Shannon Higgins a special girl born with Polymicrogyria (PMG)

MRI Report

ANES. FOR COMPUTER AXIAL; MRI BRAIN, W/O CONTRAST 5/27/99

* HISTORY *
10 month old with macrocephaly and developmental delay.

TECHNIQUE: Sagittal T!, axial T2, axial T1, coronal 3dSPGR, coronal FSE.

* FINDINGS *
The cerebral hemispheres show evidence of polymicrogyria. Specifically, there is cortical dysplasia seen in the region around the sylvian fissures bilaterally which extends more superiorly and posteriorly than normal. Also, the dysplastic cortex extends centripetally with infolding or buckling of the cortex. The dysplastic cortex has an irregular bumpy inner and outer cortical surface. This is particularly prominent in the bilateral opercular regions posteriorly where there are anomalous of draining veins.

The ventricular system shows dilatation of the lateral ventricles. The third ventricle, aqueduct and fourth ventricles are normal. Also, there is increase amount of CSF space surrounding the cerebral hemispheres. There is a suggestion of some diminution in the amount of white matter; however, this is somewhat subtle and may only be accentuated by the infolding of the overlying dysplastic cortical mantle. The posterior fossa shows no significant abnormalities.

The cervical medullary junction and pituitary fossa are normal. The cranium demonstrates flattening in the right parietal occipital and suboccipital region. Also, there is suggestion of increased distance in the area of the ethmoids between the orbits raising the question of hypertelorism.

* IMPRESSION *
Cortical dysplasia most prominent in the posterior aspect of the sylvian fissures bilaterally.

Enlargement of the supratentorial ventricular system and prominent subarachnoid space surrounding the cerebral hemispheres.

No midline anomaly is appreciated.

Some dysmorphic features of the cranium as described.

Some translation

This response submitted by Scientist Bill of the MGH Child Neurology Forum on 7/14/99.

Here are some translations that should help.

TECHNIQUE: Sagittal T!, axial T2, axial T1, coronal 3dSPGR, coronal FSE.

Terms like sagittal, axial, coronal, refer to the direction of the view from which the scan is taken. Coronal is like seeing a slice of the brain from the front, sagittal from the right or left side, etc. T1, T2, etc are ways in which the image is processed or what data is taken. These different forms have technical names, but essentially optimize the view. T2, for example, makes white matter bright and gray matter dark; T1 the opposite (I could have that backwards!). FSE stands for fast spin echo, another way of taking data.

* FINDINGS *
The cerebral hemispheres show evidence of polymicrogyria. Specifically, there is cortical dysplasia seen in the region around the sylvian fissures bilaterally which extends more superiorly and posteriorly than normal. Dysplasia means abnormal development resulting in abnormal structure; the sylvian fissure separates the frontal lobe from the temporal lobe. It is the huge infolding that you see on the right and left sides of the brain, the one that defines the "thumb" of the brain, which looks a bit like a hand in a boxing glove when seen from the side. I think they mean the Sylvian fissure extends up (superior) and back (posterior) further than it should, but they could mean the same for the area of dysplasia. (Radiologists are never strong in basic grammar!)

Also, the dysplastic cortex extends centripetally with infolding or buckling of the cortex. Centripetal means toward the midline, toward the center of the brain.

The dysplastic cortex has an irregular bumpy inner and outer cortical surface. This is particularly prominent in the bilateral opercular regions posteriorly where there are anomalous of draining veins. The operculum is the cortex of the frontal lobe on the border with the Sylvian fissure.

The ventricular system shows dilatation of the lateral ventricles. The third ventricle, aqueduct and fourth ventricles are normal. The first two ventricles - the ones on the right and left sides of the brain, are bigger than normal. The other two ventricles are normal. Also, there is increase amount of CSF space surrounding the cerebral hemispheres. There is too large a cerebrospinal fluid space around the outside of the brain; this is where the CSF is taken back up. This space is called the subarachnoid space, on top of the brain, under two of the three meninges.

There is a suggestion of some diminution in the amount of white matter; however, this is somewhat subtle and may only be accentuated by the infolding of the overlying dysplastic cortical mantle. The posterior fossa shows no significant abnormalities. Posterior fossa is the back of the brain near where it exits the skull and becomes the spinal cord.

The cervical medullary junction and pituitary fossa are normal. Back of brain where it joins the brainstem; hole in the base of the skull where the pituitary gland sits. The cranium demonstrates flattening in the right parietal occipital and suboccipital region.

Also, there is suggestion of increased distance in the area of the ethmoids between the orbits raising the question of hypertelorism. Orbits are the bones that surround the eyeball; ethmoids are bones between the eyeball and the bridge of the nose. Hypertelorism means the eyes are further apart than normal.

* IMPRESSION *
Cortical dysplasia most prominent in the posterior aspect of the sylvian fissures bilaterally.

Enlargement of the supratentorial ventricular system and prominent subarachnoid space surrounding the cerebral hemispheres. Supratentorial refers to things above a structure near the base of the brain. In this context, it simply means the first two ventricles, but not the 3rd and 4th. See above for subarachnoid space.

Hope this helps a little. Typical densely written radiology report, full of anatomical terms that there is no reason you should understand.