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.

601 results found
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 2 diseases can be challenging to distinguish, yet crucial because the treatments for these infections are particularly different 2. Radiographic features Useful distinguishing...
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 terminal ventricle of Krause, also known as the 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 filum terminale. This di...
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 endplates

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 haematogenously-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 involvin...
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 (pleural: 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 ...
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. Although the most recent version of the 'blue book' is the 4th edition from 2007, an update has been released in 2016 3, which should...
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 film when a pedicle is absent. The term, winking owl sign, where the missing pedicle corresponds to the closed eye, the contralateral pedicle to the other open eye, and the spinous process to the beak of the animal on ...
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".