Walid A. Farhat, MD Division of Paediatric Urology Department of

MRU in Children
Walid A. Farhat, MD
Division of Paediatric Urology
Department of Surgery
SPR- Pediatric Body MRI
Genitourinary Session
Toronto, 2015
Pediatric Urology: Imaging modalities
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IVP Ultrasound (US)
Cystograms
Nuclear Medicine
CT
Magnetic resonance:
MR
Renal anatomy
Renal mass
Cystograms: bladder/ urethra
Renograms: drainage and
function- UTI
MRU
Advantages
•  Elimination of ionizing radiation and ionic contrast
•  Non Contrast imaging (T2 Imaging)
Disadvantages
•  Needs GA
•  Claustro/Implants
•  Long duration: MR- 45 min
•  Not suitable for calcifications
•  Cost
MRU indications:
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Congenital anomalies: duplication, hydroneohrosis
and vague anatomical abnormalities:
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Incontinence
Renal and bladder tumors
Infections and vascular anomalies of the urinary tract
MRI- dynamic study !  
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The precontrast sequence provides morphological details
Post contrast provides functional information with
depiction of every single component of he kidney
Views and details
Protocol- DDx driven
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A sagittal T2 sequence
An axial or transverse T2
with fat saturation
A 3D T2 with fat
saturation
T1 fat saturated +post
contrast
Prone position/ contrast specific gravity
Procedural and scan modifications:
info on requisition
1. Ectopic ureter: precontrast series may suffice
postcontrast part if functional studies are
needed
2. Cyst versus diverticulum: diverticulum in a retrograde
manner later than the calyces or renal pelvis:
Delay: 1 hour or longer
Procedure
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Preparation: Hydration with IV fluid administration starting a
half hour before the scan A bladder catheter is placed (age dependant):
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The urine bag is placed below the level of the scanner table
Full bladder hinders drainage
Furosemide (Lasix) is administered IV at a dose of 1 mg/kg
(maximum 20 mg), 10 minutes before the procedure.
Complication of gadolinium
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Nephrogenic Systemic Fibrosis:
poor renal function
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contraindicated in patients with an estimated GFR <60 ml/
min and especially <30 ml/min Skin disease (dialysis patients) 1997àOther organs
2003àGadolinium 2006à No more cases reported
2012
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Clinical Case
5 year old girl who was never toilet trained, her parents
report that she has been in diapers since birth and was never
dry.
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History: she has no interest in toilet training, she is
constipated and have been on antibiotics and anti fungal for
UTI and vagintis Physical exam is completely normal
Imaging: US possible duplex kidney on the Left
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VCUG and renal scans completely normal
Imaging: embryology
Clinical Case
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5 year old girl incontinent, had been evaluated by 3
pediatricians
ADHD:
Bowel Bladder dysfuntion
US findings:
Clinical Case
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Cystoscopy: identify one ureter and retrograde pyelogram
MRU
Preoperative planning
Vague anatomical abnormalities
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Cyst or diverticulum
KEY POINTS:
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Ultrasound is the primary imaging modality for the pediatric
urinary tract.
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Urolithiasis and trauma: CT may be indicated
Functional MR urography (fMRU) provides comprehensive
morphologic and functional information.
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Clinical details are of utmost importance