Читать книгу Anatomy for the Royal College of Radiologists Fellowship - Malcolm Sperrin - Страница 23

1 Name the arrowed structure.

2 Name the arrowed structure.

3 Name the arrowed structure.

4 Name the arrowed structure.

5 Name the arrowed structure.

Answers

1 Left red nucleus.

2 Left hippocampus.

3 Quadrigeminal cistern.

4 Temporal horn of the right lateral ventricle.

5 Right substantia nigra.

Comments:

Anteriorly within the midbrain are the cerebral peduncles which connect the brainstem with the higher CNS structures. Just posterior to these on axial slices are bilateral strips containing dopaminergic cell bodies—the substantia nigra. The red nucleus is a spherical structure of cell bodies that is identifiable on MRI and is located posterior to the substantia nigra at certain axial levels.

The cerebral aqueduct runs perpendicularly through the midline of the posterior part of the midbrain, between the third and fourth ventricles. This is surrounded by a ring of grey matter—the peri-aqueductal grey. Behind the coronal plane containing the cerebral aqueduct is the tectal (quadrigeminal) plate. On the posterior side of the tectal plate are two sets of rounded protrusions called the superior and inferior colliculi, beyond which lies the quadrigeminal cistern. The superior colliculi are at the same axial level as the red nucleus.

Exam tip:

 The midbrain is recognisable on axial brain sections because of its’ ‘Mickey Mouse’ ears anteriorly, formed by the cerebral peduncles.