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.

Create new article

714 results found

Supraspinous ligament

The supraspinous ligament runs along the tips of adjacent spinous processes and is particularly thick in the cervicothoracic region. Above the level C7 spinous process the ligament no longer directly attaches to the spinous process but rather continues as the nuchal ligament up to its attachment...

Interspinous ligament

The interspinous ligaments join the spinous processes along their adjacent borders. They are composed of relatively weak fibrous tissue that fuses with the stronger, supraspinous ligaments.

Posterior atlanto-occipital membrane

The posterior atlanto-occipital membrane attaches the anterosuperior border of the posterior arch of the atlas (C1) to the posterior margin of the foramen magnum. It lies immediately posterior to the spinal theca and is continuous inferiorly with the ligamentum flavum (sometimes referred to at C...

Ligamentum flavum

The ligamenta flava (singular: ligamentum flavum) are paired ligaments which run between adjacent laminae of the vertebral bodies and are present from C2/3 to the sacrum. Above the C2/3 level, the equivalent structures are known as the posterior atlanto-occipital membrane between the skull base ...

Tectorial membrane of the spine

The tectorial membrane is the thin superior continuation of the posterior longitudinal ligament from the body of the axis. It joins the axis body to the clivus on the anterior half of the foramen magnum, and ascends as high as the spheno-occipital synchondrosis and laterally extends to the hypog...

Posterior longitudinal ligament

The posterior longitudinal ligament (PLL) is a long and important ligament located immediately posterior to the vertebral bodies (to which it attaches loosely) and intervertebral discs (to which it is firmly attached). It extends from the back of the sacrum inferiorly and gradually broadens as ...

Cruciate ligament of the atlas

The cruciate ligament of the atlas (also known as the cruciform ligament) is an important ligamentous complex that holds the posterior dens of C2 in articulation at the median atlantoaxial joint. It lies behind a large synovial bursa (surrounded by loose fibrous capsule) and consists of two band...

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...

Apical ligament

The apical ligament is a small ligament that joins the apex (tip) of the dens of C2 to the anterior margin (basion) of the foramen magnum. It is the weak, fibrous remnant of the notochord and does not contribute significantly to stability. The more posterior alar and cruciate ligaments are stro...

Anterior atlanto-occipital membrane

The anterior atlanto-occipital membrane is a thin membrane that joins the upper border of the anterior arch of the atlas (C1) to the anterior inferior surface of the foramen magnum. It is a continuation of the anterior longitudinal ligament above the C1 level. It is immediately posterior to the ...

Anterior longitudinal ligament

The anterior longitudinal ligament (ALL) runs along the anterior surface of the vertebral bodies (firmly united to the periosteum) and intervertebral discs (attaching to the anterior annulus). It ascends from the anterosuperior portion of the sacrum superiorly to become the anterior atlantooccip...

Retrodural space of Okada

The retrodural space of Okada is a wishbone-shaped potential space which links the facet joints to each other at a single level across the midline, and thus acts as a potential pathway for the spread of injected material (contrast, air, steroid, local anesthetic) as well as infection. Gross an...

Sacral dimple

Sacral dimples are a clinical and radiological feature that is associated with occult spinal dysraphism (e.g. tethered cord syndrome) but are more frequently a non-significant isolated finding. Epidemiology Common in healthy children (~5%) 1. Pathology Simple sacral dimples have the followin...

Spinal wedge fracture

Spinal wedge (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. Terminology Less commonly wedge fracture...

Subluxed facet joint

Subluxed facet joint is the mildest form of facet dislocation in which the ligamentous injury leads to partial uncovering of a facet joint (cf. complete uncovering in perched facet). This results in mild anterior displacement of one vertebral body on another (anterolisthesis).

Allen and Ferguson classification of subaxial cervical spine injuries

Allen and Ferguson classification is used for research purposes to classify subaxial spine injuries and is based purely on the mechanism of injury and position of the neck during injury. This classification was proposed by Allen and Ferguson in 19823 and at the time of writing (July 2016) remain...

Romanus lesion (vertebral bodies)

The Romanus lesion represents an early finding in inflammatory spondyloarthropathies, such as ankylosing spondylitis and enteropathic arthritis, and appears as irregularity and erosion involving the anterior and posterior edges of the vertebral endplates 1. Healing response to these inflammatory...

Atlanto-axial articulation

The atlanto-axial articulation is a complex of three synovial joints, which join the atlas (C1) to the axis (C2). Gross anatomy Articulations paired lateral atlanto-axial joints: classified as planar-type synovial joint between the lateral masses of C1 and C2, though somewhat more complex in ...

Atlanto-occipital articulation

The atlanto-occipital articulation (also known as the C0-C1 joint/articulation) is comprised of a pair of condyloid synovial joints that connect the occipital bone (C0) to the first cervical vertebra (atlas/C1). Gross anatomy Articulations Each joint is comprised of two concave articular surf...

Levine and Edwards classification

The Levine and Edwards classification is the most widely used classification system of hangman fractures of the C2 vertebra 3. The injury, also known as traumatic spondylolisthesis of the axis, and the amount and direction of displacement determines stability and guides treatment. The classifica...

Cervical spine fracture classification systems

There are several cervical spine fracture/injury classification systems. These can be divided by site and are listed below in order of recency: upper cervical spine (including craniocervical junction) injuries 1 AO Spine classification of upper cervical injuries occipital condyle fractures T...

Intercalary bone

Intercalary bones are common discal ossifications that are usually triangular in morphology, found in the anterior annular fibers of an intervertebral disc, and are thought to be degenerative in etiology. Differential diagnosis limbus vertebra flexion or extension teardrop fracture

Locked facet joint

Locked facet joint is a type of facet joint dislocation that results from jumping of the inferior articular process over the superior articular process of the vertebra below and becomes locked in the position. It can be unilateral or bilateral. Radiographic features Plain radiograph The tip ...

Anterior subluxation of the cervical spine

Anterior subluxation of the cervical spine, also known as hyperflexion sprain, is a ligamentous injury of the cervical spine. Clinical presentation Patients present with severe, focal neck pain. There may be neurological symptoms due to spinal cord injury. Pathology Anterior subluxation of t...

Bilateral facet dislocation

A bilateral facet dislocation is an unstable flexion distraction type of dislocation of the cervical spine, often a result of buckling force. Occasionally, the bilateral facet dislocation has been named a 'doubly-locked' vertebral injury giving the impression of stability. However, due to comple...

Transverse process fracture

Transverse process fractures are common sequelae of trauma, although they are considered minor and stable lumbar spine fractures. There is a strong association between transverse process fractures and other traumatic injuries. Pathology Transverse process fracture most commonly occurs in the u...

Synovial cyst

Synovial cysts are para-articular fluid-filled sacs or pouch-like structures containing synovial fluid and lined by synovial membrane. They can occur around virtually every synovial joint in the body and also around tendon sheaths and bursae. Communication with the adjacent joint always occurs. ...

Congenital lumbar spinal stenosis

Congenital lumbar spinal stenosis is a type of spinal canal stenosis and has different epidemiology with less severe degenerative change compared to acquired/degenerative lumbar spinal stenosis. Epidemiology Congenital lumbar spinal stenosis tends to affect patients at a younger age (30-50 ye...

Posterior ring apophyseal fracture

Posterior ring apophyseal fracture or separation, also called limbus fracture, occur in the immature skeleton, most commonly in the lumbar spine. They represent bony fractures of the vertebral body rim at the site of attachment of the Sharpey fibers of the intervertebral disc. Terminology Not ...

Lipomyelocele

Lipomyelocele, also known as lipomyeloschisis, is one of the most common closed spinal dysraphism. It is seen in the thoracolumbar region and usually presents as a fatty subcutaneous mass. It is twice as common as lipomyelomeningocele. Clinical presentation Affected individuals are usually as...

Spinal cord compression (summary)

This is a basic article for medical students and other non-radiologists Spinal cord compression is a surgical emergency and if unrecognised or untreated, can result in irreversible neurological damage and disability. If the spinal roots below the conus medullaris are involved, it is termed caud...

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...

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...

Quadratus lumborum muscle

The quadratus lumborum muscle is a paired, irregular quadrilateral muscle that forms part of the posterior abdominal wall. Summary location: posterior abdominal wall attachments: inferior margin of 12th rib and upper four lumbar transverse processes, iliac crest and iliolumbar ligament blood...

Cyst of the medullary conus

Cyst of the medullary conus is a rare benign ependymal cyst of the conus medullaris which probably relates to abnormal persistence and cystic dilatation of the ventriculus terminalis or "5th ventricle". This entity can be symptomatic and present in adulthood with bladder or bowel sphincter distu...

Spinal anatomy

Spinal anatomy encompasses the anatomy of all osseous and soft tissue structures of the spine, the spinal cord and its supporting structures. This anatomy section promotes the use of the Terminologia Anatomica, the international standard of anatomical nomenclature. Overview The spine is loca...

Thorax

The thorax (plural: thoraces) also known as the chest, refers to that anatomical region of the body containing the heart and lungs, thoracic aorta, great vessels and surrounding structures, all contained within the thoracic cavity. It also includes the thoracic skeleton, the thoracic spine, and ...

Neuroanatomy

Neuroanatomy encompasses the anatomy of all structures of the: central nervous system (CNS), includes brain and spinal cord peripheral nervous system (PNS) supporting tissues and structures The functional description of neuroanatomy divides the nervous system into: somatic nervous system a...

Lumbar spine

The lumbar spine (often shortened to L-spine) consists of five adjacent vertebrae of the lower vertebral column, in some cases it is possible to find 4 or 6 vertebrae as an anatomical variant. They participate in the lumbar lordosis, a natural curve in the spine, that is convex anteriorly. Art...

Cervical spine ligaments

Cervical spine ligaments ordered from anterior to posterior include: anterior longitudinal ligament (ALL) anterior atlanto-occipital membrane apical ligament alar ligaments (paired) cruciate ligament of the atlas longitudinal band: joins the body of the axis to the foramen magnum transver...

Fifth lumbar vertebra (L5)

The fifth lumbar vertebra (L5) is the largest of the five lumbar vertebrae and is considered an atypical vertebra due to its shape. Gross anatomy L5 is the largest, most inferior lumbar discovertebral unit in the vertebral column, and participates in forming the lumbar lordosis (from L1 to L5...

Ghost vertebra

Ghost vertebra is a sign, that is generally used synonymously with bone-within-a-bone vertebra, and as such, the causes form a subset of those causing bone within a bone appearance 2: Thorotrast administration: bone within a bone appearance due to temporary growth arrest 1 stress line rickets...

Pseudomeningocele

Pseudomeningoceles are abnormal collections of cerebrospinal fluid (CSF) that occur due to leakage from the CSF-filled spaces surrounding the brain and/or spinal cord as a result of trauma or surgery. Epidemiology Spinal pseudomeningoceles can occur in <2% of patients following laminectomy or...

Craniovertebral junction anomalies

Craniovertebral junction (CVJ) anomalies can be congenital, developmental or due to malformation secondary to any acquired disease process. These anomalies can lead to cranial nerve compression, vertebral artery compression, and obstructive hydrocephalus. Pathology The craniovertebral junction...

Conus medullaris syndrome

Conus medullaris syndrome is caused by an injury or insult to the conus medullaris and lumbar nerve roots. It is a clinical subset of spinal cord injury syndromes. Injuries at the level of T12 to L2 vertebrae are most likely to result in conus medullaris syndrome. Clinical presentation Patient...

Posterior spinal artery syndrome

Posterior spinal artery syndrome is a rare syndrome associated occlusion of the posterior spinal artery and results in a unilateral dorsal cord syndrome (since the posterior arteries are paired) 3. The syndrome is clinically characterized by isolated loss of proprioception and vibratory sensat...

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...

Nitrous oxide toxicity

Nitrous oxide (N2O) toxicity has serious medical sequelae affecting both the CNS and the bone marrow. Neurological effects include encephalopathy, myelopathy, and neuropathy. This results from demyelination and gliosis due to selective inhibition of vitamin B12 1. Bone marrow toxicity may lead t...

Brown-Séquard syndrome

Brown-Séquard syndrome, also known as hemicord syndrome, is the result of damage to, or impairment of, the left or right side of the spinal cord. It is characterized by a characteristic pattern of motor and sensory deficits that are determined by the decussation pattern of various white matter t...

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...

Dorsal thoracic arachnoid web

Dorsal thoracic arachnoid web refers to a thickened band of arachnoid over the dorsal aspect of the cord. It usually causes a focal thoracic cord distortion with consequent neurological dysfunction. On imaging, it is characterized by a focal dorsal indentation and anterior displacement of the ...

Scalpel sign (spinal cord)

The scalpel sign has been recently described in dorsal thoracic arachnoid web on sagittal MRI spine studies. It relates to focal distortion of the thoracic cord, appearing anteriorly displaced. The enlarged dorsal CSF space mimics the profile of a surgical scalpel. It is helpful in distinguishi...

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...

C7 vertebra

The seventh cervical vertebra, C7, also known as the vertebra prominens, shares similar characteristics of the like typical cervical vertebra C3-C6, but has some distinct features making it one of the atypical vertebrae. The name vertebra prominens arises from its long spinous process, which is ...

Atlas (C1)

The atlas (plural: atlases) is the first cervical vertebra, commonly called C1. It is an atypical cervical vertebra with unique features. It articulates with the dens of the axis and the occiput, respectively allowing rotation of the head, and flexion, extension and lateral flexion of the head. ...

Cervical spine

The cervical spine (often shortened to C-spine) is the upper part of the spine extending from the skull base to the thorax at the level of the first vertebra with a rib attached to it. It normally consists of seven vertebrae. Its main function is to support the skull and maintain the relative po...

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...

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...

Thoracolumbar injury classification and severity score (TLICS)

The thoracolumbar injury classification and severity score (TLICS), also sometimes known as the thoracolumbar injury severity score (TISS), was developed by the Spine Trauma Group in 2005 to overcome some of the perceived difficulties regarding the use of other thoracolumbar spinal fracture clas...

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...

Modic type I endplate change

Modic type I endplate change is the most controversial and important of the three types described (see Modic endplate change). It is seen on MRI of the spine and represents the presence of low T1 and high T2 signal within the bone marrow of a vertebral body adjacent to a disk. Type 1 change can...

Filum terminale

The filum terminale is a small thin filament of connective tissue that extends inferiorly from the apex of the conus medullaris to the sacrum. Gross anatomy The filum terminale is continuous with the pia mater and is described as having two sections: filum terminale internum: upper three quar...

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL)

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a systemic genetic disorder affecting the cerebral small vessels, spine and hair follicles. It should not be confused with its autosomal dominant counterpart, CADASIL. Autosomal recessive i...

Posterior spinal arteries

The posterior spinal arteries are a pair of arteries that supply the respective ipsilateral grey and white posterior columns of the spinal cord. Gross anatomy The posterior spinal arteries arise from either the posterior inferior cerebellar or vertebral arteries (V3 or V4 segments) and run ...

Spinal epidural space

The spinal epidural (extradural) space is distinctly separate from and not continuous with the cranial epidural space. Its exact definition and description are contentious 3. Gross anatomy The spinal epidural space is located in the spinal canal between the spinal dura mater and the vertebral...

Spinal epidural abscess

Spinal epidural abscess represents infection of the epidural space, located between the spinal dura mater and the vertebral periosteum. It can present with rapidly deteriorating neurological function due to compression. Imaging is best performed with MRI and emergency surgery is often required. ...

Cauda equina syndrome

Cauda equina syndrome is considered an incomplete cord syndrome, even though it occurs below the conus. Cauda equina syndrome refers to a collection of symptoms and signs that result from severe compression of the descending lumbar and sacral nerve roots. It is most commonly caused by an acutely...

Sacrum

The sacrum is the penultimate segment of the vertebral column and also forms the posterior part of the bony pelvis. It transmits the total body weight between the lower appendicular skeleton and the axial skeleton. Gross anatomy The sacrum is an irregularly-shaped bone, shaped roughly like an ...

Cauda equina

The cauda equina is the collective term given to nerve roots distal to the conus medullaris, which occupy the lumbar cistern. Its name comes from the Latin for "horse's tail". The cauda equina is contained within the thecal sac and suspended in CSF. The lower sacral (S2-S5) and coccygeal root...

Parasyndesmophytes

Parasyndesmophytes or floating syndesmophytes are, as the name suggests, paravertebral dystrophic soft tissue calcifications or heterotopic ossifications. Pathology Etiology They are known to be seen in 4: psoriatic arthritis reactive arthritis Radiographic features Initially they begin ...

Atlanto-occipital assimilation

Atlanto-occipital assimilation is the fusion of the atlas (C1) to the occiput and is one of the transitional vertebrae. Epidemiology Atlanto-occipital assimilation occurs in approximately 0.5% (range 0.08-3%) of the population 2-5,. It is thought to affect males and females equally. Clinical...

Epidural angiolipoma

Epidural angiolipomas are rare benign tumors composed of mature adipocytes and abnormal vessels. Epidemiology Epidural angiolipomas are more frequently encountered in women, and typically in middle age (40-50 years of age) 1. Clinical presentation In keeping with the slow growth of these t...

Angiolipoma

Angiolipomas (also sometimes known as haemangiolipomas, vascular lipomas, and fibromyolipomas) are rare soft tissue tumors composed of mature adipocytes and vessels. They can occur essentially anywhere and can be subclassified into infiltrating and non-infiltrating variants 1. Please refer to ...

MRI classification system for lumbar disc degeneration

Disc degeneration can be graded on MRI T2 weighted images. Usage The Pfirrmann grading system is the most widely known classification for intervertebral disc degeneration and is used in both clinical and research capabilities 2,3. The intra- and inter-observer agreement of the Pfirrmann gradin...

Bullet-shaped vertebra

Bullet-shaped vertebra, also known as ovoid vertebra, refers to the anterior beaking of the vertebral body. It is seen in the following conditions: mucopolysaccharidosis (Morquio disease, Hurler disease) achondroplasia congenital hypothyroidism progressive pseudorheumatoid dysplasia 4 Wils...

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...

Syndesmophyte

Syndesmophytes are calcifications or heterotopic ossifications inside a spinal ligament or of the annulus fibrosus. They are seen in only a limited number of conditions including: ankylosing spondylitis ochronosis fluorosis reactive arthritis psoriatic arthritis They can be ...

HIV-related vacuolar myelopathy

HIV-related vacuolar myelopathy, also known as AIDS-related myelopathy, is the most common chronic myelopathy associated with HIV infection and is typically seen in the late stages of the disease. Clinical presentation Patients tend to have slowly progressive weakness of the lower extremities,...

Spinal cord blood supply

The spinal cord blood supply is a complex arrangement of arterial and venous plexuses. Arterial supply The spinal cord receives its blood supply by contributions from both longitudinal and reinforced by segmental (aka radiculomedullary) arteries. Longitudinally, it receives supply from thre...

Cervical degenerative spondylosis (grading)

Cervical degenerative disease can be graded using a very old but reliable classification given by Kellgren et al. It is based on findings on a lateral cervical spine radiograph although it can also be applied to MRI evaluation of spine. The key parameters are osteophyte formation, intervertebra...

Opticospinal multiple sclerosis

Opticospinal multiple sclerosis (OSMS) is a demyelinating disease and has been considered a variant of multiple sclerosis (MS) encountered in Asian populations, who are generally rarely affected by normal multiple sclerosis. It has similar clinical and imaging features to neuromyelitis optica (N...

Longitudinally extensive spinal cord lesion

Longitudinally extensive spinal cord lesions (LESCL), also known as longitudinally extensive transverse myelitis (LETM), represent extensive involvement of the spinal cord, with abnormal T2 signal traversing at least three vertebral body segments in length. Differential diagnosis They are typi...

Artery of Adamkiewicz

The artery of Adamkiewicz, also known as the great anterior radiculomedullary artery or arteria radicularis anterior magna, is the name of the dominant thoracolumbar segmental medullary artery, which supplies the lower spinal cord by reinforcing the anterior spinal artery. Gross anatomy The ar...

Lipomyelomeningocele

Lipomyelomeningoceles are one of the forms of closed spinal dysraphism. They usually present as a subcutaneous fatty mass just above the intergluteal cleft. However, some lipomyelomeningoceles may occur at other locations along the spinal canal. Clinical presentation Lipomyelomeningoceles may ...

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...

Radiation-induced MRI signal changes in bone marrow

Radiation-induced MRI signal changes in bone marrow are the earliest detectable changes in bone. Their severity correlates with increasing radiation dose. Pathology 1st week: decreased marrow cellularity with edema and hemorrhage 2nd week: increased marrow cellularity due to influx from non-i...

Occipital vertebra

Occipital vertebrae are very rare anatomical variants that result from incomplete or aberrant fusion of occipital bone ossification centers. There is a broad spectrum of occipital vertebrae variations and the four most common include: third condyle (condylus tertius) basilar process paracondy...

Vertebral hemangioma

Vertebral hemangiomas are the most common benign vertebral neoplasms. That said, they are not true neoplasms but venous malformations. They are usually asymptomatic and incidentally detected due to their characteristic features on imaging for other reasons. Rarely, they can be locally aggressive...

Oppenheimer ossicle

Oppenheimer ossicles are accessory ossicles associated with the facet joints and are found in ~4% (range 1-7%) of lumbar spines 1. Gross anatomy Oppenheimer ossicles predominantly occur as a single, unilateral ossicle of the inferior articular processes of the lumbar spine although they can a...

Sesamoid ossicles of the nuchal ligament

Sesamoid ossicles of the nuchal ligament are a relatively common anatomical variant that are usually asymptomatic and most commonly occur at the C5-C6 or C6-C7 vertebral levels. Epidemiology They occur in ~7.5% of the population, with a male predominance of 3:1 1. Radiographic features Pla...

Lumbar rib

Lumbar (or 13th) ribs are a rare anatomical variant and represent transitional vertebrae at the thoracolumbar junction with a prevalence of ~1% 1. It presents as an additional rib coming off T13 or L1 (depending on numbering classification) and may be unilateral or bilateral. Lumbar ribs are mos...

Boogard's angle

Boogard's angle is measured by drawing a line from basion to opisthion and another line along the plane of the clivus to the basion intersecting the first line - the angle between these two lines is measured. The normal angle is 126° +/- 6°. If the angle measures more than 136° it is indicative...

Klaus height index

Klaus height index is the distance between tip of the dens and the tuberculum torcula line (Twining's line) 1,2. A normal height is 40-41 mm. A decreased Klaus height index is seen in basilar invagination.

Filtered (1)Done (clear)

+Systems

+Article Sections

+Sort By

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

Unable to process the form. Check for errors and try again.

Thank you for updating your details.