normal 2nd and 3rd trimester

thalamic view is also known as

biparietal view

thalamic view is seen above ____ and below ____

the orbits and cerebellum and below the ventricular atrium

a fused thalami is associated with

holoprosencephaly

2 thlamai whats in the middle

3rd ventricle

fetal right and left can only be established after?

establishing fetal lie and presentation

the basic everyday brain scan usually includes the

transventricular, transthalamic, and transcerebellar

reservoir for cerebrospinal fluid between frontal horns of lateral ventricl

cavum septum pellucidi

a present cavum septum pellucidi rules out

central nervous system anomalies

whats the fold of dura matter dividing cerebral hemispheres called

falx cerebri (seen in the thalamic view)

what should you worry about if partial or complete falx cerebri is absent

holoprosencephaly and hydraencephaly

what makes up the lateral cranium

parietal bones

___ ____ posterior portion of the skull

occipital bones

dolichocephaly vs brachycephaly

dolicho- elongated oval shaped head

brachy- round shape head

lemon shape cranium is associated with

spina bifida

clover leaf shape cranium is associated with

thanatophoric dwarfism

where to measure the BPD in transthalamic plane

outer edge of the near calvarial wall inner edge of the far calvarial wall

where to measure the HC in the transthalamic plane

outer table of the calvarium

if you see a central third line when looking for the cavum, its probably the

fornix

wheres the fornix

inferior to the CSP

what does the CSP look like

a fluid filled structure between the leaves of the septum

_____ ventricles hold cerebral spinal fluid

lateral

_____ ventricles contain the choroid plexus

lateral ( CP is hyperechoic)

for the ventricular view, the transaxial plane is above the ____ at the level of the atrium of the ____ ventricle

BPD, LATERAL

ventricular size should be

less than or equal to 10mm,

choriod plexus should fill ventricle

most CP cysts resolve around

26 wks of GA, larger cysts that dont regress are associated with trisomy 18

main landmark in the posterior brain is the

cerebellum (helps with balance)

middle part between the cerebellum is called the

cerebellar vermis

cisterna magna is evaluated in what plane

transcerebellar

the cerebellum is helpful in determining

GA age, approx 1mm per GA wk

regarding the cerebellum, smaller absent vermis suggests…

dandy walker malformation

how to measure the cisterna magna

from cerebellar vermis to inside cranium

abnormal if greater than 10mm

what does it mean if theres an obliterated cisterna magna

no fluid behind the cerebellum

how to measure the transcerebellar plane

widest part of the cerebellum, perpendicular to the falx

transcerebellar plane in mm correlated with GA up to __ wks

20, after 20 wks its larger than GA

what measurment does the transcerebellar plane have to than the estimated GA age

less than 2mm

normal measurment during 2nd to the 3rd trimester for the cisterna magna

2-10mm

are cisterna magna septa present in most fetuses? if so what do they represent

yes (84-92%), represent the walls of blakes pouch

whats known as the potential marker for normal development

blakes pouch

what plane would you assess for clefts and nostrils

coronal

nuchal fold is measured between what wks

15-21

abnormal measurments for the nuchal fold would be

greater than 5-6mm (associated with T21)

diaphragm is ___ to lungs and liver

hypoechoic

what do fetal shunts do regarding fetal circulation

allow blood to bypass lungs and deliver oxygenated blood to the brain

___ ___ allows some blood to bypass the right ventricles

foramen ovale, between right and left atria

____ ____ allows some blood to bypass liver

ductus venosus, near left portal vein

____ ____ allows some blood to enter the aorta instead of the lungs

ductus arteriosus, between aorta and pulmonary artery

most common fetal cardiac tumor

cardiac rhabdomyomas

normal fetal heart rate

120-160 bpm

bradycardia and tachycardia in a fetus

brady- less than 100

tachy- over 180bpm

___ ___ is closest to fetal spine

left atrium

what ventricle is closest ti anterior chest well

right ventricle

what valve is between the right atrium and ventricle

tricuspid

what valve is between the left atrium and ventricle

mitral valve

slide 51

candy cane view?

aortic arch, head and neck vessels

hockey stick?

ductal arch, communication between the main pulmonary artery and the descending aorta

stomach bubble visualized reliably by

13 wks, but can be seen as early as 9

non visualization of the stomach may be due to

displacement, lack of amniotic fluid or esophageal atresia

the ___ ___ is the larger part of the liver in fetuses

left lobe, not usual to see liver masses

fetal anemia may cause what to the spleen

splenomegaly

the colon is distinguishable after how many weeks

22 wks

how often does the bladder fill

every 30 mintues, seen reliably by 12-13 weeks but can be seen as early as 11

kidneys are identifyable by how many wks

12-13 wks GA

ratio of abdominal to renal circumfrence is approx

3;1

during the 3rd trimester Ap diameter of renal pelvis measures

less than 5mm

the appendicular skeleton includes:

extremities and pelvis

ossification begins in long bones by

11 wks GA

iliac wings ossify by

ischium ossifies by

12

20

ratio of foot length to femur length is

approx 1

axial skeleton consists of

cranium, ribs, scapula, clavicles and spine

cranium ossifies around

11 wks

cervical spine ossifies around-

lumbar spine ossifies around-

15-16wks

18 wks

____ ____ are best for assessing the integrity of the skin

axial views