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
Craniopagus
Craniopagus twins are conjoined twins that are fused at any part of the skull, except the face, foramen magnum, skull base and the vertebral column.
The fused structures are most often the cranium, meninges, and dural venous sinuses. Brains tend to be separate; however, they may be connected by...
Article
Rachipagus
Rachipagus twins are an extremely rare type of conjoined twins. They are joined in the dorsal aspect and face away from each other.
Fusion of the occiput with varying segments of the vertebral column may occur, resulting in the sharing of the spinal cords. The fusion terminates above the sacrum...
Article
National Early Warning Score (NEWS)
The National Early Warning Score (NEWS) is a validated clinical assessment tool developed by the Royal College of Physicians in the UK 1,2. In December 2017, NEWS2 was released superseding the original (2012) version. The score is widely used as part of the evaluation of an acutely unwell patien...
Article
Stomal ulcer
Stomal ulcers may occur after surgery for peptic ulcer disease, and are more common in settings of a retained gastric antrum or an incomplete vagotomy (occurrences which are not common with modern surgical technique). There is also a higher risk with Zollinger-Ellison syndrome.
Radiographic fea...
Article
Misty mesentery sign
Misty mesentery sign is a sign on CT in which mesenteric fat with increased attenuation mimics mistiness. Just as with fat stranding elsewhere, a number of processes can lead to the appearance including infiltration by inflammatory cells, oedema, lymphatic accumulation, haemorrhage, tumour infil...
Article
Lateral atlantodental instability
Lateral atlantoaxial instability is a subtype of atlantoaxial subluxation, and is a poorly understood entity that may be encountered in post-traumatic and rheumatic patients with equal frequency to established sagittal plane atlantoaxial subluxation 1.
There is limited information regarding cl...
Article
Chen sign
Chen sign on chest radiography is the prominence of the left basal pulmonary vasculature, compared to the right, seen in valvular pulmonary stenosis. It is due to the asymmetric increase in pulmonary blood flow to the left lung due to preferential blood flow into the left pulmonary artery after ...
Article
Meyers and McKeever classification of ACL avulsion fractures
Meyers and McKeever classification is used to categorise 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 oedema, which is often used as a synonymous term. Periportal haloes may occur a...
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 haemorrhage.
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...
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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 tumours of the ovary
Germ cell tumours of the ovary account for approximately 15-20% of all ovarian tumours. In children and adolescents, up to 60% of ovarian tumours can be of germ cell origin.
They include:
ovarian teratoma(s): commonest primary benign tumour of ovary and commonest germ cell tumour:
mature (cys...
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
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
Hepatic lymphoma
Hepatic lymphoma is a term given to any form of hepatic involvement with lymphoma. This can be broadly divided into:
secondary hepatic involvement with lymphoma: most common by far, many tend to be non-Hodgkin lymphoma (NHL) 1
primary hepatic lymphoma: extremely rare
Pathology
Risk factors f...
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