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.
16,868 results found
Article
Sclerosing angiomatoid nodular transformation of the spleen
Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a rare, non-neoplastic vascular splenic lesion of uncertain etiology.
Terminology
The term SANT first appeared in the literature in a 2004 article by Martel et al. which examined a series of 25 cases 3. This relatively unco...
Article
CT myelography
CT myelography (CTM) is a myelography technique used mainly to assess for potential spinal canal stenosis when MRI is contraindicated or when dynamic imaging is required.
History
CT myelography was first performed in 1976 2 and became the gold standard for imaging the spinal canal and cord unt...
Article
Transcatheter mitral valve intervention
Transcatheter mitral valve interventions (TMVI) or percutaneous mitral valve interventions are less-invasive, highly technical procedures available for the management of selected patients with mitral valve regurgitation and include several transcatheter mitral valve repair (TMVr) and transcathet...
Article
External auditory canal cholesteatoma
External auditory canal cholesteatomas are a rare subtype of acquired cholesteatoma.
Epidemiology
The external acoustic canal is a rare location for a cholesteatoma with an estimated incidence of around 1.2 per 1,000 new otological patients ref. The overall incidence rate in one large study wa...
Article
Acquired cholesteatoma
Acquired cholesteatomas are far more common than congenital cholesteatomas and are almost always closely related to the tympanic membrane and pneumatized portion of the temporal bone from which most are thought to arise 9.
Cholesteatomas occur far more commonly in the middle ear than in the ex...
Article
Lymphomas of the central nervous system
Lymphomas of the central nervous system, the most common of which is primary diffuse large B-cell lymphoma of the CNS, are the second most common primary brain tumor after gliomas 17. By definition, there is no co-existing systemic disease at the time of diagnosis, distinguishing it from CNS inv...
Article
Facet joint injection
Facet (zygapophyseal) joint injections are performed primarily for the diagnosis and differentiation of facet syndrome and radicular pain syndrome, and are one of the spinal interventional procedures. They can be performed under fluoroscopic, or CT image guidance, and cervical, thoracic or most ...
Article
Wallerian degeneration
Wallerian degeneration is the process of antegrade degeneration of the axons and their accompanying myelin sheaths following proximal axonal or neuronal cell body lesions. It may result following neuronal loss due to cerebral infarction, trauma, necrosis, focal demyelination, or hemorrhage.
Pa...
Article
Papillary thyroid cancer
Papillary thyroid carcinoma (PTC) is the most common malignancy of the thyroid gland and frequently has nodal metastases at presentation.
Terminology
When the tumor measures <1 cm, the term micropapillary carcinoma (mPTC) is used 14.
Epidemiology
Papillary thyroid cancer (as is the case wit...
Article
Lymphedema
Lymphedema is the pathologic accumulation of fluid in the soft tissues as the result of impaired lymphatic drainage, with resultant inflammation, adipose tissue hypertrophy, and fibrosis. It can be either primary or secondary, due to surgery or disease processes. The condition can cause disfigur...
Article
Isolated inferior vermian hypoplasia
Isolated inferior vermian hypoplasia (IIVH), also referred to as part of the Dandy-Walker variant (DWV), is a congenital malformation characterized by partial absence of the inferior portion of the cerebellar vermis.
Terminology
The term Dandy-Walker variant was created to include those malfor...
Article
Sonographic values in obstetrics and gynecology
Obstetric and gynecological ultrasound is rampant with numerous cut-off values. Some of these get revised over the years. The following list is a useful aid to refer to and revise.
1 mm
rate of increase of a mean sac diameter per day in early pregnancy
2 mm
generally accepted value for a thi...
Article
CSF rhinorrhea
CSF rhinorrhea refers to a symptom of cerebrospinal fluid (CSF) leakage extracranially into the paranasal sinuses, thence into the nasal cavity, and exiting via the anterior nares. It can occur whenever there is an osseous and dural defect of the skull base that communicates directly or indirect...
Article
Endometrioma
Endometriomas, also known as chocolate cysts or endometriotic cysts, are a localized form of endometriosis and are usually within the ovary. They are readily diagnosed on ultrasound, with most demonstrating classical radiographic features.
Epidemiology
These occur in up to 10% of women of rep...
Article
SADDAN syndrome
SADDAN syndrome is an acronym for severe achondroplasia with developmental delay and acanthosis nigricans. It is an extremely rare condition, and as the name states, comprises a combination of skeletal anomalies includes craniosynostosis 2, brain and cutaneous anomalies.
Pathology
Genetics
Th...
Article
Orbitomeatal line
The orbitomeatal line, also known as the canthomeatal line, was the traditional axial plane used for CT of the brain. It was easily identified on the inspection of the patient's head when tilting the gantry or patient's head to achieve a standard axial plane.
The orbitomeatal line was defined ...
Article
Mazabraud syndrome
Mazabraud syndrome is a rare syndrome characterized by skeletal fibrous dysplasia and intramuscular myxomas 1-3.
Epidemiology
Only 107 cases have been reported in the global literature (as of 2019) 1,3-5,15. The prevalence is ~ 1 in 1,000,000 3 with a strong female predilection (68-84%) 1,3. T...
Article
Ebola virus disease
Ebola virus disease (EVD) (also known as Ebola hemorrhagic fever (EHF) or simply Ebola) is a viral hemorrhagic disease caused by the Ebola filovirus. Ebola is an extremely virulent virus with a case fatality rate of ~70% 1.
Epidemiology
First recognized in 1967 after polio vaccine laboratory w...
Article
Embryonal tumor with multilayered rosettes
Embryonal tumors with multilayered rosettes (ETMR) are rare small round blue cell tumor of the central nervous system. They are one of the most aggressive brain tumors usually encountered in children and are WHO grade 4 tumors.
Terminology
Previously embryonal tumors with multilayered rosette...
Article
COVID-19
For a quick reference guide, please see our COVID-19 summary article.
COVID-19 (coronavirus disease-2019) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a strain of coronavirus. The first cases were seen in Wuhan, China, in December 2019 before ...
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