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
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
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
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
Mid-talar axis
The mid-talar axis represents a line drawn down the longitudinal axis of the talus and can be drawn on lateral and DP radiographs.
Measurement
Independent on the view on which the line is drawn, it should bisect the neck of the talus and the head.
On the lateral and DP views, the line should...
Article
Lateral talocalcaneal angle
The lateral talocalcaneal angle is one of the angles that can be measured for the assessment of pes planus and pes cavus and assessment of hindfoot deformity.
Measurement
The lateral talocalcaneal angle is drawn on a weight-bearing lateral foot radiograph. There are two ways that it has been d...
Article
Chordoma
Chordomas are uncommon malignant tumors of the axial skeleton that account for 1% of intracranial tumors and 4% of all primary bone tumors.
They originate from embryonic remnants of the primitive notochord (earliest fetal axial skeleton, extending from the Rathke's pouch to the tip of the cocc...
Article
Internal oblique muscle
The internal oblique muscle is one of the muscles that form the anterior abdominal wall. Inferiorly, it contributes towards the formation of the inguinal ligament.
Summary
origin: originates along the whole length of the lumbar fascia, from the anterior two-thirds of the intermediate line of t...
Article
Transversus abdominis muscle
The transversus abdominis muscle, named according to the direction of its muscle fibers, is one of the flat muscles that form the anterior abdominal wall. It is deep to the internal oblique muscle and ends in the anterior aponeurosis, which ultimately blends with the linea alba.
Summary
origi...
Article
External oblique muscle
The external oblique muscle is one of the muscles that forms the anterior abdominal wall. Its free inferior border forms the inguinal ligament, and its aponeurotic part contributes to the anterior wall of the inguinal canal.
Summary
origin: outer surface of the shaft of the lower eight ribs 3...
Article
Congenital diaphragmatic hernia
Congenital diaphragmatic herniation (CDH) accounts for a small proportion of all diaphragmatic herniae. However, it is one of the most common non-cardiac fetal intrathoracic anomalies.
Epidemiology
Congenital diaphragmatic hernias are seen in 1 of every 2000-4000 live births. 84% are left-side...
Article
Foot pain
Foot pain is a very common symptom. The differential diagnosis depends mainly on age, weight, level of physical activity, and the exact location of the pain.
As neoplastic lesions are ubiquitary, they will not be added to the sections below.
Hindfoot pain
inferior heel pain
trauma and bone b...
Article
Osteolytic bone lesion
Osteolytic lesions, lytic or lucent bone lesions are descriptive terms for lesions that replace normal bone or with a vast proportion showing a lower density or attenuation than the normal cancellous bone. This comprises lesions with fatty liquid and solid soft tissue components.
Pathology
Luc...
Article
Celery stalk metaphysis
Celery stalk metaphysis refers to a plain film appearance of the metaphyses in a number of conditions characterized by longitudinally aligned linear bands of sclerosis. They are seen in:
congenital infections
congenital rubella
congenital syphilis
congenital cytomegalovirus (CMV)
osteopathi...
Article
AP Meary's angle
AP Meary's angle or AP talus-first metatarsal angle is used to assess for midfoot abduction/adduction in pes planus and pes cavus to assist with pre-operative planning 1.
Measurement
On a weight-bearing AP foot radiograph, a line is drawn down the longitudinal axis of the first metatarsal to ...
Article
Tendinopathy
Tendinopathy has been defined as "persistent tendon pain and loss of function related to mechanical loading" 7 but is also used as a broad term used to describe any problem involving a tendon.
Epidemiology
The prevalence of tendinopathy in the general population is 2-5%. Active and sporting in...
Article
Focal fatty deposits in bone marrow
Focal fatty deposits, also known as marrow islands or replacements in the bone marrow, are well-defined focal fat islands within the bone marrow of the spine or other parts of the axial skeleton 1,2.
Epidemiology
Common in older individuals, related to age but not to sex.
Associations
Focal ...
Article
Posterior tibial line
The posterior tibial line is drawn along the posterior aspect of the distal tibial shaft on a lateral ankle x-ray and can be used to assess the sagittal alignment of the talus when comparing side-to-side and/or calculate the posterior tibial line-talar ratio 1,2.
Article
Periosteal chondrosarcoma
Periosteal chondrosarcomas, previously also known as juxta-cortical chondrosarcomas, are cartilagineous or chondroid matrix-generating neoplasms originating in close association with the periosteum from the bony surface 1-3.
Terminology
The term ‘juxta-cortical chondrosarcoma’ is no longer rec...
Article
Ciliopathies
Ciliopathies refer to diseases due to malfunctioning cilia (singular: cilium). Cilia are organelles that are external extensions of the cell membrane. Cilia fall into two main types: primary (or immotile) cilia and motile cilia.
Clinical presentation
Primary cilia are found in virtually every...
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