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
Contrast medium
Contrast media are a group of chemical agents developed to aid in the characterization of pathology by improving the contrast resolution of an imaging modality. Specific contrast media have been developed for every structural imaging modality, and every conceivable route of administration.
Bari...
Article
Aortic dissection
Aortic dissection is the prototype and most common form of acute aortic syndromes and a type of arterial dissection. It occurs when blood enters the medial layer of the aortic wall through a tear or penetrating ulcer in the intima and tracks longitudinally along with the media, forming a second ...
Article
DNA
DNA (deoxyribonucleic acid) is a nucleic acid that encodes the genetic information (genome) necessary for RNA (ribonucleic acid) transcription (transcriptome) and protein synthesis (proteome) 1. It is contained in the nucleus of eukaryotic cells in the form of chromatin or chromosomes 7,8.
Mole...
Article
Cardiac venous malformations
Cardiac venous malformations (also known as cardiac hemangiomas) consists of a slow flow venous malformation and is composed of numerous non-neoplastic endothelial-lined thin-walled channels with interspersed fat and fibrous septae.
Terminology
It is important to note that according to nomencl...
Article
Salivary gland tumors
Salivary gland tumors are variable in location, origin, and malignant potential.
Pathology
In general, the ratio of benign to malignant tumors is proportional to the gland size; i.e. the parotid gland tends to have benign neoplasms, the submandibular gland 50:50, and the sublingual glands and...
Article
Machine learning
Machine learning is a specific practical application of computer science and mathematics that allows computers to extrapolate information based on observed patterns without explicit programming. A defining characteristic of machine learning programs is the improved performance at tasks such as c...
Article
Zero echo time imaging
Zero echo time (ZTE) imaging is a development in MR technology, with the aim to better visualize tissues such as bone with the shortest T2 values.
Physics
In ZTE, the signal is acquired immediately after applying the radiofrequency pulse resulting in near-zero echo times. After initial data r...
Article
PSA density
The PSA density (PSAD) is a calculation performed at diagnosis and is the serum prostate specific antigen (PSA) level (ng/mL) divided by the volume of the prostate gland (mL), resulting in a value with the units, ng/mL2 1. Prostate volume is calculated from TRUS measurements 2,3.
Alternatively...
Article
Focal cortical dysplasia
Focal cortical dysplasias (FCD) represent a heterogeneous group of disorders of cortical formation, which may demonstrate both architectural and proliferative features. They are one of the most common causes of epilepsy and can be associated with hippocampal sclerosis and cortical glioneuronal n...
Article
Chronic myocarditis
Chronic myocarditis is a prolonged or ongoing myocardial inflammation in the setting of non-dilated or mildly dilated cardiomyopathy 1-5. There have been significant differences concerning the exact definition of the concept as well as the time interval after the onset of symptoms, with the latt...
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...
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