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.

13,614 results found
Article

Widening of the diploic space

Widening of the diploic space refers to expansion of the spongy or cancellous bone between the inner and outer tables of the calvaria. The diploic space is the medullary cavity of the skull, and a location of normal physiologic hematopoiesis in adults. Thus, expansion of this structure most comm...
Article

Widening of the presacral space (differential)

Widening of the presacral space is one of the diagnostic indicators of the diseases involving pelvic pathology and rectal involvement. It is ideally measured on barium studies at the level of S3/4 disc level on lateral radiographs and the normal value of the presacral space is <15 mm in adults.​...
Article

Widow's peak hair anomaly

Widow's peak hair anomaly refers to a frontal hairline projection. Epidemiology Associations Aarskog syndrome Opitz syndrome Waardenburg syndrome frontonasal dysplasia craniofrontonasal dysplasia Clinical presentation Prominent V-shaped hairline projection. Ocular hypertelorism might be...
Article

Wildervanck syndrome

Wildervanck syndrome, also known as cervico-ocular-acoustic dysplasia, consists of the triad of: Klippel-Feil syndrome congenital ossicular anomalies: usually diffuse ossicular ankylosis and sensorineural deafness. Duane syndrome: an ocular motility disturbance due to fibrosis of the extraocu...
Article

Wilhelm Roentgen

Wilhelm C Roentgen (1845-1923) was a German physicist who is celebrated globally for his discovery of x-rays on 8 November 1895. Early life Wilhelm Conrad Roentgen (Röntgen in German) was born on 27 March 1845 in Lennep, Germany. He attended the primary and secondary school run by Martinus Her...
Article

Williams-Campbell syndrome

Williams-Campbell syndrome (WCS) is a rare form of congenital cystic bronchiectasis, in which distal bronchial cartilage is defective. Pathology It is thought to result from a deficiency of cartilage formation in the 4th to 6th order segmental bronchi. Radiographic features CT Shows cystic ...
Article

Williams syndrome

Williams syndrome (WS) is characterized by some or all of the following features: craniofacial dysmorphism (e.g. elfin facies) oral abnormalities short stature (50% of cases) mild to moderate intellectual disability  supravalvular aortic stenosis 2 pulmonary artery stenosis 3 renal insuff...
Article

Will Rogers phenomenon

The Will Rogers phenomenon is encountered in many disciplines but is particularly relevant to radiology in the setting of staging scans and is due to reclassifying borderline individuals also known as stage migration 1. The most common example in medicine is upstaging certain patients with mali...
Article

Wilms tumor

Wilms tumor, also known as nephroblastoma, is a malignant pediatric renal tumor. Epidemiology Wilms tumors are the most common pediatric renal mass, accounting for over 85% of cases 1,8 and accounts for 6% of all childhood cancers 2. It typically occurs in early childhood (1-11 years) with pea...
Article

Wilms tumor (staging)

Wilms' tumor staging is largely anatomical and relates to the invasion and spread of the tumor. Where there is invasion or metastasizes, prognosis is poorer. Wilms tumor, is one of the more common childhood malignancies. stage I confined to kidney complete resection possible stage II local ...
Article

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...
Article

Wilson disease (CNS manifestations)

Wilson disease, also known as hepatolenticular degeneration, is a multisystem disease due to abnormal accumulation of copper. It is characterized by early onset liver cirrhosis with CNS findings most frequently affecting the basal ganglia and midbrain. This article aims to discuss the central n...
Article

Wilson disease (hepatobiliary manifestations)

Hepatobiliary manifestations of Wilson disease vary largely from fatty changes to cirrhosis and occasionally fulminant hepatic necrosis. They result from accumulation of copper in the liver. For a general discussion of the underlying condition, please refer to the article Wilson disease.  Epid...
Article

Wilson disease (musculoskeletal manifestations)

Wilson disease, also known as hepatolenticular degeneration, is a multisystem disease, which rarely has musculoskeletal manifestations secondary to the accumulation of copper in the articular cartilage.  Radiographic features Plain radiographs Reported manifestations include 1-3 premature os...
Article

Wilson Mikity syndrome

Wilson Mikity syndrome (WMS) refers to chronic lung disease in premature infants, characterized by early development of cystic interstitial emphysema (PIE). This is now sometimes considered as part of the spectrum of bronchopulmonary dysplasia. See also chronic pulmonary insufficiency of prema...
Article

Wimberger ring sign

Wimberger ring sign , often simply just called Wimberger ring, 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 for congenital syphilis. Histor...
Article

Wimberger sign

The Wimberger sign, also called Wimberger corner sign, refers to localized bilateral metaphyseal destruction of the medial proximal tibias. It is a pathognomonic sign for congenital syphilis. It must not be mixed up with Wimberger ring sign seen in scurvy, which is sometimes also confusingly re...
Article

Windmill artifact

In CT imaging, the windmill artifact is an image distortion in the axial plane, encountered during helical multidetector acquisitions. The telltale appearance is characterized by equally distanced bright streaks diverging from a focal high-density structure. The streaks seemingly rotate while sc...
Article

Windowing (CT)

Windowing, also known as grey-level mapping, contrast stretching, histogram modification or contrast enhancement is the process in which the CT image greyscale component of an image is manipulated via the CT numbers; doing this will change the appearance of the picture to highlight particular st...
Article

Windsock sign (aortic dissection)

The windsock sign refers to appearances seen in type A thoracic aortic dissections on contrast CT. It results from intimo-intimal intussusception between the true and false dissected lumens of the thoracic aorta. The altering density of contrast between the dissection lumens which taper distally...
Article

Windsock sign (disambiguation)

The windsock sign can refer to different anatomical structures or pathologies: windsock sign (duodenal web) windsock sign (aortic dissection)
Article

Windsock sign (duodenal web)

The windsock sign is a typical appearance of a duodenal web (intraluminal duodenal diverticulum) on upper gastrointestinal contrast series which consists of an intraduodenal barium contrast-filled sac that is surrounded by a narrow lucent line (web or intraluminal mucosal diaphragm) which is wel...
Article

Windswept pelvis

Windswept pelvis fracture is a complex bony pelvic injury caused by a combination of 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 s...
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

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 ...
Article

Wirsungocele

Wirsungocele refers to a cystic dilatation of the pancreatic duct of Wirsung, which is the portion of ventral duct between the dorsal-ventral junction and major duodenal papilla. It is believed to be analogous to choledochocele and santorinicele. Clinical presentation It may be an incidental f...
Article

Wiskott-Aldrich syndrome

Wiskott-Aldrich syndrome (WAS) is a rare immunodeficiency disease with a characteristic phenotype that includes: X-linked recessive petechiae, bloody diarrhea, epistaxis due to thrombocytopenia with small platelets eczema starts in the first month of life recurrent infections with encapsulat...
Article

Woggle technique (interventional procedure)

The Woggle technique is the purse-string suture modified using to close a puncture site after a percutaneous procedure. Techniques common to all procedure include: a purse-string suture is done around the introducer sheath (the short plastic tube placed within a vein or artery) cut the needle...
Article

Wolff-Chaikoff effect

Wolff-Chaikoff effect is an autoregulatory phenomenon, whereby a large amount of ingested iodine acutely inhibits thyroid hormone synthesis within the follicular cells, irrespective of the serum level of thyroid-stimulating hormone (TSH) 1.  Pathology The Wolff-Chaikoff effect is thought to be...
Article

Wolffian duct

The Wolffian duct (also known as the mesonephric duct) is one of the paired embryogenic tubules that drain the primitive kidney (mesonephros) to the cloaca. It also gives off a lateral branch forming the ureteric bud. In both the male and the female the Wolffian duct develops into the trigone of...
Article

Wolff parkinson white syndrome

The Wolff-Parkinson-White syndrome describes paroxysmal tachydysrhythmias in the presence of a specific accessory pathway (AP) which allows direct electrical connection between the atria and ventricles, which usually exclusively occurs via the atrioventricular node. The accessory pathway is usua...
Article

Wolf-Hirschhorn syndrome

Wolf-Hirschhorn syndrome (WHS) is an extremely rare chromosomal anomaly characterized by partial deletion of the p arm of chromosome 4 (4p16.3). Clinical presentation There is a large clinical spectrum: CNS agenesis of the corpus callosum hypertelorism coloboma seizures 4 craniofacial c...
Article

Wolfram syndrome (type one)

Wolfram syndrome type one, also known as DIDMOAD, is a disease caused by an autosomal recessive genetic trait, caused by mutations in the WFS1 gene, with incomplete penetrance. The syndrome presents with early onset of insulin-dependent diabetes mellitus, progressive optic atrophy, diabetes ins...
Article

Wolman disease

Wolman disease is a rare autosomal recessive inborn error of metabolism resulting in the deposition of fats in multiple organs.  Clinical presentation Patients with Wolman disease typically present during the first two months of life with failure to thrive, diarrhea and vomiting. Abdominal dis...
Article

Woodruff plexus

Woodruff plexus is a venous plexus located in the posterior end of the inferior meatus 1. It accounts for between 5-10% of epistaxis and are associated with hypertension. These bleeds typically do not respond to anterior nasal packing.
Article

Words we never use

There are a number of words we never use at Radiopaedia.org. This may be the result of an international consensus on correct spelling, other times it is a local decision about how we can improve consistency on the site. This is separate to the differences between British (UK) and American (US) ...
Article

World Health Organization (WHO)

The World Health Organization (WHO) is an agency of the United Nations (UN) that was established in 1948 and acts as the leader in coordinating global health, especially in relation to the developing world. From a radiology perspective, a key role of the WHO is in spearheading international radi...
Article

World Radiography Day

World Radiography Day (WRD) is an annual event held on November 8th to celebrate the anniversary of the discovery of x-rays by Wilhelm Roentgen, and is organized by the International Society of Radiographers and Radiological Technologists (ISRRT) 1. World Radiography Day occurs simultaneously w...
Article

Wormian bone

Wormian bones (also knows as 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 proxi...
Article

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 ...
Article

Wound dehiscence

Wound dehiscence is a surgical complication whereby there is rupture of a wound along the surgical scar (dehiscence, refers to "splitting open"). This may occur on the skin surface, or along a deeper suture line. Clinical presentation Presentation may be with pain (e.g. sternal dehiscence), or...
Article

Wrisberg rip

Wrisberg rips, also known as zip tears or zipper tears, are longitudinal vertical meniscal tears. They occur 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 bridge view)

The carpal bridge view an additional view to the three view series of the wrist and carpal bones. It is used to assess the dorsal aspect of the scaphoid, lunate and the triquetrum. Patient position the patient is seated alongside the table dorsal aspect of affected wrist is placed on the dete...
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 utilized 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...
Article

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...
Article

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 ligaments

The intrinsic and extrinsic wrist ligaments play a vital role in the stability of the wrist joint. There are numerous ligaments but included below are the most clinically significant. Wrist ligaments are best assessed with dedicated wrist MRI. Gross anatomy intrinsic ligaments (only attach to ...
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 (radial deviation view)

The wrist PA radial deviation view is specialized projection employed to better demonstrate the carpal bones that lay on the ulnar aspect of the 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 tab...
Article

Wrist radiograph

Wrist radiographs are ubiquitous in the emergency departments. They are commonly performed in the pediatric and elderly populations after a fall on an outstretched hand as well as in patients after higher force trauma. Moreover, they may be performed as part of a skeletal survey looking for meta...
Article

Wrist radiograph (an approach)

Wrist radiographs are ubiquitous on any night of the week in emergency departments, especially when pavements are icy! Choosing a search strategy and using it consistently is a helpful method to overcome common errors seen in diagnostic radiology. Systematic review Distal radial contour Check...
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...
Article

Wrist radiograph (summary approach)

This is a basic article for medical students and other non-radiologists 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 ...
Article

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

Wrist series (summary)

This is a basic article for medical students and other non-radiologists A wrist series (or wrist x-ray) may be performed for a multitude of reasons. However, they are most commonly used in the assessment of trauma, by clinical teams within the Emergency Department or Orthopedic service. Refere...
Article

Wunderlich syndrome

Wunderlich syndrome is a rare condition, in which spontaneous nontraumatic renal hemorrhage occurs into the subcapsular and perirenal spaces 2. Clinical presentation Wunderlich syndrome is clinically characterized by Lenk's triad: acute flank pain flank mass hypovolemic shock Pathology Et...
Article

Wyburn-Mason syndrome

Wyburn-Mason syndrome (also known as Bonnet-Dechaume-Blanc syndrome) is a rare, nonhereditary neurocutaneous disorder that typically presents with unilateral vascular malformations that primarily involve the brain, orbits and facial structures. It is currently classified as a craniofacial arteri...
Article

Xanthogranulomatous cholecystitis

Xanthogranulomatous cholecystitis (XGC) is an uncommon inflammatory disease of the gallbladder which may be difficult to differentiate from malignancy, both on imaging and pathologically. It is characterized by presence of multiple intramural nodules. Epidemiology It is seen predominantly in f...
Article

Xanthogranulomatous pyelonephritis

Xanthogranulomatous pyelonephritis (XGP) is a rare form of chronic pyelonephritis and represents a chronic granulomatous disease resulting in a non-functioning kidney. Radiographic features are usually specific. Epidemiology Xanthogranulomatous pyelonephritis is seen essentially in all age gro...
Article

Xanthomatous meningioma

Xanthomatous meningiomas are rare histological variants of meningiomas grouped into the subtype of metaplastic meningiomas, being WHO grade I tumors. They are characterized by cells with a lipid-filled vacuolated cytoplasm. Although reported numbers are too small to confirm that this is definit...
Article

XCCL view

An XCCL view is a supplementary mammographic view. It is a type of exaggerated cranio-caudal view. It is particularly good for imaging the lateral aspect of the breast.  It is often done when a lesion is suspected on a MLO view but cannot be seen on the CC view. In this view, the lateral aspect...
Article

XCCM view

An XCCM view is a supplementary mammographic view. It is a type of exaggerated cranio-caudal view. It is particularly good for imaging the medial portion of the breast. In this view, the medial portion of the breast is placed forward. A negative 15° tube tilt is suggested. An optimal XCCM view ...
Article

Xenon-127

Xenon-127 is a radiopharmaceutical principally used when a performing VQ scan. It is not a widely used alternative to xenon-133 with the main advantage being a higher proton energy allowing for post perfusion scanning.  photon energy: 203 KeV physical half life: 36.3 days
Article

Xenon-133

Xenon-133 is a radiopharmaceutical principally used when a performing VQ scan. Inhalation of this gas can also be used to assess cerebral blood flow. Mode of decay: Beta decay photon energy: 81 KeV physical half-life: 5.27 days biological half-life: 30 seconds normal distribution: lungs <1...
Article

Xerostomia

Xerostomia is the medical term for a dry mouth, and is most commonly due to hyposalivation. Epidemiology Xerostomia is the most frequently observed salivary abnormality in clinical practice 1. Clinical presentation dryness of the mouth uncomfortable swallowing vocalisation difficulties: to...
Article

Xiphisternal joint

The xiphisternal joint (or more rarely, the sternoxiphoid joint) is a symphysis between the inferior margin of the body of the sternum and the superior margin of the xiphoid process. In most people it ossifies with age, usually becoming fully fused by the age of 40 years, forming a synostosis.  ...
Article

Xiphisternum

The xiphisternum (also known as the xiphoid process or simply the xiphoid) is the smallest of the three parts of the sternum (manubrium, body or gladiolus, and xiphisternum). It arises from the inferior and posterior margin of the sternal body and projects inferiorly. It is a small cartilaginous...
Article

Xiphoid shape variations

There is considerable anatomic variation in the shape of the xiphoid of the sternum: xiphoid ending is classified as single, double, or triple. xiphoid size varies (e.g. elongated process) xiphoid morphology (e.g. ventral or dorsal deviation, hook-like, reverse S-shape). Clinical presentatio...
Article

X-linked adrenoleukodystrophy

X-linked adrenoleukodystrophy is an inherited metabolic peroxisomal disorder and one of the more common leukodystrophies in both children and adults. It is characterized by a lack of oxidation of very long chain fatty acids (VLCFAs) that results in severe inflammatory demyelination typically of ...
Article

X-linked Opitz G/BBB syndrome

X-linked Opitz G/BBB syndrome (XLOS) is an x-linked disorder with a spectrum of congenital anomalies. Anomalies that may be seen are: facial anomalies  ocular hypertelorism prominent forehead widow's peak broad nasal bridge anteverted nares cleft lip and/or palate  laryngotracheoesophage...
Article

X-marks-the-spot sign (large bowel volvulus)

The X-marks-the-spot is a sign of complete bowel volvulus and refers to the crossing loops of the bowel at the site of the transition. It has been reported to improve diagnostic confidence in detecting cecal and sigmoid volvulus. This is in contrast to the split-wall sign which indicates partial...
Article

X-ray artifacts

X-ray artifacts can present in a variety of ways including abnormal shadows noted on a radiograph or degraded image quality, and have been produced by artificial means from hardware failure, operator error and software (post-processing) artifacts.  There are common and distinct artifacts for fi...
Article

X-ray film

X-ray film displays the radiographic image and consists of emulsion (single or double) of silver halide (silver bromide (AgBr) is most common) which when exposed to light, produces a silver ion (Ag+) and an electron. The electrons get attached to the sensitivity specks and attract the silver ion...
Article

X-ray interaction with matter

X-rays in the diagnostic range interact with matter primarily via two major processes, which are fundamental in understanding how an image is formed in a radiographic exam. These processes are the: photoelectric effect  Compton scatter 
Article

X-ray production

X-rays are produced due to sudden deceleration of fast-moving electrons when they collide and interact with the target anode. In this process of deceleration, more than 99% of the electron energy is converted into heat and less than 1% of energy is converted into x-rays. Definitions Generator ...
Article

X-ray quantity and quality

X-ray photon quantity refers to the number of photons produced during an exposure. Factors influencing x-ray quantity includes: peak voltage (kVp): beam quantity is approximately proportional to the square of the tube potential generator type/voltage waveform: reducing ripple increases beam q...
Article

X-rays

X-rays (or much more rarely, and usually historically, x-radiation or Roentgen rays) represent a form of ionizing electromagnetic radiation. They are produced by an x-ray tube, using a high voltage to accelerate the electrons produced by its cathode. The produced electrons interact with the anod...
Article

X-ray tube

An x-ray tube functions as a specific energy converter, receiving the electrical energy and converting it into two other forms of energy: x-radiation and heat. Heat is considered the undesirable product of this conversion process; therefore x-radiation is created by taking the energy from the el...
Article

Yasargil classification of vein of Galen aneurysmal malformations

The Yasargil classification is one of the two common systems for classifying vein of Galen malformations that is currently in use at the time of writing (mid 2016).  Classification type I: small pure cisternal fistula between the vein of Galen (voG) and either the pericallosal arteries (anteri...
Article

Yaws

Yaws, also known as framboesia, is a tropical disease produced by the Treponema pallidum subspecies pertenue. Epidemiology Yaws is a tropical disease. Infections have declined dramatically over the last century, however the disease is still present in several countries in Africa and Asia 1. Y...
Article

Yellow nail syndrome

The yellow nail syndrome (YNS) is a rare disorder principally affecting the lymphatic system. It is characterized by a clinical triad: nail discolouration: yellow slow-growing dystrophic nails (scleronychia) lymphedema (peripheral/primary) pulmonary disease: see yellow nail syndrome (pulmona...
Article

Yellow nail syndrome (pulmonary manifestations)

Pulmonary manifestations of yellow nail syndrome are principally centered around chronic cough effects for recurrent lung infections (bronchiectasis) and pleural effusions. The role of proposed lymphatic impairment could account for the development of pleural effusions and smooth interlobula...
Article

Yin-yang sign (solitary fibrous tumor)

The yin-yang sign is a radiologic appearance described in solitary fibrous tumor of the dura on MR. On T2-weighted images, these tumors have two separate solid components, one that is hyperintense and one that is iso- to hypointense relative to brain parenchyma. Histologically, the former repre...
Article

Yin-yang sign (vascular)

The yin-yang sign, also known as the Pepsi sign, is a radiological sign described in both true and false aneurysms on various imaging modalities. Radiographic features Ultrasound On Doppler ultrasound, the yin-yang sign indicates bidirectional flow due to the swirling of blood within the true...
Article

Yolk sac

Yolk sac is the first anatomical structure identified within the gestational sac. It plays a critical role in embryonal development by providing nutrients, serving as the site of initial hematopoiesis, providing endocrine, metabolic and immunological functions and contributing to the development...
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. Three basic mechanistic ...
Article

Young's modulus

Young's modulus is a relationship between elasticity, strain, and stress: elasticity x (change in length / original length) = (force / area) put another way, this is elasticity x (strain) = stress or elasticity = stress / strain Elasticity is measured in kilopascals (kPa). This relationsh...
Article

Young syndrome

Young syndrome shares similar clinical and radiological findings to primary ciliary dyskinesia and cystic fibrosis, however, the underlying pathogenesis is yet to be fully elucidated. Obstructive azoospermia at the level of the epididymis is thought to be the cause of infertility. The commonly r...
Article

Yo-yo on a string sign (Stener lesion)

The yo-yo on a string sign denotes the characteristic appearance of the torn, proximally retracted and superficially displaced ulnar collateral ligament (UCL) due to a Stener lesion. Mechanism The sign occurs as a consequence of the tear of the ulnar collateral ligament of the thumb (gamekeepe...
Article

Yo-yo reflux

Yo-yo reflux or uretero-ureteral reflux is noted in partial duplication of ureters 1,2. It is the reflux of urine from normal caliber ureter to dilated ureter.  Radiographic features Yo-yo reflux should be suspected when there is asymmetric dilatation of ureters. It can be diagnosed with color...
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". 

Updating… Please wait.

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

 Thank you for updating your details.