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Westermark sign

Westermark sign is a sign of pulmonary embolus seen on chest radiographs. It is one of several described signs of pulmonary embolus on chest radiographs. Pathology The theory behind the sign is either obstruction of the pulmonary artery or distal vasoconstriction in hypoxic lung 3. In one stu...

Whipple disease (thoracic manifestations)

Thoraco-pulmonary manifestations of Whipple disease are uncommon and present in the late stages of the disease. Epidemiology Lung involvement is seen in 35-60% of patients with gastrointestinal whipple disease. Clinical presentation Majority of patients present with non-specific pulmonary an...

WHO classification scheme for thymic epithelial tumours

The WHO classification scheme for thymic epithelial tumours is one of many classifications systems for thymoma and related tumours, and classifies them according to histology: type a medullary thymoma spindle cell thymoma type ab: mixed thymoma type b1: lymphocyte rich predominantly cortic...

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 ...

Williams syndrome

Williams syndrome (WS) is characterised 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...

Wilson Mikity syndrome

Wilson Mikity syndrome (WMS) refers to chronic lung disease in premature infants, characterised 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...

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...


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


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. photon energy: 81 KeV physical half-life: 5.27 days biological half-life: 30 seconds normal distribution: lungs <15% of inhaled gas is absorb...

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.  ...


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...

Yellow nail syndrome

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

Yellow nail syndrome (pulmonary manifestations)

Pulmonary manifestations of yellow nail syndrome are principally centred 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 interlobular...

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...

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