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
Arterial occlusive mesenteric ischemia
Arterial occlusive mesenteric ischemia can be a life-threatening event related to obstruction of the mesenteric arteries, most commonly the superior mesenteric artery (SMA), supplying the small bowel and colon. It is the most common cause of mesenteric ischemia.
Epidemiology
An acute occlusi...
Article
Cerebral cortical restricted diffusion
Cerebral cortical restricted diffusion, also known as gyriform restricted diffusion, cortical ribboning or cortical ribbon sign, refers to curvilinear hyperintense signal involving the cerebral cortex on DWI images with a corresponding low signal on ADC images.
Causes include the following diso...
Article
CT neck, chest, abdomen-pelvis (NCAP protocol)
The CT neck chest-abdomen-pelvis protocol aims to evaluate the neck, thoracic and abdominal structures using contrast in trauma imaging. The use of contrast facilitates the assessment of pathologies globally whilst minimizing dose by potentially disregarding a non-contrast scan.
Note: This art...
Article
Bowel wall calcification
Bowel wall calcification is not common and can occur secondary to various mechanisms due to benign, premalignant, or malignant lesions.
The differential diagnoses include:
mucinous adenocarcinoma
gastrointestinal stromal tumor (GIST)
metastatic calcification - due to renal failure
hemangio...
Article
Point-of-care ultrasound (curriculum)
The point-of-care ultrasound (PoCUS) curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core applications of ultrasonography in a point-of-care setting.
Point-of-care ultrasound refers to ultrasonography which may be simultaneously performed,...
Article
Bowel wall fat deposition
Bowel wall fat deposition refers to the infiltration of the submucosa with fat and usually occurs in chronic processes such as inflammatory bowel disease, causing characteristic fat halo sign on CT images.
Other differential diagnoses include:
normal variant - particularly in obese patients w...
Article
Bridging of the sella turcica
Bridging of the sella turcica is the fusion of the anterior and posterior clinoid processes.
Epidemiology
The prevalence of a sella turcica bridge in a healthy population is estimated to be ~4% (range 1.75-6%) in anatomical and radiographic studies.
Pathology
It has been reported to occur in...
Article
Anterior angulation of the coccyx
Anterior angulation of the coccyx may be a normal variant but poses a diagnostic challenge for those considering coccygeal trauma 1.
Classification
Six types of coccyx have been described initially by Postacchini and Massobrio and later modified by Nathan et al. 2,3:
type I: the coccyx is cur...
Article
Osteogenesis imperfecta
Osteogenesis imperfecta (OI) refers to a heterogeneous group of congenital, non-sex-linked, genetic disorders of collagen type I production, involving connective tissues and bones.
The hallmark feature of osteogenesis imperfecta is osteoporosis and fragile bones that fracture easily, as well a...
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
Cystic renal diseases
Cystic renal disease can be confusing. There are many conditions, many of which have similar names or are eponymous, and with a few exceptions, are relatively rare. It is easiest to think of them into two separate demographic:
pediatric cystic renal diseases
adult cystic renal disease
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...
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) ...