Brain pt 2 Flashcards
what defines a premature baby?
a baby born brfore 37 weeks GA
what is seen in a sagittal midling scan of an immature brain?
The midline cystic cavum septum pellucidum (CS) and cavum vergae (CV) are prominent in the premature infant
what is cavum vergae?
- extension of CSP
- persistence of embryological fluid- filled space between the leaflets of the septum pellucidum and is a common anatomical varient
where is cavum vergae located?
0 on coronal view located between bodies of lateral ventricles
when does closure of the cavum vergae start?
6 month gestation
Superior to the cavum is the?
- hypoechoic corpus callosum
- 3rd and 4th ventrivles, with 4th ventricle seen as a triangular lucency indenting the vermis
what is visible anterior to the vermis?
the cisterna magna
what is seen anterior to the 4th ventricle?
midbrain
what is the posterior approach?
- sagittal imaging plane through the posterior frontanelle
- coronal plane is obtained by rotating the transducer 90 degrees
Ventricular asymmetry. Coronal scan shows the left lateral ventricle larger than the right. Is this normal?
yes this is a normal varient
Intracranial Pathologies? (9)
Intracranial Hemorrhage - ICH Hydrocephalus Cerebellar Hemorrhage Periventricular Leukomalacia – PVL Agenesis of Corpus Callosum Dandy-Walker complex Chiari Malformation Holoprosencephaly Intracranial Infections
what is an Intracranial hemorrhage?
- one of the main indications for u/s and a major cause of morbidity and mortality in premature infant
what is a Germinal Matrix Intraventricular Hemorrhage (GM-IVH) ?
- Majority occur within 3 days of life in premature infants
what is a germinal matrix?
- fetal structure
- fine network of blood vessels and primitive neural tissue
- located in subepindymal region of lateral ventricles
where us the most prominent portion of germinal matrix?
- lies in caudothalamic groove
- between caudate nucleus and thalamus
Germinal matrix structure?
- has immature fragile blood vessels with poor supporting connective tissues
- highly susceptible to pressure and metabolic changes, which lead to rupture of vessels
when does Germinal matrix reach its greatest size?
- at 23-24 weeks
- then it starts to regress
- completely incolutes by 36 weeks
Germinal matrix is rare in term babies T or F?
true because it completely involutes by 26 weeks
Ependyma?
thin epithelium-like lining of theventricular systemof thebrainand thecentral canalof thespinal cord
intracranial hemorrhage grade 1?
subepindymal hemorrhage
intracranial hemorrhage type 2?
IVH without ventricular dialation
intracranial hemorrhage type 3?
IVH with ventricular dialation
intracranial hemorrhage type 4?
- intraparnchymal hemorrhage with or withough ventricular dilation
Germinal Matrix Hemorrhage (SEH): Grade I primary site?
caudothalmic groove (CTG)
3 steps to scanning a Germinal Matrix Hemorrhage (SEH): Grade I?
A: Parasag scan through the area of the caudothalamic groove shows a focal area of increased echogenicity (arrow)
B: Cor. scan - bilateral echogenic foci at the CTG (arrows).
C: Resolving grade I hemorrhage.
The same infant several weeks later shows clot has undergone cystic liquefaction (arrow).
there are long tern neurologic complications with a Germinal Matrix Hemorrhage (SEH): Grade I T or F?
False
Grade II Hemorrhage characteristics?
- GMH ruptures through epyndymal lining and enters ventricles
- no ventricular dilation
Grade II Hemorrhage clot?
- Clot can adhere to normal CP making it appear irregular and thick.
- This may be difficult to see on ultrasound
- Doppler will show flow in CP, no flow in clot
in Grade II Hemorrhage where does blood most often accumulate?
in the most dependent part of ventricle- occipital horn
occipital horns are best seen through?
posterior frontanelle
Grade II Hemorrhage on u/s?
- echogenic
- material in occipital horn
grade III hemorrhage
A- Parasag scan shows blood-filled lateral ventricle with clot filling the entire ventricle and forming an echogenic cast of the ventricle (arrow)
B- Coronal scan shows clot in both lateral ventricles with hydrocephalus (arrow)
C- Same patient 14 days later shows evolution of clot. Coronal scan shows area of liquefaction of clot (arrow)
D- Parasag scan shows some retraction of the intraventricular clot.
Grade III hemorrhage
A- Coronal scan posteriorly
- Dilation of the lateral ventricles
- Echogenic material (blood clot) in the ventricles
B- Coronal scan in the same infant posteriorly
- The lateral ventricles are dilated with large amount of intraventricular hemorrhage which, on the - - right, is taking the shape of the ventricle (arrow)
C- Sagittal scan of the left lateral ventricle.
- The blood clot has settled posteriorly and is lying primarily in the occipital horn
- The echogenic CP can be seen separate and anterior to this (arrow).
Grade IV Hemorrhage?
- Parenchymal involvement with or without ventricular dilatation
- Most common in frontal and parietal lobes
- Resorption of hemorrhagic area may lead to formation of porencephaly
Porencephaly?
- fluid filled space that have replaced normal brain parenchyma due to destructive process
- These cysts rarely resolve
long term complications of grade IV hemorrhage?
- cerebral palsy
- developmental delays
- seizures