Articles

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669 results found
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Abducens nerve

The abducens nerve is the sixth cranial nerve (CN VI). It is a motor nerve responsible for abduction of the eye (TA: nervus abducens or nervus cranialis VI). It courses from the abducens nucleus, located in the dorsal pons, up to the cavernous sinus, via a long cisternal segment that is prone to...
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Superior medullary velum

The superior (or anterior) medullary velum is a thin layer of tissue that is suspended between the superior cerebellar peduncles forming the roof of the fourth ventricle along with the inferior medullary velum. It is enclosed by pia mater dorsally and ependyma ventrally. The lingula of the vermi...
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Caudate nucleus

Caudate nuclei are paired nuclei which along with the globus pallidus and putamen are referred to as the corpus striatum, and collectively make up the basal ganglia. The caudate nuclei have both motor and behavioral functions, in particular maintaining body and limb posture, as well as controlli...
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Velum interpositum

The velum interpositum is a small membrane containing a potential space just above and anterior to the pineal gland which can become enlarged to form a cavum veli interpositi.  Gross anatomy The velum interpositum is formed by an invagination of pia mater forming a triangular membrane the apex...
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Choroidal fissure

The choroidal fissure, or choroid fissure, is a cleft of the medial surface of the cerebral hemisphere running immediately above the hippocampus and extends around the thalamus to the interventricular foramen of Monroe. It forms the medial wall of the lateral ventricle and attachment site for th...
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Anterior corticospinal tract

The anterior corticospinal tract is formed at the level of the of the medullary pyramids, where the majority (90%) of descending corticospinal tract fibers decussate to form the lateral corticospinal tract. The remaining non-decussating fibers (10%) form the much smaller anterior corticospinal t...
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Rathke pouch

Rathke pouch, also known as hypophyseal diverticulum, is an ectodermal outpouching of stomodeum (primitive oral cavity lined by ectoderm) which forms at approximately 3-4 weeks gestation and goes on to form the adenohypophysis of the pituitary gland. Gross anatomy The anterior wall of the pouc...
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Pituitary gland

The pituitary gland (a.k.a. hypophysis cerebri), together with its connections to the hypothalamus, acts as the main endocrine interface between the central nervous system and the rest of the body.  Gross anatomy The pituitary gland sits atop the base of the skull in a concavity within the sph...
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Corticospinal tract

The corticospinal tract (also known as the pyramidal tract) is a descending white matter tract primarily concerned with motor function that extends caudally from the motor cortex to synapse with motor neurons of the spinal cord in the anterior horns.  Gross anatomy Central connections Cortico...
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Internal capsule

The internal capsule (TA: capsula interna) is a deep subcortical structure that contains a concentration of afferent and efferent white matter projection fibers. Anatomically, this is an important area because of the high concentration of both motor and sensory projection fibers 1,2. Afferent fi...
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Fornix (brain)

The fornix (plural: fornices) is the main efferent system of the hippocampus and an important part of the limbic system. It is one of the commissural fibers connecting the cerebral hemispheres. Gross anatomy Roughly C-shaped, the fornix extends from the hippocampus to the mammillary bodies of ...
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Spinal nucleus of the trigeminal nerve

The spinal nucleus of the trigeminal nerve is one of three major nuclei that make up the trigeminal sensory nerve nuclear complex along with the main sensory nucleus and the mesencephalic nucleus 1,2. Gross anatomy The spinal nucleus of the trigeminal nerve is a paired structure and is an infe...
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Arterial vasocorona

The arterial vasocorona is part of the spinal cord blood supply and is formed by pial anastomoses between the anterior and posterior spinal arteries on the surface of the spinal cord. It encircles the cord and supplies the peripheral lateral aspect of the spinal cord.  Engorgement of arterial v...
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Empty sella

An empty sella, also known as an empty pituitary fossa, refers to the appearance of the sella turcica when the pituitary gland appears shrunken or invisible and CSF fills the space instead. It is commonly an incidental finding of no clinical significance, but there exists a well-established asso...
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Posterior cerebral artery

The posterior cerebral arteries are the terminal branches of the basilar artery and supply the occipital lobes and posteromedial temporal lobes. Summary origin: terminal branches of the basilar artery course: from basilar towards occiput main branches posterior communicating artery (not rea...
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Habenula

The habenula is located anterolateraly to the pineal gland, posteromedial to the thalamus and is part of the epithalamus. It measures 5 to 9 mm in size 1,3. The habenula has traditionally been divided into lateral (limbic) and medial (motor) parts, although the lateral part can be further divide...
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Olfactory nerve

The olfactory nerve is the first (CN I) cranial nerve (TA: nervus olfactorius or nervus cranialis I) and is responsible for conveying the sense of smell from the nasal cavity to the brain. Strictly speaking, the term olfactory 'nerve' refers only to the short first order neurons (olfactory filam...
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Calcarine fissure

The calcarine fissure, or calcarine sulcus, is located on the medial surface of the occipital lobe and divides the primary visual cortex (a.k.a. calcarine cortex) into two halves. The fissure is variable in course but is generally oriented horizontally, anteriorly joining the parieto-occipital...
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Corpus callosum

The corpus callosum (plural: corpora callosa) is the largest of the commissural fibers, linking the cerebral cortex of the left and right cerebral hemispheres. It is the largest white matter tract in the brain. Summary located inferior to the cerebral cortices, and superior to the thalamus co...
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Asymmetry of the lateral ventricles

The lateral ventricles occasionally show small side to side differences in size on CT or MRI of the brain. This asymmetry of the lateral ventricles (ALV) is an anatomic variant in most cases. Epidemiology The prevalence of asymmetry in lateral ventricle size in those without evidence of underl...

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