The coronary sinus is the major coronary vein. It returns the majority of the left ventricular blood flow to the right atrium.
The coronary sinus courses along the posterior wall of the left atrium into the left atrioventricular groove. It normally drains into the right atrium. T...
The coronary veins return deoxygenated blood from the myocardium back to the right atrium. Most venous blood returns via the coronary sinus. Coronary venous anatomy is highly variable, but is generally comprised of three groups:
cardiac veins which drain into the coronary sinus:
great cardiac ...
Cortical vein thrombosis, also known as superficial cerebral vein thrombosis, is a subset of cerebral venous thrombosis involving the superficial cerebral veins besides the dural sinus, often coexisting with deep cerebral vein thrombosis or dural venous sinus thrombosis. It has different clinica...
The costocervical trunk is one of the branches of the second part of the subclavian artery. It arises from the posterior wall of the subclavian artery, posterior or medial to the anterior scalene muscle and courses posterosuperiorly across the suprapleural membrane where it divides into 2 branc...
The costoclavicular space is the anterior portion of the superior thoracic aperture, between the clavicle and first rib. The subclavian vessels and brachial plexus pass though the space related to the scalene muscles. Proximally, the plexus passes through the interscalene space, and distally thr...
Coup de poignard of Michon refers to spinal subarachnoid haemorrhage, usually as a result of a spinal AVM.
Presentation is with sudden excruciating back pain, akin to being stabbed with a dagger (poignard = french for dagger). It is the corollary of the thunderclap headache.
The cremasteric artery is a small branch of the inferior epigastric artery that enters the deep inguinal ring of the inguinal canal and supplies the layers of the spermatic cord and also the skin of the scrotum, including the cremaster muscle.
History and etymology
The word "cremaster" derives...
The crescent sign refers to the high signal crescent seen in the wall of a vessel when dissected. This may be seen both on T1 or T2 sequences depending on the age of the blood (see ageing blood on MRI). It is classically referred to in internal carotid artery dissection.
It should not be confus...
Cryoglobulinaemic vasculitis (CV) is a form of immune mediated primary vasculitis involving small to medium sized vessels. It may involve multiple organs and can have a range of clinical presentations.
There are three main types of cryoglobulinaemia which are grouped, as per the Br...
This is a basic article for medical students and other non-radiologists
CT abdomen is an increasingly common investigation that is used to help make diagnoses of a broad range of pathologies. A CT abdomen in its simplest form is a CT from diaphragm to symphysis pubis performed 60 seconds after ...
Multi-slice CT angiography of the splanchnic vessels is a powerful minimally invasive technique for evaluation of the splanchnic vascular system.
The actual procedure will vary depending on institutional protocol/guidelines but below is a typical description 2, 4:
CT cerebral venography is a contrast enhanced examination with an acquisition delay providing an accurate detailed depiction of the cerebral venous system.
Rapid diagnosis of cerebral venous thrombosis.
general CT contraindications such as pregnancy, etc.
CT perfusion in ischaemic stroke has become established in most centres with stroke services as an important adjunct, along with CT angiography (CTA), to conventional unenhanced CT brain imaging.
It enables differentiation of salvageable ischaemic brain tissue (the penumbra) from irrevocably d...
The cubital fossa is a triangular space which forms the transition between the arm and the forearm. It is located anterior to the elbow joint.
superior: the line joining the medial and lateral humeral epicondyles
lateral: medial border of brachioradialis
Cutaneous leukocytoclastic angiitis is a form of vasculitis that affect the skin. This is considered the most common of vasculitis affecting the skin and usually results from deposition of immune complexes at the vessel wall. Patients usually have a palpable purpura.
Cystic adventitial disease (CAD) is an uncommon vascular pathology predominantly affecting peripheral vessels. The vast majority of cases occur in arteries, with venous involvement being an extremely rare occurrence 8.
It typically affects young to middle-aged individuals without ...
The cystic artery represents the main blood supply to the gallbladder. It most commonly arises from the right hepatic artery within Calots triangle 1.
The cystic artery passes posterior to the cystic duct to reach the neck of the gallbladder. At this point, it gives off two-to-fo...
Cystic hygroma, also known as cystic or nuchal lymphangioma, refers to the cystic variety of congenital lymphangioma which, most commonly, occur in the cervicofacial regions, particularly at the posterior cervical triangle.
They usually occur in the fetal/infantile and paediatri...
D-dimer is a commonly tested biological marker which is produced by the enzymatic breakdown of cross-linked fibrin which forms the fibrous mesh of a blood clot. The measurement of D-dimer in the circulation acts as a marker of coagulation and fibrinolysis, which can be useful in the diagnosis of...
The DeBakey classification, along with the Stanford classification, is used to separate aortic dissections into those that need surgical repair, and those that usually require only medical management.
The DeBakey classification divides dissections into 1-5:
type I: involves asc...
A mnemonic used to remember the DeBakey classification 1 is:
B: both ascending and descending aorta (type I)
A: ascending aorta (type II)
D: descending aorta (type III)
The deep brachial artery or profunda brachii artery is a large branch of the brachial artery, located in the arm.
origin: brachial artery
location: posterior aspect of the arm
supply: triceps brachii
main branches: middle collateral and radial collateral arteries
Deep cerebral vein thrombosis is a subset of cerebral venous thrombosis involving the internal cerebral veins, often coexisting with cortical vein thrombosis or dural venous sinus thrombosis, and with different clinical presentations relying on which segment is involved.
As such please refer to...
The deep circumflex iliac artery arises from the external iliac artery.
origin: lateral aspect of the external iliac artery above the inguinal ligament, almost opposite to the inferior epigastric artery
course: travels superiorly parallel to the inguinal ligament towards the ant...
The deep femoral vein or the profunda femoris vein lies anterior to its artery, and receives tributaries corresponding to the branches of the artery. Through these tributaries it connects distally with the popliteal and proximally with the inferior gluteal veins. It sometimes drains the medial a...
The term deep vein thrombosis (DVT) is practically a synonym for clots occuring in the lower limbs. However, it can also be used for those that occur in the upper limbs and neck veins. Other types of venous thrombosis, such as intra-abdominal and intracranial, are discussed in separate articles....
Dehiscent jugular bulbs are present when the sigmoid plate between a high riding jugular bulb and the middle ear is absent, allowing the wall of the jugular bulb to bulge into the middle ear cavity.
The estimated incidence is ~5% (range 3.5-7%) of the symptomatic population (e.g. ...
The descending aorta is the continuation of the aortic arch in the posterior mediastinum.
The descending aorta commences at the level of the fourth thoracic vertebra body, on its left, in the plane of Ludwig as the continuation of the aortic arch. It descends in the posterior med...
The descending branch of the lateral circumflex femoral artery descends from the lateral aspect of the femoral neck and extends as far as the knee where it provides blood to the patellar network (the complex arterial anastomosis around the knee).
origin: lateral circumflex femoral arte...
The descending geniculate artery arises from the distal portion of the superficial femoral artery before it becomes the popliteal artery. Along with other arterial branches, it provides blood to the patella network and the knee.
origin: superficial femoral artery
supply: patella netwo...
Developmental venous anomaly (DVA), also known as cerebral venous angioma, is a congenital malformation of veins which drain normal brain. They were thought to be rare before cross-sectional imaging but are now recognised as being the most common cerebral vascular malformation, accounting for ~5...
Diabetes mellitus, often referred to simply as diabetes, is a group of metabolic conditions characterised by hyperglycaemia.
These conditions should not be confused with diabetes insipidus which is clinically distinct and not related to hyperglycaemia.
Diagonal branches of the left anterior descending coronary artery supply blood flow to the anterior and anterolateral walls of the left ventricle. There are usually denoted as D1, D2, D3, etc.
There are termed "diagonal" due to them branching from their parent vessel at acute angles. They ext...
The diaphragm is the dome-shaped muscle that separates the thoracic cavity from the abdominal cavity, enclosing the inferior thoracic aperture.
The muscular fibres of the diaphragm originate around the circumference of the inferior thorax and converge to a common insertion point ...
The diaphragmatic apertures are a series of apertures that permit the passage of structures between the thoracic and abdominal cavities. There are three main apertures:
aortic hiatus (T12) (not a true aperture)
oesophageal hiatus (T10)
vena caval foramen (T8)
The vertebral levels of these ap...
Diastolic pseudogating appears as periodic bright and dark signal in arteries such as the aorta as one progresses through a series of images. Synchronization of the cardiac cycle and the pulse sequence results in high signal in the artery during diastole when blood is relatively stationary and l...
The differential diagnosis of vascular calcification is very wide with many common and uncommon conditions.
end-stage renal failure 3
hemangioma; arteriovenous malformation
hyperparathyroidism, primary or secondary (renal osteodystrop...
Dilated mammary veins can result from many pathologies. These include:
as a secondary but non specific sign of breast malignancy 1
ipsilateral subclavian venous obstruction
Mondor disease: can be dilated as well as being thrombosed
The disappearing basal ganglia sign is one of the early signs of a middle cerebral artery (MCA) infarction. It is defined as the loss of delineation of the basal ganglia, due to blurring of their grey-white matter interface and hypoattenuation, consequent to cytotoxic oedema at the time of an is...
The "dog leg" sign is a secondary angiographic sign on popliteal angiography, which demonstrates an irregular lumen of the popliteal artery with acute bend in the course of the popliteal artery. It is characteristically seen in popliteal artery aneurysms with mural thrombus.
It is an important ...
Doppler angle corrects for the usual clinical situation when an ultrasound beam is not parallel to the Doppler signal.
For instance, if one wants to evaluate an artery, the best angle for evaluation would be at zero degrees (parallel to the vessel). The strongest signal and best waveforms would...
Doppler waveforms are often misinterpreted and/or overlooked. They can provide great deal of information if carefully understood.
The three basic arterial waveforms are 1,2:
forward flow in systole
reverse flow in late systole / early dia...
The dorsal nasal artery, also known as the dorsonasal artery, is a terminal branch of the ophthalmic artery.
Arising as a terminal branch of the ophthalmic artery, the dorsal nasal artery exits the orbit after piercing the orbital septum above the medial canthal tendon (medial pa...
The dorsal pancreatic artery is a branch of the splenic artery that supplies the pancreas. It arises from the proximal splenic artery and descends a short distance to run along the posterior margin of the pancreas where it divides in to left and right branches.
the right branches pass either an...
The dorsal scapular artery is a branch of either the transverse cervical artery (from the thyrocervical trunk off the first part of the subclavian artery) or an independent branch from the third (or less commonly second) part of the subclavian artery.
It accompanies the dorsal scapular nerve, c...
Double aortic arch is the most common symptomatic type of the aortic arch variant. It may account for up to 50-60% of vascular rings.
Double aortic arch is mostly diagnosed in childhood due to symptoms related to oesophageal and/or tracheal obstruction. Respiratory sympto...
Double barrel sign is an imaging appearance of two lumens adjacent to each other.
It can be seen in:
dilated bile duct adjacent to portal vein
double barrel aorta: aortic dissection
double barrel oesophagus: oesophageal dissection
Double density sign of berry aneurysms refers to the angiographic appearance of a small intracranial aneurysm projecting in front or behind a vessel of similar calibre. As such, the border of the aneurysm cannot easily be seen, but the extra contrast within it can be seen as a rounded area of in...
The double lumen cannula enables veno-venous extracorporeal membrane oxygenation (VV ECMO) to patients with severe respiratory failure. It is often used as a bridge to lung transplant.
The cannulation is usually performed via the right jugular vein. This position allows the patients to stay aw...
Double outlet right ventricle (DORV) is a congenital cardiac anomaly where both the aorta and pulmonary trunk arise from the morphologically right ventricle. It is reported to account for ~2% of congenital cardiac defects 1. It is usually classed as a conotruncal anomaly. There is almost always ...
Double retroaortic left renal vein is a very rare entity that is usually clinically silent and detected incidentally at imaging, surgery or autopsy.
The knowledge of anatomical variations helps the surgeon or interventionist to avoid complications during surgery and interventional procedures 4 ...
The double switch procedure is a surgical technique used to repair congenitally corrected transposition of the great arteries (L-TGA), which is a cardiovascular anomaly with atrioventricular and ventriculoarterial discordance.
The procedure consists of any of the following surgical combinations...
The draped aorta sign is an important imaging feature that can be seen in contained rupture of an abdominal aortic aneurysm. It is highly indicative of aortic wall deficiency.
This sign is considered present when the posterior wall of an aortic aneurysm drapes or moulds to the anterior surface...
Drug rash with eosinophilia and systemic symptoms (DRESS) is a syndrome reflecting a marked hypersensitivity reaction to drugs or medications.
Clinical presentation can be variable and symptoms may arise from 2 to 8 weeks after initiating the offending drug. Typical cli...
The ductus arteriosum (or arteriosus) is the thick short conduit for blood to bypass the non-ventilated lungs in the fetus. It is located between and connects the proximal left pulmonary artery and the undersurface of the aortic arch distal to the origin of the last branch of the arch, at the ao...
Aortic ductus diverticulum is a developmental outpouching of the thoracic aorta which may be mistaken for an acute aortic injury.
It is usually seen at the anteromedial aspect of the aorta at site of the aortic isthmus, where the ligamentum arteriosum attaches. It is also the sit...
The duplicated middle cerebral artery is an anatomical variant in which there are two middle cerebral arteries originating from the distal end of the internal carotid artery.
The duplicated artery supplies the anterior temporal lobe.
It should not be confused wi...
Duplication of the inferior vena cava is a relatively rare vascular anomaly, but this caval abnormality needs to be recognised, especially in association with renal anomalies like crossed fused ectopia or circumaortic renal collar 1-2.
The incidence of inferior vena caval duplicat...
Dural arteriovenous fistulas (dAVF) are a heterogeneous collection of conditions that share arteriovenous shunts from dural vessels. They present variably with haemorrhage or venous hypertension, and can be challenging to treat.
Most dural arteriovenous fistulas present in adultho...
Dural sinus occlusive disease (DSOD) is an infective form of dural sinus thrombosis (thrombophlebitis) commonly seen in the setting of acute otomastoiditis. It typically presents with:
sixth nerve palsy - due to involvement of Dorello's canal
altered conscious st...
Dural venous sinuses are venous channels located intracranially between the two layers of dura mater (endosteal layer and meningeal layer). They can be conceptualised as trapped epidural veins. Unlike other veins in the body they run alone, not parallel to arteries. Furthermore, they are valvele...
Dural venous sinus thrombosis is a subset of cerebral venous thrombosis, often coexisting with cortical or deep vein thrombosis, and presenting in similar fashions, depending mainly on which sinus is involved.
As such, please refer to the cerebral venous thrombosis article for a general discuss...
Dysphagia lusoria is an impairment of swallowing due to compression from an aberrant right subclavian artery (arteria lusoria).
Most patients with aberrant right subclavian arteries do not have symptoms. Some present with mild dysphagia, while a small minority have a seve...
Eagle syndrome refers to symptomatic elongation of the styloid process or calcified stylohyoid ligament 1,2. It is often bilateral. In most cases, the cause is unknown; however, the condition is sometimes associated with disorders causing heterotopic calcification such as abnormal calcium/phosph...
Ehlers-Danlos syndrome comprises a heterogeneous group of collagen disorders (hereditary connective tissue disease).
There is a recognised male predominance.
Clinically manifests by skin hyperelasticity and fragility, joint hypermobility and blood vessel fr...
Elephantiasis nostras verrucosa is a rare cause of chronic lymphoedema, arising in the setting of chronic nonfilarial lymphedema caused by bacterial or noninfectious obstruction of the lymphatics.
It presents mostly as grossly oedematous and disfigured lower extremities, ...
An elephant trunk repair is a type of open repair procedure devised to address combined aneurysms, it is often a two staged procedure wherein the arch repair is facilitated by sternotomy and a second staged procedure is performed via left thoracotomy for the descending or thoracoabdominal aorta...
The empty delta sign is a CT sign of dural venous sinus thrombosis of the superior sagittal sinus, where contrast outlines a triangular filling defect, which represents thrombus. It is only described with CECT-scan or MRI, not with NECT nor non-contrast MRI.
An equivalent appearance can be note...
Endoleaks are characterised by persistent blood flow within the aneurysm sac following endovascular aneurysm repair (EVAR). Normally the aortic stent-graft used for EVAR excludes the aneurysm from the circulation by providing a conduit for blood to bypass the sac.
An endoleak is a...
Endotension, also referred to as a type V endoleak, is not a true leak but is defined as continued expansion of the aneurysm sac greater than 5 mm, without radiographic evidence of a leak site.
It is a poorly understood phenomenon but thought to be formation of a transudate due to ul...
Endovascular aneurysm repair (EVAR) was first pioneered in the early 1990s. Since then technology of the devices has rapidly progressed and EVAR is now widely used as treatment of thoracic and abdominal aortic aneurysms (AAA).
The advantages of endovascular repair over open repair are that they...
Endovascular aneurysm sealing system (EVAS) was developed with the intention to expand beyond the anatomic limitations of endovascular aneurysm repair (EVAR) devices, as well as to decrease the rates of re-intervention secondary to graft migration and type II endoleaks.
EVAS was designed by End...
An enlarged/dilated azygos vein may result from a number of physiological as well as pathological causes. The enlarged azygos vein may be seen as a widened right paratracheal/paraspinal stripe on a frontal chest radiograph.
Causes for dilatation
There are a number of physiological causes for e...
The differential of an enlarged pulmonary trunk/main pulmonary artery on chest radiography includes:
may appear prominent in young patients especially women
rotation of the heart
left lower lobe collapse
pulmonary arterial hyp...
Epithelioid haemangioendothelioma (EHE) is a rare relatively low grade vascular tumour. It occurs around medium to large venous structures.
It consists of rounded or slightly spindle-shaped eosinophilic endothelial (epitheloid) cells with rounded nuclei and prominent cytoplasmic vacu...
The external carotid artery (ECA) is one of the two terminal branches of the common carotid artery. The other terminal branch is the internal carotid (ICA), which is somewhat larger than the ECA.
origin: bifurcation of the common carotid artery
course: under the submandibular gland an...
The external iliac artery is the larger of the two terminal branches of the common iliac artery.
The common iliac artery bifurcates into the internal iliac artery and external iliac artery at the level of the pelvic brim anterior to the sacroiliac joint.
The external iliac vein (EIV) is located along the pelvic brim between the inguinal ligament and the sacroiliac joint.
posterior to inguinal ligament within lacuna vasorum 1 as continuation of femoral vein
The external iliac vein unites with the internal il...
The external jugular vein (EJV) drains the head, face, and part of the pectoral region.
Origin and course
The posterior division of the retromandibular vein and posterior auricular vein unite to form the external jugular vein at the angle of the mandible.
It courses inferiorly ...
A mnemonic to remember external jugular vein (formed by the retromandibular and posterior auricular veins) tributaries is:
P: posterior external jugular vein
A: anterior jugular vein
S: suprascapular vein
T: transverse cervical vein
Extracorporeal membrane oxygenation (ECMO) is used as a modified pulmonary or cardiopulmonary bypass technique in those with severe cardiac and/or respiratory failure refractory to conventional ventilatory support and medical intervention 1,3. There are two access paths for extracorporeal life s...
Extra-hepatic portal vein obstruction is the most common cause of noncirrhotic portal hypertension in children and young adults in developing countries. It may or may not extend into intrahepatic portal veins.
It usually occurs in children and young adults, presenting as ...
The facial artery is one of the branches of the external carotid artery and supplies blood to the structures of the face.
origin: branch of the external carotid artery a little above the level of the lingual artery, in the carotid triangle of the neck
course: passes deep to the poster...
The facial-cavernous anastomoses are the communications of the facial and deep facial veins with the cavernous sinus.
At the medial canthus of the eye there is a communication with the ophthalmic veins, which drain into the cavernous sinus. Blood from the frontal scalp normally f...
The facial vein (previously known as the anterior facial vein) is the continuation of the angular vein and joins the anterior branch of the retromandibular vein to form the common facial vein 1-3.
At the level of the lower margin of the orbit, the angular vein becomes the facial ...
The falciform artery, also known as the hepatic falciform artery (FHA) is an uncommon vascular anatomic variant that most commonly arises as the terminal branch of the middle hepatic artery which courses anteriorly through the falciform ligament into and supplying the supraumbilical anterior abd...
False aneurysms, also known as a pseudoaneurysm, is when there is a breach in the vessel wall such that blood leaks through the wall but is contained by the adventitia or surrounding perivascular soft tissue. A direct communication of blood flow exists between the vessel lumen and the aneurysm l...
Familial multiple cavernous malformation syndrome(s) are uncommon, accounting for only a minority of cavernous malformations.
It has been more frequently reported in patients of Hispanic descent 1.
The presentation is most commonly with seizures (38-55%) 1 ...
Femoral artery pseudoaneurysms are usually iatrogenic as the femoral artery is the vessel of choice for most endovascular arterial interventions.
inadequate compression following endovascular intervention
improper arterial puncture tec...
The femoral canal, or the medial compartment of the femoral sheath, is the inverted cone-shaped fascial space medial to the femoral vein within the upper femoral triangle. It is only 1-2 cm long and opens superiorly as the femoral ring. It serves two purposes:
allows the femoral vein to expand ...
The femoral ring is the superior opening of the femoral canal. Its boundaries are:
medial: lacunar ligament
anterior: medial part of the inguinal ligament
lateral: femoral vein within the intermediate compartment of the femoral sheath
posterior: pectineal ligament overlying the pectineus and...
The femoral sheath is the funnel-shaped fascial space that extends from the abdomen, inferior to the inguinal ligament, into the femoral triangle. It has variable length and terminates by blending in with the adventitia of the femoral vessels. It is formed from the transversalis and psoas fascia...
The femoral vein is the main deep vein of the thigh and accompanies the superficial femoral artery and common femoral artery.
The term "superficial femoral vein" or its abbreviation, "SFV" should not be used as it is a misnomer (i.e. it is not a superficial vein), and can be especi...