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.

2,637 results found
Article

Weiss classification of lateral humeral condyle fractures

The Weiss classification is one of the classification systems used for lateral humeral condyle fractures and is based on the degree of displacement measured on an internal oblique view of the elbow: type 1: <2 mm displacement type 2: 2-4 mm displacement type 3: >4 mm displacement The degree ...
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Werner syndrome

Werner syndrome is a progeroid rare autosomal recessive condition attributed to chromosome 8. It should not to be confused with similarly sounding Wermer syndrome. Pathology Werner syndrome is characterised by premature senescence cataracts short stature scleroderma-like skin changes such ...
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Wiberg classification of patella shape

Wiberg classification is a system used to describe the shape of the patella based mainly on the asymmetry between the patellar medial and lateral facets on axial views of the patella. Increasing number type indicates a larger degree of asymmetry. Classification Wiberg type 1 or a roughly symm...
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Widened intercondylar notch

A widened intercondylar notch on knee radiographs is a sign associated with: haemophilic arthropathy (most commonly bilateral) juvenile rheumatoid arthritis (most commonly bilateral) tuberculosis arthropathy (usually unilateral) (3)
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Widening of diploic space

Widening of diploic space refers to diffuse, most commonly bilateral, calvarium widening secondary to extramedullary hematopoiesis within the skull. Causes Most commonly caused by systemic underlying pathologies such as: chronic haemolytic disorders: may be associated with vertical striations...
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Widening of interpedicular distance

The interpedicular (IP) distance which is the distance measured between the pedicles on frontal / coronal imaging can be widened in a number of situations. Pathology Causes include diastematomyelia syringomyelia conditions that can cause dural ectasia (can potentially cause widening) Marfa...
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Wilson disease

Wilson disease, also known as hepatolenticular degeneration, is a rare autosomal recessive disorder of copper metabolism affecting multiple systems.  Epidemiology Wilson disease is commonly found in Japan. It affects 1 in 30,000-40,000 individuals 12. Clinical presentation Clinical presentat...
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Wilson disease (musculoskeletal manifestations)

Wilson disease, also known as hepatolenticular degeneration, is a multisystem disease, which rarely has musculoskeletal manifestations when there is accumulation of copper in the articular cartilage.  Radiographic features Plain radiographs Reported manifestations include 1,2,3 premature ost...
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Wimberger ring sign

Wimberger ring sign refers to a circular calcification surrounding the osteoporotic epiphyseal center of ossification in scurvy, which may result from bleeding. It must not be confused with Wimberger sign, pathognomonic of congenital syphilis.
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Wimberger sign

The Wimberger sign, also called Wimberger corner sign, refers to localised bilateral metaphyseal destruction of the medial proximal tibias. It is a pathognomonic sign for congenital syphilis. It must not be confused with Wimberger ring sign seen in scurvy, which is sometimes also referred to as...
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Windswept pelvis

Wind-swept pelvis fracture is a combination a unilateral AP compression (open book) injury with a contralateral lateral compression injury.  It occurs when the internal rotation of one iliac wing causes a unilateral sacral compression fracture, while the same forces cause external rotation of t...
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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 ...
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Winquist classification of femoral shaft fractures

The Winquist classification of femoral shaft fractures is based on fracture comminution and was proposed by Winquist in 1980. This classification is used with regards to management decision making, in determining whether a fracture requires an intramedullary nail or open reduction.  Type 0: no ...
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Wormian bones

Wormian bones (a.k.a. intrasutural bones) is the name given to the additional small bones sometimes found between the cranial sutures of the bones of the skull vault, most commonly in relation to the lambdoid suture. Some reserve the term Wormian bones to just the intrasutural bones proximate to...
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Wormian bones (mnemonic)

A mnemonic to remember ten of the numerous conditions associated with Wormian bones is: PORKCHOPS Mnemonic P - pyknodysostosis O - osteogenesis imperfecta R - rickets K - kinky hair syndrome C - cleidocranial dysostosis H - hypothyroidism/hypophosphatasia O - otopalatodigital syndrome ...
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Wrisberg rip

Wrisberg rips are longitudinal vertical meniscal tears. They occur at the at the junction of the ligament of Wrisberg and the posterior horn of the lateral meniscus, and are commonly associated with anterior cruciate ligament tears 1. 
Article

Wrist (carpal tunnel view)

The carpal tunnel view is an axial projection to demonstrate the medial and lateral prominences and the concavity. It can be utilised to investigate potential hook of hamate, pisiform and trapezium factures. Patient position patient stands with the back facing the table palmar surface of hand...
Article

Wrist (clenched fist view)

The clenched fist view is an additional projection used to evaluate suspected widening of the scapholunate interval, often performed bilaterally it is a functional view that requires the patient to clench both hands.  Patient position patient is seated in front of the table  both hands are pl...
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Wrist (horizontal beam lateral view)

The horizontal beam lateral wrist view is a modified lateral projection when performing the three view series of the wrist and carpal bones in trauma. It is the orthogonal projection of the PA wrist without any patient movement, making it the most appropriate projection for patients in pain. Pa...
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Wrist (lateral view)

The lateral wrist view is part of a three view series of the wrist and carpal bones. It is the orthogonal projection of the PA wrist. Patient position patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and wrist can rest on the table abduct the hum...
Article

Wrist (oblique view)

The oblique wrist view is part of a three view series of the wrist and carpal bones. It is not generally performed in follow-up studies unless specifically requested. Patient position patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and wrist can ...
Article

Wrist (PA view)

The PA wrist view is part of a three view series of the wrist and carpal bones. Although performed PA the view can often be referred to an AP view. Patient position patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and wrist can rest on the table ...
Article

Wrist radiograph (an approach)

Wrist radiographs are ubiquitous on any night of the week in emergency departments, especially when pavements are icy! Systematic review Distal radial contour Check the contour of the distal radius: AP the distal radial articular surface should cup the carpals the articular surface should ...
Article

Wrist radiograph (approach)

Wrist x-rays are commonly used for the assessment of the wrist following trauma. This is usually a fall onto an outstretched hand. Systematic review It is useful to have a systematic approach; I tend to start proximally and work distally looking at structures on both views together: distal ra...
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Wrist radiograph (summary approach)

Wrist radiographs are commonly used for the assessment of the wrist following trauma.  Summary approach alignment AP distal radius and ulna have smooth joint surface carpal arcs are smooth carpal bones do not overlap apart from pisiform and trapezium metacarpals do not overlap and distal...
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Wrist series

The wrist series is comprised of a posteroanterior, oblique, and lateral projection. The series examines the carpal bones that are consisting of the scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate and hamate. It also examines the radiocarpal and distal radiocarpal joint al...
Article

Young and Burgess classification of pelvic ring fractures

The Young and Burgess classification is a modification of the Tile classification 1. It is the recommended 5 and most widely used classification system for pelvic ring fractures. It takes into account force type, severity, and direction, as well as injury instability. Anteroposterior compress...
Article

Yunis-Varón syndrome

Yunis Varón syndrome is a rare skeletal dysplasia. It is thought to be autosomal recessive. Radiographic features severe neurologic impairment cleidocranial dysplasia absent clavicles macrocrania diastasis of sutures micrognathia absent thumbs and distal phalanges of fingers hypoplasia ...
Article

Z deformity

The Z deformity is one of the musculoskeletal manifestation of rheumatoid arthritis in hand: radial deviation at the wrist ulnar deviation of the digits, and often palmar subluxation of the proximal phalanges
Article

Zebra stripe sign (bones)

The zebra stripe sign occurs where children with osteogenesis imperfecta have been treated with cyclical bisphosphonate therapy, e.g. pamidronate. When the drug is delivered in cycles, dense bone is formed while treatment is being given. This results in dense stripes across the metaphyses of bon...
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Zona orbicularis

The zona orbicularis are circular fibres of the hip joint capsule and form a collar around the femoral neck. Though partly blended with the pubofemoral and ischiofemoral ligaments, these fibres are not directly attached to bone. 
Article

Z-score

Z-scores are a way to translate individual data points into terms of a standard deviation.  Z = (X - Xbar) / σ X: individual data point Xbar: the arithmetic mean σ: the standard deviation The purpose of the Z-score is to allow comparison between values in different normal distributions. Two...
Article

Zygoma

The zygoma (or zygomatic bone) is an important facial bone which forms the prominence of the cheek. It is roughly quadrangular in shape. Gross anatomy Zygoma has three surfaces, five borders, and two processes. Surfaces anterolateral surface is convex, pierced at its orbital border by the zy...

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