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.

966 results found
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Vascular Ehlers Danlos syndrome

Vascular Ehlers-Danlos syndrome (EDS) or type IV Ehlers-Danlos syndrome (EDS 4) is the most malignant form of Ehlers-Danlos syndrome. This form is often accompanied by neurovascular complications secondary to vessel dissections and/or aneurysms. Epidemiology Vascular EDS represents about 4% of...
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Vascular malformations and tumours

Vascular malformations and tumours are a heterogeneous group of lesions that may affect the arterial, capillary, venous or lymphatic system or any combination thereof. They encompass a bewildering range of lesions,  syndromes, and masses ranging from the relatively common (e.g. infantile hemangi...
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Vascular pathology

Venous pathology is common and includes: arteriosclerosis hypertension fibromuscular dysplasia inherited disorders of vessel wall aneurysms dissection thromboembolism vasculitis vasospasm vascular trauma intimal hyperplasia tum...
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Vascular rings and slings

Vascular rings and slings refer to the congenital vascular encirclement of the oesophagus and/or trachea by anomalous/aberrant vessels.  Epidemiology Vascular rings are rare, occurring in <1% of patients 1. No gender or ethnic predispositions have been identified 3.  Clinical presentation Ma...
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Vascular syndromes

The are numerous vascular syndromes that can occur in the body. There include Syndromes principally involving the vascular system Budd-Chiari syndrome coeliac artery compression syndrome hereditary haemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) hypothenar hammer syndrome Kasabach...
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Vascular trauma

Great vessels thoracic aortic injury Solid organ renal pedicle injury
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Vasculitis

Vasculitis describes generalised inflammation of vessels. Vasculitides carry a broad range of clinical presentations and as a whole can involve almost any organ system. Pathology Some vasculitides are due to direct vessel injury from an infectious agent. However a large proportion show evidenc...
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Vein of Galen

The vein of Galen, also known as the great cerebral vein or great vein of Galen, is a short trunk formed by the union of the two internal cerebral veins and basal veins of Rosenthal. It lies in the quadrigeminal cistern. It curves backward and upward around the posterior border of the splenium o...
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Vein of Galen aneurysmal malformation

Vein of Galen aneurysmal malformations (VGAMs), probably better termed as median prosencephalic arteriovenous fistulas, are uncommon intracranial anomalies that tend to present dramatically during early childhood with features of a left-to-right shunt and high-output cardiac failure. Epidemiolo...
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Vein of Labbé

The vein of Labbé, also known as inferior anastomotic vein, is part of the superficial venous system of the brain.  The vein of Labbé is the largest channel that crosses the temporal lobe between the Sylvian fissure and the transverse sinus and connects the superficial middle cerebral vein to t...
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Vein of Marshall

The vein of Marshall, oblique vein of Marshall or the oblique vein of the left atrium is a small vein that descends on and drains the posterior wall of the left atrium. It drains directly into the coronary sinus at the same end as the great cardiac vein, marking the origin of the sinus. It repr...
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Veins of Sappey

Veins of Sappey are small veins around the falciform ligament that drain the venous blood from the anterior part of the abdominal wall directly into the liver. This flow dilutes the portal perfusion at these sites, causing hepatic pseudolesions. Gross anatomy The superior vein of Sappey drains...
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Vena cava filter

Vena cava filter is an endovascular device which is typically placed in the infrarenal inferior vena cava (IVC) to prevent pulmonary embolism in selected patients. This procedure is most often performed by interventional radiologists under fluoroscopic guidance. Indications contraindication to...
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Vena caval foramen

The vena caval foramen is one of the three major apertures in the diaphragm. It is the highest of the three and situated at the level of T8-9. It is quadrilateral and placed at the junction of the right and middle leaflets of the central tendon. It transmits several structures between the thora...
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Venae cordis minimae

The venae cordis minimae (smallest cardiac veins or thebesian veins) are a small group of valveless myocardial coronary veins within the walls of each of the 4 cardiac chambers that drain venous blood directly into each of the respective chambers. They are most frequent in the right atrium and t...
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Venous drainage of the thoracic wall

The venous drainage of the thoracic wall drains deoxygenated venous blood from the peripheries of the thoracic cage back into systemic circulation. Gross anatomy Anterior thoracic wall Anterior intercostal veins The anterior intercostal veins originate from the intercostal space just inferio...
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Venous thromboembolism

Venous thromboembolism covers a wide spectrum of diseases. Individual conditions and complicating condition include: deep vein thrombosis (DVT) pulmonary embolism (PE) dural venous sinus thrombosis Lemierre's syndrome tumour thrombus
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Vertebral artery

The vertebral arteries (VA) are paired arteries, each arising from the respective subclavian artery and ascending in the neck to supply the posterior fossa and occipital lobes, as well as provide segmental vertebral and spinal column blood supply. Summary origin: branches off the 1st part of t...
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Vertebral artery dissection

Vertebral artery dissection, like arterial dissection elsewhere, is a result of blood entering the media through a tear in the intima. It is potentially lethal and can be difficult to diagnose clinically and radiologically. Epidemiology Vertebral artery dissections have an incidence of 1-5 per...
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Vertebral artery ectasia

Vertebral artery ectasia refers to an abnormal dilatation of the vertebral artery. It is also known as a dolichoarterial loop (of Danziger). Clinical presentation Symptoms occur due to radicular compression or pathologic fracture (rare) from extensive bone erosion. Generally, patients present ...
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Vertebral artery thrombosis

Vertebral artery thrombosis results in complete or partial occlusion of the vertebral artery and alteration of blood flow to the posterior cerebral circulation. Ischaemia or infarction to structures supplied by these arteries may result in a range of symptoms. brainstem cerebellum occipital l...
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Vertebral venous plexus

The vertebral venous plexus is a highly anastomotic network of valveless veins running along the entire length of the vertebral column from the foramen magnum to the sacral hiatus. Gross anatomy The vertebral venous plexus is comprised of three interconnected divisions: internal vertebral ven...
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Vidian artery

There are two arteries passing through Vidian canal from the pterygopalatine fossa to the petrous portion of the ICA. One is a branch of the internal maxillary artery (itself a branch of the ECA) and the other is from the C2 segment of the ICA. It therefore forms one of the ICA to ECA anastamoses.
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Virchow triad

Virchow triad refers to the factors which can promote thrombosis, and are useful when thinking about the possible causes in a particular situation. They are: hypercoagulability primary thrombophilia factor V Laden deficiency  protein S deficiency  protein C deficiency  antithrombin III def...
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Visceral artery aneurysms

Visceral artery aneurysms (VAA) are abnormal focal dilatations of arteries supplying an organ in the abdomen. VAAs include both true and pseudoaneurysms. With different clinical manifestations and a more characteristic pathology, the renal artery aneurysms are discussed separately.  Epidemiolo...
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Wells criteria for deep venous thrombosis

Wells criteria for deep venous thrombosis is a risk stratification score and clinical decision rule to estimate the pretest probability for acute deep venous thrombosis (DVT). It is intended to be combined with noninvasive diagnostic tests (e.g. ultrasound or D-dimer) for suspected cases. Crite...
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Westermark sign (lungs)

Westermark sign is a sign of pulmonary embolus (PE) seen on chest radiographs. Along with Fleishner sign and Hampton hump, it makes one of the three described signs of pulmonary embolus on chest radiographs. Pathology In one study (PIOPED) this sign was present on ~10% of chest x-rays of pati...
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WFNS grading system

The WFNS (World Federation of Neurosurgical Societies) grading system uses the Glasgow Coma Scale and presence of focal neurological deficits to grade the severity of subarachnoid haemorrhage. This grading system was proposed in 1988, and this is one of the accepted systems (although not conside...
Article

White coat effect

The white coat effect (WCE), not to be confused with white coat hypertension, is a measure of change that is commonly defined as the difference between in-clinic and out-of-clinic blood pressure readings 1,2.  Alternatively, the white coat effect can be defined as the increase in the arterial b...
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White coat hypertension

White coat hypertension (abbreviated alternatively as WCH or WCHT), not to be confused with the white coat effect (WCE), is commonly defined as typical in-clinic blood pressure (BP) measurements of 140/90 mm Hg or more in the presence of multiple daytime out-of-clinic home or ambulatory BP readi...
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Williams syndrome

Williams syndrome (WS) is characterised by some or all or the following features: craniofacial dysmorphism (e.g. elfin facies) oral abnormalities short stature (50% of cases) mild to moderate mental retardation supravalvular aortic stenosis 2 pulmonary artery stenosis 3 renal insufficienc...
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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...
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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...
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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...
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Yellow nail syndrome

The yellow nail syndrome (YNS) is rare disorder principally affecting lymphatic system It is characterised by  nail discolouration: yellow slow growing dystrophic nails peripheral / primary lymphoedema pulmonary manifestations exudative pleural effusions (least common manifestation) bronch...
Article

Yin-yang sign

The yin-yang sign is a radiological sign described in both true and false aneurysms on various imaging modalities.  Radiographic features Doppler sonography The yin-yang sign indicates bidirectional flow due to swirling of blood within the (true or false) aneurysm. Contrast-enhanced CT The ...

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