAG3 at
< 20 mm Seldom
marked
3/12 9/12
20 – 30mm Not marked 9/52 6/12 - 9/12
20 – 30mm Marked 6/52 3/12 – 6/12
30 - 40mm Not marked 6/52 6/52 – 3/12
30 – 40mm Marked 3/52 3/52 - 6/52
> 40 mm uncommon at 50/50% DRF
Ultrasound studies are booked between
two MAG3 studies. If the ultrasound
results are of concern the MAG3 study is
moved forward.
DRF 30/70% follow-up MAG3 and
ultrasound studies are done earlier
because the one kidney is already
compromised
As with DRF 50/50% the MAG3 renogram
is moved forward if the ultrasound results
are of concern .
DRF 15/85% - 20/80%.
The follow-up MAG3 is done 2/52 - 4/52
after initial study.
Consider doing a MCUG here.
These patients are candidates for nephrostomy
early surgery
early stent.
DRF of affected kidney < 10%.
Probably not salvageable, surgery often
technically very difficult.
Probably not worth saving.
Do MCUG if the
ureter is visible or
bladder abnormal
Follow-up depends on the result of each study.
E.g. no change on the 3 month follow-up do the repeat MAG3 renogram in 6 months time, with an intervening ultrasound.
Children with stable total renal function and DRF for 3 years very unlikely to need intervention.
Follow-up is determined by:
1. Renal function, serum creatinine or GFR
2. AP diameter.
3. Cortical thickness.
4. Communication between calyces and
pelvis, pelvis and ureter and also ureter
and bladder.
5. Bladder morphology.
Investigations are done earlier and more frequent.
The timing of the investigations depends mostly on the
serum creatinine/ GFR and AP pelvis.
If the bladder morphology is deranged
MCUG is done in the neonatal period.
Please note that the absence or presence
of a Lasix response is not used to make
any treatment decisions.
90% of 474 neonates allocated to
watchful waiting were not operated on.
Only 10 % were subjected to delayed
pyeloplasty, mostly because of an
increase in pelvic size and/or decreasing
renal function.(4)
Josephson S. Antenatal detected, unilateral dilatation of the renal pelvis: a
critical review. 1 post natal non-operative treatment 20 years on is it safe?
Scand J Urol Nephrol 2002;36: 243-250.
The child needs to be potty trained!!
A basic renogram is done.
In most children the bladder will be full
of activity, and the kidneys would have
cleared 40 minutes after injecting the
tracer.
We take 2- 5 ml of the child’s own milk and label it with 99m Tc tin colloid.
The child drinks this in front of the camera. Preferably on mommy’s lap.
The child then drinks the rest of their normal feed.
The child is burped. The reflux and aspiration search is then
done for 35 min. One hour brake, no eating no drinking. The one last 5 minute image for aspiration
check and gastric emptying calculation.
Two 5 minute static images, one after the
reflux search and another two hours after
the feed.
Normal Glucose:
Plasma
Glucose Glucose-6-PO4
Glucose
Glycolysis
GLUT-1
Hexokinase
G-6-P
Tumor cell:
FDG
FDG FDG-6-PO4
Glycolysis
GLUT-1
Hexokinase
G-6-P
3 03 2011 13 01 2011