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
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Olisthesis

Olisthesis, also known as the etymologically less correct listhesis, means slipping or sliding. Pathology Types include: anterolisthesis spondylolisthesis spondylolisthesis grading retrolisthesis
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Oppenheimer ossicle

Oppenheimer ossicles are accessory ossicles associated with the facet joints found in ~4% (range 1-7%) 1 of lumbar spines.  Oppenheimer ossicles are thought to arise as a result of non-union of a secondary ossification center of the articular process. They predominantly occur as a single, unila...
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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...
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Os odontoideum

Os odontoideum (plural: ossa odontoidea) is an anatomic variant of the odontoid process of C2 and needs to be differentiated from persistent ossiculum terminale and from a type 2 odontoid fracture. It can be associated with atlantoaxial instability.  Although it was originally thought to be a c...
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Ossification centers of the vertebral column

Ossification of the vertebral column is complex but an overview of primary and secondary ossification centers is given below: Primary ossification centers The C3-L5 vertebrae typically have three primary ossification centers that start appearing at 9 weeks in utero and finish primary ossificat...
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Ossification of the ligamentum flavum

Ossification of the ligamentum flavum (OLF) is a phenomenon where there is a formation of ossific-calcific components in the ligamentum flavum. It is recognized causes of myelopathy (especially in the thoracic and to a lesser degree the cervical region). Epidemiology The condition as a whole i...
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Ossification of the posterior longitudinal ligament

Ossification of the posterior longitudinal ligament (OPLL) is typically an entity seen in patients of Asian descent, although it is seen in all ethnic groups. It is characterized by, as the name suggests, ossification of the posterior longitudinal ligament. Epidemiology There is a recognized g...
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Osteoarthritis of the vertebral column

Osteoarthritis of the vertebral column, also known as spondylosis deformans, is common and usually merely referred to as spinal "degenerative change". Complications such as spinal stenosis are important to recognize.  Radiographic features The hallmark of osteoarthritis in the spine, as is the...
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Osteophyte

Osteophytes are cartilage-capped bony proliferations (spurs) that most commonly develop at the margins of a synovial joint as a response to articular cartilage damage, as seen very commonly in degenerative joint disease. Central osteophytes can develop from cartilage lesions within a joint. They...
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Osteoporotic spinal compression fracture

Osteoporotic spinal compression fractures occur as a result of injury, commonly fall onto the buttock or pressure from normal activities, to the weakened vertebrae due to osteoporosis. Epidemiology They have a reported incidence of 1.2 per 1000 person-years after 85 years of age in the United ...
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Owl-eyes sign (spinal cord)

The owl-eyes sign, also referred to as snake-eyes sign or fried-eggs sign, represents bilaterally symmetric circular to ovoid foci of high T2-weighted signals in the anterior horn cells of the spinal cord and is seen on axial MR imaging. The sagittal corollary is a "pencil-like" vertical linear ...
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Paracondylar process

Paracondylar process is a rare anatomical variant of the occipital bone, where a bony exostosis extends caudally from the paracondylar region (lateral to the native occipital condyles), typically articulating with the superior surface of a transverse process of the atlas. This may be unilateral ...
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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 ...
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Pars interarticularis

The pars interarticularis or simply pars is the part of a vertebra located between the superior and inferior articular processes. In the axial plane the pars in located at the junction of the pedicle and lamina. In the oblique lumbar radiograph, the neck of the Scottie dog represents the pars. ...
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Pathology checklists

Pathology checklists are series of sometimes missed pathological entities possible to see on radiological studies. They are helpful when reporting a radiograph, ultrasound, or cross-sectional examination as a way to ensure that you fully review a film and don't fall foul of satisfaction of searc...
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Perched facet joint

Perched facet joint is a vertebral facet joint whose inferior articular process appears to sit 'perched' on the ipsilateral superior articular process of the vertebra below. Any further anterior subluxation will result in dislocation, with one facet "jumping" over the other and becoming locked ...
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Peripheral nerve sheath tumors

Peripheral nerve sheath tumors (PNSTs) are a group of primary neurogenic tumors that arise from nerve sheaths outside of the central nervous system. The vast majority are benign, however, malignant transformation is seen particularly in large tumors and those associated with neurofibromatosis ty...
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Perivertebral space

The perivertebral space is one of the deep compartments of the head and neck and includes the prevertebral space and paraspinal space. Gross anatomy The perivertebral space is a cylinder of soft tissue lying posterior to the retropharyngeal space and danger space surrounded by the prevertebral...
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Persistent ossiculum terminale

The ossiculum terminale appears as a secondary ossification center of the dens between 3-6 years and normally fuses by 12 years. Failure of fusion results in a persistent ossiculum terminale (also called Bergmann's ossicle or ossiculum terminale of Bergmann) and is considered a normal anatomical...
Article

Picture frame vertebral body

Picture frame vertebral body is a radiologic appearance in which the cortex of the vertebral body is thickened. This sign can be seen in patients with Paget disease.  It is a result of disorganized new cortical bone formation after excessive osteoclastic activity causes the resorption of normal...
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Pine cone bladder

A pine cone bladder or Christmas tree bladder is a cystographic appearance in which the bladder is elongated and pointed with a thickened, trabeculated wall. It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesion...
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Pneumatic nerve root compression

Pneumatic nerve root compression is a term given nerve root compression due to a presence of a juxtadiscal herniated gas locule. It is not a common occurence 2. The gas locules in these instances typically arise from herniation of intradiscal gas which occurs as part of disc degenerative change....
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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 ...
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Poliomyelitis-like syndrome

Poliomyelitis-like syndrome, or polio-like paralysis, is an uncommon 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 infective etiol...
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Polka-dot sign (vertebral hemangioma)

The polka-dot sign is the result of the replacement of the normal cancellous bone by thickened vertical trabeculae surrounded by fat marrow or vascular lacunae in vertebral intraosseous hemangiomas 2. It is the axial equivalent of the corduroy sign seen on sagittal and coronal images. On CT the ...
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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...
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Posterior inferior cerebellar artery

Posterior inferior cerebellar artery (PICA) is one of the three vessels that provide arterial supply to the cerebellum. It is the most variable and tortuous cerebellar artery. Gross anatomy Origin Its origin is highly variable: ~20% arise extracranially, inferior to the foramen magnum 10% a...
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Posterior ligamentous complex

The posterior ligamentous complex acts to stabilize the vertebral column and prevents injurious flexion, distraction, rotation and translation. It is sometimes referred to as the posterior tension band although the latter also includes the spinous process.  The posterior ligamentous complex com...
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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 ...
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Posterior lumbar interbody fusion (PLIF)

Posterior lumbar interbody fusion (PLIF) is a commonly performed spinal fusion procedure that can be performed at a single level or a multiple adjacent levels. It relies on the introduction of pedicle screws with connecting rods posteriorly. A partial laminectomy is performed to gain access to ...
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Posterior lumbar subcutaneous edema

Posterior lumbar subcutaneous edema is a very frequent finding on MRI of the spine. Clinical correlation is almost always required to identify the significance of this. Epidemiology It is more common in elderly and female patients.  Pathology Etiology It is a result of poor lymphatic draina...
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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 ...
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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 runs t...
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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...
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Posterior vertebral element lesions (mnemonic)

A mnemonic for posterior vertebral element lesions is: GO TAPE Mnemonic G: giant cell tumor  O: osteoid osteoma / osteoblastoma T: tuberculosis A: aneurysmal bone cyst P: Paget disease E: eosinophilic granuloma
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Posterior vertebral fusion anomalies

Posterior vertebral fusion anomalies are relatively common and should not be mistaken for fractures. They are thought to be both developmental and pathological (e.g. spondylolysis) but are typically asymptomatic and incidental, and considered as anatomical variants. There are six types of poster...
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Posterior vertebral scalloping (mnemonic)

A useful mnemonic to remember the differential diagnoses for posterior vertebral scalloping is: SALMON Mnemonic S: spinal cord tumor (e.g. astrocytoma, ependymoma, schwannoma) A: achondroplasia, acromegaly L: Loeys-Dietz syndrome (and other connective tissue disorders) M: Marfan's syndrome...
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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...
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Primary bone tumors of the spine

The most common tumor of the spine is metastatic deposits. A number of both benign and malignant tumors may arise primarily from the spine. Benign osteoid osteoma osteoblastoma osteochondroma giant cell tumor (GCT) aneurysmal bone cyst (ABC) eosinophilic granuloma (EG) hemangioma Malign...
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Pseudosinus tract

A pseudosinus tract is a normal fibrous cord extending from the coccyx to an overlying sacral dimple. These have no associated mass and contain no fluid (if CSF drainage is occurring via the sacral dimple, then a true dorsal dermal sinus should be considered). Diagnosis Ultrasound Hypoechoic ...
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Pseudosubluxation of the cervical spine

Pseudosubluxation of the cervical spine is the physiological anterior displacement of C2 on C3 in children. It is common in children <7 years, and less often present in older children. Less often it is seen at C3 on C4. It is more pronounced in flexion and is of clinical significance as it can b...
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Pyogenic spondylitis

Pyogenic spondylitis refers to infections of the spine which involve the vertebrae, intervertebral disc, paraspinal soft tissue, or epidural space 1,2. It is a broad term that includes vertebral osteomyelitis, spondylodiskitis, and epidural abscess. This article is a general discussion of pyoge...
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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...
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Rachischisis totalis

Rachischisis totalis, also known as complete spina bifida, refers to a severe form of spina bifida where there is a cleft through the entire spine. Pathology There is often a severe or complete defect of the neural tube involving the entire spine from the cervical region through to the sacrum....
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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...
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Red and yellow flags for guiding imaging of lower back pain

Lower back pain (also known as lumbago) is very common and often referred for imaging, with the vast majority of cases due to benign self-limiting causes which don't require imaging and resolve with conservative measures. Numerous authors have described various methods for supporting appropriate...
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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...
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Retrolisthesis

The term retrolisthesis (less commonly known as retrospondylolisthesis or posterolisthesis, or reverse vertebral slip) refers to posterior displacement of a vertebral body relative to the caudal vertebral body. Pathology Causes include: trauma facet joint osteoarthritis congenital anomalies...
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Retro-odontoid pseudotumor

Retro-odontoid pseudotumors, also known as periodontoid pseudotumors, are non-neoplastic soft tissue masses adjacent to the odontoid process (dens) of C2, which can cause cervicomedullary compression. Epidemiology The prevalence of retro-odontoid soft tissue thickening, particularly with miner...
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Retropulsed fragment

A retropulsed fragment is any vertebral fracture fragment that is displaced into the spinal canal, thereby potentially causing spinal cord injury. They usually arise from the vertebral body with or without a portion of the pedicle, and are displaced posteriorly, hence the prefix 'retro'.
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Rim sign (spinal cord metastasis)

The rim sign has been described as a helpful MRI sign of spinal cord metastases, enabling them to be distinguished from other enhancing spinal cord lesions (e.g. ependymoma and astrocytoma).  Radiographic features MRI The rim sign is seen on sagittal post contrast T1 weighted imaging of the s...
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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...
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Roy-Camille classification of odontoid process fracture

The Roy-Camille classification of fractures of the odontoid process of C2 depends on the direction of the fracture line 1. The level of fracture line as described by the Anderson and D’Alonzo classification is not predictive of the degree of instability or the risk of non-union. This classifica...
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Rubrospinal tract

The rubrospinal tract contains neurons that carry signals from the corticorubral tract. The tract is thought to excite flexor muscles and inhibit extensor muscles. Gross anatomy Central connections The magnocellular portion of the red nucleus gives rise to the rubrospinal tract. It decussates...
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Rugger jersey spine (hyperparathyroidism)

Rugger jersey spine describes the prominent endplate densities at multiple contiguous vertebral levels to produce an alternating sclerotic-lucent-sclerotic appearance. This mimics the horizontal stripes of a rugby jersey. This term and pattern are distinctive for hyperparathyroidism. Pathology ...
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Sacral agenesis

Sacral agenesis (also considered as part of the caudal regression syndrome) is a rare and severe sacral developmental abnormality. Epidemiology In normal pregnancy, the incidence is between 0.005 and 0.1%. However, in fetuses with diabetic mothers, the incidence rises to 0.2%. Of those with th...
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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...
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Sacral hiatus

The sacral hiatus corresponds to the posterior caudal opening at the end of the sacral canal, which usually occurs at the fifth sacral vertebra (S5), at the posterior surface of the sacrum. Gross anatomy Location Commonly, the sacral hiatus corresponds to the non-formation of S5 spinous proce...
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Sacral insufficiency fracture

Sacral insufficiency fractures are a subtype of stress fractures, which are the result of normal stresses on abnormal bone, most frequently seen in the setting of osteoporosis. They fall under the broader group of pelvic insufficiency fractures. Clinical presentation They are usually seen in e...
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Sacral lesions

A very wide range of lesions can occur in and around the sacrum.  Tumors primary sacral tumors malignant sacral chordoma: most common primary sacral tumor 1 chondrosarcoma Ewing sarcoma / pPNET osteosarcoma: often arises from Paget disease in this location multiple myeloma/plasmacytoma ...
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Sacrococcygeal teratoma

Sacrococcygeal teratoma (SCT) refers to a teratoma arising in the sacrococcygeal region. The coccyx is almost always involved 6. Epidemiology It is the commonest congenital tumor in fetus 11 and neonate 3. The incidence is estimated at ~1:35000-40000. There is recognized female predilection wi...
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Sacroiliac joint

The sacroiliac joint (SIJ) is a synovial joint between ilium and the sacrum. It has little movement and its main function is to transfer weight between the axial and lower appendicular skeletons. The SI joint is symmetrical joint (i.e. is paired) with an oblique coronal orientation and is locate...
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Sacroiliac joint (AP sacrum view)

The AP sacrum projection is part of the sacroiliac series that includes an oblique projection (PA/AP) of the joint on both sides. Although usually taken as an AP projection it can also be taken PA with a reverse caudal central ray angulation of 30° to 35° when patients cannot assume supine posit...
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Sacroiliac joint (PA oblique view)

The posteroanterior (PA) oblique sacroiliac joint view demonstrates the sacroiliac joints (SIJs) in an open profile. It is commonly used in conjunction with the sacroiliac AP view.  Indications This projection examines both left and right sacroiliac joints for comparison purposes in the evalua...
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Sacroiliitis

Sacroiliitis is an inflammation of one or both sacroiliac (SI) joints, and a common cause of buttocks or lower back pain. They can be a manifestation of a wide range of disease processes. Clinical presentation Symptoms of sacroiliitis can vary. People with sacroiliitis commonly present with ip...
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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 ...
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Sacrum and coccyx (lateral view)

The sacrum and coccyx lateral view is utilized to demonstrate the most distal region of the spine in a lateral position. Indications This projection is commonly used in conjunction with the AP projection or can be used as a sole projection, depending on department protocols. It helps to visual...
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Sacrum (AP view)

The sacrum anteroposterior (AP) view is used to demonstrate the sacrum and its articulations. The efficacy of this radiographic projection is debatable, with radiographers encouraged to follow department protocol when imaging this region 1.  Indications This view can be utilized in the event o...
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Sagittal balance (C7 plumb line)

Sagittal balance forms part of the plain radiographic assessment of spinal deformity including kyphotic or lordotic deformities and scoliosis. There are numerous ways of assessing this, using various bony landmarks and angles to evaluate whether or not a normal distribution of weight and stresse...
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Sandwich sign (disambiguation)

The sandwich sign is used for two different imaging appearances: sandwich sign (Marchiafava-Bignami disease) sandwich sign (mesentery) Sandwich sign has also been coined for the appearance of: primary pleural lymphoma 1,2 mediastinal lymphoma 3 marrow edema and hemorrhage on MRI of flexion...
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Sandwich vertebral body

Sandwich vertebral body is a radiologic appearance in which the endplates are densely sclerotic, giving the appearance of a sandwich. This term and pattern are distinctive for benign adult autosomal dominant osteopetrosis. Differential diagnosis rugger jersey spine: sandwich vertebrae appears ...
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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...
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Scheuermann disease

Scheuermann disease, also known as juvenile kyphosis, juvenile discogenic disease 11, or vertebral epiphysitis, is a common condition which results in kyphosis of the thoracic or thoracolumbar spine. The diagnosis is usually made on plain film. Epidemiology occurs in ~5% (range 0.4-8%) of the ...
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Schmorl nodes

Schmorl nodes, also referred as intravertebral disc herniations, refer to protrusions of the cartilage of the intervertebral disc through the vertebral body endplate and into the adjacent vertebra. The protrusions may contact the marrow of the vertebra, leading to inflammation. Epidemiology Qu...
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Scimitar (disambiguation)

The term scimitar, referring to the characteristic shape of the Middle Eastern sword, may refer to the following: scimitar syndrome (lungs) scimitar sign (cystic adventitial disease) scimitar sacrum (bones)
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Scoliosis

Scoliosis (plural: scolioses) is defined as an abnormal lateral curvature of the spine. It is quite common in young individuals and is often idiopathic and asymptomatic. In some cases, however, it is the result of underlying structural or neurological abnormalities. Terminology By definition, ...
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Scoliosis (erect lateral view)

The scoliosis erect lateral view is performed to visualize the thoracic and lumbar vertebrae of interest in profile. Indications This projection is done in cases of scoliosis and often done upon first presentation as a useful examination in identifying spondylolisthesis and the degree of kyph...
Article

Scoliosis (lateral bending view)

Scoliosis lateral bending views are additional scoliosis projections accompanying the standard PA/AP and lateral views. Indications The aim of this view is to assess patients' lateral range of spinal motion 1 in the vertebral column as part of a scoliosis series. Patient position patient er...
Article

Scoliosis (PA/AP view)

The scoliosis posteroanterior/anteroposterior (PA/AP) view allows for the visualization of the thoracic and lumbar vertebral bodies of interest. Indications This projection is used in determining scoliosis in patients and allows for the severity of lateral spinal curvature to be assessed 1. P...
Article

Scoliosis radiography

Scoliosis radiography is useful in identifying the degree of the scoliosis curvature (major/minor or primary/compensatory curves), as well as observe its progression to determine the best method of treatment 1.   Indications Scoliosis radiographs are performed specifically when the disease is...
Article

Scottie dog sign (spine)

The Scottie dog sign (often seen spelled Scotty but Scottie is the correct spelling) refers to the normal appearance of the lumbar spine when seen on oblique radiographic projection. On oblique views, the posterior elements of the vertebra form the figure of a Scottie dog with: the transverse p...
Article

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 C5/6 or C6/7 vertebral levels.  Epidemiology They occur in ~7.5% of the population, with a male predominance of 3:1 1.  Radiographic features Plain...
Article

Shiny corner sign (ankylosing spondylitis)

The shiny corner sign is a spinal finding in ankylosing spondylitis, representing reactive sclerosis secondary to inflammatory erosions at the superior and inferior endplates (corners on lateral radiograph) of the vertebral bodies which are known as Romanus lesions. Eventually, the vertebral bod...
Article

Sickle cell disease (skeletal manifestations)

Skeletal manifestations of sickle cell disease result from three interconnected sequelae of sickle cell disease 5:  vaso-occlusive crises resulting in bone infarcts and subperiosteal hemorrhages chronic anemia resulting in expansion of the medullary spaces infection These, in turn, can predi...
Article

Sinuvertebral nerve

A branch from primary ventral ramus and grey ramus communicans join to give rise sinuvertebral nerve in the intervertebral foramen. It enters the spinal canal and supplies the posterior portion of the annulus of the intervertebral disc, the posterior longitudinal ligament and the periosteum of t...
Article

Solitary bone plasmacytoma

Solitary bone plasmacytomas is an uncommon plasma cell tumor which is localized to bone. They may involve any bone, but they have a predisposition for the red marrow-containing axial skeleton: spinal disease is observed in ~50% (range 34-72%) of cases the thoracic vertebrae are most commonly i...
Article

Spina bifida

Spina bifida is a type of neural tube defect/spinal dysraphism which can occur to varying degrees of severity. It is often considered the most common congenital CNS malformation. Terminology Spina bifida in its strictest sense means defective fusion of the vertebral posterior elements, leading...
Article

Spina bifida occulta

Spina bifida occulta is the mildest form of spina bifida/spinal dysraphism and is a type of neural tube defect.  Terminology While typically referring to asymptomatic posterior fusion defects, some authors 5 use it as a broad term that encompasses closed spinal defects such as: diastematomyel...
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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...
Article

Spinal arachnoid cyst

Spinal arachnoid cysts are relatively uncommon and may be either intradural (type III meningeal cyst) or extradural (type IA meningeal cyst). This article specifically focuses on spinal arachnoid cysts. For a general discussion of arachnoid cysts, refer to the main article: arachnoid cyst. Epi...
Article

Spinal arachnoid mater

The spinal arachnoid mater is a thin, delicate and avascular connective tissue membrane which forms the middle layer of the meninges and covers the spinal cord1. Gross Anatomy The spinal arachnoid mater becomes continuous with the cerebral arachnoid mater as it traverses the foramen magnum and...
Article

Spinal arteriovenous fistula

Spinal arteriovenous fistulas (spinal AVFs) are characterized by abnormal communication and shunting of blood from an artery to a vein of the spine that bypasses the capillary bed. Epidemiology Spinal arteriovenous fistulas represent approximately 70% of all spinal vascular malformations 1,2. ...
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Spinal arteriovenous malformations

Spinal arteriovenous malformations (AVMs) are characterized by arteriovenous shunting with a true nidus. They represent ~25% of spinal vascular malformations.  Epidemiology Different types of spinal AVM (see below) have differing age of presentation, but overall 80% present between the age 20 ...

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