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 continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
16,906 results found
Article
Splenosis
Splenosis is one type of ectopic splenic tissue (the other being accessory spleen). It is an acquired condition and is defined as autoimplantation of one or more focal deposits of splenic tissue in various compartments of the body.
Pathology
Etiology
Abdominal splenosis is seen after abdomina...
Article
Pulmonary cyst
A pulmonary cyst is any well-circumscribed gas-containing structure within lung parenchyma with a thin, typically regular wall. Occasionally a cyst may contain fluid or solid material instead of gas 10.
Terminology
The term ‘cystic’ denotes lesions with central gas attenuation contained by a w...
Article
Granulomatosis with polyangiitis
Granulomatosis with polyangiitis (GPA), previously known as Wegener granulomatosis, is a multisystem necrotizing non-caseating granulomatous c-ANCA positive vasculitis affecting small to medium-sized arteries, capillaries, and veins, with a predilection for the respiratory system and kidneys.
T...
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Granulomatosis with polyangiitis (orbital manifestations)
Ophthalmologic manifestations of granulomatosis with polyangiitis (GPA) is not uncommon and can occur in either the classic or limited form of the disease.
For a general discussion of the condition, please refer to the main article on granulomatosis with polyangiitis (GPA). For other organ-spec...
Article
Osmotic demyelination syndrome
Osmotic demyelination syndrome refers to acute demyelination seen in the setting of osmotic changes, typically with the rapid correction of hyponatremia.
Terminology
Osmotic demyelination syndrome is the preferred term, replacing central pontine myelinolysis, recognizing that extrapontine stru...
Article
Neurosarcoidosis
Central nervous system involvement by sarcoidosis, also termed neurosarcoidosis, is relatively common among patients with systemic sarcoidosis and has a bewildering variety of manifestations, often making diagnosis difficult.
For a general discussion of the underlying condition, please refer t...
Article
Birt-Hogg-Dubé syndrome
Birt-Hogg-Dubé syndrome (BHDS), also known as folliculin gene-associated syndrome, is a multi-system disease characterized by:
cutaneous manifestations, typically fibrofolliculomas
multiple lung cysts and spontaneous pneumothoraces
increased risk of renal tumors in some families, typically ch...
Article
Hippocampus
The hippocampus (plural: hippocampi) or historically the cornu Ammonis, is an important component of the human brain, situated in the temporal lobe. It plays a role in information processing and the reproductive cycle and is involved in Alzheimer disease.
Gross anatomy
Location
The hippocampu...
Article
Diffuse pulmonary nodules
Diffuse pulmonary nodules are usually seen as multiple pulmonary nodular opacifications on a HRCT chest scan. They can signify disease processes affecting either the interstitium or the airspace. They can range from a few millimeters to up to 1 cm and when very small and numerous there can be so...
Article
Persistent carotid-vertebrobasilar anastomoses
The persistent carotid-vertebrobasilar anastomoses are variant anatomical arterial communications between the anterior and posterior circulations due to abnormal embryological development of the vertebrobasilar system. They are named, with the exception of the proatlantal artery, using the crani...
Article
Sclerotic bone metastases
Sclerotic or osteoblastic bone metastases are distant tumor deposits of a primary tumor within bone characterized by new bone deposition or new bone formation.
Epidemiology
Bone metastases are the most common bone malignancy, with sclerotic bone metastases being less common than lytic bone met...
Article
Lytic bone metastases
Lytic bone (osteolytic) metastases are distant tumor deposits of a primary tumor within bone characterized by a loss of bone with the destruction of the bone matrix.
Epidemiology
Lytic bone metastases are more common than sclerotic bone metastases.
Diagnosis
The diagnosis is usually establis...
Article
Mixed lytic and sclerotic bone metastases
Mixed lytic and sclerotic bone (osteolytic and osteoblastic) metastases refer to metastatic bone disease with both sclerotic and lytic bone metastases or bone metastases with both components.
Diagnosis
The diagnosis is established by proof of sclerotic and lytic bone metastases of one primary ...
Article
Monochorionic monoamniotic twin pregnancy
A monochorionic monoamniotic (MCMA) twin pregnancy is a subtype of monozygotic twin pregnancy. These fetuses share a single chorionic sac, a single amniotic sac, and, in general, a single yolk sac.
Epidemiology
It accounts for the minority (~5%) of monozygotic twin pregnancies and ~1-2% of al...
Article
Lipomyelocele
Lipomyelocele, also known as lipomyeloschisis, is one of the most common closed spinal dysraphisms. It is most commonly encountered in the thoracolumbar region and usually presents as a fatty subcutaneous mass.
It should not be confused with myeloschisis which is a severe form of open spinal dy...
Article
Spinal instability neoplastic score (SINS)
The spinal instability neoplastic score (SINS) helps to assess tumor-related instability of the vertebral column. It has been shown to be useful in guiding the mobilization or operative management of patients with neoplastic spinal disease and correlates with patient-reported outcomes 1-4.
Stud...
Article
Spinal dysraphism
Spinal dysraphisms refer to a broad group of malformations affecting the spine and/or surrounding structures in the dorsum of the embryo. They are a form of neural tube defect.
Terminology
The term dysraphism implies that the cause of the abnormality is due to anomalous midline fusion and shou...
Article
Spatial compounding (ultrasound)
Spatial compounding is an advanced ultrasound technique that utilizes multiple angles of insonation to create a single averaged image 1.
Clinical applications
The advantages of spatial compounding are that angle-dependent artefacts are reduced, curved surfaces appear more continuous and backgr...
Article
Soft tissue abscess
Soft tissue abscesses are focal or localized collections of pus caused by an immune response to pathogenic microorganisms. They are surrounded by a peripheral rim or abscess membrane and can be found within the soft tissues in any body part 1.
Soft tissue abscesses include subcutaneous abscesse...
Article
Penumbra sign (intraosseous abscess)
In musculoskeletal radiology, the penumbra sign represents a rim of vascularized granulation tissue surrounding an intraosseous abscess cavity, with a higher T1 signal intensity than the cavity itself 1. This finding is a specific (~98%) but relatively insensitive (~55%) sign to distinguish suba...
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