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
Suprasellar arachnoid cyst
Suprasellar arachnoid cysts can be challenging to diagnose and, unlike many other arachnoid cysts, are usually symptomatic.
For a general discussion, please refer to the article on arachnoid cysts.
Clinical presentation
As can be expected from its location, suprasellar arachnoid cysts manife...
Article
Angioinvasive aspergillosis
Angioinvasive aspergillosis is the most severe and aggressive form of invasive aspergillosis. It is a life-threatening condition that requires prompt treatment. Fortunately, it is not seen in the general population and only occurs in profoundly immunocompromised patients.
Epidemiology
Angioin...
Article
Idiopathic intracranial hypertension
Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a syndrome with signs and symptoms of increased intracranial pressure but where a causative mass or hydrocephalus is not identified.
Terminology
The older term benign intracranial hypertension is generally frowne...
Article
Patella baja
Patella baja, also known as patella infera, is an abnormally low lying patella, which is associated with restricted range of motion, crepitations, and retropatellar pain. If longstanding, extensor dysfunction may ensue with significant morbidity.
Pathology
It is seen in a variety of clinical s...
Article
Retrobulbar hemorrhage
Retrobulbar hemorrhage is the presence of a post septal orbital hematoma and is usually due to craniofacial trauma causing an extraconal hematoma. It may cause orbital compartment syndrome which is an ophthalmologic emergency.
Clinical features
If small, there may be no orbital or ocular sympt...
Article
Cone beam effect
Cone beam effect artifacts are seen in multidetector row CT (cone beam CT) acquisitions 1. Modern CT scanners use more detector arrays to increase the number of sections acquired per rotation. This causes the x-ray beams to become cone-shaped as opposed to fan-shaped 2. As a result instead of co...
Article
Bowing fracture
Bowing fractures are incomplete fractures of tubular long bones in pediatric patients (especially the radius and ulna) that often require no intervention and heal with remodeling.
Epidemiology
Bowing fractures are almost exclusively found in children. However, there have been several case repo...
Article
Hill-Sachs defect
Hill-Sachs defects are a posterolateral humeral head depression fracture, resulting from the impaction with the anterior glenoid rim, and indicative of an anterior glenohumeral dislocation. It is often associated with a Bankart lesion of the glenoid.
Terminology
A Hill-Sachs defect is the term...
Article
Mediastinal seminoma
Mediastinal seminomas or mediastinal germinomas are primary malignant germ cell tumors of the mediastinum.
Epidemiology
Mediastinal seminomas are rare mediastinal tumors and account for up to one-third of primary malignant mediastinal germ cell tumors 1. They are almost only found in males ≥10...
Article
Small bowel ischemia
Small bowel ischemia may be a life-threatening condition, arising from any one of numerous causes of disturbance of the normal blood flow through the small bowel wall.
Pathology
Etiology
It can be divided into acute and chronic forms, with the main underlying etiologies (each discussed separ...
Article
Uterine inversion
Uterine inversion is a rare condition in which the uterus is essentially turned inside out. There are two types: "puerperal" (within six weeks of childbirth) and "non-puerperal". The reason for uterine inversion is unclear. In the puerperal form, it is theorized that excessive traction on the um...
Article
Meyers and McKeever classification of ACL avulsion fractures
Meyers and McKeever classification is used to categorize ACL avulsion fractures.
Usage
The Meyers and McKeever classification is the most frequently used system (c. 2024) to describe ACL avulsion fractures 2.
Classification
Under the Meyers and McKeever system (with modifications by Zariczny...
Article
Periportal halo (CT/US)
Periportal halo or periportal collar sign refers to a zone of low attenuation seen around the intrahepatic portal veins on contrast-enhanced CT or hypoechogenicity on liver ultrasound. It likely represents periportal edema, which is often used as a synonymous term. Periportal haloes may occur ar...
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
Right lower lobe collapse
Right lower lobe (RLL) collapse forms a triangular opacity extending from the hilum to the diaphragm. There is less overlap with the heart shadow compared to left lower lobe collapse.
Findings of lower lobe collapse can be grouped together as they are almost identical on both sides.
For a gen...
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
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
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...
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