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.

156 results found
Article

Basal ganglia and thalamus signal abnormalities

Basal ganglia and thalamus signal abnormalities occur in a wide variety of conditions. Ischaemia/hypoxia, metabolic disorders and toxins, particularly those that affect the respiratory chain, have a predilection for affecting the basal ganglia as they are highly metabolically active.  They can ...
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Basal ganglia calcification

Basal ganglia calcification is common and is seen in approximately 1% of all CT scans of the brain, depending on the demographics of the scanned population. It is seen more frequently in older patients and is considered a normal incidental and idiopathic finding in an elderly patient but should ...
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Basal ganglia T1 hyperintensity

There are many causes of basal ganglia T1 hyperintensity, but the majority relate to deposition of T1-intense elements within the basal ganglia such as: calcium idiopathic calcification calcium and phosphate abnormalities hepatic failure acquired non-wilsonian hepatocerebral degeneration W...
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Basal ganglia T2 hyperintensity

The causes of basal ganglia T2 hyperintensity can be remembered using the mnemonic LINT: lymphoma ischaemia hypoxia venous infarction (internal cerebral vein thrombosis) neurodegenerative / metabolic autoimmune encephalitis (e.g. anti-D2 dopamine antibody encephalitis) Creutzfeldt-Jakob d...
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Basal ganglia T2 hypointensity

Basal ganglia T2 hypointensities can be caused by any of the following and is commonly remembered using the mnemonic ChOMP. childhood hypoxia old age multiple sclerosis Parkinson disease: more in globus pallidus Parkinson-plus syndrome: more in putamen deoxyhaemoglobin of haemorrhage haem...
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Basilar invagination

Basilar invagination, also called basilar impression, is a congenital or acquired craniocervical junction abnormality where the tip of the odontoid process projects above the foramen magnum.  Terminology The terms basilar invagination and basilar impression are often used interchangeably becau...
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Bilateral middle cerebellar peduncle lesions

Involvement of both middle cerebellar peduncles is uncommon, but has a relatively long list of differential diagnoses, including 1: neurodegenerative diseases multiple systemic atrophy (MSA) olivopontocerebellar atrophy Shy-Drager syndrome spinocerebellar atrophy metabolic diseases  adre...
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Calcification of the globe (differential)

Calcification of the globe has many causes, varying from the benign to malignant. When calcification is seen of the posterior half of the globe, it could relate to any of the layers (scleral, choroidal or retinal), as it is not possible to separate them out on CT. Retinal drusen: 1% population...
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Calvarial thickening

Calvarial thickening can occur from a number of causes. These include: idiopathic chronic ventricular shunting 1 antiepileptics phenytoin 3 osteopetrosis 2 fibrous dysplasia acromegaly anaemias (largely associated with massive haematopoiesis) Paget disease hyperparathyroidism certain ...
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Carotid artery stenosis

Carotid artery stenosis also known as extracranial carotid artery stenosis, is usually caused by an atherosclerotic process and is one of the major causes of stroke and transient ischaemic attack (TIA) 1.  This article refers to stenosis involving carotid bulb and the proximal segment of intern...
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Cavernous sinus mass

A cavernous sinus mass has a wide differential including:  meningioma orbital apical inflammation with cavernous sinus involvement (Tolosa-Hunt syndrome) infection  schwannoma  any of the cranial nerves traversing the cavernous sinus: III, IV, V (V1 and V2) and VI trigeminal schwannoma is ...
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Cerebellopontine angle mass

Cerebellopontine angle (CPA) masses are relatively common. Although a diverse range of pathologies may be seen in this region, the most common by far is a vestibular schwannoma. Pathology Cerebellopontine angle masses can be divided into four groups, based on imaging characteristics:  enhanci...
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Cerebral atrophy

Cerebral atrophy is the morphological presentation of brain parenchymal volume loss that is frequently seen on cross sectional imaging. Rather than being a primary diagnosis, it is the common endpoint for range disease processes that affect the central nervous system. Though often no identifiabl...
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Cerebral herniation

Cerebral herniation, also referred to as acquired intracranial herniation, refers to shift of cerebral tissue from its normal location, into an adjacent space as a result of mass effect. It is a life-threatening condition that requires prompt diagnosis.  Pathology There are a number of differe...
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Cerebral ring enhancing lesions

The differential for peripheral or ring enhancing cerebral lesions includes: cerebral abscess tuberculoma neurocysticercosis metastasis glioblastoma subacute infarct/haemorrhage/contusion demyelination (incomplete ring) tumefactive demyelinating lesion (incomplete ring) radiation necros...
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Cerebral vascular malformations

Vascular malformations of the central nervous system can be divided, as they can elsewhere, into high and low flow malformations. High flow arteriovenous malformation (AVM) cerebral AVM (pial/parenchymal AVM) cerebral proliferative angiopathy dural arteriovenous fistula (DAVF) pial arteri...
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Cervical spine injury

Cervical spine injuries can involve the cervical vertebral column, intervertebral discs and cervical spine ligaments, and/or cervical spinal cord. The cervical spine accounts for ~50% of all spinal injuries.  Epidemiology 5-10% of patients with blunt trauma have a cervical spine injury 1.  Pa...
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Chorioretinitis

Chorioretinitis refers to inflammation of the retina and choroid. As a delayed sequelae, it is one of the causes of calcification of the globe. It is often considered a form of posterior uveitis. Pathology Aetiology various congenital infections such as  2,3 rubella: ocular rubella cytomega...
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Chronic encephalitides

There are several viral and prion infections which can result in a chronic encephalitis with slow progression into brain atrophy. These have a very poor prognosis with no effective treatment. Some of these include: progressive multifocal leukoencephalitis subacute sclerosing panencephalitis ...
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Clival masses

The differential of a mass involving or arising from the clivus is a relatively narrow one and can be divided into whether the lesion arises from the skull base itself, the intracranial compartment above or the base of skull below. When evaluating the clivus it is important to compare the marro...
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Colpocephaly

Colpocephaly is a descriptive term for a disproportionate prominence of the occipital horns of the lateral ventricles. It can result from a wide range of congenital insults. Clinical presentation Patients may present with motor abnormalities, cognitive deficit, visual abnormalities, and seizur...
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Communicating hydrocephalus

Communicating hydrocephalus is a type of hydrocephalus where CSF is able to leave the ventricular system.  Terminology Communicating hydrocephalus is commonly used as the opposite of obstructive hydrocephalus which leads to much unnecessary confusion, as most causes of communicating hydrocepha...
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Complications of cranial radiotherapy

Complications of cranial radiation therapy are fairly common, particularly in long-term survivors, and especially in paediatric patients. Cranial radiotherapy is used for a variety of brain tumours, either in isolation or in combination with concurrent chemotherapy. Complications from irradiati...
Article

Congenital calvarial defects

Congenital calvarial defects are a group of disorders characterised by congenital calvarial bone defects that vary in severity. Radiographic features CT with 3D shaded surface reformats is the best imaging tool as it demonstrates calvarial defects and bone margins: parietal foramina parietal...
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Congenital syndromes associated with enlarged ventricles

Congenital ventriculomegaly can have a large number of syndromic associations. Common acrocephalosyndactylies Apert syndrome Pfeiffer syndrome acrocephalopolysyndactylies Crouzon syndrome  achondroplasia fetal alcohol syndrome lissencephaly osteopetrosis Sotos syndrome  X-linked hyd...
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Convexal subarachnoid haemorrhage

Convexal subarachnoid haemorrhages (cSAH) are non-traumatic intracranial haemorrhages that occur within the surface sulci of the brain (cf. basal cisternal distribution of aneurysmal SAH). Pathology There are various causes of convexal subarachnoid haemorrhage, some of which include: dural ve...
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Coup-contrecoup injury (brain)

A coup-contrecoup injury is a term applied to head injuries and most often cerebral contusions and traumatic subarachnoid haemorrhage. It refers to the common pattern of injury whereby damage is located both at the site of impact (often less marked) and on the opposite side of the head to the po...
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Cystic spinal cord lesions

A cystic spinal lesion can result from a number of disease entities. They include: Primary Chiari malformations Dandy walker malformation diastematomyelia spinal dysraphism certain skeletal dysplasias 2 achondroplasia tricho-rhino-phalangeal syndrome type I Acquired due to a tumour as...
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Cytotoxic lesions of the corpus callosum (CLOCCs)

Cytotoxic lesions of the corpus callosum (CLOCCs) represent a collection of disparate conditions that can cause signal change in the corpus callosum, usually involving the splenium.  Terminology The term cytotoxic lesions of the corpus callosum (CLOCCs) has been proposed recently 12 as a more ...
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Demyelinating disorders

Demyelinating disorders are a subgroup of white matter disorders characterised by the destruction or damage of normally myelinated structures. These disorders may be inflammatory, infective, ischaemic or toxic in origin and include 1-7: autoimmune demyelination multiple sclerosis (MS) Marburg...
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Differential diagnoses for temporal lobe tumours

Most tumours of the CNS can potentially occur in the temporal lobe, but entities with a predilection for being diagnosed in this location include: pleomorphic xanthoastrocytoma (PXA) ganglioglioma pilocytic astrocytoma dysembryoplastic neuroepithelial tumour (DNET) multinodular and vacuolat...
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Diffuse cerebellar atrophy

Diffuse atrophy of the cerebellum refers to a progressive and irreversible reduction in cerebellar volume. It is a relatively common finding and found in a wide variety of clinical scenarios.  Terminology Diffuse cerebellar atrophy can be difficult to distinguish from global cerebellar hypopla...
Article

Dural arteriovenous shunts

Dural arteriovenous shunts (DAVS) are rare congenital arteriovenous malformations (CAVMs). On the basis of clinical and anatomical features DAVS have three different types: dural sinus malformations (DSMs) infantile or juvenile DAVS (IDAVS) adult DAVS (ADAVS)
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Dural ectasia

Dural ectasia refers to ballooning or widening of the dural sac which can result in posterior vertebral scalloping and is associated with herniation of nerve root sleeves. Clinical presentation Patients with dural ectasia may present with low back pain or radicular pain in the buttocks or legs...
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Dural enhancement

Pachymeningeal enhancement, also known as dura-arachnoid enhancement 4, refers to a dural and outer layer of arachnoid pattern of enhancement seen following contrast administration and may occur in the conditions listed below: infection intracranial tumour metastases intracranial hypotension...
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Dural masses

Dural masses can be the result of a number of different tumours and conditions, although meningiomas are by far the most common. The differential of a dural mass includes: meningioma haemangiopericytoma primary dural lymphoma Rosai-Dorfman disease solitary fibrous tumour of the dura primar...
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Ectopia lentis

Ectopia lentis refers to subluxation or dislocation of the lens of the eye secondary to dysfunction or disruption of zonular fibres.  Pathology Aetiology trauma systemic and syndromic disorders Marfan syndrome typically upwards and out most common spontaneous cause 2 homocystinuria -  ty...
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Elevated prolactin (differential)

Elevated prolactin can be due to a number of causes, including elevated production/secretion as well as reduced inhibition.  Prolactin is controlled by numerous homeostatic mechanisms, with tonic secretion of prolactin inhibitory hormone (dopamine) by the hypothalamus having a dominant effect 1...
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Empyema

Empyemas are purulent inflammatory collections within a body cavity. Contrast this with abscesses, which arise within parenchymal tissue, rather than occupying a pre-existing anatomical space. Terminology Colloquially, the standalone term empyema is used to refer to thoracic empyemas but there...
Article

Encephalitis due to herpesvirus family

Although sporadic viral encephalitis is most commonly due to herpes simplex virus 1 (HSV-1) the extended herpesvirus family consists of many other viruses many of which can also infect the central nervous system. Encephalitis due to herpesvirus family include 1:   herpes simplex virus 1 (HSV-1)...
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Enlarged posterior fossa 'CSF' space

An enlarged posterior fossa 'CSF' space posterior to the cerebellum has a number of differentials that include: mega cisterna magna epidermoid cyst arachnoid cyst Careful attention to the cerebellum needs to paid as also to be considered are: cerebellar atrophy Dandy-Walker malformations ...
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Enlarged sella turcica (differential)

Enlargement of sella turcica can be seen in situations including the following: empty sella syndrome slight globular enlargement of the sella with no erosion, destruction or posterior displacement of dorsum sellae intracranial hypertension enlargement with erosion of anterior cortex of dorsu...
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Epilepsy

Epilepsy is a common neurological disorder that has a varied presentation and requires two or more unprovoked seizures at least 24 hours apart for diagnosis. MRI is the modality of choice for epilepsy, most often investigating for an underlying cause, especially in adults.  Epidemiology Epilep...
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Epiphora

Epiphora (plural: epiphoras) represents excessive tearing of the eye and is a common clinical presentation to ophthalmological practice. It is most frequently due to an obstruction of the nasolacrimal drainage apparatus. Less commonly, overproduction of tears may be responsible.  Epidemiology ...
Article

Extra-axial

Extra-axial is a descriptive term to denote lesions that are external to the brain parenchyma, in contrast to intra-axial which describes lesions within the brain substance.  Radiographic features Often it is trivially easy to distinguish an intra-axial from an extra-axial mass. In many cases,...
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Extra-axial masses (differential)

Extra-axial masses of the intracranial compartment have a wide range of differentials, ranging from benign developmental cysts to malignant tumours.  Differential diagnosis neoplasms chordoma choroid plexus papilloma/carcinoma cranial nerve schwannoma meninges meningioma solitary fibrous...
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Extraconal orbital lesions

Extraconal orbital lesions include lesions which arise from structures within the extraconal orbital space and those extending from adjacent structures into the orbits. Differential diagnosis Intraorbital lesions dermoid cyst: most common lesion in paediatrics  lacrimial gland lesions dacry...
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Extraneural spread of intracranial neoplasm

Extraneural spread of primary intracranial neoplasm is distinctly uncommon, occurring far less frequently than CSF spread.  The most frequent neoplasms to do so, in decreasing order of frequency, are: glioblastoma (GBM) meningioma medulloblastoma
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Facial palsy

Facial palsy refers to the neurological syndrome of facial paralysis. It can result from a broad range of physiological insults to the facial nerve or its central nervous system origins. The most common causes of this is Bell palsy.  Terminology While facial palsy refers to the clinical presen...
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Fetal brain tumours

Fetal brain tumours are uncommon and tends to have very different pathological spectrum than that observed in adults; in order of decreasing frequency: fetal intracranial teratoma: most common tumour by far astrocytoma/glioblastoma: next most common craniopharyngioma: papillary type primitiv...
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Fetal intracranial calcification

Fetal intracranial calcification refers to intracranial calcification detected in utero. This can arise from a number of pathologies which include: in utero infections fetal toxoplasmosis infection: calcification tends to be randomly distributed fetal cytomegalovirus infection1: calcificatio...
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Fetal intracranial cystic lesions

Fetal intracranial cystic lesions can arise from a number of pathologies, including: Non-tumourous fetal arachnoid cyst  fetal choroid plexus cyst fetal connatal cyst fetal porencephalic cyst fetal interhemispheric cyst fetal subependymal cyst dorsal cyst of holoprosencephaly Blake pouc...
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Fetal intracranial haemorrhage

Fetal intracranial haemorrhage may occur either within the cerebral ventricles, subdural space or infratentorial fossa. Pathology Haemorrhages can occur in a number of situations: mechanical trauma, e.g. maternal abdominal blunt or birth trauma severe fetal hypoxia background fetal thromboc...
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Fetal ventriculomegaly (differential)

Fetal ventriculomegaly (ventricle width >10 mm) is an important finding in itself and it is also associated with other central nervous system abnormalities. For more information, see the main article fetal ventriculomegaly. Differential diagnosis Fetal ventriculomegaly can be thought of in ter...
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Focal calvarial thinning

Focal calvarial thinning can result from a number of causes. They include: bilateral thinning of the parietal bones (normal variant) most common arachnoid cyst mega cisterna magna peripherally located tumours (e.g. oligodendroglioma) See also calvarial thinning calvarial thickening
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Gyral enhancement

Gyral enhancement, also known as gyriform, cortical, or grey matter enhancement, is a pattern of contrast enhancement in the superficial brain parenchyma that conforms to the serpentine morphology of the cerebral gyri. It should be distinguished from leptomeningeal enhancement, which is also ser...
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Haemorrhagic intracranial metastases

Haemorrhagic intracranial metastases are considered to represent between 3-14% of all cerebral metastases (cf. 1-3% of gliomas are haemorrhagic). These classically originate from: melanoma renal cell carcinoma choriocarcinoma thyroid carcinoma: papillary carcinoma of the thyroid has the hig...
Article

Hiccups

Hiccups (or hiccoughs), medical term singultus (rarely used), are an unpleasant phenomenon, experienced by everyone on occasion, and usually self-limiting. However the much rarer intractable chronic form can be extremely debilitating. Epidemiology Hiccups are a symptom that has probably been e...
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HIV/AIDS (CNS manifestations)

The CNS manifestations of HIV/AIDS (neuroAIDS) occur secondary to a wide range of neurodegenerative, infectious, inflammatory, or neoplastic processes.  Epidemiology Since the introduction of highly active antiretroviral therapy (HAART) in 1996, there has been a shift in the epidemiology of CN...
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Holocord presentation

Holocord presentation refers to a process which involves the spinal cord, from cervicomedullary junction to the tip of the conus. It does not relate to a specific condition nor does it distinguish between involvement by cystic expansion or solid tumour, or by a combination of both. It merely den...
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Hydrocephalus versus atrophy

Distinguishing primary hydrocephalus from atrophy resulting in compensatory enlargement of the CSF spaces as the cause of ventriculomegaly can be, at times, challenging in image interpretation. Radiographic features Features that favour hydrocephalus include: dilatation of the temporal horns ...
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Hyperattenuating cerebral metastases

Hyperattenuating cerebral metastases on CT can be due to haemorrhage, calcium, or highly cellular tumours. Differential diagnosis There is overlap between the entities, with some cerebral metastases appearing in more than one list 1-6:  haemorrhagic cerebral metastases (mnemonic) malignant m...
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Hypomyelinating disorders

Hypomyelinating disorders are a heterogeneous subset of white matter disorders characterised by abnormally low amounts of myelination. In distinction to other myelin disorders, hypomyelination is a permanent deficiency in myelin deposition rather than myelin destruction (i.e. demyelination) or ...
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Hypothalamic lesions

Hypothalamic lesions are numerous representing some entities that are unique to the hypothalamus, as well as many lesions that can be seen elsewhere within the brain. Additionally, due to its proximity to the optic chiasm, third ventricle and pituitary region, many lesions of these locations can...
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Intracranial arterial beading

Intracranial arterial beading represents alternating areas of constriction in the intracranial arteries that gives the appearance of beads strung together. Differential diagnosis The various conditions where this may be seen are: cerebral vasculitis radiation therapy cerebral vasospasm post...
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Intracranial cystic lesions in the perinatal period

Intracranial cystic lesions in the perinatal period can carry a relatively wide differential which includes: Supratentorial cystic lesions cysts arachnoid cyst choroid plexus cyst connatal cyst holoprosencephaly multicystic encephalomalacia periventricular leukomalacia porencephalic cys...
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Intracranial lesions which show high signal on DWI

The following intracranial lesions may show high signal on diffusion-weighted imaging (DWI): lesions with intense high signal acute ischaemia meningiomas abscess empyema cytotoxic cerebral oedema chordoma intracranial epidermoid cyst CJD 6 lesions with variable or moderately high signa...
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Intracranial metastases

Intracranial metastases from non-CNS primary neoplasms are becoming more common due to significant advances in cancer treatment over the last few decades. Increasing numbers of patients live longer and present with metastasis in locations considered unusual previously: brain (parenchymal) metas...
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Intracranial tumours with calcification

A variety of intracranial tumours exhibit different forms of calcification. Some lesions commonly show calcification while in some tumours, calcification is seen only in few number of cases. In this article these tumours are classified on the basis of frequency of calcification. Commonly calcif...
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Intradural extramedullary spinal tumours

Intradural extramedullary neoplasms are located outside the spinal cord but within the dural sheath.  Epidemiology The majority (70-80%) of spinal canal tumours are intradural extramedullary 1. Clinical presentation Patients present with signs and symptoms of spinal cord or nerve root compre...
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Intralaminar dural haemorrhage

Intralaminar dural haematomas in the intracranial space, are exceedingly rare, and represent haemorrhage between the two layers of the dura mater. As a result, it has distinctive features allowing it to be distinguished from extradural haematomas but mimics subdural haematomas. They are equivale...
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Intraventricular metastases

Intraventricular metastases are a very rare finding. A few intracranial tumours and some extracranial tumours metastasise to the ventricles. The most common site of intraventricular metastasis is the trigone of the lateral ventricles due to high vascularity of the choroid plexuses. The next most...
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Intraventricular neoplasms and lesions

Intraventricular neoplasms are rare and arise from periventricular structures such as the walls of the ventricular system, the septum pellucidum and the choroid plexus. Many tumour types arise from, or can bulge into the ventricular system, although there are certain lesions that are relatively ...
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J-shaped sella

A J-shaped sella is a variant morphology of the sella turcica, whereby the tuberculum sellae is flattened, thus forming the straight edge of the "J". The dorsum sellae remains rounded and forms the loop of the "J". Differential diagnosis Differential diagnosis for a J-shaped sella includes 1,2...
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Lead poisoning

Lead poisoning or plumbism is a multisystem condition due to the way in which lead interferes with the function of virtually every organ system. Plumbism most severely manifests due to its devastating effects on the CNS, but it also has important deleterious consequences on the skeletal, renal, ...
Article

Leptomeningeal enhancement

Leptomeningeal enhancement refers to a diffuse or focal gyriform or serpentine enhancement that can be seen in the following conditions: Diffuse meningitis pyogenic meningitis viral meningitis tuberculous meningitis (can also be focal) CNS cryptococcal infection coccidioidal meningitis (c...
Article

Lesions of the corpus callosum (differential)

Lesions of the corpus callosum are uncommon and arise from multiple different aetiologies. The lesions can be classified according to underlying pathophysiology 4-6. Congenital agenesis of the corpus callosum enlarged perivascular spaces tubonodular pericallosal lipoma: associated with dysge...
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Longitudinally extensive spinal cord lesion

Longitudinally extensive spinal cord lesions (LESCL), also known as longitudinally extensive transverse myelitis (LETM), represent extensive involvement of the spinal cord, with abnormal T2 signal traversing at least three vertebral body segments in length. Differential diagnosis They are typi...
Article

Lytic skull lesion

Lytic skull lesions have a relatively wide differential that can be narrowed, by considering if there are more than one lesion and whether the mandible is involved. Pathology Causes lytic skeletal metastases multiple myeloma epidermoid - scalloped border with a sclerotic rim eosinophilic g...
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Macrophthalmia

The increased globe size or macrophthalmia may have many differentials: buphthalmos (congenital glaucoma) axial myopia macrophthalmus in neurofibromatosis type 1 (NF1) connective tissue disorders: Marfan syndrome, Ehlers-Danlos syndrome Focal enlargement: staphyloma coloboma See also mi...
Article

Masses arising from the foramen of Monro (differential)

The differential diagnosis of masses arising from the foramen of Monro can be approached depending on the age of the patient. Paediatric choroid plexus papilloma craniopharyngioma germinoma glioma Langerhans cell histiocytosis neurofibromatosis pilocytic astrocytoma subependymal giant c...
Article

Meckel cave lesions (differential)

Meckel cave lesions are numerous. The aim of this article is to list them in an easy way for revision and assessment of differential diagnosis.  Neoplastic Meckel cave tumours account for only 0.5% of all intracranial tumours. The most common histologies include: trigeminal schwannoma: most c...
Article

Medical devices in the abdomen and pelvis

Medical devices in the abdomen and pelvis are important to be recognised, just like medical devices of the chest. Often we ignore these devices, considering them to be incidental and non-pathological, however it is essential to be aware of potential complications. Gastrointestinal tubes stomac...
Article

Medical devices in the neck

Medical devices in the neck are regularly observed by radiologists on plain film and CT reporting. They include devices which pass through the neck into the chest and stomach or ascend to/into the head. Vascular access devices dialysis catheters peripherally inserted central catheters (PICC) ...
Article

Meningeal enhancement

Meningeal enhancement is a generic term related to the enhancement of the membranes that envelop the brain and spinal cord. Due the anatomical features, this enhancement can be divided in two subtypes: leptomeningeal enhancement (pial or pial-arachnoid enhancement) pachymeningeal enhancement (...
Article

Meningocele

Meningoceles are protrusions of the meninges through a defect or weak point in the skull or spine, usually involving the soft tissues beneath the surface of the skin. They are typically categorised into congenital, iatrogenic (e.g. following a craniotomy, sinus surgery, or as a laminectomy compl...
Article

Midline shift

One of the most important indicators of increased intracranial pressure due to mass effect is midline shift. Pathology Any intra-axial or extra-axial lesion (tumour, haemorrhage, abscess, etc) has the potential to exert mass effect on the brain parenchyma and cause lateral shift of the midline...
Article

Mitochondrial disorders

There are numerous mitochondrial disorders that affect the neurological and muscular systems in a variety of ways:  Kearns-Sayre syndrome Leigh syndrome mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) myoclonus epilepsy with ragged red fibres (MERRF) mitoc...
Article

Mixed cystic and solid pituitary region mass

A mixed cystic and solid pituitary region mass has a limited differential. Differential diagnosis craniopharyngioma both papillary (more solid) and adamantimonatous (more cystic) macroadenoma cystic change / necrosis / previous haemorrhage Most other solid and enhancing pituitary region ma...
Article

Mostly/purely cystic pituitary region masses

Mostly/purely cystic pituitary region masses have a small differential. Differential diagnosis Rathke's cleft cyst arachnoid cyst empty sella craniopharyngioma (adamantimonatous type): 90% have calcification  epidermoid cyst
Article

Moyamoya syndrome

Moyamoya syndrome, also termed the moyamoya pattern or phenomenon, is due to numerous conditions that can cause arterial occlusion of the circle of Willis, with resultant collaterals, and appearances reminiscent of moyamoya disease. These conditions include 1-4 : vessel wall abnormalities athe...
Article

Multiple cranial nerve thickening and enhancement

The most common causes of multiple cranial nerve thickening and enhancement include: metastasis (most common) neurofibromatosis type II lymphoma and leukaemia  multiple sclerosis chronic inflammatory demyelinating polyneuropathy Lyme disease  See also cranial nerve enhancement: for compl...
Article

Multiple intracranial calcifications

Intracranial calcifications are common in certain locations and often are of no clinical concern. The two most commonly encountered types of calcification include:  normal age-related intracranial calcifications intracranial arterial atherosclerosis Concerning calcifications are much less co...

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