peds Flashcards
schizencephaly
CSF fluid filled clefts in the grey matter leading from the ventricles to the surface of the cortex; lined by GM.
may be bilateral in up to 50%
- open or closed.
- polymicrogyria
relationship between SNR and voxel size?
linear -> SNR increases with voxel volume.
SNR increases by sqrt of measurements (# phase encoding steps, # excitations) and decreases with sqrt of receive bandwidth
effect of decreasing matrix size and increasing slice thickness on voxel size and SNR?
increase voxel volume and SNR
Imaging time for a single slice is ?
TR x number of phase encoding steps x averages or number of excitations.
decreasing matrix size in phase encoding direction will also affect imaging time for a single slice how?
decrease time
pediatric UTI - % with duplication?
quoted as 25-40%
Hutch diverticulum
congenital bladder diverticulum at the VUJ, in absence of posterior valves
VUR demographics
retrograde flow of urine from bladder ot ureter, 1-3% of kids, 40-50% of kids with UTI
more common in caucasians, M>F in newborns, then 5-6x F>M after age 1
VUR etiologies
primary (ectopic ureters, lack/short intravesicular ureteric course, detrusor muscle abnormality)
secondary: cystitis/UTI, bladder diverticulum, calculi)
grading VUR
1: ureter only
2: reflux to renal pelvis, no dilation/blunting
3: mild dilation of ureters/calyces
4: moderate dilation, tortuosity, blunting of calcyces
5: severe dilation and tortuosity
spinning top urethra
seen in young children/girls
- dilated posterior urethra resulting from increased bladder pressure against closed sphincter
- bladder retraining needed
ureterocele
congenital abnormal dilation of the distal ureter. intra (at UVJ) or extra-vesciular( below/medial to expected UVJ)
appears as cystic intravesciular mass near UVJ/early filling defect posteriorly
- 5-7X F>M, up to 10% bilateral
Think: duplication
Weigert-Meyer law
describes the relationship of renal moieties to drainage in a completely duplicated system
- upper: ectopic ureter (medial inferior), often ending in ureterocele, and usually obstructed
- lower: normal ureter insertion, reflux
mesoblastic nephroma
aka fetal renal hamartoma
- most common congenital renal mass
- solid unencapsulated mass, usually near the renal hilum, tends to invade renal parenchyma and surrounding structures
- classic and cellular subtypes (and mixed)
DDx for infant retroperitoneal mass
mesoblastic nephroma
MCDK
Wilms
Rhabdoid tumor
retroperitoneal sarcoma
teratoma
neuroblastoma
extrapulmonary sequestration
MCDK
multiple renal cysts of variable size, with thinning and fibrotic changes of the renal parenchyma
due to oibstruction of the UPJ
- usually prenatal Dx
- unilateral, non-functional kidney
Wilm’s tumor
aka nephroblastoma
most common pediatric renal malignancy and abdominal CA
- slight F>M, usually <5yo
what are nephrogenic rests?
persistent metanephric tissue, usually regress during childhood
- found in up to 100% of bilateral Wilm’s
nephroblastomatosis
single renal mass <1yo
mesopblastic nephroma
wilms
rhabdoid
single renal mass in 1-10yo
wilms
rhabdoid (rare, 2% peds malignancies)
clear cell sarcoma (rare younger than 6 mo)
omphalocele vs gastroschisis
OM: midline abdominal wall defect with herniation covered by peritoneum/membrane with the umbilical cord inserting on it. 50-70% have associated anomalies (genetic syndromes),. prognosis determined by other anomalies.
GS: abdominal wall defect (right of midline) without membrane covering herniated bowel. usually isolated. prognosis determined by bowel condition
pentalogy of Cantrell
classic 5 malformations:
1. midline abdo defect
2. lower sternal defect/cleft
3. anterior diaphragmatic defect
4. defect of the diaphragmatic pericardium
5. intracardiac defect
Other
- omphalocele
- cardiac position outside the chest, or rotated with apex pointing towards the chin,
other cardiac anomalies (septum, tetralogy, ebstein, LV diverticulum, effusions)
best clue for pentalogy of Cantrell?
ectopia cordis + omphalocele
