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
Poliomyelitis-like syndrome
Poliomyelitis-like syndrome, or polio-like paralysis, is an uncommon form of myelitis that presents similar to polio, due to non-poliovirus pathologies which selectively involve the anterior horn cells of the spinal cord and result in an anterior horn syndrome. Although it usually has an infecti...
Article
Cervical plexus
The cervical plexus is formed by the ventral (anterior) rami of the C1 to C5 nerve roots and innervates the diaphragm, provides motor supply to some neck muscles and cutaneous sensation to the skin of the head, neck, and chest.
Gross anatomy
Roots
anterior rami of C1 to C5 nerves
Course
run...
Article
Thoracic spine protocol (MRI)
The MRI thoracic spine protocol encompasses a set of MRI sequences for the routine assessment of the thoracic spine.
Note: This article aims to frame a general concept of an MRI protocol for the assessment of the thoracic spine. An MR thoracic spine protocol might be combined with a cervical sp...
Article
Powers ratio
The Powers ratio is a measurement of the relationship of the foramen magnum to the atlas, used in the diagnosis of atlanto-occipital dissociation injuries.
The ratio, AB/CD, is measured as the ratio of the distance in the median (midsagittal) plane between the:
basion (A) and the posterior spi...
Article
Alar ligament
The alar ligaments join the lateral margins of the sloping upper posterior margin of the dens of C2 to the lateral margins of the foramen magnum (adjacent to the occipital condyles) and lie on either side of the apical ligament. They may be oblique or vertical and are thickest at the occipital a...
Article
Annulus fibrosus calcification
Annulus fibrosus calcification is a form of intervertebral disc calcification where the peripheral annular portion (annulus fibrosus) can get calcified. This may occur in isolation or in conjunction with other sites of disc calcification. It could involve any portion of the spine. Some suggest t...
Article
Spinal epidural venous plexus congestion
Spinal epidural venous plexus congestion or dilatation is typically a complication of other pathologies.
Clinical presentation
Radiculopathy caused by the dilated epidural veins is not uncommon 1. More severe symptoms such as cauda equina compression syndrome have been reported 6, 7.
Patholo...
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
Pneumorrhachis
Pneumorrhachis refers to the presence of gas within the spinal canal (either intra- or extradural). It is rare.
Clinical presentation
Patients can often be asymptomatic 3.
Pathology
Etiology
Pneumorrhachis can result from a number of causes:
trauma (traumatic pneumorrhachis): can occur in ...
Article
Sinuvertebral nerve
The sinuvertebral nerve, also known as the recurrent meningeal nerve, or the recurrent nerve of Luschka, is a branch of the primary ventral ramus and grey ramus communicans in the intervertebral foramen. It enters the spinal canal and supplies the posterior portion of the annulus of the interver...
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
Chalk stick fracture
Chalk stick, also known as carrot stick fractures, are fractures of the fused spine, classically seen in ankylosing spondylitis.
Terminology
Some authors define the chalk stick fracture as a fracture through a Pagetoid long bone (see Paget disease) 3.
Pathology
They usually occur through the...
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
Diplomyelia
Diplomyelia is a rare spinal cord malformation in which the cord is duplicated. It should be distinguished from diastematomyelia in which a single cord is split. Having said that it has been proposed that the term be abandoned in favor of split cord malformation, which encompasses both diastemat...
Article
Intramedullary spinal tumors
Intramedullary spinal tumors are rare, representing 4-10% of all CNS tumors and <10% of all pediatric CNS neoplasms 5. They account for 20% of all intraspinal tumors in adults and 35% of all intraspinal tumors in children 8.
A long duration of symptoms prior to diagnosis is typical.
Pathology
...
Article
Cortical bone
The outer shell of compact bone is called cortical bone or cortex. It is formed by compact bone which is one of the two macroscopic forms of bone, the other being cancellous bone.
Gross anatomy
Cortical bone contains Haversian systems (osteons) which contain a central Haversian canal surround...
Article
McRae line
McRae line is a radiographic line drawn on a lateral skull radiograph or on a midsagittal section of CT or MRI that connects the anterior and posterior margins of the foramen magnum (basion to opisthion).
Significance
indicates the presence of basilar invagination (atlantoaxial impaction): the...
Article
Cervical spine (AP oblique view)
The AP oblique cervical spine projections are supplementary views to the standard AP, odontoid and lateral images in the cervical spine series and are always done bilaterally for comparison purposes. However, the PA oblique projection is preferred as it reduces radiation dose to the thyroid 1 co...
Article
Arterial vasocorona
The arterial vasocorona is part of the spinal cord blood supply and is formed by pial anastomoses between the anterior and posterior spinal arteries on the surface of the spinal cord. It encircles the cord and supplies the peripheral lateral aspect of the spinal cord.
Engorgement of arterial v...
Article
Burst fracture
Burst fractures are a type of compression fracture related to high-energy axial loading spinal trauma that results in disruption of a vertebral body endplate and the posterior vertebral body cortex. Retropulsion of posterior cortex fragments into the spinal canal is frequently included in the de...