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.
742 results found
Article
Atypical cervical vertebrae
Of the cervical vertebrae, the atlas (C1), axis (C2) and vertebra prominens (C7) are considered atypical cervical vertebrae.
The atlas (C1) lacks a body or spinous process. It has anterior and posterior arches with lateral masses. Its superior articular surfaces articulate with the occiput at t...
Article
Atypical lumbar vertebrae
Of the five lumbar vertebrae, L5 is considered atypical due to its shape. The remaining lumbar vertebrae are largely typical.
For a basic anatomic description of the structure a generic vertebra, see vertebrae.
Article
Atypical thoracic vertebrae
T1 and T9 - T12 are considered atypical thoracic vertebrae.
T1 bears some resemblance to low cervical vertebrae
T9 has no inferior demifacet
T10 often, but not always, shares features with T11 and T12.
For a basic anatomic description of the structure a generic vertebra, see vertebrae.
Article
Autoimmune glial fibrillary acid protein (GFAP) astrocytopathy
Autoimmune glial fibrillary acid protein (GFAP) astrocytopathy, or simply GFAP astrocytopathy, is a rare inflammatory central nervous system (CNS) disorder.
Epidemiology
Given the rarity of the condition, epidemiological data pertaining to autoimmune GFAP astrocytopathy are not well establishe...
Article
Autonomic dysreflexia
Autonomic dysreflexia (AD) is a life-threatening condition prevalent amongst patients with high spinal cord injury (SCI) and may occur any time after injury. It is a syndrome characterized by an exaggerated reflex increase in blood pressure, usually accompanied by bradycardia in response to a st...
Article
Autonomic nervous system
The autonomic nervous system (ANS) is a subdivision of the peripheral nervous system. The autonomic system provides innervation of the involuntary muscles, i.e. myocardium and smooth muscle, and glands, through which fine control of homeostasis is maintained.
The afferent innervation of the aut...
Article
Axial spondyloarthritis
Axial spondyloarthrititis (SpA) is a clinical subset of the seronegative spondyloarthritides that present primarily with back pain and morning stiffness. There is a long delay, on average 14 years, between symptoms onset and diagnosis 1.
Epidemiology
The prevalence of axial SpA is ~1% 1. Age o...
Article
Axis (C2)
The axis is the second cervical vertebra, commonly called C2. It is an atypical cervical vertebra with unique features and important relations that make it easily recognisable. Its most prominent feature is the odontoid process (also know as the dens or peg), which is embryologically the body of...
Article
Baastrup disease
Baastrup disease or syndrome (also referred to as kissing spines) is a cause of low back pain characterized by interspinous bursitis and other degenerative changes of the bones and soft tissues where adjacent spinous processes in the lumbar spine rub against each other.
Epidemiology
It tends t...
Article
Backfill
Backfill refers to intra-articular high signal intensity on T1 weighted images seen in axial spondylarthritis within the sacroiliac joint filling up excavated bone erosions 1. It has been characterized as a complete loss of the cortical bone within the sacroiliac joint at the anticipated locatio...
Article
Bagel sign (Behçet disease)
The bagel sign is a radiological sign appreciated on MRI spine that is described in patients with neuro-Behçet disease-associated myelitis.
The sign describes the involvement of the spinal cord as seen on axial T2 sequences in patients with myelitis, whereby there is a round hyperintense lesion...
Article
Bamboo spine (ankylosing spondylitis)
Bamboo spine is a pathognomonic radiographic feature seen in ankylosing spondylitis that occurs as a result of vertebral body fusion by marginal syndesmophytes. It is often accompanied by fusion of the posterior vertebral elements as well.
A bamboo spine typically involves the thoracolumbar and...
Article
Basilar invagination
Basilar invagination, also called basilar impression, is a congenital or acquired craniocervical junction abnormality where the tip of the odontoid process projects above the foramen magnum.
Terminology
The following terms are often used interchangeably because they describe upwards migration...
Article
Basilar invagination (mnemonic)
A mnemonic to help recall the causes of basilar invagination is:
PF ROACH
Mnemonic
P: Paget disease of bone
F: fibrous dysplasia
R: rheumatoid arthritis, rickets
O: osteogenesis imperfecta, osteomalacia
A: achondroplasia
C: Chiari I and Chiari II, cleidocranial dysostosis
H: hyperparath...
Article
Basilar process
The basilar process, also known as the mammillar or papillar process, is a rare anatomical variant of the occipital bone that is part of the spectrum of occipital vertebrae 1.
Epidemiology
The basilar process is a rare variant, with a reported prevalence of 4% 2.
Clinical presentation
A basi...
Article
Basion-axial interval
The basion-axial interval (BAI) is the horizontal distance between the basion and the posterior cortex of the axis, used in the diagnosis of atlanto-occipital dissociation injuries.
It is the distance (in mm) between the basion and the superior extension of the posterior cortical margin of the ...
Article
Basion-dens interval
The basion-dens interval (BDI) is the distance between the basion and the tip of the dens, used in the diagnosis of atlanto-occipital dissociation injuries.
It is the distance from the most inferior portion of the basion to the closest point of the superior aspect of the dens in the median (mid...
Article
Basivertebral nerve
The basivertebral nerve supplies the vertebral endplates and can be a target for treating back pain.
Gross anatomy
The basivertebral nerve is a paired nerve arising from the sinuvertebral nerve. It ascends from its origin to enter the spinal canal, traversing centrally 1. It courses with the ...
Article
Batson venous plexus
Batson venous plexus, also known as Batson veins, are a network of paravertebral veins with no valves that connect thoracic vessels and deep pelvic veins draining the bladder, prostate, and rectum to the internal vertebral venous plexus 1. These veins are important because they are believed to p...
Article
Benign notochordal cell tumor
Benign notochordal cell tumors are vertebral lesions that are usually asymptomatic and discovered incidentally on imaging of the head or spine. As this is a poorly-recognized entity, it can often be confused with aggressive vertebral lesions, such as a chordoma, when it is seen on imaging.
Term...
Unable to process the form. Check for errors and try again.