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 edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.
618 results found
Article
Thoracolumbar spine fracture
Thoracolumbar spine fractures are often the result of significant blunt trauma such as motor vehicle accidents or falling from a height. Fractures in this region range from non-complex to highly complex and will vary in prognosis.
Epidemiology
Males are affected more commonly than females wit...
Article
Three column concept of spinal fractures
The three-column concept of thoracolumbar spinal fractures (of Denis) forms the basis of a number of widely used thoracolumbar spinal fracture classification systems.
Usage
While the three-column concept was initially developed for classification of thoracolumbar spinal fractures, it can also ...
Article
Tight filum terminale syndrome
Tight filum terminale syndrome, or tight filum syndrome, is a subtype of the tethered cord syndrome that is attributed to a thick, short, and/or otherwise inelastic filum terminale rather than other tethering agents.
Terminology
The term "tight filum terminale syndrome" is synonymous with "tet...
Article
Toothpaste sign
The toothpaste sign in spinal imaging represents an extrusion of an intervertebral disc into the epidural space. It is called after the shape of extruded material relatively to the parent disc in a sagittal plane.
Article
Torticollis
Torticollis (wryneck) is a clinical finding of head tilt with or without rotational spinal malalignment. It is not a diagnosis in itself and there are a wide range of underlying conditions. It is most common in the pediatric age group.
Pathology
Torticollis can be acute (<1 week) or chronic (...
Article
Transforaminal epidural steroid injection
Transforaminal epidural steroid injections (TFESI), also known as transforaminal nerve root injection or nerve root blocks, are performed for treatment and diagnosis of radicular pain. They differ from selective nerve root blocks (SNRB), as the aim is to get "epidural spill" and get the injectat...
Article
Transforaminal lumbar interbody fusion (TLIF)
Transforaminal lumbar interbody fusion (TLIF) is a spinal fusion procedure performed as an alternative to posterior lumbar interbody fusion (PLIF) when posterior decompression of the spinal canal is not required 1.
A facetectomy is usually performed followed by a discectomy and insertion of in...
Article
Transitional vertebra
A transitional vertebra is one that has indeterminate characteristics and features of vertebrae from adjacent vertebral segments. They occur at the junction between spinal morphological segments:
atlanto-occipital junction
atlanto-occipital assimilation: complete or partial fusion of C1 and th...
Article
Translation-rotation spine injury
Translation-rotation spine injuries are severe injuries characterized by horizontal displacement or rotation of one vertebral body with respect to another.
Pathology
These injuries result from torsional and shear forces. This type of injury is usually severe and involves the posterior ligament...
Article
Transpyloric plane
The transpyloric plane, also known as Addison's plane, is an imaginary axial plane located midway between the jugular notch and superior border of pubic symphysis, at approximately the level of L1 vertebral body. It an important landmark as many key structures are visualized at this level, altho...
Article
Transverse myelitis
Acute transverse myelitis (ATM) is an inflammatory condition affecting both halves of the spinal cord and associated with rapidly progressive motor, sensory, and autonomic dysfunction.
It is mostly imaged with MRI, which generally shows a long segment (3-4 segments or more) of T2 increased sign...
Article
Transverse process fracture
Transverse process fractures are common sequelae of trauma, although they are considered a minor and stable lumbar spine fracture. There is a strong association between transverse process fractures and other traumatic injuries.
Pathology
Transverse process fracture most commonly occurs in the ...
Article
Transversospinalis muscle group
The transversospinalis muscle group is the deep layer of the intrinsic back muscles. These muscles lie between the transverse and spinous processes and are grouped by length of the fascicles, as well as region covered. The groups are rotatores, multifidus, and semispinalis.
Gross anatomy
Rotat...
Article
Traumatic spinal cord injury
Traumatic spinal cord injury can manifest as a wide variety of clinical syndromes resulting from damage to the spinal cord or its surrounding structures. It can result from minor injury if the spine is weakened from disease such as ankylosing spondylitis or if there is pre-existing spinal stenos...
Article
Traynelis classification of atlanto-occipital dislocations
The Traynelis classification of atlanto-occipital dislocations describes injuries of the atlanto-occipital joint according to the displacement of the occipital condyles relative to the atlas:
type I: anterior displacement
type II: distraction (inferior displacement)
type III: posterior displa...
Article
Tuberculosis
Tuberculosis (commonly abbreviated to TB, short for tubercle bacillus) encompasses an enormously wide disease spectrum affecting multiple organs and body systems predominantly caused by the organism Mycobacterium tuberculosis. A small proportion can also be caused by Mycobacterium bovis.
Epide...
Article
Tuberculosis (musculoskeletal manifestations)
Musculoskeletal tuberculosis is always secondary to a primary lesion in the lung.
Epidemiology
The prevalence of the disease is around 30 million globally and 1-3% of the 30 million have involvement of their bones and/or joints. Mycobacterium tuberculosis is responsible for almost all of the c...
Article
Tuberculous spondylitis
Tuberculous spondylitis, also known as Pott disease, refers to vertebral body osteomyelitis and intervertebral diskitis from tuberculosis (TB). The spine is the most frequent location of musculoskeletal tuberculosis, and commonly related symptoms are back pain and lower limb weakness/paraplegia....
Article
Tuberculous spondylitis versus pyogenic spondylitis
Tuberculous spondylitis and pyogenic spondylitis are both common causes of spinal infection. Imaging findings of these two diseases can be challenging to distinguish, yet crucial because the treatments for these infections are particularly different 2.
Radiographic features
Useful distinguishi...
Article
Typical cervical vertebrae
Of the seven cervical vertebrae, C3 through C6 have typical anatomy, while C7 looks very similar. C1 (atlas) and C2 (axis) have very distinct anatomical features. For a basic anatomic description of the structure a generic vertebra, see vertebrae.
Gross anatomy
small, oval-shaped vertebral bod...
Article
Typical thoracic vertebrae
Given the twelve thoracic vertebrae are largely similar, most are considered typical thoracic vertebrae with the exceptions T1 and T9 to T12. For a basic anatomic description of the structure of typical vertebrae, see vertebrae.
Terminology
In medical English, some doctors and texts refer to t...
Article
Ultrasound-guided spinal anesthesia
With the growing incidence of obesity in the western world, ultrasound-guided anesthesia is becoming more common. Spinal anesthesia is traditionally administered by identifying relevant surface anatomy and imaging is rarely used for pre-procedural identification of structures.
Indications
low...
Article
Uncinate process of the cervical spine
The uncinate process of the cervical spine is a hook-shaped process found bilaterally on the superolateral margin of the cervical vertebral bodies of C3-C7.
The uncinate processes are more anteriorly positioned in the upper cervical spine and more posteriorly location in the lower cervical spin...
Article
Uncovertebral joint
Uncovertebral joints, also called Luschka’s joints, are seen bilaterally between adjacent cervical vertebrae, identified by the cat ear shaped uncinate processes of the C3-7 vertebrae (C1 and C2 have no uncinate processes).
Gross anatomy
Articulations
The articulation forms between the uncina...
Article
Unfused spinous process
Unfused spinous process, which is really failure of fusion of the neural arch, is a relatively common anatomical variant and is part of the spectrum of spina bifida occulta.
This should be differentiated from accessory ossicles of the spinous process, which appear after non-fusion of the secon...
Article
Unilateral facet dislocation
Unilateral facet dislocation is a relatively stable type of facet dislocation.
Pathology
Mechanism
Flexion/distraction associated with rotation. The inferior articular facet of vertebral above moves over the superior facet of the vertebral below and becomes locked. It usually affects C4-C5 or...
Article
Vanishing vertebrae
Vanishing vertebrae is a rare ischemic manifestation of sickle cell disease, in which a completely infarcted vertebral body literally disappears or vanishes, as a result of infarction. In the few reported cases, the posterior elements remain intact.
See also
codfish or h-shaped vertebrae
ante...
Article
Ventral cord herniation
Ventral cord herniation, also known by a variety of other terms such as spontaneous thoracic cord herniation or idiopathic spinal cord herniation, is a rare cause of focal myelopathy due to herniation of the thoracic cord through a dural defect.
Post-surgical cord herniation can occur at any l...
Article
Ventral cord syndrome
Ventral cord syndrome (also known as anterior cord syndrome) is one of the incomplete cord syndromes and affects the anterior parts of the cord resulting in a pattern of neurological dysfunction dominated by motor paralysis and loss of pain, temperature and autonomic function. Anterior spinal ar...
Article
Ventral horn
The ventral horn of the spinal cord is one of the grey longitudinal columns found within the spinal cord. It contains the cell bodies of the lower motor neurons which have axons leaving via the ventral spinal roots on their way to innervate muscle fibers.
Gross anatomy
On transverse section of...
Article
Ventriculus terminalis
The ventriculus terminalis (or persistent terminal ventricle, or terminal ventricle of Krause, or 5th ventricle) is an ependymal-lined fusiform dilatation of the terminal central canal of the spinal cord, positioned at the transition from the tip of the conus medullaris to the origin of the filu...
Article
Vertebra
The vertebra (plural: vertebrae) is the fundamental segmental unit of the vertebral column (also known as the spine).
Gross anatomy
Vertebrae, apart from those that are atypical, have a similar basic structure which can be described as an anterior vertebral body and a posterior neural (or vert...
Article
Vertebral anomalies
The vertebral column is affected by a range of anatomical variants of the body and/or neural arch as well as accessory ossicles. Knowledge of basic vertebral anatomy and ossification is essential for describing and understanding the range of anomalies.
Variant anatomy
Vertebral body
hemiverte...
Article
Vertebral artery
The vertebral arteries (VA) are paired arteries, each arising from the respective subclavian artery and ascending in the neck to supply the posterior fossa and occipital lobes, as well as provide segmental vertebral and spinal column blood supply.
Summary
origin: branches of the 1st part of th...
Article
Vertebral artery loop
Vertebral artery loops occur when a portion of the vertebral artery contains an unusual coil. It can be a rare anatomical variant or can be acquired.
Epidemiology
Vertebral artery loops tend to be mostly diagnosed in the 5th and 6th decades. Its prevalence is uncertain but is thought to be pre...
Article
Vertebral body endplate
Vertebral body endplates form the interface between the vertebral bodies and the adjacent intervertebral discs. They are constituted peripherally by an epiphyseal bone ring and centrally by a cartilaginous layer. The cartilaginous layer is related to the nucleus pulposus and annulus fibrosus and...
Article
Vertebral body mass
The differential diagnosis for a vertebral body mass is broad and may range from a completely benign, sclerotic enostosis (bone island) to a malignant primary bone tumor.
Classification
Broadly, these lesions can be separated into:
non-neoplastic lesions
primary bone tumors
secondary metast...
Article
Vertebral body squaring (differential)
Vertebral body squaring refers to the loss of normal concavity of the anterior border. It is seen in a variety of conditions including:
Differential diagnosis
Ankylosing spondylitis
Ankylosing spondylitis is the most common cause of vertebral body squaring. It usually involves multiple level...
Article
Vertebral centroid angle
The vertebral centroid angle is considered an alternative to the Cobb angle especially in kyphosis and lordosis measurement. It is considered less susceptible to variations in the vertebral end-plate architecture 2.
Article
Vertebral hemangioma
Vertebral hemangiomas are the most common benign vertebral neoplasms. They are usually asymptomatic and incidentally detected due to their characteristic features on imaging for other reasons. Rarely, they can be locally aggressive (see: aggressive vertebral hemangioma).
Please refer to the art...
Article
Vertebral lesion (differential)
Differential diagnosis of vertebral lesions includes:
Lesion originating in vertebral body
intraosseous hemangioma
metastases
Paget disease
multiple myeloma
osteonecrosis
vertebral body osteomyelitis
lymphoma
plasmacytoma
giant cell tumor
Langerhans cell histiocytosis
fibrous dyspl...
Article
Vertebral levels (anatomical landmarks)
Many vertebral levels are associated with key anatomical landmarks. Below is a summary of vertebral levels and associated internal or surface anatomy. Please note that some texts differ slightly on certain levels and levels may be altered by patient positioning (supine versus erect) and patient ...
Article
Vertebral metastases
Vertebral metastases represent the secondary involvement of the vertebral spine by hematogenously-disseminated metastatic cells. They must be included in any differential diagnosis of a spinal bone lesion in a patient older than 40 years.
This article will focus only on the metastasis involving...
Article
Vertebral pneumatocyst
Vertebral pneumatocysts are gas-filled cavities within the spinal vertebrae. They are most common at cervical levels. In general, vertebral pneumatocysts are less common than intraosseous pneumatocysts in the pelvis, especially adjacent to the sacroiliac joint.
Pathogenesis
Although not comple...
Article
Vertebral scalloping
Vertebral scalloping is a concavity to the posterior (or less commonly anterior) aspect of the vertebral body when viewed in a lateral projection. A small amount of concavity is normal, as is concavity of the anterior vertebral body (see vertebral body squaring).
Posterior scalloping
Causes of...
Article
Vertebral vascular foramen
Vertebral vascular foramina, also known as Hahn canal or cleft, are normal findings seen on cross-sectional imaging and should not be mistaken for a fracture, especially in the setting of trauma. They transmit:
basivertebral veins (forms Hahn's canal): foramen is seen on the posterior surface o...
Article
Vertebral venous plexus
The vertebral venous plexus is a highly anastomotic network of valveless veins running along the entire length of the vertebral column from the foramen magnum to the sacral hiatus.
Gross anatomy
The vertebral venous plexus is comprised of three interconnected divisions:
internal vertebral ven...
Article
Vertebra plana
Vertebra plana (plural: vertebrae planae), also known as the pancake or silver dollar or coin-on-edge vertebra, is the term given when a vertebral body has lost almost its entire height anteriorly and posteriorly, representing a very advanced compression fracture.
Pathology
It can occur in a v...
Article
Vertebra plana (mnemonic)
Mnemonics to remember the causes of vertebra plana include:
I MELT
FETISH
Mnemonics
I MELT
I: infection
M: metastasis/myeloma
E: eosinophilic granuloma
L: lymphoma/leukemia
T: trauma/tuberculosis
FETISH
F: fracture (trauma)
E: eosinophilic granuloma
T: tumor (e.g. metastases, myelom...
Article
Vertebroplasty
Vertebroplasty is an imaging-guided procedure which entails percutaneous injection of surgical polymethylmethacrylate (PMMA) cement into a diseased vertebral body. Vertebroplasty provides pain relief and strengthening of the bone of vertebrae weakened by disease.
Indications
It can be used as ...
Article
Wedge fracture
Wedge fractures (also known as compression fractures) are hyperflexion injuries to the vertebral body resulting from axial loading. Most commonly affecting the anterior aspect of the vertebral body, wedge fractures are considered a single-column (i.e. stable) fracture.
Less commonly wedge frac...
Article
Whiplash syndrome
Whiplash syndrome, also known as whiplash-associated disorders (WAD), are the various symptoms caused by rapid acceleration and/or deceleration injuries, which result in cervical sprain or strain.
Epidemiology
Whiplash is a common injury, usually associated with motor vehicle collisions 1-5. T...
Article
White cord syndrome
White cord syndrome refers to the sudden onset of neurological deterioration following spinal decompressive surgery. The condition is believed to be a form of reperfusion injury of the spinal cord, not to be confused with central cord syndrome.
Epidemiology
White cord syndrome is rare with onl...
Article
White matter
The white matter is the substance of the brain and spinal cord that contains the fiber tracts of neuronal axons in the central nervous system. The term is due to the paler color of the lipid-rich myelin that encases the axons in the tracts compared to the grey matter, which contains predominantl...
Article
White matter tracts of the spinal cord
The spinal cord has numerous tracts of white matter that ascend and descend in the peripheral substance of the cord. They can be divided by their location and function:
anterolateral columns
anterior corticospinal tract
medial longitudinal fasiculus
spinothalamic tracts
lateral spinothalami...
Article
WHO classification of CNS tumors
The WHO classification of CNS tumors is the most widely accepted system for classifying CNS tumors and was based on the histological characteristics of the tumor. The most recent version of the 'blue book' is the revised 4th edition released in 2016 3.
This 2016 update has, for the first time, ...
Article
Widening of interpedicular distance
The interpedicular distance, which is the distance measured between the pedicles on frontal/coronal imaging, can be widened in a number of situations.
Pathology
Etiology
diastematomyelia
syringomyelia
conditions that can cause dural ectasia (can potentially cause widening)
Marfan syndrome
...
Article
Wiltse classification (spondylolisthesis)
Spondylolisthesis can be classified according to broad etiologies as described by Wiltse in 1981 1. Typically when reporting studies with spondylolisthesis the Wiltse type is merely stated without referring to its number, whereas the grade of spondylolisthesis is explicitly stated: e.g. "Grade 1...
Article
Winking owl sign (spine)
The (absent) pedicle sign, also called the winking owl sign, occurs on plain radiograph of the spine when a pedicle is absent 5.
The term, winking owl sign, where the missing pedicle corresponds to the closed eye, the contralateral pedicle to the other round open eye, and the spinous process to...
Article
Y sign (epidural lipomatosis)
The Y sign refers to a common appearance in lumbar epidural lipomatosis where excess fat in the extradural space compresses the dural sac into the shape of the letter "Y".
NB: Y sign also refers to the appearance of incudomalleolar disarticulation on CT, more commonly known to radiologists as t...