Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

2,880 results found
Article

Cerebellar bottom-of-fissure dysplasia

Cerebellar bottom-of-fissure dysplasia is a rare grey matter dysplasia occurring in cerebellar hemispheres. Terminology Cerebellar bottom-of-fissure dysplasia is so named because it exclusively involves the cerebellar grey matter at the depths of the cerebellar fissures. Epidemiology To date...
Article

Dementia

Dementia, relabelled major neurocognitive disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), is a clinical syndrome defined by progressive decline in one or more cognitive domains relative to a person's premorbid functional level. To fulfill criteria for dementia, the...
Article

Pseudodementia

Pseudodementia describes the phenomenon whereby a psychiatric condition may mimic the clinical presentation of dementia, generating cognitive symptoms (e.g. poor memory) that resolve when the condition is treated 1,2. Terminology The term pseudodementia is commonly used to describe cognitive ...
Article

Causes of delirium (mnemonic)

Delirium may have numerous contributory factors in a given patient. Common, readily reversible causes of delirium can be remembered using the mnemonic 1: PINCH ME Mnemonic P: pain I: infection N: nutrition C: constipation H: hydration M: medications E: environment
Article

Investigating diplopia (summary)

This is a basic article for medical students and other non-radiologists Diplopia, also known as double vision, is a visual symptom of seeing two images of a single object. Reference article This is a summary article; there is not a more in-depth reference article currently. Summary epidemio...
Article

Funiculus (disambiguation)

The funiculus (plural: funiculi) is an anatomical term and means a cordlike structure. It may refer to: funiculus (medulla oblongata) funiculus (fourth ventricle) funiculus (male genitals) funiculus (spinal cord) funiculus (umbilicus) funiculus (wrist ligament) History and etymology The ...
Article

Neuronal nuclear antigen (NeuN)

Neuronal nuclear antigen (NeuN) is a protein expressed in mature (post-mitotic) neurons and is commonly used as an immunohistochemical target to identify neuronal differentiation (e.g. in ganglioglioma and gangliocytomas). It is primarily expressed in the nuclei of neurons with less pronounced...
Article

Kindling effect

The kindling effect is a neurological phenomenon encountered experimentally in animal models and is thought to play an important role in the development of epilepsy in humans 1,2. The repeated application of sub-threshold electrical or chemical stimulations to specific brain regions results in ...
Article

Orbital blastomycosis

Orbital blastomycosis, less commonly known as Gilchrist disease, is an orbital infection from the fungus Blastomyces dermatidis. Blastomycosis is typically acquired via inhalation of conidia (spores). Blastomycosis is a systemic pyogranulomatous infection. Epidemiology Even in endemic areas, b...
Article

HIV-associated CD8+ encephalitis

HIV-associated CD8+ encephalitis, or simply CD8+ encephalitis, is an inflammatory encephalopathy caused by perivascular and intraparenchymal CD8+ T cell infiltration, occurring in patients with human immunodeficiency virus (HIV) infection, despite often having adequate viral suppression. It is a...
Article

Bloomy rind sign (leptomeningeal metastases)

The bloomy rind sign is a radiological sign appreciated on MRI brain that is rarely but characteristically described in patients with leptomeningeal metastases (leptomeningeal carcinomatosis). The sign describes the appearance of a curvilinear T2/FLAIR hyperintensity on the brainstem surface, t...
Article

Botulism

Botulism is a neuroparalytic syndrome manifesting as diffuse generalized flaccid paralysis caused by exposure to botulinum neurotoxin. It can be potentially fatal. Botulinum toxin is the deadliest toxin due to high lethality and potency. The lethal dose (LD 50) is 1-3 ng of toxin per 1 kg of bo...
Article

Alice in Wonderland syndrome

Alice in Wonderland syndrome, also known as Todd syndrome, is a rare condition affecting the sensory inputs in the brain. Epidemiology Alice in Wonderland syndrome most common in children with over two-third of cases occurring in the pediatric demographic 1. Clinical presentation Alice in Wo...
Article

H sign (spinal cord)

The H sign is a radiological sign appreciated on MRI spine that is classically described in patients with myelin oligodendrocyte glycoprotein​ antibody-associated disease (MOGAD). The sign describes the involvement of spinal cord grey matter as seen on axial T2 sequences in patients with myelit...
Article

Trident sign (neurosarcoidosis)

The trident sign is a radiological (MRI) sign described in spinal cord neurosarcoidosis. The sign is formed by the axial appearance of a longitudinally extensive transverse myelitis due to spinal cord neurosarcoidosis, whereby on a T1 post-contrast (gadolinium) MRI sequence, there is central ca...
Article

Pancake sign

The pancake sign represents flat, tranverse gadolinium enhancement at the midpoint of a hyperintense, spindle-shaped T2 signal and is seen on sagittal and axial MR imaging 1. The axial corollary is formed by circumferential enhancement with sparing the spinal gray matter 2. Of note, the enhancem...
Article

Superior cerebellar cistern

The superior cerebellar cistern is a cerebrospinal fluid-filled subarachnoid cistern located at the level of the superior surface of the cerebellar vermis. Boundaries The boundaries of the superior cerebellar cistern are 1–3: ventral: communicates with the quadrigeminal cistern dorsal: commu...
Article

Posterior communicating artery hypoplasia

Posterior communicating artery hypoplasia refers to the absence of the posterior communicating artery, a blood vessel that connects the posterior cerebral artery with the internal carotid artery, thus acting as a connection between the anterior and posterior portions of the circle of willis. I...
Article

Long term epilepsy associated tumors

Long-term epilepsy-associated tumors (LEATs) is a pragmatic grouping of varied primary brain tumors that share a number of features including slow indolent growth rate, localization to the cortex and a predilection for the temporal lobe. These characteristics combine to make them a common cause...
Article

Isomorphic diffuse glioma

Isomorphic diffuse glioma is a recently identified indolent low-grade diffuse glioma, often considered one of the long-term epilepsy-associated tumors (LEATs), closely related to pediatric diffuse astrocytoma MYB or MYBL1 altered but demonstrating distinct DNA-methylation profile 1. It is critic...
Article

Lateral pontomedullary membranes

The lateral pontomedullary membranes are arachnoid membranes located anterolateral to the brainstem at the pontomedullary junction, separating the cerebellopontine cisterns superiorly from the cerebellomedullary cisterns inferiorly 1–3. Cadaveric studies indicate the lateral pontomedullary membr...
Article

Fasciola cinerea

The fasciola cinerea is located in the mesial temporal lobe 1,2. The fasciola cinerea is a posterior grey matter continuation of the margo denticularis and forms part of the hippocampal formation 3–5. The fasciolar cinerea demonstrates robust interconnection and receives input from the lateral ...
Article

Leber hereditary optic neuropathy

Leber hereditary optic neuropathy (LHON) is a mitochondrial genetic disorder characterized by bilateral, progressive, central vision loss secondary to loss of the retinal ganglionic cell layer 1,2. Epidemiology Leber hereditary optic neuropathy classically presents in young, Caucasian, adult m...
Article

Barkovich classification of agenesis of the corpus callosum with interhemispheric cyst

The Barkovich classification of agenesis of the corpus callosum with interhemispheric cyst divides interhemispheric cysts that are diagnosed in individuals with concurrent agenesis of the corpus callosum into two types based on the presence or absence of communication with the ventricular system...
Article

Hartnup disease

Hartnup disease is an autosomal recessive disorder caused by the defective transport of neutral amino acids (monoamino-monocarboxylic acids) in the small intestine and kidneys. Clinical presentation pellagra-like skin eruptions cerebellar ataxia signs of spastic paraplegia with peripheral ne...
Article

Sydenham chorea

Sydenham chorea, also referred to as Chorea minor or historically as St. Vitus dance is a manifestation of rheumatic fever. Clinical presentation hyperkinetic movement disorder neuropsychiatric manifestations with or without the presence of carditis or arthritis. cognitive and behavioral sym...
Article

Fabry disease (neurological manifestations)

Fabry disease, also known as Anderson-Fabry disease, is a multisystem X-linked lysosomal storage disorder, with frequent neurological manifestations. These are either due to direct involvement of the central nervous system, the peripheral nervous system and/or the autonomic nervous system. This ...
Article

Circle of Zinn

The circle of Zinn is an arterial anastomotic ring surrounding the optic nerve head in the sclera formed by branches of the short posterior ciliary arteries. Multiple small branches from the circle of Zinn supply the anterior pia of the optic nerve, the optic disc and contribute to the blood sup...
Article

Posterior ciliary arteries

The posterior ciliary arteries are usually paired branches arising from the ophthalmic artery, one medial and one lateral, each giving off a number of branches that supply the uvea 1. Close to the optic nerve, are the short posterior ciliary arteries, usually numbering 16-20; these supply the ...
Article

Short posterior ciliary arteries

The short posterior ciliary arteries are branches of the posterior ciliary arteries which are, in turn, branches of the ophthalmic artery. Each eye has multiple small short posterior ciliary arteries (16-20) which pierce the sclera adjacent to the optic nerve. Within the sclera, they anastomose...
Article

Long posterior ciliary arteries

The long posterior ciliary arteries are branches of the posterior ciliary arteries which are in turn branches of the ophthalmic artery. They supply the anterior part of the choroid of the ocular globe as well as the iris and ciliary muscle 1,2. Each eye has a number of long ciliary arteries. T...
Article

Glaucoma

Glaucoma is a group of slow progressive eye diseases that is defined as an optic neuropathy. Although there are up to eight types described, there are two main types: open-angle closed angle glaucoma (interchangeably referred to as angle-closure or narrow-angle) Epidemiology Glaucoma is one ...
Article

Green bell pepper sign

The green bell pepper sign refers to the appearance of a rosette-forming glioneuronal tumor on gadolinium-enhanced magnetic resonance imaging (MRI). Following administration of contrast, these tumors typically demonstrate central T1 low attenuation. Classically, there is a peripheral rim of in...
Article

Snowball sign (Susac syndrome)

The snowball sign refers to the appearance of the corpus callosum on FLAIR and T2 weighted sequences in patients with Susac syndrome. Within the substance of the body and splenium of the corpus callosum, best seen on sagittal images, are spherical well-demarcated high-signal regions 1,2. This ...
Article

Laminoplasty

Laminoplasty, also known as osteoplastic reconstruction of the lamina, is a surgical procedure that involves the replacement of the lamina of the vertebral body following a laminectomy procedure in an attempt to provide better post-operative stabilization. Indications spinal stenosis compress...
Article

Vigabatrin-associated toxicity

Vigabatrin-associated toxicity is a potential neurological complication in patients treated with vigabatrin, an antiepileptic drug whose mechanism of action includes GABA levels retention at the level of synapses in the brain. It is primarily used as a treatment of focal seizures and infantile s...
Article

Akeret staging of neuroepithelial tumors

The Akeret or anatomical staging of neuroepithelial tumors adheres loosely to the general scheme underlying AJCC TNM staging. Like other cancer staging systems it assists in estimating the individual prognosis, in tailoring patient-specific therapy and surveillance, and in improving the comparab...
Article

Ageusia

Ageusia refers to a complete loss of taste. In instances where it is partial it is then falls under the spectrum of the conditions such as hypogeusia (decreased sensitivity to all tastants) hyperguesia (enhanced gustatory sensitivity) dysgeusia (unpleasant perception of a tastant) an...
Article

Kang grading system of cervical canal stenosis

The Kang grading system of cervical canal stenosis is used to grade the severity of cervical canal stenosis as demonstrated on MRI. It is derived from the earlier Muhle staging system 1,2. It categorizes cervical stenosis into four grades from 0 to 3 according to the severity of spinal cord com...
Article

Anteroposterior diameter of the lateral ventricle index

The anteroposterior diameter of the lateral ventricle index (ALVI) is a quantitative metric to evaluate the size of the lateral ventricles, particularly in normal pressure hydrocephalus. Usage The anteroposterior diameter of the lateral ventricle index has only recently been described and is n...
Article

Dorsolateral fasciculus

The dorsolateral fasciculus (also known as Lissaeur's tract or the posterolateral tract) is a bundle of white matter fibers within the posterolateral spinal cord. Summary The dorsolateral fasciculus lies between the apex of the dorsal grey matter and the surface of the cord, surrounding the af...
Article

Locus coeruleus

The locus coeruleus is a paired pigmented brainstem nucleus and the brain's main noradrenergic nucleus. It is located in the posterior rostral pons near the lateral floor of the fourth ventricle and is the leading site of norepinephrine synthesis in the brain. Locus coeruleus neurons densely i...
Article

Artery of Davidoff and Schechter

The artery of Davidoff and Schechter is the only dural radicle of the posterior cerebral artery (PCA) and supplies parts of the falx cerebri and tentorium cerebelli 1. Summary origin: either the P1 or P2 segment of the PCA course: inferior to the superior cerebellar artery and superior to the...
Article

Essential tremor

Essential tremor describes a chronic, progressive, predominantly bilateral upper limb, action tremor syndrome, present without parkinsonism, dystonia and ataxia. Essential tremor associated with other 'soft' neurological signs is known as essential tremor plus. Epidemiology Essential tremor is...
Article

Overshunting-associated myelopathy

Overshunting-associated myelopathy, also known as Miyazaki syndrome, is a very rare form of compressive myelopathy that is a complication of intracranial hypotension due to excessive cerebrospinal fluid (CSF) diversion. Clinical presentation Patients present with progressive cervical myelopath...
Article

Immune effector cell-associated neurotoxicity syndrome (ICANS)

Immune effector cell-associated neurotoxicity syndrome (ICANS), previously known as cytokine release encephalopathy syndrome (CRES) or chimeric antigen receptor (CAR) T-cell-related encephalopathy syndrome, is a neuropsychiatric syndrome that can occur days to weeks following the administration ...
Article

Soap bubble appearance (DNET)

The soap bubble appearance, also known as the bubbly appearance, has been described in dysembryoplastic neuroepithelial tumors (DNET). It describes a multi-loculated pseudocystic appearance of the DNET on T2 weighted images 1,2. These areas show partial suppression on FLAIR and are often associa...
Article

Murphey's teat

Murphey’s teat, also known as Murphey’s tit or Murphey’s excrescence, refers to the cerebral angiographic finding of a focal outpouching within an intracranial aneurysm that indicates the likely site of rupture in a patient with subarachnoid hemorrhage 1,2. This sign, when present, is particular...
Article

Numb chin syndrome

Numb chin syndrome describes a sensory neuropathy occurring in the distribution of either the mental nerve or inferior alveolar nerve. While numb chin syndrome has a multitude of causes, it is considered an ominous entity due to its strong association with heralding advanced malignancy 1. Clini...
Article

CNS tumor with BCOR internal tandem duplication

CNS tumor with BCOR internal tandem duplication (BCOR-ITD) is a rare and relatively new brain tumor type that has been added to the WHO classification of CNS tumors 5th edition as part of the embryonal family of tumors. Originally identified through molecular analysis of tumors classified as pri...
Article

Microcephaly with a simplified gyral pattern

Microcephaly with a simplified gyral pattern (MSG) is a congenital malformation characterized by microcephaly accompanied by a simplified gyral pattern. The term “simplified gyral pattern” often describes a reduced number of gyri and shallow sulci with a normal cortical thickness and architectur...
Article

Garcin syndrome

Garcin syndrome, also known as hemibasal syndrome or Guillain-Alajouanine-Garcin syndrome, is characterized by progressive ipsilateral cranial neuropathies of at least seven cranial nerves, with no evidence of raised intracranial pressure, long-tract signs, or cerebellar signs, classically attri...
Article

iNPH Radscale

The iNPH Radscale is a reproducible semiquantified grading scale for the imaging findings of normal pressure hydrocephalus (NPH). Scale The iNPH Radscale uses the following imaging findings on both CT and MRI 1,4: Evans index ≤0.25: 0 points 0.26-0.3: 1 point >0.3: 2 points narrow parieta...
Article

Ganglion

A ganglion (plural: ganglia) is a group of neuronal cell bodies and processes located in the peripheral nervous system 1. Ganglia can be categorized into two groups - sensory ganglia and autonomic ganglia. Sensory ganglia primarily contain the cell bodies of neurons as well as their central an...
Article

Disseminated histoplasmosis

Disseminated histoplasmosis, also known as progressive disseminated histoplasmosis, is a severe form of histoplasmosis infection typically seen in immunosuppressed patients, especially in the setting of HIV infection. It results from hematogenous dissemination of the infection, involving multipl...
Article

Lumbar nerve root anomaly classification

There are a number of systems for lumbar nerve root anomaly classification with the Neidre and MacNab classification the most commonly cited; other systems include the Postacchini classification, and the Kadish and Simmons classification 2. Classification Neidre and MacNab classification modif...
Article

Cestan-Chenais syndrome

Cestan-Chenais syndrome is a rare brainstem stroke syndrome with features between that of the hemimedullary syndrome (Reinhold syndrome) and the lateral medullary syndrome (Wallenberg syndrome), but distinct to that of Babinski-Nageotte syndrome 1,2.  Clinical presentation Cestan-Chenais syndr...
Article

Cathepsin A-related arteriopathy with strokes and leukoencephalopathy (CARASAL)

Cathepsin A-related arteriopathy with strokes and leukoencephalopathy (CARASAL) is a very rare monogenic autosomal dominant cerebral small-vessel disease. Epidemiology CARASAL is considered extremely rare, with less than thirty cases reported in the literature 1-5. The condition tends to clini...
Article

Stasis filling

Stasis filling describes persistent visualization of intravenous contrast within the proximal cerebral arteries but not within the cortical branches or venous outflow in suspected brain death patients, mimicking true cerebral blood flow (CBF). Pathology Etiology During brain death, raised int...
Article

Subdural hematohygroma

Subdural hematohygromas are subdural hygromas into which bleeding has occurred. They are distinct from, and should not be confused with, acute on chronic subdural hematomas or with acute subdural hematomas with separation of blood into plasma and hematocrit. Radiographic features CT Subdural ...
Article

Pontine autosomal dominant microangiopathy with leukoencephalopathy (PADMAL)

Pontine autosomal dominant microangiopathy with leukoencephalopathy (PADMAL) is an autosomal dominant monogenic COL4A1-related disorder that primarily causes cerebral small vessel disease. It is a distinct entity to COL4A1 brain small-vessel disease, but very likely on the same spectrum of disea...
Article

Black toenail sign

The black toenail sign is a radiological sign described in mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) on MRI. The sign describes the subacute appearance of radiological correlates of stroke-like episodes, whereby there are small regions of deep cortica...
Article

Subarachnoid lymphatic-like membrane

The subarachnoid lymphatic-like membrane (SLYM) is a recently discovered fourth meningeal layer which compartmentalizes the subarachnoid space into two functional compartments. Gross anatomy The subarachnoid lymphatic-like membrane is only a few cells thin layer, which renders it invisible usi...
Article

Metastatic glioblastoma

Metastatic glioblastoma is a rare progression of glioblastoma, with an incidence of 0.4-0.5% of all glioblastoma cases. The locations can be extraneural, such as leptomeninges and dural venous sinuses, or both extraneural and extracranial, such as solid organs and lymph nodes. Epidemiology In ...
Article

Neurocysticercosis (mnemonic)

A mnemonic to remember the stages of neurocysticercosis is: Vegans Can't Get Neurocysticercosis Mnemonic V: vesicular C: colloidal vesicular G: granular nodular N: nodular calcified
Article

Trepanation

Trepanation or trephination, commonly known as burr holes, is the act of intentionally perforating the skull for the purpose of healing or diagnosis. Indications Emergency indications evacuation of extradural or subdural hematoma insertion of intracranial pressure monitor insertion of exter...
Article

Stern-Garcin variant of sporadic Creutzfeldt-Jakob disease

The Stern-Garcin variant of sporadic Creutzfeldt-Jakob disease (CJD) is a phenotypical variant characterized by prominent early extrapyramidal symptoms, such as parkinsonism 1. Radiographic features MRI MRI shows early involvement of the basal ganglia (striatum) and thalamus, in addition to o...
Article

Cerebral arteries

Cerebral arteries refers to the three paired main arteries that supply the brain. anterior cerebral arteries (ACAs) middle cerebral arteries (MCAs) posterior cerebral arteries (PCAs) The anterior and middle cerebral arteries arise as terminal branches of the internal carotid arteries. The p...
Article

Anterior circulation infarction

Anterior circulation infarction describes any infarct in an area of the brain that is within the vascular territory of the anterior circulation, which includes most of the supratentorial structures excluding the occipital lobes. These structures derive their arterial supply from the internal car...
Article

Subarachnoid hemorrhage grading systems

Subarachnoid hemorrhage grading systems are numerous, seeking to variably group patients presenting with subarachnoid hemorrhage in an attempt to categorize, quantify or prognosticate. Some are dedicated to subarachnoid hemorrhage (e.g. Hunt and Hess Scale), others are used in a broader clinical...
Article

Non-ischemic cerebral enhancing (NICE) lesions

Non-ischemic cerebral enhancing (NICE) lesions are an uncommon delayed complication of cerebrovascular procedures, including aneurysm coiling, thrombectomy and placement flow-diverting stent placement 1,2,4. Epidemiology As NICE lesions are seen following endovascular procedures most commonly ...
Article

Nasal dermoid cyst

Nasal dermoids (or nasal dermoid sinus cysts) are the most common congenital midline nasal lesion typically presenting in early childhood. Epidemiology Nasal dermoids are rare and account for only 4-12% of all dermoid cysts of the head and neck, far less common than angular dermoids 1,2. They ...
Article

Furstenberg sign

Furstenberg sign is a clinical feature of masses of the head that communicate with the intracranial compartment. Due to this connection, an increase in intracranial pressure will result in bulging or swelling of the mass. This can occur spontaneously during crying or can be elicited with a Valsa...
Article

Persistent limbic arch

A persistent limbic arch (or ring) is a cerebral vascular anatomical variant whereby a complete vascular ring encircles the limbic system and corpus callosum. In the embryo, this connection is between the anterior choroidal artery and the anterior cerebral artery (via pericallosal artery) 2. T...
Article

Pseudohypoxic brain swelling

Pseudohypoxic brain swelling, also known as postoperative intracranial hypotension-associated venous congestion, is a rare condition with restricted diffusion on MRI in the basal ganglia and thalami following surgery. This can mimic cerebral hypoxic changes in the absence of vascular pathology. ...
Article

Symmetrical cerebral restricted diffusion

Symmetrical cerebral restricted diffusion is seen in a broad range of pathologies. The differential depends on the location of the lesions. Symmetrical central tegmental tract lesions central tegmental tract T2 hyperintensity  symmetrical hyperintensities of the extrapyramidal tract conn...
Article

Thoracic splanchnic nerves

The thoracic splanchnic nerves are three paired autonomic nerves that provide sympathetic innervation of the abdominopelvic viscera and vessels. They contain efferent and afferent fibers. Gross anatomy Three pairs of thoracic splanchnic nerves arise from the T5 to T12 sympathetic ganglia. Gre...
Article

Somatic nervous system

The somatic nervous system (SNS) is a subdivision of the peripheral nervous system which provides innervation to the somatic structures of the body, that is the parts excluding the viscera, smooth muscle, and glands. The SNS is distributed throughout the body through somatosensory neurons withi...
Article

Phrenic plexus

The phrenic plexus (plural: plexuses) is an autonomic nerve plexus and ganglia in the upper abdomen. It is a lateral epiarterial extension of the celiac plexus. Summary location: the bilateral ganglia and plexuses lie along the inferior phrenic arteries origin: preganglionic sympathetic fiber...
Article

Renal plexus

The renal plexus (plural: plexuses) is an autonomic nerve plexus and ganglia located in the upper abdomen and is a lateral perivascular extension of the aorticorenal plexus. Summary location: bilateral plexuses and ganglia lie on the renal arteries lateral to the aorticorenal plexuses origin:...
Article

Aorticorenal plexus

The aorticorenal plexus (plural: plexuses) is an autonomic nerve plexus and ganglia located in the upper abdomen and is an inferior perivascular extension of the larger celiac plexus. Some descriptions separate the aortic and aorticorenal plexuses but they are considerably interconnected and con...
Article

Hepatic plexus

The hepatic plexus (plural: plexuses) is an autonomic nerve plexus and ganglia  located in the upper abdomen. Most descriptions are of a periarterial extension of the celiac plexus along the common hepatic artery and portal vein. Summary location: the plexus and ganglia extends to the right fr...
Article

Celiac plexus

The celiac plexus (plural: plexuses) is an autonomic nerve plexus and ganglia in the upper abdomen. It is the largest major autonomic plexus. Summary location: the ganglion and plexus lie close to the celiac trunk origin: preganglionic sympathetic fibers via the greater and les...
Article

Ganglion impar

The ganglion impar, also know as the ganglion of Walther, is the midline autonomic ganglion located in the lower pelvis. It is the most distal convergence of the pelvic sympathetic chain which is usually located anterior to the coccyx.  It can be found anywhere between the sacrococcygeal joint a...
Article

Pulmonary plexus

The pulmonary plexus is a network of autonomic nerves and ganglia situated at the pulmonary hila of each lung which regulates bronchial smooth muscle tone, submucosal glandular mucous secretion, vascular permeability and blood flow. It is derived from both the sympathetic and parasympathetic ner...
Article

Autonomic ganglia and plexuses

The autonomic ganglia and plexuses are a collection of ganglia where autonomic preganglionic neurons arising from the CNS synapse with postganglionic neurons outside the CNS, i.e. in the peripheral nervous system. Many of the ganglia contain nerves of the sympathetic and parasympathetic nervous ...
Article

Parasympathetic nervous system

The parasympathetic nervous system (PaNS/PNS), mediated by the head and neck ganglia and pelvic splanchnic nerves, is a major division of the autonomic nervous system. It is composed of general visceral afferent and efferent axons that allow for involuntary control of bodily functions via severa...
Article

Normal imaging examples

This article lists examples of normal imaging divided by body region and system. brain head and neck spine chest breast gastrointestinal genitourinary hepatobiliary upper limb lower limb pediatrics
Article

Duplication of the pituitary gland - plus syndrome

Duplication of the pituitary gland (DPG) is a rare developmental anomaly that may occur in an isolated fashion or in combination with other congenital craniofacial anomalies, hence, the term DPG-plus syndrome. Epidemiology Duplication of the pituitary gland is a very rare disease with a small ...
Article

Satellite sign

The satellite sign is a radiological sign seen on non-contrast CT of the brain in the setting of intracerebral hemorrhage, and refers to a small hemorrhage adjacent to, and separate from, the main hematoma. It is a predictor of hemorrhage expansion.  Epidemiology The satellite sign can be seen...
Article

Island sign

The island sign is a radiological sign seen on non-contrast CT of the brain. It is used as a marker to predict hematoma expansion and prognosis in patients with intracerebral hemorrhage 1. It is posited that the small islands of hematomas represent multiple sources of hemorrhage from injury to a...
Article

Cashew nut sign

The cashew nut sign is a radiological sign described in juxtacortical intracerebral hemorrhages due to cerebral venous thrombosis, typically on CT. The sign describes a small (<20 mm), concave-shaped intracerebral hemorrhage in the juxtacortical white matter, often near the bottom of a cortical...
Article

SPACE (MRI sequence)

The SPACE MRI sequence, is a spin echo type MRI sequence, which creates high spatial resolution three-dimensional datasets. SPACE is an abbreviation for Sampling Perfection with Application optimized Contrast using different flip angle Evolution. The sequence was developed by Siemens. The SPACE...

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.