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.
More than 200 results
Article
Cerebral cavernous venous malformation
Cerebral cavernous venous malformations, also commonly known as cavernous hemangiomas or cavernomas, are common cerebral vascular malformations, usually with characteristic appearances on MRI. It is the third most common cerebral vascular malformation after developmental venous anomaly and capil...
Article
Dead pixel artifact
Dead pixel artifact is an artifact seen in direct digital radiography systems where a detector element fails to receive a proper signal and therefore appears as a bright white dot in an x-ray image.
A defective pixel on the display monitor can also lead to a white dot appearance (termed stuck p...
Article
Cyclops lesion (knee)
The cyclops lesion, also known as localized anterior arthrofibrosis, is a painful anterior knee mass associated with loss of extension that arises as a complication of anterior cruciate ligament (ACL) reconstruction, although has rarely been reported in patients with ACL injuries that have not b...
Article
Nasogastric tube positioning
Assessment of nasogastric (NG) tube positioning is a key competency of all doctors as unidentified malpositioning may have dire consequences, including death.
Radiographic features
Plain radiograph
A correctly placed nasogastric tube should 10:
descend in the midline, following the path of ...
Article
Medical abbreviations and acronyms (O)
This article contains a list of commonly used medical abbreviations and acronyms that start with the letter O and may be encountered in medicine and radiology (please keep the main list and any sublists in alphabetic order).
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R...
Article
Turtleback sign
Turtleback sign or carapace sign, described as tortoise-shell appearance, represents a characteristic appearance of chronic hepatic schistosomiasis in which liver margins are irregular and nodular. Dystrophic calcifications within a polygonal network of fibrous septa are seen in the periphery, o...
Article
Connective tissue disease-related interstitial lung disease (CTD-ILD)
Connective tissue disease-interstitial lung disease (CTD-ILD) has various manifestations however the most frequent patterns seen on CT are NSIP or UIP. CTD-ILD should be suspected in younger patients especially women and never-smokers and particulary if there is involvement of pleura, airways or...
Article
Osgood-Schlatter disease
Osgood-Schlatter disease, also known as apophysitis of the tibial tubercle, is a chronic fatigue injury due to repeated microtrauma at the patellar tendon insertion onto the tibial tuberosity, usually affecting boys between ages 10-15 years.
Terminology
Unresolved Osgood-Schlatter disease is t...
Article
Ovarian torsion
Ovarian torsion occurs when the ovary rotates around its supporting ligaments, twisting and compressing the accompanying blood vessels and lymphatics. The term adnexal torsion is preferred because a portion of the fallopian tube is commonly torsed along with the ovary. The term adnexal torsion a...
Article
Budd-Chiari syndrome
Budd-Chiari syndrome, also known as hepatic venous outflow obstruction (HVOO), refers to the clinical picture that occurs when there is partial or complete obstruction of the hepatic veins.
There is no clear consensus regarding the number of occluded veins, some authors claim that there should...
Article
Trigeminal schwannoma
Trigeminal schwannomas are uncommon slow-growing encapsulated tumors composed of schwann cells. They are the second most common intracranial schwannoma, far less common than vestibular schwannoma, and has a predominantly benign growth.
Epidemiology
Patients usually present in middle age, typ...
Article
Infrapiriform foramen (mnemonic)
A mnemonic to remember the structures passing below the piriformis muscle in the greater sciatic foramen is:
PIN PINS or SNIP NIP
Mnemonic
P: posterior cutaneous nerve of thigh (S1-3)
I: inferior gluteal artery, vein and nerve (L5-S2)
N: nerve to quadratus femoris (L4-S1)
P: pudendal nerve...
Article
Splenic amyloidosis
Splenic amyloidosis is rare as an isolated entity. Most often it is associated with either systemic amyloidosis or hepatic amyloidosis.
Epidemiology
In general, splenic involvement in amyloidosis is rather frequent (5-10% of cases 6,7).
Clinical presentation
Symptoms include abdominal mass a...
Article
Radical cystectomy
A radical cystectomy is a surgical treatment in patients most commonly indicated for patients with muscle-invasive bladder cancer.
Indications
muscle-invasive bladder cancer 8
non-muscle invasive bladder cancer to local treatment (e.g. BCG therapy) 2,8
neurogenic or nonfunctioning bladder in...
Article
Susac syndrome
Susac syndrome, also known as retinocochleocerebral vasculopathy or SICRET syndrome (small infarctions of cochlear, retinal and encephalic tissue), is a rare syndrome typically affecting young to middle-aged women that is clinically characterized by the triad of acute or subacute encephalopathy,...
Article
Deep vein thrombosis
Deep vein thrombosis (DVT) most commonly occurs in the lower limbs; however, it is not uncommon in the upper limb and neck deep veins. Other types of venous thrombosis, such as intra-abdominal and intracranial, are discussed in separate articles.
Terminology
The term indeterminate (equivocal) ...
Article
Meniscal degeneration
Meniscal degeneration is a process that often occurs due to gradual wear and is commonly associated with advanced knee osteoarthritis. It may or may not be associated with a chronic tear.
See also
meniscal tear
meniscal fraying
Article
Multiple endocrine neoplasia syndromes
Multiple endocrine neoplasia (MEN) syndromes are a collection of syndromes characterized by the presence of, as the name would suggest, multiple neuroendocrine tumors. They are autosomal dominant in inheritance.
MEN1 (Wermer syndrome)
MEN2 (multiple endocrine adenomatosis)
MEN2a (Sipple syndr...
Article
Congenital pseudoarthrosis of the tibia
Congenital pseudoarthrosis of the tibia, or anterolateral bowing of the tibia with congenital dysplasia, describes abnormal bowing that can progress to a segment of bone loss simulating the appearance of a joint. The condition is usually apparent shortly after birth and rarely diagnosed after ag...
Article
Crawford classification of thoracoabdominal aneurysms
The Crawford classification system is used to classify thoracoabdominal aneurysms and has important therapeutic implications. Precise classification of anatomical features allows accurate risk stratification and appropriate operative planning 1,2.
Classification
The system divides thoracoabdo...
Unable to process the form. Check for errors and try again.