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.
31 results found
Article
Inferior vena caval contrast reflux
Reflux of contrast into inferior vena cava can be common findings seen on CT. It is considered a specific but insensitive sign of right-sided heart disease / right heart dysfunction at low contrast injection rates although the usefulness decreases with high injection rates.
Conditions associate...
Article
Intrahepatic arteriovenous shunt
Intrahepatic arteriovenous shunts, also referred to as intrahepatic arteriovenous malformations (AVMs) or hepatic arteriosystemic venous shunts, represent a spectrum of abnormal communications between the hepatic arterial system and the hepatic veins.
Please note that arterioportal shunts, whi...
Article
Iliac vein occlusion
Iliac vein occlusion can be due to a variety of causes including:
iatrogenic
neonatal catheters
catheter dissection injuries
IVC filter insertion
dialysis catheters
malignancy-related
direct tumor invasion
radiotherapy
enlarged lymph nodes
hypercoagulable state
prior DVTs
May-Thrun...
Article
Spinal vascular malformations
Spinal vascular malformations are rare but knowledge of them is important as if undiagnosed and untreated they can lead to serious complications. The main types are arteriovenous fistulae, arteriovenous malformations, cavernous malformations, and capillary telangiectasia.
Pathology
Classificat...
Article
Valsalva maneuver
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 u...
Article
Medical devices in the head and neck
Medical devices in the head and neck are regularly observed by radiologists on plain film, CT and MRI reporting. They include devices which pass through the neck into the chest and stomach or ascend to/into the head.
Vascular access devices
dialysis catheters
peripherally inserted central cat...
Article
Pulmonary arterial calcification
Pulmonary arterial calcification is a phenomenon which is usually seen in the setting of advanced pulmonary hypertension. It can however be uncommonly present in those without pulmonary hypertension.
Pathology
The general mechanism in the vast majority is thought to be from high end pulmonary ...
Article
Visceral artery aneurysm
Visceral artery aneurysms are abnormal focal dilatations of splanchnic 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 discuss...
Article
Hemoptysis
Hemoptysis (plural: hemoptyses) refers to coughing up of blood. Generally, it appears bright red in color as opposed to blood from the gastrointestinal tract which appears dark red. It is considered an alarming sign of a serious underlying etiology.
Terminology
Massive hemoptysis is referred t...
Article
Small aorta (differential)
Causes of a small aorta include:
Williams syndrome
Takayasu arteritis
giant cell arteritis
neurofibromatosis
midaortic syndrome
small aorta syndrome
idiopathic
Article
Ascending aorta dilatation
Dilatation of the ascending aorta is a common finding in the elderly but unusual in younger patients.
Pathology
In adults, an ascending aortic diameter greater than 4 cm is considered to indicate dilatation 4. Aneurysmal dilatation is considered when the ascending aortic diameter reaches or ex...
Article
Pulmonary vasculitis
Pulmonary vasculitis refers to vasculitides that affect the lung or pulmonary vessels. If this definition is used, a large group of conditions can fall into this category. The respiratory system may be potentially involved in all systemic vasculitides, although to a variable degree.
Pathology
...
Article
Renal vein varices
Renal vein varices (singular: varix) develop for various reasons and are usually asymptomatic.
Clinical presentation
Renal vein varices are usually asymptomatic. Some patients may present with flank pain and/or hematuria.
Pathology
Etiology
chronic renal vein thrombosis
nutcracker syndrom...
Article
Medical devices in the thorax
Medical devices in the thorax are regularly observed by radiologists when reviewing radiographs and CT scans.
Extrathoracic devices
tubing, clamps, syringes, scissors, lying on or under the patient
rubber sheets, foam mattresses, clothing, hair braids, nipple piercings, etc. may also be visib...
Article
Carotid pacemaker
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...
Article
Moyamoya syndrome
Moyamoya syndrome, also termed the moyamoya pattern or phenomenon, is due to numerous conditions that can cause arterial occlusion of the circle of Willis, with resultant collaterals, and appearances reminiscent of moyamoya disease. These conditions include 1-4 :
vessel wall abnormalities
athe...
Article
Differential diagnosis of vascular calcification
The differential diagnosis of vascular calcification is very wide with many common and uncommon conditions.
Differential diagnosis
Common
aneurysm
atherosclerosis
end-stage renal failure 3
hemangioma; arteriovenous malformation
hyperparathyroidism, primary or secondary (renal osteodystrop...
Article
Enlarged azygos vein
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.
Terminology
Spelling it "azygous" when referring to the vein is incorr...
Article
Left paramediastinal catheter position (differential)
When a central venous catheter that is supposed to terminate in the superior vena cava or right atrium is abnormally located to the left of the mediastinum and below the level of the brachiocephalic vein, a limited differential of left paramediastinal catheter position should be considered 1:
l...
Article
Causes of ascending aorta calcification
There are relatively few causes of calcification of the ascending aorta 1-3:
atherosclerosis (this usually spares the ascending aorta)
aortitis
syphilis
Takayasu arteritis
idiopathic
See also
porcelain aorta
Article
Enlarged pulmonary trunk on chest radiography (differential)
The differential of an enlarged pulmonary trunk/main pulmonary artery on chest radiography includes:
normal
may appear prominent in young patients especially women
projectional
rotation
lordotic view
rotation of the heart
pectus excavatum
left lower lobe collapse
pulmonary arterial hyp...
Article
Pulmonary hypertension (differential)
Pulmonary hypertension has many causes, and these can be divided in many ways. A simple and systematic approach is to proceed along the cardiopulmonary pulmonary circulation, as causes are found at each site (for a more official classification system see 2003 third world symposium on pulmonary a...
Article
Lower gastrointestinal bleeding (differential)
Lower gastrointestinal bleeding usually occurs distal to the ligament of Treitz, and has a wide differential diagnosis:
diverticular disease
enterocolitis
infective
Crohn’s disease
ulcerative colitis
ischemic colitis
vascular malformation
vascular ectasia
angiodysplasia
arteriovenous m...
Article
Upper gastrointestinal bleeding (differential)
An upper gastrointestinal bleed usually refers to bleeding proximal to the ligament of Treitz.
Pathology
Aetiolology
peptic ulcer
gastritis
esophagitis
duodenitis
Mallory-Weiss tear
varices
tumor
vascular abnormality
vascular ectasia
angiodysplasia
Dieulafoy lesion
vascular malform...
Article
Hyperreninaemic hypertension (differential)
Hyperreninaemic hypertension may have many causes including:
renal artery stenosis
renal secreting tumor, e.g. renal cell carcinoma, reninoma
renal compression: large renal mass, subcapsular hemorrhage (Page kidney)
Article
Renal artery stenosis
Renal artery stenosis (RAS) (plural: stenoses) refers to a narrowing of a renal artery. When the process occurs slowly, it leads to secondary hypertension. Acute renal artery stenosis does not lead to hypersecretion of renin.
Pathology
When the stenosis occurs slowly, collateral vessels form a...
Article
Thoracic aortic stenosis (differential)
The differential for thoracic aortic stenosis includes:
atherosclerosis
aortitis (especially Takayasu arteritis)
radiotherapy
coarctation
pseudocoarctation
Williams syndrome: supravalvular aortic stenosis
congenital rubella syndrome: supravalvular aortic stenosis
Article
Thoracic aortic dilatation (differential)
There is a broad differential for thoracic aortic dilatation.
Differential diagnosis
senile ectasia
hypertension
post-stenotic dilatation, e.g. bicuspid aortic valve
thoracic aortic aneurysm
atherosclerosis (usually descending thoracic aorta)
collagen disorders
Marfan syndrome
Ehlers-Da...
Article
Hypervascular liver lesions
Hypervascular liver lesions are findings that enhance more or similarly to the background hepatic parenchyma in the late arterial phase, on contrast-enhanced CT or MRI.
Differential diagnosis
Primary lesions
hepatocellular carcinoma (HCC)
most common hypervascular primary liver malignancy
e...
Article
Cerebrovascular malformations
Cerebrovascular malformations are vascular malformations related to the vessels that supply the brain and other cranial structures.
Classification
Over the years, cerebrovascular malformations have been classified in a variety of ways by different authors.
Over the years cerebral vascular mal...
Article
Venous thromboembolism
Venous thromboembolism covers a wide spectrum of diseases. Individual conditions and complicating condition include:
head and neck
cerebral vein thrombosis
dural venous sinus thrombosis
cavernous sinus thrombosis
deep cerebral vein thrombosis
cortical vein thrombosis
superior ophthalmic v...