The anatomy of the brain’s lobes with MRI

Clinical History

The study of the brain' s lobes anatomy with the magnetic resonance imaging

Imaging Findings

The telencephalon has the form of an ovoid with the posterior region more developed respect to others parts and occupies the mostly of the skull cavity. The telencephalon is separated from the internal surface of the skull bone by the meninges. His dorsal surface is convex instead the ventral surface is linear; it’s divided in two hemispheres by the deep inter-hemispheric scissure where a meningeal edge penetrates in, the big falx cerebri. Caudally the telencephalon is separated from the medulla oblongata by the transversal fissure, and from the cerebellum by the tentorial meninges.Every hemisphere has three faces: the lateral face that is in rapport with the internal surface of the skull bone; the medial face that is in rapport with the correspondent opposite site; and the inferior surface that is in rapport with the orbital arch, the sphenoid big wing, sphenoid sella, temporal pyramid and the occipital bone. Several sulcus divide the cerebral matter in six lobes: the frontal, the parietal, the occipital, the temporal, the insula, and the limbic lobe. The sulcus are: the central sulcus, (of Rolando), the lateral sulcus (of Sylvius), the parietoccipital sulcus, the calcarine sulcus, and the limbic sulcus (cingulate sulcus).The central sulcus, on the lateral surface of the hemisphere, divides the frontal lobe from the parietal lobe.This sulcus presents three convolutions called knees; the inferior and the superior are convex forward, instead the middle is convex posterior.(1, 3)

Discussion

The Rolando’s sulcus doesn’t arrive at the lateral sulcus and divides two convolution, the prerolandic and postrolandic convolution. The lateral sulcus divides the frontal lobe (to whom belongs the frontal pole) form the temporal lobe that with this anterior part, the temporal pole, sits in the middle cranial fossa. The lateral sulcus begins on the inferior surface of the hemisphere then goes on the lateral face and bifurcates in two branches, the posterior and the anterior. The posterior branch has a posterior direction, and the anterior ramification bifurcates like a “Y” with an horizontal ramus and a vertical ramus which delimit a part of the frontal convolution, the promontory. The parietoccipital sulcus origins behind the corpus callosum splenio where inflows with the calcarine sulcus and keeps the name of internal perpendicular sulcus arriving at the superior edge of the hemisphere. With the name of external perpendicular sulcus, the parietoccipital sulcus divides the parietal lobe from the occipital lobe on the lateral face of the hemisphere. The calcarine sulcus is situated on the posterior region of the hemisphere medial face, goes from the parietoccipital sulcus to the occipital lobe and in this lobe divides the cuneo region (superiorly) from the lingual lobe (inferiorly). The limbic sulcus has a superior convexity and a sagittal direction following the structure of the corpus callosum. It divides the limbic lobe from the others lobes. The limbic sulcus origins on the hemisphere medial face under the corpus callosum rostro and goes posterior under the corpus callosum splenio. The frontal lobe has an anterior area composed by the lateral, medial and inferior faces of every hemisphere. The mostly anterior part is represent by the frontal pole. The frontal lobe presents on the hemisphere lateral surface, some convolutions: the inferior, the medial, the superior, and the pre-central convolution. The parietal lobe has on the lateral face the post-central sulcus, and the intra-parietal sulcus that form three convolutions: the post-central, the parietal superior and the parietal inferior convolution. The temporal lobe presents the middle and the inferior convolution. The occipital lobe is like a pyramid with posterior apex and an anterior base and presents the occipital pole. The insula lobe is located internal to the lateral sulcus, has the form of a triangle with the base on top and is separated from others lobes by the circular sulcus. The limbic lobe is created by the limbic convolution that is like an incomplete ring, it surrounds the medial surface of the corpus callosum and is separated from the frontal and the parietal lobes by the cingulate sulcus. It’s divided in the callosum convolution upper the corpus callosum middle portion and in the hippocampus convolution under the splenio (1, 3). We can see many of the structures described with the magnetic resonance imaging in several projections without contrast agents and with many type of sequences (2).

Differential Diagnosis List

Final Diagnosis

The anatomy of the brain' s lobes

URL:	https://www.eurorad.org/case/3541
DOI:	10.1594/EURORAD/CASE.3541
ISSN:	1563-4086