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
External auditory canal atresia
External auditory canal atresia, also known as congenital aural atresia, is characterized by complete or incomplete bony atresia of the external auditory canal (EAC), often in association with a dysplastic auricle and an abnormal middle ear cavity or ossicles.
Epidemiology
The incidence is 1 i...
Article
Hemimegalencephaly
Hemimegalencephaly is a rare congenital disorder of cortical formation with hamartomatous overgrowth of all or part of a cerebral hemisphere. This results from either increased proliferation or decreased apoptosis (or both) of developing neurons 2.
Epidemiology
Hemimegalencephaly is a cryptoge...
Article
Early pregnancy
Early pregnancy roughly spans the first ten weeks of the first trimester.
Radiographic features
Antenatal ultrasound
0-4.3 weeks: no ultrasound findings
4.3-5.0 weeks:
possible small gestational sac
possible double decidual sac sign (DDSS)
possible intradecidual sac s...
Article
External ear
The external ear (or outer ear) comprises the auricle (or pinna), the external auditory meatus, and the tympanic membrane ("eardrum"). The auricle concentrates and amplifies sound waves and funnels them through the outer acoustic pore into the external auditory meatus to the tympanic membrane.
...
Article
Hirschsprung disease
Hirschsprung disease is the most common cause of neonatal colonic obstruction (15-20%). It is commonly characterized by a short segment of colonic aganglionosis affecting term neonates, especially boys.
Epidemiology
Hirschsprung disease affects approximately 1:5000-8000 live births. In short-...
Article
Facet joint injection
Facet (zygapophyseal) joint injections are performed primarily for the diagnosis and differentiation of facet syndrome and radicular pain syndrome, and are one of the spinal interventional procedures. They can be performed under fluoroscopic, or CT image guidance, and cervical, thoracic or most ...
Article
Superior vermian vein
The superior vermian vein is formed in the midline over the superior aspect of the cerebellar vermis (over the anterior lobe) by multiple tributaries draining not just the subjacent vermis but also the adjacent cerebellar hemispheres. These tributaries most often coalesce into a single trunk ove...
Article
Hypermetropia
Hypermetropia, also known as long-sightedness or hyperopia, is a refractive disorder. Though it can happen in any age group, it usually starts from mid-late adulthood.
Clinical presentation
In this condition, distant objects are seen better than close objects.
Pathology
The blurriness of nea...
Article
Ciliopathies
Ciliopathies refer to diseases due to malfunctioning cilia (singular: cilium). Cilia are organelles that are external extensions of the cell membrane. Cilia fall into two main types: primary (or immotile) cilia and motile cilia.
Clinical presentation
Primary cilia are found in virtually every...
Article
Shoulder (supine lateral scapula view)
The supine lateral scapula view (anterior oblique AP) is a modified lateral shoulder projection often utilized in trauma imaging. Orthogonal to the AP shoulder (note so is an axillary view); It is a pertinent projection to assess suspected dislocations, scapula fractures and degenerative changes...
Article
Periosteal chondrosarcoma
Periosteal chondrosarcomas, previously also known as juxta-cortical chondrosarcomas, are cartilagineous or chondroid matrix-generating neoplasms originating in close association with the periosteum from the bony surface 1-3.
Terminology
The term ‘juxta-cortical chondrosarcoma’ is no longer rec...
Article
Subdural hygroma
Subdural hygromas (alternative plural: hygromata 9) refer to the accumulation of fluid in the subdural space. In many cases, it is considered an epiphenomenon of head injury when it is called a traumatic subdural hygroma.
Epidemiology
Subdural hygromas are encountered in all age-groups but ar...
Article
Osteonecrosis of the femoral head
Osteonecrosis of the femoral head, previously known as avascular necrosis (AVN) of the hip, is the most common site for osteonecrosis, presumably due to a combination of precarious blood supply and high loading when standing.
Idiopathic osteonecrosis of the femoral head epiphysis in children (...
Article
Facial nerve
The facial nerve is the seventh (CN VII) cranial nerve and comprises two roots, a motor root and a smaller mixed sensory, taste and parasympathetic root, known as nervus intermedius, which join together within the temporal bone (TA: nervus facialis or nervus cranialis VII).
The facial nerve has...
Article
Meningocele
Meningoceles (also spelled meningocoele) 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 categorized into congenital, iatrogenic (e.g. following a craniotomy, sinus surger...
Article
Gastrointestinal leiomyoma (overview)
Gastrointestinal leiomyomas are smooth muscle tumors without malignant potential that may develop in any part of the gastrointestinal system:
esophageal leiomyoma
gastric leiomyoma
small bowel leiomyoma
colonic leiomyoma
Article
Meningeal hemangiopericytoma (historical)
Hemangiopericytomas of the meninges are rare tumors of the meninges, now considered to be an aggressive form of solitary fibrous tumors of the dura. They often present as large and locally aggressive dural masses, frequently extending through the skull vault. They are difficult to distinguish on...
Article
Fitz-Hugh-Curtis syndrome
Fitz-Hugh-Curtis syndrome (FHCS), or perihepatitis, is the inflammation of the liver capsule and overlying peritoneum associated with adhesion formation, without the involvement of the hepatic parenchyma. It is a chronic complication of pelvic inflammatory disease (PID).
Epidemiology
The preva...
Article
Malignant transformation
Malignant transformation is the term given to the process whereby either normal, metaplastic, or benign neoplastic tissue, becomes a cancer. The process usually occurs in a series of steps and the affected tissue gradually accumulates the genetic mutations that express a malignant phenotype. The...
Article
Canalis basilaris medianus
The canalis basilaris medianus (median basal canal), also known as clival canal, median clival canal, or inferior median clival canal, refers to a number of anatomic variant midline canals in the clivus, typically involving the basioccipital portion.
Gross anatomy
These canals are generally we...
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