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.
16,861 results found
Article
Electrical impedance tomography
Electrical impedance tomography (EIT) is a type of imaging based on sending small amounts of electrical current across tissue (when used for medical imaging), and measuring conductivity. Such measurements are done with electrodes around the object measured, and reconstruction algorithms are used...
Article
Infratemporal fossa
The infratemporal fossa is a complex space of the face that lies posterolateral to the maxillary sinus, below the skull base, and between the pharyngeal sidewall and mandibular ramus. It overlaps with the masticator space and prestyloid parapharyngeal space.
Gross anatomy
The infratemporal fos...
Article
Methylguanine-DNA methyltransferase (MGMT)
O6-Methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme that is important in predicting the effects of alkylating chemotherapeutic agents (e.g. temozolomide) in the treatment of high-grade gliomas (astrocytomas and glioblastomas).
Mechanism of action
MGMT is an enzyme that removes...
Article
Stupp protocol
The Stupp protocol has become the standard of care for the treatment of high-grade astrocytoma and glioblastoma since its publication in 2005 and has led to significant survival improvements 1. It consists of radiotherapy and concomitant chemotherapy with temozolomide, an alkylating agent.
Prot...
Article
Lipoma
Lipomas are benign tumors composed of mature adipocytes. They are the most common soft tissue tumor, seen in ~2% of the population.
Epidemiology
Patients typically present in adulthood (5th-7th decades).
Associations
In some cases, multiple lipomas are associated with syndromes and other di...
Article
Nevoid hyperkeratosis of the nipple and the areola
Nevoid hyperkeratosis of the nipple and the areola (NHNA) is a rare, idiopathic, and benign dermatological condition of the nipple and areola.
Epidemiology
Most often seen in females of reproductive age, especially during the 2nd and 3rd decades of life. Less than 70 cases have been reported t...
Article
Spinal epidural venous plexus congestion
Spinal epidural venous plexus congestion or dilatation is typically a complication of other pathologies.
Clinical presentation
Radiculopathy caused by the dilated epidural veins is not uncommon 1. More severe symptoms such as cauda equina compression syndrome have been reported 6, 7.
Patholo...
Article
Placental site trophoblastic tumor
Placental site trophoblastic tumors (PSTT) are rare and one of the least common (~0.2% 7) forms of gestational trophoblastic disease.
Epidemiology
Placental site trophoblastic tumors typically occur in women of reproductive age with an average age of ~30 years. They may occur after a normal pr...
Article
Craniovertebral junction anomalies
Craniovertebral junction (CVJ) anomalies can be congenital, developmental or due to malformation secondary to an acquired disease process. These anomalies can lead to cranial nerve compression, vertebral artery compression, and obstructive hydrocephalus.
Pathology
The craniovertebral junction ...
Article
Gastric lymph node stations
The gastric lymph node stations were originally divided into 16 groups, as proposed by the Japanese Research Society for Gastric Cancer in 1973.
Gross anatomy
There are three major groups of lymph drainage from the stomach, namely, left gastric, gastroepiploic, and pyloric nodes 4, as shown in...
Article
Diffuse hepatic steatosis (grading)
Grading of diffuse hepatic steatosis on ultrasound has been used to communicate to the clinician about the extent of fatty changes in the liver.
Grading using ultrasound B-mode
grade I: diffusely increased hepatic echogenicity but periportal and diaphragmatic echogenicity is still appreciable...
Article
Vagal schwannoma
Vagal schwannomas are uncommon benign masses that can occur anywhere along the course of the vagus nerve but most commonly occur in the cervical region.
Epidemiology
Most commonly occurs in the 3rd to 5th decades. No sex predilection 3.
Clinical presentation
Patients may be asymptomatic. Whe...
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
Skull vault osteoma
Skull vault osteomas are benign primary bone tumors that are commonly incidentally discovered. They are less common than paranasal sinus or mandibular osteomas.
Clinical presentation
Skull vault osteomas are typically asymptomatic but may present as painless, slow-growing masses or with compr...
Article
Caudate nucleus
Caudate nuclei are paired nuclei which along with the globus pallidus and putamen are referred to as the corpus striatum, and collectively make up the basal ganglia. The caudate nuclei have both motor and behavioral functions, in particular maintaining body and limb posture, as well as controlli...
Article
Pituitary gland
The pituitary gland (a.k.a. hypophysis cerebri), together with its connections to the hypothalamus, acts as the main endocrine interface between the central nervous system and the rest of the body.
Gross anatomy
The pituitary gland sits atop the base of the skull in a concavity within the sph...
Article
CEUS LI-RADS
Contrast-enhanced Ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) is a standardized classification system, algorithm and terminology for diagnosis of HCC in high-risk patients using CEUS with blood-pool intravenous contrast agents.
The current version is CEUS LI-RADS v2017 Cor...
Article
Diastematomyelia
Diastematomyelia, also known as a split cord malformation, refers to a type of spinal dysraphism (spina bifida occulta) characterized by a longitudinal split in the spinal cord.
Terminology
Although traditionally, it has been distinguished from diplomyelia (in which the cord is duplicated rat...
Article
Aortopulmonary window (radiograph)
The aortopulmonary (aortic-pulmonary or AP) window (also known as APW, but see 'Terminology' below) is a radiological mediastinal space seen on frontal chest radiographs.
Terminology
The term should also not be confused with an aortopulmonary septal defect, which is occasionally also - unfortu...
Article
Transient hepatic echogenicity differences
Transient hepatic echogenicity differences (THED) are areas of differential enhancement of the liver parenchyma depected with CEUS using microbubble intravascular contrast agents. They are equivalent to transient hepatic attenuation differences (THAD) with contrast enhanced CT and transient hepa...
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