Type:
Educational Exhibit
Keywords:
Toxicity, Metabolic disorders, Imaging sequences, Diagnostic procedure, MR-Spectroscopy, MR, CT, Neuroradiology brain, CNS
Authors:
S. A. Mohammad1, M. M. M. Ashour2, P. M. A. D. Mohamed Abouelhoda1, S. Salah1, R. N. M. Abdalla3, A. D. Metry1, R. A. M. A. Helal1; 1Cairo/EG, 2Cairo, New Cairo/EG, 3Cairo, ca/EG
DOI:
10.26044/ecr2019/C-2111
Background
The deep brain structures are complex.
It is important to understand the anatomy of the basal ganglia and to recognize diseases affecting these structures
MR Imaging Anatomy of the Basal Ganglia and Thalamus
The deep gray matter nuclei include the basal ganglia and thalamus [1,
2].
Basal ganglia
Basal ganglia contains three paired nuclei that together comprise the corpus striatum:
- caudate nucleus
- putamen
- globus pallidus (together with the putamen known as the lentiform nucleus)
Two additional nuclei are functionally connected to the basal ganglia:
- subthalamic nuclei
- substantia nigra
On axial brain images,
the lentiform nucleus and the head of the caudate nucleus can be visualized as paired symmetric structures located between the lateral ventricle and the insular cortex.
The caudate and putamen,
together form the striatum (figure 1). The globus pallidus is located medial to the putamen and lateral to the posterior limb of the internal capsule.
At MR imaging,
the caudate nucleus and putamen are isointense relative to the cortical gray matter with all pulse sequences and do not enhance after contrast material injection.
The globus pallidus demonstrates less signal intensity than the adjacent putamen on T2-weighted MR imaging due to iron deposition and is relatively T1-hyperintense due to myelination (figure 1).
Thalamus
The pair of thalami forms the borders of the third ventricle,
located posterior to the interventricular foramen of Monro and medial to the posterior limb of the internal capsule.
The thalamus is T2-isointense to gray matter (figure 1).