Capillary hemangiomas of the orbit, also known as strawberry hemangiomas, on account of its coloring, or orbital infantile hemangiomas, are the most common orbital tumors of infancy, and unlike orbital cavernous hemangiomas, they are neoplasms rather than vascular malformations.
The Capps triad refers to the constellation of clinical and imaging findings in patients with spontaneous retropharyngeal hematomas, and consists of:
tracheal and esophageal compression
anterior displacement of the trachea
subcutaneous bruising over the neck and anterior chest
History and et...
Caput medusae sign can refer to:
caput medusae sign (portal hypertension)
caput medusae sign (developmental venous anomaly)
History and etymology
The appearance is reminiscent of Medusa, a gorgon of Greek mythology, who was encountered and defeated by Perseus.
A multi-gated (MUGA) cardiac blood pool scan (sometimes just called a MUGA scan) is a common study performed in patients who are receiving potentially cardiotoxic chemotherapy.
acute myocardial infarction (AMI)
coronary artery disease (CAD)
evaluation after coronary artery bypas...
Cardiac MRI consists of using MRI to study heart anatomy, physiology, and pathology.
In comparison to other techniques, cardiac MRI offers:
improved soft tissue definition
protocol can be tailored to likely differential diagnoses
a large number of sequences are available
Cardiac myxomas, although uncommon are one of the commonest primary cardiac tumors and account for ~50% primary benign cardiac tumors.
Cardiac myxomas are the most common primary cardiac tumor in adults but are relatively infrequent in childhood, where cardiac rhabdomyomas are mo...
Cardiac venous malformations (also known as cardiac hemangiomas) consists of a slow flow venous malformation and is composed of numerous non-neoplastic endothelial-lined thin-walled channels with interspersed fat and fibrous septae.
It is important to note that according to newer n...
Carney complex (not to be confused with the Carney triad) is a rare multiple endocrine neoplasia syndrome characterized by 1-4:
seen in two-thirds of patients with Carney complex
skin pigmentation (blue nevi): especially of the face, trunk, lips, and sclera
Caroticocavernous fistulas (CCF) represent abnormal communication between the carotid circulation and the cavernous sinus. They can be classified as direct or indirect which are separate conditions with different etiologies.
Direct CCFs are often secondary to trauma, and as such...
The caroticotympanic branch (tympanic branch) is a small branch from the C2 segment of the internal carotid artery. It is a vestigial remnant of the hyoid artery.
It passes posterolaterally into the middle ear cavity and anastomoses with the inferior tympanic artery (a branch of the external ca...
Carotid arterial stenting (CAS) is a minimally invasive endovascular interventional procedure that can potentially offer the same advantage as surgery (carotid endarterectomy).
Indications for carotid stenting are evolving with endarterectomy trials that evaluate the carotid stenos...
Carotid artery pseudoaneurysms can refer to pseudoaneurysms involving any segment of the carotid arteries:
common carotid artery pseudoaneurysm
internal carotid artery pseudoaneurysm
external carotid artery pseudoaneurysm
As with pseudoaneurysms elsewhere, these lack all three lay...
Carotid artery stenosis also known as extracranial carotid artery stenosis, is usually caused by an atherosclerotic process and is one of the major causes of stroke and transient ischemic attack (TIA) 1.
This article refers to stenosis involving carotid bulb and the proximal segment of interna...
The carotid bifurcation is the point at which the common carotid artery terminates. As it does so, it forms the internal and external carotid arteries which go on to supply the head and neck.
It is closely related anatomically to the carotid body, a small group of chemoreceptors and supporting ...
Carotid body tumor, also known as a chemodectoma or carotid body paraganglioma, is a highly vascular glomus tumor that arises from the paraganglion cells of the carotid body. It is located at the carotid bifurcation with characteristic splaying of the ICA and ECA.
Carotid endarterectomy (CEA) is a surgical procedure that involves removing athersclerotic plaque causing internal carotid artery stenosis in order to to prevent ischemic stroke. It can be used in both in the setting of symptomatic and asymptomatic carotid stenosis.
More recently, percutaneous ...
Carotid pacemakers, also known as implantable carotid sinus stimulators, are devices that deliver activation energy, via carotid leads, to the carotid baroreceptors. This is sometimes offered for drug-resistant hypertension. The baroreceptors send signals to the brain and the signals are interpr...
The carotid space, the suprahyoid portion of which is also known as the poststyloid parapharyngeal space, is a deep compartment of the head and neck bound by the carotid sheath.
The "carotid space" terminology was introduced by some radiologists to facilitate differential diagnosis...
Carotid webs, also known as carotid intimal variant fibromuscular dysplasia, are rare vascular pathologies of the internal carotid artery that are an important cause of cryptogenic and recurrent ischemic stroke.
Carotid webs have had many different names in the literature, includin...
Carotidynia, also known as Fay syndrome, is a rare syndrome characterized by neck pain in the region of the carotid bifurcation.
It was classified by the International Headache Society (IHS) in 1988 as an idiopathic neck pain syndrome associated with tenderness over the carotid bifurcation with...
Catheter-directed thrombolysis (CDT) is an endovascular approach to the treatment of acute iliofemoral deep vein thrombosis. It involves the administration of a lytic agent directly into a thrombus.
precise diagnosis of iliofemoral deep vein thrombosis
first episode of acute ili...
There are relatively few causes of calcification of the ascending aorta 1-3:
atherosclerosis (this usually spares the ascending aorta)
Causes of a small aorta include:
giant cell arteritis
small aorta syndrome
Many caval variants exist, due to the complex embryology of the venous system. These are important for a number of reasons:
not to confuse them with pathology
suggest the presence of frequently associated other abnormalities
planning of vascular intervention or surgery
superior vena ...
The cavernous sinuses are paired dural venous sinuses.
The cavernous sinus is located on either side of the pituitary fossa and body of the sphenoid bone between the endosteal and meningeal layers of the dura. It spans from the apex of the orbit to the apex of the petrous tempor...
Cavernous sinus hemangioma is an uncommon cause of a cavernous sinus mass. Preoperative diagnosis is important to avoid unexpected surgical blood loss.
Cavernous hemangiomas of the cavernous sinus account for less than 1% of all parasellar masses 1. They have a predilection for m...
Cavernous sinus thrombosis (CST) is a rare condition, most commonly infectious in nature, and the diagnosis on imaging is not always straightforward. It has high mortality and morbidity rates.
CST is rare with ~4.5 cases per 1,000,000 per year 5. It is the least common dural venou...
Cavernous transformation of the portal vein (CTPV) is a sequela of portal vein thrombosis and is the replacement of the normal single channel portal vein with numerous tortuous venous channels.
For a discussion of demographics and presentation, please refer to the article on portal vein thrombo...
The central artery of the retina or central retinal artery (CRA) arises from the ophthalmic artery.
The central artery of the retina courses anteriorly and inferior to the optic nerve, It then pierces the dura and the arachnoid of the optic nerve. It then runs in the center of t...
Central nervous system (CNS) vasculitides represent a heterogeneous group of inflammatory diseases affecting the walls of blood vessels in the brain, spinal cord, and the meninges.
Please refer to the article on vasculitis for a general discussion of that entity.
The aim of this article will ...
Central venous catheters (CVC) or lines (CVL) refer to a wide range of central venous access devices but can broadly be divided into four categories. They may be inserted by medical, surgical, anesthetic/ITU, or radiology specialists.
peripherally inserted central catheters (PIC...
The cephalic vein, along with the basilic vein, is one of the primary superficial veins that drain the upper limb 1. It courses through both the forearm and arm and terminates by draining into the axillary vein.
origin: radial aspect of the superficial venous network of the dorsum of...
Cerebral arteriovenous malformations (CAVMs), also known as classic brain AVMs, are a common form of cerebral vascular malformation and are composed of a nidus of vessels through which arteriovenous shunting occurs.
This article corresponds to the classic form of arteriovenous malf...
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant microvasculopathy characterized by recurrent lacunar and subcortical white matter ischemic strokes and vascular dementia in young and middle age patients without known va...
Cerebral cavernous venous malformations, commonly known as cavernous hemangioma or cavernoma, are common cerebral vascular malformations, usually with characteristic appearances on MRI.
Cavernous malformations are found throughout the body. This article focuses on cerebral cavernous venous mal...
Cerebral proliferative angiopathy (CPA), previously known as diffuse nidus type AVM, is a cerebral vascular malformation separated from classic brain arteriovenous malformation (AVM) and characterized by the presence of normal brain parenchyma interspersed throughout the tangle of vessels that c...
Vascular malformations of the central nervous system can be divided, as they can elsewhere, into high and low flow malformations.
arteriovenous malformation (AVM)
cerebral AVM (pial/parenchymal AVM)
cerebral proliferative angiopathy
dural arteriovenous fistula (DAVF)
An understanding of cerebral vascular territories is important in understanding stroke and complications from surgery and endovascular procedures.
Although one could be excused for thinking that within the brain, such a carefully organized organ, blood supply would be constant, the truth is th...
Cerebral vasospasm following subarachnoid hemorrhage is a major complication of subarachnoid hemorrhage (SAH). It is overtaking rebleed as the major cause of mortality and morbidity in the subgroup of patients with SAH who reach the hospital and receive medical care. It usually occurs after a fe...
The cerebral veins drain the brain parenchyma and are located in the subarachnoid space. They pierce the meninges and drain further into the cranial venous sinuses.
The cerebral veins lack muscular tissue and valves. The cerebral venous system can be divided into:
superficial (cortical) cerebr...
Cerebral venous infarction is an uncommon form of stroke, and is most commonly secondary to cerebral venous thrombosis and frequently manifests with hemorrhage. It should be considered in infarcts (with or without hemorrhage) which do not correspond to a typical arterial territory 1.
The cerebral venous system, somewhat unlike the majority of the rest of the body, does not even remotely follow the cerebral arterial system.
The cortical veins lie superficially, unlike cortical arteries, and are adherent to the deep surface of the arachnoid mater so that they keep the sulci o...
Cerebral venous thrombosis (CVT) refers to occlusion of venous channels in the cranial cavity, including dural venous thrombosis, cortical vein thrombosis and deep cerebral vein thrombosis. They often co-exist and the clinical presentation among them is very similar and nonspecific. Furthermore,...
Cerebrofacial arteriovenous metameric syndrome (CAMS) encompasses maxillofacial/intracranial vascular malformation complexes including Wyburn-Mason Syndrome and Sturge-Weber syndrome 1-4. Three types are described depending on location 2,6:
CAMS I: medial prosencephalic group with involvement o...
Cervical aortic arches are a rare aortic arch anomaly characterized by an elongated, high-lying aortic arch extending at or above the level of the medial ends of the clavicles.
Patients with cervical aortic arch are usually asymptomatic. Symptomatic patients may present w...
Charles T Dotter (1920-1985) is often considered the father of interventional radiology who in 1964 performed the very first peripheral angioplasty, and made many other major contributions in this field.
Charles Theodore Dotter was born in Boston on 14th June 1920. He graduated with...
Chen sign on chest radiography is the prominence of left basal pulmonary vasculature compared the right base seen in valvular pulmonary stenosis. It is due to the asymmetric increase in pulmonary blood flow to the left lung due to preferential blood flow into the left pulmonary artery after pass...
This is a basic article for medical students and other non-radiologists
Chest x-ray PICC (peripherally inserted central catheter) position should be assessed following initial placement and on subsequent radiographs.
This is a summary article; we do have a more in-depth refe...
Chronic hereditary lymphedema (also known as Milroy disease) is a condition characterized by lower limb lymphedema. Patients typically present with pedal edema at or before birth or soon after. Occasionally, it develops later in life.
Mutations in the FLT4 gene are thought ...
Chronic mesenteric ischemia is an uncommon type of intestinal ischemia usually affecting elderly patients as a result of significant stenosis of two or more mesenteric arteries.
Normally seen in patients older than 60 years of age and is three times more common in women.
Chronic periaortitis is an inflammatory condition which typically involves the infrarenal portion of the abdominal aorta. It is a rare disease usually occurring in middle-aged men.
It has various clinical presentations:
idiopathic retroperitoneal fibrosis (IRF)
perianeurysmal retroperitoneal ...
Chronic pulmonary emboli are mainly a consequence of incomplete resolution of pulmonary thromboembolism.
vascular CT signs include
direct pulmonary artery signs
calcified thrombus - calcific pulmonary ...
Chronic venous insufficiency (CVI) occurs due to inadequate functioning of venous wall and/or valves in lower limb veins resulting in excessive pooling of blood.
The condition results from venous hypertension which in turn is usually caused by reflux in the superficial venous compart...
The Circle of Willis is an arterial polygon (heptagon) formed as the internal carotid and vertebral systems anastomose around the optic chiasm and infundibulum of the pituitary stalk in the suprasellar cistern. This communicating pathway allows equalization of blood-flow between the two sides of...
Circumaortic left renal vein, also known as circumaortic renal collar is an anomaly of left renal vein when a supernumerary or accessory left renal vein passes posterior to the aorta, apart from the normal renal vein passing anterior to the aorta. This anomaly is potentially hazardous, if unreco...
Circumflex aorta is a rare aortic arch anomaly caused by retroesophageal crossing of the aorta to the contralateral side. A vascular ring is formed when a ductus or ligamentum arteriosum contralateral to the aortic arch connects the descending aorta to the pulmonary artery.
The circumflex artery (Cx) is one of the two major coronary arteries that arise from the bifurcation of the left main coronary artery (the other branch being the left anterior descending (LAD) artery).
The circumflex artery can be referred to by multiple terms:
circumflex artery (...
The circumflex fibular artery is a minor artery of the leg.
Origin and course
Most often arises from the posterior tibial artery, passes laterally round the neck of the fibula through the soleus to anastomose with the lateral inferior genicular, medial genicular and anterior tib...
Cirsoid aneurysms are rare arteriovenous malformations of the scalp and extremities.
Patients often present with a slow-growing pulsatile mass and may also experience bleeding, tinnitus and/or a headache 3.
Cirsoid aneurysms develop due to an abnormal arteri...
The cisterna chyli (CC), also known as the receptaculum chyli, is a normal anatomical structure in the lymphatic system. It is seen as a saccular area of dilatation in the lymphatic channels that are located in the retrocrural space, usually to the immediate right of the abdominal aorta.
Endoleaks occur when an aneurysmal sac continues to be pressurised despite endoluminal stent placement. See the full article on endoleaks here.
There are five types:
type I: leak at graft ends (inadequate seal) - most common after repair of thoracic aortic aneurysms 4
CNS capillary telangiectasiae(s) are small, asymptomatic low flow vascular lesions of the brain.
As these lesions are asymptomatic, diagnosis usually matches the age of first imaging with MRI, and as such are most frequently found in middle-aged and elderly adults. Their inciden...
Coarctation of the aorta (CoA) refers to a narrowing of the aortic lumen.
Coarctations account for between 5-8% of all congenital heart defects. They are more frequent in males, M:F ratio of ~2-3:1.
Varies accordingly to the degree of stenosis and the assoc...
The cobweb sign is seen in cases of arterial dissection (usually aortic dissection) on CT angiogram (CTA) examinations and represents strands or ribbons of media crossing the false lumen, and appearing as thin filiform filling defects.
Although it is a specific sign for the false lumen, it is i...
Celiac artery, also known as the celiac axis or celiac trunk, is a major visceral artery in the abdominal cavity supplying the foregut. It arises from the abdominal aorta and commonly gives rise to three branches: left gastric artery, splenic artery, and common hepatic artery.
Celiac artery aneurysms are a form of visceral artery aneurysm and account for around 4% of such cases (fourth most common visceral arterial aneurysm).
An association with non-visceral arterial aneurysms is considered frequent 2.
While some pati...
Celiac artery compression syndrome, also known as median arcuate ligament syndrome, Dunbar syndrome, or Harjola-Marable syndrome, is a rare condition characterized by upper abdominal pain in the setting of compression of the celiac trunk by the diaphragmatic crurae.
Although well-recognized as ...
Celiac artery dissection is a type of arterial dissection. It is rarely seen as a primary phenomenon and is most often encountered due to propagation of an aortic dissection.
Celiac artery dissection is usually iatrogenic but may also be secondary to:
The celiacomesenteric trunk represents an uncommon vascular anatomical variant where both the celiac trunk and the superior mesenteric artery have a common origin from the abdominal aorta as a single trunk. Its frequency has been reported to occur in about 1.5% of the population 1,2.
Cogan syndrome is a rare vasculitis of young adults that is primarily characterized by 1,4,6:
inflammatory eye disease (classically interstitial keratitis) 6
audiovestibular dysfunction (similar to Meniere disease) 6
Cogan syndrome is rare and can occur in people of any age and ...
A coil herniation refers to the part of a detachable coil prolapsing out of the aneurysm and into the parent artery. It is an uncommon complication and is typically seen at the end of the embolization procedure. Contributing factors include 1:
wide aneurysm neck
instability of the coil in the ...
COL4A1-related disorders are a group of autosomal dominant disorders caused by a mutation in the COL4A1 gene.
The exact prevalence is unknown, but the group of disorders is considered to be under-recognized, especially asymptomatic variants 1.
The clinical ...
There are several collateral systems between the primary vascular supply of the foregut and midgut.
The collateral between the celiac trunk and superior mesenteric artery include:
gastroduodenal artery (GDA)
branch of the common hepatic artery and anastomoses with branches of the inferior pa...
The color flash artifact is a commonly encountered artifact on color Doppler ultrasound, representing spurious flow signal arising due to tissue/transducer motion.
The flash artifact is caused by movement of reflective tissues (e.g. due to respiration), or the transducer, which genera...
The comet tail sign (in urological imaging) is helpful in distinguishing a ureteric calculus from a phlebolith and strongly favors the latter.
The sign refers to a tail of soft tissue extending from a calcification, representing the collapsed/scarred/thrombosed parent vein. When well seen, it ...
The common carotid artery is a paired structure that supplies blood to the head and neck.
left: branch of the aortic arch
right: branch of the brachiocephalic trunk
course: posterior to sternoclavicular joint, lateral to thyroid and trachea
supply: head and neck
The common facial vein is formed by the joining of the facial vein and anterior branch of the retromandibular vein. It is part of the venous drainage system of the face.
origin and termination: the facial vein (along with the facial artery) pierces the deep investing fascia of the neck...
The common femoral artery (CFA) is the continuation of the external iliac artery (EIA) at the level of the inguinal ligament. As well as supplying oxygenated blood to the leg, it gives off smaller branches to the anterior abdominal wall and superficial pelvis.
origin: continuation of ...
The common femoral vein (CFV) forms from the confluence of the femoral vein and the deep femoral vein, and continues as the external iliac vein at the inguinal ligament. It accompanies the common femoral artery.
"Common femoral vein" is not listed in Terminologia Anatomica, however...
The common hepatic artery (CHA) is one of the 3 branches of the celiac artery.
Origin and course
The CHA is a terminal branch of the celiac arter. It passes over the top of the pancreas, and downwards to the right in the lesser sac towards the first part of duodenum. It gives of...
The common iliac arteries (CIAs) are the large paired terminal branches of the abdominal aorta.
The abdominal aorta bifurcates anterolateral (to the left side) of the L4 vertebra, into the right and left common iliac arteries.
The common iliac arteries (CIAs) en...
The common iliac vein, corresponding with the common iliac artery, drains venous blood from the pelvis, lower limbs and their associated structures.
location: pelvis, anterior to the sacroiliac joint
origin and termination: union of internal and external iliac veins; into the inferior...
The common interosseous artery is a branch of the proximal part of the ulnar artery at the level of the pronator teres in the distal part of the cubital fossa. It is a short vessel that dives laterally and deeply before bifurcating into anterior and posterior interosseous arteries.
The concentric ring sign is a pathognomonic sign for a subacute hematoma on MRI. A subacute hematoma may show three characteristic layers of signal intensity:
a thin peripheral rim of low signal intensity on all pulse sequences corresponding to hemosiderin
an inner peripheral high-signal inten...
The confluence of sinuses, also known as the torcula or torcular herophili is the site of the confluence of:
superior sagittal sinus
The anatomy is highly variable and three types can be distinguished:
type 1: superior sagittal sinus drains...
Congenital absence of the internal carotid artery (ICA) is a rare anomaly that occurs in less than 0.01% of the population. It encompasses agenesis, aplasia, and hypoplasia 1.
The most common type of collateral flow is through the circle of Willis, through the anterior communicating artery (ACO...
Congenital coronary artery anomalies (CCAAs) are not common, found only in ~1% (range 0.1-2%) of patients 1,3.The most important finding to look for is the "malignant" course of anomalous coronary artery, i.e. does the artery run between big pulsating objects - right ventricular outflow tract / ...
This congenital extrahepatic portosystemic shunt classification was proposed by Morgan and Superina in 1994 1:
type 1: complete diversion of portal blood into the inferior vena cava with congenital absence of the portal vein
1a: superior mesenteric vein and splenic vein do not join to form a c...
Congenital hemangiomas are benign vascular tumors of childhood that are present at birth. They are mostly indistinguishable from infantile hemangioma on imaging but have distinct histological and clinical features.
While the majority are cutaneous or subcutaneous in nature, they can occur extra...
This congenital intrahepatic portosystemic shunt classification was proposed by Park et al. in 1990 1:
type 1: single large vessel of constant diameter connecting the right portal vein to the inferior vena cava
type 2: localized, peripheral shunt with one or more communications in a single hep...
Congenitally corrected transposition of the great arteries, also known as levo- or L-loop transposition (L-TGA), is a rare cardiovascular anomaly with inversion of the ventricles and great arteries.
This anomaly comprises less than 1% of all congenital heart diseases 1,2,7.
Congenital portosystemic shunts are rare, extrahepatic or intrahepatic, anatomical abnormalities shunting blood from the portal venous system to the systemic venous system and, thus, avoiding passage through the hepatic acinus.
The term “portosystemic shunt” can be used to refer t...
Congenital vascular anomalies is a subgroup of vascular anomalies present at birth. They comprise both vascular tumors and vascular malformations.
Based on the ISSVA classification of vascular anomalies1 here is a non-comprehensive list with examples of vascular anomalies that are usually conge...