Items tagged “refs”
2,968 results found
Article
Bilateral megalencephaly
Bilateral megalencephaly refers to megalencephaly affecting both cerebral hemispheres.
Pathology
Associations
achondroplasia
acromegaly
Alexander disease
Canavan disease
mucopolysaccharidoses
neurofibromatosis type 1 (NF1)
Proteus syndrome
Tay-Sachs disease
tuberous sclerosis (TS)
va...
Article
Bochdalek hernia
Bochdalek hernias , also known as pleuroperitoneal hernias, (alternative plural: herniae) are the commonest type of congenital diaphragmatic hernia. They occur posteriorly and are due to a defect in the posterior attachment of the diaphragm when there is a failure of pleuroperitoneal membrane cl...
Article
Bony humeral avulsion of the glenohumeral ligament lesion
Bony humeral avulsion of the glenohumeral ligament (BHAGL) lesion is just like its slightly shorter relative HAGL lesion, except as the name suggests a bony avulsion fracture is seen at humeral insertion of the inferior glenohumeral ligament.
It is often associated with a subscapularis tear, an...
Article
Bovine arch
Bovine arch is the most common variant of the aortic arch and occurs when the brachiocephalic (innominate) artery shares a common origin with the left common carotid artery.
Epidemiology
A bovine arch is present in ~15% (range 8-27%) of the population and is more common in individuals of Afri...
Article
Brain tumours in infancy
Common brain tumours in infancy (i.e. under one year of age) are quite different from those of brain tumours in adulthood. Most are located in the supratentorial region (~65%) and they carry a poor prognosis.
The frequency of these tumours varies according to studies, but the most common brain ...
Article
Bright rim sign (DNET)
The bright rim sign, also known as the hyperintense ring sign, is an MRI sign described most frequently in dysembryoplastic neuroepithelial tumours (DNET) but is also seen in some other tumours.
Terminology
Although the sign is most associated with DNETs, and should probably be reserved in ca...
Article
CREST syndrome
CREST syndrome (also known as limited systemic sclerosis or limited scleroderma) is a variant of progressive systemic sclerosis (PSS) and stands for
C - calcinosis
R - Raynaud phenomenon
E - oesophageal dysmotility
S - sclerodactyly
T - telangiectasia
See also
systemic sclerosis
Article
Cataract
Cataracts are an opacification or thickening of the lens within the globe and are the leading cause of blindness in the world.
Clinical presentation
Visual deterioration occurs with increasing degrees of severity, and left untreated may present as complete blindness. The diagnosis is made cli...
Article
Cerebrovascular malformations
Cerebrovascular malformations are vascular malformations related to the vessels that supply the brain and other cranial structures.
Classification
Over the years, cerebral vascular malformations have been classified in a variety of ways by many authors, often on the basis of the presence or ab...
Article
Cervical intraepithelial neoplasia (staging)
Cervical intraepithelial neoplasia (CIN) (also known as cervical dysplasia) is the potentailly premalignant stage in the dysplastic changes in the squamous epithelium of the cervix.
Grading of CIN is based on the degree of dysplasia seen in a sample of cervical tissue:
CIN I
similar to condy...
Article
Chemical shift artifact
Chemical shift artifact or misregistration is a type of MRI artifact. It is a common finding on some MRI sequences and used in magnetic resonance spectroscopy (MRS). This artifact occurs in the frequency-encoding direction and is due to spatial misregistration of fat and water molecules.
Chemi...
Article
Chemotherapy induced cholangitis
Chemotherapy induced cholangitis is caused when intra-arterial chemotherapy is introduced to treat liver metastases. This causes strictures of the common hepatic duct and main ducts, but spares distal and proximal (i.e. common bile duct and intrahepatic ducts).
Radiographic features
similar t...
Article
Cholesteatoma
Cholesteatomas are histologically equivalent to an epidermoid cyst and are composed of desquamated keratinising stratified squamous epithelium forming a mass.
Clinical presentation
They may be asymptomatic, or may present with conductive hearing loss, dizziness, or otorrhoea.
Pathology
The m...
Article
Chronic bilateral airspace opacification (differential)
Chronic bilateral airspace opacification is a subset of the differential diagnosis for airspace opacification. An exhaustive list of all possible causes of chronic bilateral airspace opacities is long, but a useful framework is as follows:
inflammatory
sarcoidosis
granulomatosis with polyangi...
Article
Chronic unilateral airspace opacification (differential)
Chronic unilateral airspace opacification is a subset of the differential diagnoses for airspace opacification. An exhaustive list of all possible causes of chronic unilateral airspace opacities is long, but a useful framework is as follows:
neoplastic
post obstructive
lymphoma
lymphocytic ...
Article
Circle of Willis
The Circle of Willis is an arterial polygon (heptagon) formed as the internal carotid and vertebral systems anastomose around the optic chiasm and infundibulum of the pituitary stalk in the suprasellar cistern. This communicating pathway allows equalisation of blood-flow between the two sides of...
Article
CSF cleft sign
The CSF cleft sign in neuroimaging can be used to distinguish an extra-axial lesion from an intra-axial lesion and is typically used in the description of a meningioma.
Classically, the cleft was regarded as representing a thin rim of CSF between a tumour and brain parenchyma. However, it often...
Article
Clinically isolated syndrome
Clinically isolated syndrome (CIS) is the first episode suggestive of demyelination 1,2. It can either be monofocal (single lesion) or multifocal 1,2. Not all patients with CIS will go on to develop multiple sclerosis however if at presentation there are changes on MRI suggestive of MS, then the...
Article
Codman triangle periosteal reaction
A Codman triangle is a type of periosteal reaction seen with aggressive bone lesions. The periosteum does not have time to ossify with shells of new bone (e.g. as seen in a single layer and multilayered periosteal reaction) in aggressive lesions, so only the edge of the raised periosteum will os...
Article
Colonic stricture
Colonic strictures can be long (>10 cm) or short.
Short
scirrhous colorectal carcinoma (apple core sign)
post surgical (anastamotic stricture)
Long
malignancy
scirrhous colorectal carcinoma
gastrointestinal lymphoma
inflammatory bowel disease
ulcerative colitis
Crohn disease
post radi...