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.
16,873 results found
Article
Skeletal survey (overview)
The skeletal survey is a radiographic series performed to survey the entire skeleton (axial skeleton, upper and lower limbs) for pathology or injury. Specific projections vary depending on the clinical indication and the institution's protocol.
There are various clinical indications that may wa...
Article
Bowl of grapes sign
The bowl of grapes sign has been described in synovial sarcoma. It refers to the characteristic multilobulated lesion subdivided by multiple septa, forming large cystic foci with regions of hemorrhage.
Article
Psoriasis
Psoriasis is an inflammatory dermatological disease with several variants. The most common variant is plaque psoriasis, other variants of the disease are guttate, erythrodermic and pustular psoriasis 1.
Epidemiology
There is a geographic variation in the prevalence of psoriasis such that popul...
Article
Extradural neural axis compartment
Extradural neural axis compartment (EDNAC) exists from the tip of the coccyx all the way to the back of the globe, and yet it is relatively unknown as a concept. It is bounded externally by the periosteum of the vertebrae and sacrum inferiorly and the skull superiorly, and the visceral (meningea...
Article
Right lower lobe collapse
Right lower lobe (RLL) collapse has distinctive features, and is usually relatively easily identified. The smaller overlying heart shadow obscures less lung compared with left lower lobe collapse.
Findings of lower lobe collapse can be grouped together as they are almost identical on both side...
Article
Os odontoideum
Os odontoideum (plural: ossa odontoidea) is an anatomic variant of the odontoid process of C2 and needs to be differentiated from persistent ossiculum terminale and from a type 2 odontoid fracture. It can be associated with atlantoaxial instability.
Although it was originally thought to be a c...
Article
Anderson and Montesano classification of occipital condyle fractures
The Anderson and Montesano classification is a widely used system for describing occipital condyle fractures. It divides injuries into three types based on morphology and mechanism of injury 1-5.
Classification
type I: impacted type occipital condyle fracture
morphology: comminution of the co...
Article
Bone age (radiograph)
The bone age radiograph of the hand and wrist is a commonly performed examination to determine the radiographic age of the patient via the assessment of growth centers.
Indications
Bone age radiographs may be indicated for both clinical and non-clinical purposes 6,7:
for the investigation ...
Article
Caput medusae sign (developmental venous anomaly)
The caput medusae sign also sometimes known as a palm tree sign refers to developmental venous anomalies of the brain, where a number of veins converge centrally into a single draining vein.
The sign is seen on both CT and MRI when contrast medium is administered. Angiographically the caput me...
Article
Shear wave elastography
Shear wave elastography is a developing variation of ultrasound imaging.
The concept is similar to strain elastography, but instead of using transducer pressure to compare a shift in an ultrasound A-line (thereby measuring changes in strain), a higher intensity pulse is transmitted to produce s...
Article
Arterial thoracic outlet syndrome
Arterial thoracic outlet syndrome (aTOS) is considered rarest from of
thoracic outlet syndrome and can result in compression of arterial structures (especially the subclavian artery) at thoracic outlet, or superior thoracic aperture.
Many of these patients may also have concurrent venous thora...
Article
Germ cell tumors of the ovary
Germ cell tumors of the ovary account for approximately 15-20% of all ovarian tumors. In children and adolescents, up to 60% of ovarian tumors can be of germ cell origin.
They include:
ovarian teratoma(s): commonest primary benign tumor of ovary and commonest germ cell tumor:
mature (cystic) ...
Article
Aortic arch
The aortic arch represents the direct continuation of the ascending aorta and represents a key area for a review of normal variant anatomy and a wide range of pathological processes that range from congenital anomalies to traumatic injury.
Summary
origin: continuation of the ascending aorta at...
Article
Thoracic outlet syndrome
Thoracic outlet syndrome refers to a group of clinical syndromes caused by congenital or acquired compression of the brachial plexus or subclavian vessels as they pass through the superior thoracic aperture 11.
Clinical presentation
Clinical presentation will depend on the structure compresse...
Article
Orthopantomography
The orthopantomogram (also known as an orthopantomograph, pantomogram, OPG or OPT) is a panoramic single image radiograph of the mandible, maxilla and teeth. It is often encountered in dental practice and occasionally in the emergency department; providing a convenient, inexpensive and rapid way...
Article
Flame sign (carotid)
The flame sign refers to a gradual tapering of contrast opacification in the mid-cervical internal carotid artery, sparing the carotid bulb. The sign can be observed on angiography (digital subtraction angiography 1, CT angiography 1, or contrast-enhanced MR angiography 2) in either of two scena...
Article
Hepatic lymphoma
Hepatic lymphoma is a term given to any form of hepatic involvement with lymphoma. This can be broadly divided into:
secondary hepatic involvement with lymphoma: most common by far, many tend to be non-Hodgkin lymphoma (NHL) 1
primary hepatic lymphoma: extremely rare
Pathology
Risk factors f...
Article
Tinnitus causes (mnemonic)
A mnemonic to remember the commonest causes of tinnitus is:
HAMMER
Mnemonic
H: hypertension
A: anemia / acoustic neuroma
M: migraine / Menière's disease
M: medication (quinine, NSAIDs, streptomycin)
E: ear pathology (wax, foreign body, otitis media)
R: rare (temporomandibular joint ...
Article
Avulsion injury
Avulsion injuries or fractures occur where the joint capsule, ligament, tendon or muscle attachment site is pulled off from the bone, usually taking a fragment of cortical bone. Avulsion fractures are commonly distracted due to the high tensile forces involved. There are numerous sites at which ...
Article
Biliary atresia
Biliary atresia is a congenital biliary disorder that is characterized by an absence or severe deficiency of the extrahepatic biliary tree. It is one of the most common causes of neonatal cholestasis, often causing cirrhosis immediately and leading to death and accounts for over half of children...
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