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

Light chain deposition disease (pulmonary manifestations)

Pulmonary light chain deposition disease is a rare manifestation of systemic light chain deposition disease (LCDD). Pathology Fragments of immunoglobulin light chains secreted by a plasma clone are deposited as amorphous eosinophilic material in the alveolar walls, small airways, and vessels 2...
Article

Tuberous sclerosis (mnemonic)

The findings of tuberous sclerosis can be remembered with the help of the following mnemonic: HAMARTOMAS Mnemonic H: hamartomas (CNS, retinal and skin) A: angiofibroma (facial) or adenoma sebaceum M: mitral regurgitation A: ash-leaf spots R: rhabdomyoma (cardiac) T: tubers (cortical, sub...
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

Crohn disease

Crohn disease, also known as regional enteritis, is an idiopathic inflammatory bowel disease characterized by widespread discontinuous gastrointestinal tract inflammation. The terminal ileum and proximal colon are most often affected. Extraintestinal disease is common. Epidemiology The diagnos...
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

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

Baby bird’s beak sign

The baby bird's beak sign is an antenatal ultrasound appearance formed by the pulmonary artery abnormally arising from the left ventricle in fetuses with transposition of the great arteries. In these cases, the pulmonary artery bifurcation and abnormal outflow tracts mimic the head of a baby bi...
Article

Cervical cancer (staging)

Staging of cervical cancer can either be based on the TNM or FIGO system. Classification Revised FIGO staging of cervical carcinoma (2018) FIGO no longer includes stage 0 (Tis) I: confined to cervix uteri (extension to the corpus should be disregarded) IA: invasive carcinoma only diagnosed ...
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

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

Echogenic fetal bowel

Echogenic fetal bowel is an observation in antenatal ultrasound imaging, in which fetal bowel appears to be brighter than it is supposed to be. It is a soft marker for trisomy 21 and has several other associations. When observed, it needs to be interpreted in the context of other associated abno...
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

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...

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.