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 continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
2,954 results found
Article
Axial plane for imaging of the brain
A consistent axial plane for imaging of the brain needs to be chosen to allow for reproducible image acquisition and comparison. Unlike the sagittal plane, which is intrinsically defined by our inherent left-right plane of symmetry, axial and coronal planes need to be agreed upon and over the ye...
Article
Frontotemporal brain sagging syndrome
Frontotemporal brain sagging syndrome (FBSS) is an uncommon presentation of spontaneous intracranial hypotension where the dominant clinical features are neuropsychiatric signs and symptoms that can be mistaken for frontotemporal lobar degeneration.
Clinical presentation
Patients with frontote...
Article
Variably protease-sensitive prionopathy
Variably protease-sensitive prionopathy (VPSPr) is a very rare type of sporadic human prion disease that was first described in 2008.
Epidemiology
Variably protease-sensitive prionopathy is very rare, with an annual incidence of 1-2 per million 5.
Clinical presentation
Clinical presentation ...
Article
Scalpel sign (spinal cord)
The scalpel sign is described in dorsal thoracic arachnoid web on sagittal MRI spine studies. It relates to focal distortion of the thoracic cord, appearing anteriorly displaced. The enlarged dorsal CSF space mimics the profile of a surgical scalpel.
It is helpful in distinguishing cases where ...
Article
Vertebral artery thrombosis
Vertebral artery thrombosis results in complete or partial occlusion of the vertebral artery and alteration of blood flow to the posterior cerebral circulation.
Clinical presentation
Ischemia or infarction to structures supplied by these arteries (e.g. brainstem, cerebellum, occipital lobes) m...
Article
Homocystinuria
Homocystinuria is a rare congenital disorder of metabolism.
Clinical presentation
The disease may affect one or more of the systems below 1,2:
eye: ectopia lentis (typically downwards and inwards)
CNS: seizures, dystonia, developmental delay
skeletal: scoliosis, pectus excavatum, long limb...
Article
Investigating amblyopia (summary)
This is a basic article for medical students and other non-radiologists
Amblyopia, often referred to as a "lazy eye", is a vision development disorder where an eye fails to achieve normal visual acuity, despite the use of prescription spectacles or contact lenses.
Reference article
This is a ...
Article
Pineal parenchymal tumors
Pineal parenchymal tumors comprise a group of related tumors ranging from relatively benign to highly malignant. There are 5 diagnoses recognized in the 5th edition (2021) WHO classification of CNS tumors 4:
pineocytoma
14-30% of pineal parenchymal tumors 2
mature well-differentiated tumor
W...
Article
Phenylketonuria
Phenylketonuria (PKU) is an inborn error of metabolism resulting from abnormal metabolism of phenylalanine. If untreated, patients can develop central nervous system impairment.
Epidemiology
PKU is inherited as an autosomal recessive disorder with an incidence of 1 in 10,000. It is more commo...
Article
Infantile retinal hemorrhage
Infantile retinal hemorrhages occur when, in infants, blood leaks from retinal capillaries into the surrounding retinal tissue.
Retinal hemorrhages are usually diagnosed by ophthalmologists, but they may be seen by ER, ICU, or hospitalist physicians. They are occasionally seen on MR SWI imaging...
Article
Optic chiasm
The optic chiasm or chiasma is the midline structure where the nasal (medial) fibers of the optic nerves decussate to continue posteriorly as the optic tracts. It lies in the chiasmatic cistern and along with the pituitary stalk, is completely encircled by the circle of Willis.
Gross anatomy
R...
Article
Astrocytic tumors
Astrocytic tumors are primary central nervous system tumors that either arises from astrocytes or appear similar to astrocytes on histology having arisen from precursor cells. They are the most common tumors arising from glial cells and can be broadly divided into three groups:
diffuse, adult-...
Article
Barbell sign (progressive multifocal leukoencephalopathy)
The barbell sign is a radiological sign present in progressive multifocal leukoencephalopathy (PML) on MRI brain.
This describes confluent T2/FLAIR parieto-occipital abnormalities with a thin continuation of signal abnormality across the splenium 1,2. Given the lack of mass effect typically exh...
Article
Interpeduncular angle
The interpeduncular angle is defined as the angle formed by the posterior half of the cerebral peduncles on axial images. The interpeduncular angle has been proposed as a sensitive and specific measure of intracranial hypotension (reduced) and progressive supranuclear palsy (PSP) (increased)1,2....
Article
Nervus terminalis
The nervus terminalis, also referred to as cranial nerve zero, cranial nerve XIII, zero nerve, nerve N or NT, is a previously unnumbered cranial nerve, most rostral of all cranial nerves.
Gross anatomy
It is a bilateral bundle of nerve fibers, which runs in the subarachnoid space from the medi...
Article
Neurolymphomatosis
Neurolymphomatosis is a rare cause of neuropathy due to infiltration of the peripheral nervous system by a hematologic malignancy, in the great majority a B-cell non-Hodgkin lymphoma.
It should be differentiated from non-tumor neuropathies associated with lymphoma, such as irradiation, chemothe...
Article
Proatlantal artery
The proatlantal artery is one of the persistent carotid-vertebrobasilar anastomoses, and can be subdivided into two types depending on its origin:
type I: (~55%)
corresponds to the first segmental artery
arises from the internal carotid artery
also known as the proatlantal intersegmental art...
Article
Terson syndrome
Terson syndrome refers to intraocular hemorrhage in patients with intracranial hemorrhage.
Terminology
The traditional definition of Terson syndrome was vitreous hemorrhage associated with subarachnoid hemorrhage. However, there is also a broader definition which captures intraocular hemorrhag...
Article
Craniorachischisis
Craniorachischisis, also known as craniorachischisis totalis, is a rare birth defect and the most severe of the neural tube defects. It refers to the presence of both anencephaly and spina bifida.
Epidemiology
In one study the prevalence of craniorachischisis was 0.51 per 10,000 live births in...
Article
Basal ganglia T2 hyperintensity
The causes of basal ganglia T2 hyperintensity can be remembered using the mnemonic LINT:
lymphoma
ischemia
hypoxic-ischemic encephalopathy
venous infarction (internal cerebral vein thrombosis)
neurodegenerative
autoimmune encephalitis (e.g. anti-D2 dopamine receptor encephalitis, anti-CV2...
Unable to process the form. Check for errors and try again.