Upper limb anatomy encompasses the anatomy of the shoulder, arm, elbow, forearm, wrist and hand.
This anatomy section promotes the use of the Terminologia Anatomica, the global standard for correct gross anatomical nomenclature.
Uterine arteriovenous malformations (UAVM) result from the formation of multiple arteriovenous fistulous communications within the uterus without an intervening capillary network.
The presentation can vary. UAVMs can cause life-threatening massive bleeding in young women....
The uterine artery is seen bilaterally and is a branch of the anterior division of the internal iliac artery.
It runs medially in the pelvis, within the base of the broad ligament, to the outer surface of the uterus. From lateral to medial it has a descending, transverse ...
Uterine artery embolization (UAE) is an interventional radiological technique to occlude the arterial supply to the uterus and is performed for various reasons.
Uterine artery embolization has been practised for more than 20 years for controlling hemorrhage following delivery / abortio...
Uterine artery embolization (UAE) is used as an alternative to hysterectomy in selected patients and MRI assessment is key in allowing not only pre-procedure assessment but also assessing post-procedural outcome.
For a general discussion of the underlying condition refer to the article on ute...
Uterine artery flow notching refers to a phenomenon observed in uterine arterial Doppler ultrasound assessment.
The presence of notching after 22 weeks is associated with several other conditions including adverse pregnancy outcomes. These include
pregnancy induced hyp...
Uterine artery pseudoaneurysm (UAP) is a rare cause of secondary postpartum hemorrhage.
UAP usually presents as delayed (secondary) postpartum hemorrhage, that is per vaginal bleeding which occurs more than 24 hours and up to 6 weeks postpartum. However, some reported ca...
The vaginal artery is a branch of the anterior division of the internal iliac artery, and should not to be mistaken with the vaginal branch of the uterine artery. It is often considered to be a homolog of the inferior vesical artery, which is present only in males.
origin: anterior div...
The Valsalva maneuver is the forced expiration of air against a closed airway, resulting in increased intra-abdominal, intrathoracic and pharyngeal pressure. It can be performed against a closed glottis or by one closing the mouth and pinching the nose while forcibly exhaling.
It is commonly us...
Variant anatomy of the aortic arch occurs when there is failure of normal aortic development. It results in a number of heterogenous anomalies of the aorta and its branch vessels.
Normally, the aorta ascends in the superior mediastinum to the level of the sternal notch before arc...
Variation in hepatic arterial anatomy is seen in 40-45% of people. Classic branching of the common hepatic artery from the celiac artery, and the proper hepatic artery into right and left hepatic arteries to supply the entire liver, is seen in 55-60% of the population.
Varicocele is the dilatation of the pampiniform plexus of veins, a network of many small veins found in the male spermatic cord. It is the most frequently encountered mass of the spermatic cord.
The estimated incidence is at ~15% of the general male population and ~40% of subferti...
Varicocele embolization is a minimally invasive method of treating varicoceles by embolizing the testicular vein (internal spermatic veins).
failed surgical ligation
Relative contraindications include:
Varicocele grading on color Doppler can be done variably. The most elaborate and widely-accepted grading was given by Sarteschi, as below.
For a general discussion of this condition refer to the article: varicocele.
baseline greyscale study in supine position and measure the diame...
Varicose veins are dilated tortuous superficially located venous channels that accompany the superficial veins of the upper or lower limbs.
Varicose veins are more common in women than men and are more common in the lower limb than in the upper limb 5. Risk factors include:
Vascular anatomical variants are common.
SVC & IVC - variants
Intracranial arteries - variants
Vascular compression disorders are numerous and can be divided into those cases where a vascular structure is the "compress-er" or the "compress-ee" . Some conditions fall into both categories, where one vessel compresses another.
Compression of a vascular structure
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.
Vascular EDS represents about 4% of...
Vascular malformations and tumors 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 hemangio...
Vascular pathologies are common and include:
inherited disorders of the vessel wall
tumors of blood vessels
congenital vascular anomali...
Vascular rings and slings refer to the congenital vascular encirclement of the esophagus and/or trachea by anomalous/aberrant vessels.
Vascular rings are rare, occurring in <1% of patients 1. No gender or ethnic predispositions have been identified 3.
The are numerous vascular syndromes that can occur in the body. There include
Syndromes principally involving the vascular system
celiac artery compression syndrome
hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome)
hypothenar hammer syndrome
thoracic aortic injury
renal pedicle injury
Vasculitis describes generalised inflammation of vessels. Vasculitides carry a broad range of clinical presentations and as a whole can involve almost any organ system.
Some vasculitides are due to direct vessel injury from an infectious agent. However a large proportion show evidenc...
Vasculopathies caused by varicella zoster virus (VZV) represent a group of illnesses involving both small and large CNS arteries caused by a inflammatory process involving the media and the vascular endothelium. Usually it occurs in immunocompromised individuals due the viral reactivation and sp...
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...
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.
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...
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.
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.
The superior vein of Sappey drains...
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...
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...
The venous drainage of the thoracic wall drains deoxygenated venous blood from the peripheries of the thoracic cage back into systemic circulation.
Anterior thoracic wall
Anterior intercostal veins
The anterior intercostal veins originate from the intercostal space just inferio...
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
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.
origin: branches off the 1st part of t...
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.
Vertebral artery dissections have an incidence of 1-5 per...
Vertebral artery ectasia refers to an abnormal dilatation of the vertebral artery. It is also known as a dolichoarterial loop (of Danziger).
Symptoms occur due to radicular compression or pathologic fracture (rare) from extensive bone erosion. Generally, patients present ...
Vertebral artery loop formations occur when a portion of the vertebral artery contains an unusual coil. It can be a rare anatomical variant or can be acquired.
Vertebral artery loops tend to be mostly diagnosed in the 5th and 6th decades. Its prevalence is uncertain but is thought...
Vertebral artery thrombosis results in complete or partial occlusion of the vertebral artery and alteration of blood flow to the posterior cerebral circulation. Ischemia or infarction to structures supplied by these arteries may result in a range of symptoms.
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.
The vertebral venous plexus is comprised of three interconnected divisions:
internal vertebral ven...
A vestibule is an anatomical term and refers to a small cavity at the proximal end of a tube.
History and etymology
Vestibule derives ultimately from the Latin...
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.
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:
factor V Laden deficiency
protein S deficiency
protein C deficiency
antithrombin III def...
Visceral artery aneurysms are abnormal focal dilatations of arteries supplying abdominal organs. Visceral artery aneurysms include both true aneurysms and pseudoaneurysms.
Owing to different clinical manifestations and a unique, specific, pathology, renal artery aneurysms are discussed separate...
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. D-dime...
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.
The theory behind the sign is either obstruction of the pulmonary artery or distal vasoconstriction in hypoxic lung 3.
In one stu...
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 hemorrhage. This grading system was proposed in 1988, and this is one of the accepted systems (although not consider...
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...
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...
Williams syndrome (WS) is characterized by some or all or the following features:
craniofacial dysmorphism (e.g. elfin facies)
short stature (50% of cases)
mild to moderate mental retardation
supravalvular aortic stenosis 2
pulmonary artery stenosis 3
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...
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...
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).
type I: small pure cisternal fistula between the vein of Galen (voG) and either the pericallosal arteries (anteri...
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)
exudative pleural effusions (lea...
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.
On Doppler ultrasound, the yin-yang sign indicates bidirectional flow due to the swirling of blood within the true...