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This is an MRI of the brain in a newborn that

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had an abnormal fetal ultrasound,

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and axial T2-weighted image

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shows a couple of things.

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First of all,

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we see this anterior sloping of the frontal

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bones that goes up to the midline.

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And midline,

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while we don't get a great view of bone on MRI

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compared to CT,

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it looks like there's actually bone continuity

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between the two frontal bones,

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whereas at this young of an age,

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the metopic suture should be there.

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So, this raises the possibility of

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metopic suture craniosynostosis,

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which can result in a skull configuration

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known as trigonocephaly.

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Now, if we go down further on this coronal image,

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we can see anteriorly across the interhemispheric

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fissure, we have gray matter continuity.

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We have cortex going all the way across and

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white matter going across beneath that

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that's unrelated to the corpus callosum.

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So, that's not normal.

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The two cerebral hemispheres should be separate

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from one another other than commissural fibers,

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such as the corpus callosum

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and anterior commissure.

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So, this gray matter continuity is abnormal.

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We also have a slightly dysmorphic

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ventricular system,

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but much less so than in the case of semilobar

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holoprosencephaly that we saw,

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and much closer to normal than the case of a

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lobar holoprosencephaly, which we saw.

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There's some fusion of the thalami,

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but the thalami are otherwise separately formed.

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This almost looks like a large

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mass of intermedia.

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So, this patient has a very mild

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holoprosencephaly spectrum disorder.

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It is, truly speaking,

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a holoprosencephaly spectrum disorder,

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because we have the gray matter of the cortex here,

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which is a part of the telencephalon,

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and the thalamic abnormality,

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which is a part of the diencephalon.

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But this is a milder end of the spectrum

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of the holoprosencephaly spectrum disorders,

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known as lobar holoprosencephaly.

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We have an interhemispheric fissure.

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We still have an Azagus anterior cerebral artery here.

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We have midline continuity.

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Anteriorly, the falx cerebri is not well developed.

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Posteriorly, it is developed.

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So, it has some features more normal than

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the semilobar holoprosencephaly,

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but it has definitely abnormalities that

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differentiate this from a normal

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appearing brain from this age.