Sonography of the Infant Brain-Hemorrhage Grades 1-2 - SD

Use of Ultrasound for Evaluating Hemorrhage

Let's consider the use of ultrasound for the evaluation of hemorrhage.

This has really evolved as the imaging modality of choice as a very sensitive and accurate way to diagnose subependymal hemorrhage, as well as intraventricular hemorrhage and paraventricular hemorrhage.

It is a useful predictor of outcome.

We can do this examination right at the baby's bedside without radiation, without contrast material, and without sedation.

Ventricular Size

I wanna take one minute to just talk about ventricular size.

People always ask, what is the normal size of a lateral ventricle?

And, a general rule of thumb is that if you measure the frontal horn from one border to the other in a cross-sectional image, this really should not measure more than approximately two to three millimeters tops.

Intracranial Hemorrhage in the Premature Infant

We're gonna start our discussion of hemorrhage in the infant brain by talking about intracranial hemorrhage in the premature infant.

Those infants who are prone to intracranial hemorrhage generally are less than 32 weeks gestation.

They weigh less than 1500 grams at birth, and there is a significant incidence of hemorrhage in very tiny preemies up to 70%.

In babies who have assisted ventilation.

Most of the hemorrhages occur within the first three days of life.

Most major hemorrhages are noted on day one, and about 91% of the babies with hemorrhage have the diagnosis made by the end of the first week of life.

Risk Factors

The risk factors are multiple.

First of all, prematurity and low birth weight hemorrhage in the premature infant is more common in male babies than female babies.

It's more common in babies who are part of a multiple gestation, which of course is a high risk factor for being born premature if there's prolonged labor, any type of trauma at delivery.

If there's a problem with hyperosmolarity, hypercoagulation, hypoxia pneumothorax, and patent ductus arteriosis, one of the most important factors that affects the risk for intracranial hemorrhage in the premature infant is the fact that premature babies have very little, if any, autoregulation as regards the cerebral circulation.

Therefore, anything that causes an increase or decrease in cerebral blood flow can be directly transmitted to the brain if the systemic blood pressure suddenly goes up or down.

The area of the germinal matrix is extremely fragile and prone to hemorrhage.

And then there is a problem regarding intra cerebral vaso dilatation, which can happen in the presence of hypertension, hypercapnia acidosis, and vasoactive substances such as prostaglandin.

Classification of Hemorrhage

We use a classification that is based on serial ultrasound findings where we consider basically four grades for grade zero.

This is a normal brain with grade one hemorrhage.

This refers to hemorrhage involving the germinal matrix and also hemorrhage that is in the region of the choroid plexus.

The gloma portion in the atrium of the lateral ventricle grade two hemorrhage includes intraventricular hemorrhage, no ventricular dilatation with or without germinal matrix hemorrhage.

It used to be thought that intraventricular hemorrhage was a breakthrough of germinal matrix hemorrhage, but we've seen many babies who have intraventricular hemorrhage but no evidence of germinal matrix hemorrhage.

Grade threes according to the literature, refers to intraventricular hemorrhage, ventricular dilatation, and germinal matrix hemorrhage.

Subclassification of Grade Three Hemorrhage

Based on a study that we've done in babies with grade three hemorrhage, we derived a sub classification in these babies that distinguishes between mild, moderate, and severe degrees of intraventricular hemorrhage and ventricular dilatation.

Babies with mild are referred to as grade three A.

Those with moderate hemorrhage and dilatation are referred to as grade three B, and grade three C refers to babies with severe IVH and severe ventricular dilatation.

These babies may or may not have germinal matrix hemorrhage, whether they're an A or a B or a C within the grade three category.

We decided to do this study because we noticed a long time ago that when parents were confronted with news that their baby had hemorrhage in the brain, they often became extremely anxious and had difficulty bonding with their baby.

What we learned from our study is that there's quite a significant difference between mild hemorrhage, moderate and severe.

In terms of the outcome.

We'll talk a little bit more about this later, but suffice it to say that babies with mild hemorrhage and dilatation often have no structural damage to the brain on follow up, whereas the babies with more severe intraventricular hemorrhage and ventricular dilatation have structural changes and often need therapy with grade four hemorrhage.

In addition to intraventricular hemorrhage, ventricular dilatation with or without germinal matrix hemorrhage, there is additional hemorrhage into the parenchyma of the brain.

So basically our classification allows for identification of infants in whom structural changes may be expected to resolve or progress, and allows for identification of infants who may require intervention.

Most grade one and two hemorrhages show normal follow up on ultrasound most grade three a's show normal follow up on ultrasound or no changes.

Most grade three B's and C's have persistent structural changes, and with grade four hemorrhage, there is development of a communicating poor and cephalic cyst in the region of the parenchymal hemorrhage.

The Germinal Matrix

Just a few words about the germinal matrix.

The germinal matrix is located just adjacent to the cardio thalamic groove.

It is the zone of neuronal and glial cell proliferation.

It is highly cellular, richly vascular, and metabolically active in the developing brain.

This area of the germinal matrix involutes by 34 weeks gestation, at which point it is no longer as vulnerable to developing hemorrhage.

The germinal matrix is quite susceptible to hypoxic changes.

Now when there's hemorrhage in the germinal matrix, we suspect this based on the fact that we will notice a small area of bright echogenicity that is inferior lateral to the frontal horn and posterior to the foramen of Monroe.

It may be unilateral, it may be bilateral.

Larger hemorrhages may cause focal compression of the inferior lateral margin of the ventricle germinal matrix hemorrhages may result in sub penal cysts within a few weeks after the insult.

And here we can see the right and left lateral ventricles with small cysts in the region of the germinal matrix.

This is the choroid plexus at the region of the forer of Monroe bilaterally, as well as choroid plexus in the roof of the third ventricle.

So again, here is the coth thalamic groove.

There's a bright area of increased echogenicity adjacent to it.

One might ask, how do we know that this is hemorrhage?

For we know that non shadowing calcification could look the same.

Tumors could look the same.

Areas of infections such as an abscess that contains densely packed purulent material could look like this.

Just as in any other imaging study, we have to consider the gestational age of the baby and the risk factors.

So in a premature baby, an area of bright genicity in this very vulnerable portion of the brain is consistent with germinal matrix hemorrhage.

Choroid Plexus Hemorrhage

Now, choroid plexus hemorrhage may be manifest only by the presence of a somewhat lumpy, bumpy appearance to the gloma of the choroid plexus or even to other parts of the choroid plexus.

So here's the germinal matrix hemorrhage, and this is the area of the choroid plexus hemorrhage.

Intraventricular Hemorrhage

Now, intraventricular hemorrhage can result from intraventricular extension of a germinal matrix hemorrhage.

It may actually arise from the region of the choroid plexus.

It may be unilateral or bilateral.

Initially, blood appears brightly.

A coic on ultrasound, and it may be difficult to identify in a non dilated ventricle, and at times may be difficult to differentiate from a germinal matrix hemorrhage.

A large hemorrhage will form a cast of the ventricle.

This is an example of a very immature baby. Notice.

There are no convolutional markings.

This is the interhemispheric fissure, the region of the corpus callosum.

Here's the cavem septum lucidum, and this is the left lateral ventricle, normal size choroid plexus, choroid plexus in the roof of the third.

These are the hippocampal gyri. Notice choroid plexus here.

But also notice that within the right lateral ventricle, there is a small area of brightly, a coic material consistent with hemorrhage.

As we look somewhat more posteriorly, notice there are no convolutional markings, implying this baby is less than 26 weeks gestation.

And notice that there is an area of bright echogenicity lying dependently within the occipital horn of this ventricle, consistent with intraventricular hemorrhage.

Here's the para sagittal view, the frontal horn, the body, the atrium housing the gloma, which tapers toward the codo thalamic groove and the temporal horn.

And here we see the area of hemorrhage that is located dependently in the occipital horn.

So grade two is hemorrhage within the ventricle with no dilatation of the ventricular system.

I mentioned before that sometimes it can be difficult to decide is the hemorrhage in the ventricle or is it adjacent to the ventricle as a subependymal hemorrhage and very meticulous scanning is necessary to make that differentiation.