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.

42 results found
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...
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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...
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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
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Causes of a small aorta

Causes of a small aorta include: Williams syndrome Takayasu arteritis giant cell arteritis neurofibromatosis midaortic syndrome small aorta syndrome idiopathic
Article

Cerebral vascular malformations

Vascular malformations of the central nervous system can be divided, as they can elsewhere, into high and low flow malformations. High flow arteriovenous malformation (AVM) cerebral AVM (pial/parenchymal AVM) cerebral proliferative angiopathy dural arteriovenous fistula (DAVF) pial arteri...
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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...
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Endoleak

Endoleaks are characterized 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. Epidemiology An endoleak is a...
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

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

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...
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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

Hypervascular liver lesions

Hypervascular liver lesions may be caused by primary liver pathology or metastatic disease. Differential diagnosis Primary lesions hepatocellular carcinoma (HCC) most common hypervascular primary liver malignancy early arterial phase enhancement and then rapid wash out rim enhancement of c...
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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

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

Large vessel vasculitis

The term large vessel vasculitis (LVV) usually denotes the spectrum of primary vasculitides that causes chronic granulomatous inflammation predominantly involving the aorta and its major branches. Pathology The two major entities in this group are giant cell arteritis (GCA): affects older ind...
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

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

Medical devices in the neck

Medical devices in the neck are regularly observed by radiologists on plain film and CT 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 catheters (PICC) ...
Article

Medical devices in the thorax

Medical devices in the thorax are regularly observed by radiologists when reviewing radiographs and CTs. 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 visible T...
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

Phleboliths

Phleboliths are literally "vein stones", and represent calcification within venous structures. They are particularly common in the pelvis where they may mimic ureteric calculi, and are also encountered frequently in venous malformations. There is an association with Maffucci syndrome.  Radiogra...
Article

Polymyalgia rheumatica

Polymyalgia rheumatica (PMR) is a common inflammatory condition typically affecting elderly people. It is a multisystem disorder but usually affects the musculoskeletal system. It can manifest in various ways, which are best discussed in the separate articles below: polymyalgia rheumatica (mus...
Article

Pulmonary arterial calcification

Pulmonary arterial calcification is the 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 pulmonar...
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

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

Pulsatile tinnitus

Pulsatile tinnitus is a specific type of tinnitus and refers to the perception of rhythmic noise, usually in time with the patient's heartbeat, in the absence of an external source, which is most commonly but not exclusively due to underlying vascular pathology. Clinical presentation Patients ...
Article

Renal artery dissection

Renal artery dissection may occur as a result of the following processes 1: aortic dissection extending to involve the renal artery iatrogenic (e.g. catheterization) trauma atherosclerosis fibromuscular dysplasia connective tissue disease (eg. Marfan syndrome) idiopathic
Article

Renal artery stenosis

Renal artery stenosis (RAS) 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 and supply the kidne...
Article

Renal vein varices

Renal vein varices 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 syndrome retroaortic le...
Article

Retroperitoneal lymphatic malformation

Retroperitoneal lymphatic malformations are rare benign cystic lesions of vascular origin that show lymphatic differentiation. For a broader discussion, please refer to the parental article on lymphangioma.  Terminology These malformations were formerly called lymphangiomas. This expression is...
Article

Soft-tissue sarcoma

Soft-tissue sarcomas are a heterogeneous group of malignant tumors of mesenchymal origin (sarcoma) that originate from the soft tissues rather than bone. They are classified on the basis of tissue seen on histology. The commoner sarcomas in the adult and pediatric population are listed below. A...
Article

Spinal vascular malformations

Spinal vascular malformations (SVM) are rare but knowledge of them is important as if undiagnosed and untreated they can lead to serious complications.  Pathology There are two main types of SVMs 1,2: spinal arteriovenous fistula (AVF): 70% of SVMs pial: small, large, or giant dural AVF (DA...
Article

Superficial thrombophlebitis

Superficial thrombophlebitis, also called superficial venous thrombosis (SVT), is a pathological condition characterized by the presence of a thrombus in the lumen of a superficial vein, accompanied by inflammatory reaction of adjacent tissues. Terminology Some authors, however, reserve the te...
Article

Third inflow

Third inflow refers to anatomical variants leading to an additional venous inflow to the liver apart from the usual dual blood supply (portal vein and hepatic artery). They tend to be associated with parenchymal pseudolesions (focal hyperenhancement on post-contrast imaging, focal fat infiltrati...
Article

Thoracic aortic dilatation (differential)

There are a number of causes and mimics of 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 ...
Article

Thoracic aortic stenosis (differential)

The differential for thoracic aortic stenosis includes: atherosclerosis aortitis (especially Takayasu arteritis) radiation coarctation pseudocoarctation Williams syndrome: supravalvular aortic stenosis congenital rubella syndrome: supravalvular aortic stenosis
Article

Upper gastrointestinal bleeding (differential)

An upper gastrointestinal bleed usually refers to bleeding proximal to the ligament of Treitz. Pathology Causes peptic ulcer gastritis esophagitis duodenitis Mallory-Weiss tear varices tumor vascular abnormality vascular ectasia angiodysplasia Dieulafoy lesion vascular malformation...
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 us...
Article

Vascular rings and slings

Vascular rings and slings refer to the congenital vascular encirclement of the esophagus 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 Man...
Article

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 syndrome tumor thrombus
Article

Visceral artery aneurysm

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...
Article

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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