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.
1,110 results found
Article
3D conformal radiation therapy
3D conformal radiation therapy (3D-CRT) is a radiation therapy technique that involves CT planning where the volume to be treated is defined on a 3D data set. Therefore, organs at risk can also be delineated to shield these and reduce treatment side effects. Radiotherapy planning software is use...
Article
5-ALA fluorescence-guided surgery
5-ALA fluorescence-guided surgery is an intraoperative technique that takes advantage of tumor cells accumulating a fluorescent compound to make the location of the tumor more readily apparent. It is primarily used in the resection of high-grade gliomas (e.g. glioblastoma, grade 3 or 4 astrocyto...
Article
Abdominal distension (mnemonic)
A mnemonic for causes of abdominal distension (6 Fs) is:
F: fat
F: fluid
F: flatus
F: feces
F: fetus
F: fulminant mass
Article
Acanthosis nigricans
Acanthosis nigricans is a cutaneous disorder characterized by symmetric hyperpigmented velvety plaques on the neck, axillae, antecubital and popliteal fossae, inframammary, and groin areas. It is associated with acquired lipodystrophy.
Pathology
The benign form of acanthosis nigricans is assoc...
Article
Acinic cell carcinoma (lung)
Acinic cell carcinoma of the lung (also known as a Fechner tumor) is a type of lung carcinoma of the salivary gland type. It is extremely rare, especially when it presents in the form of primary acinic cell carcinoma.
Pathology
Histologically, they are comprised of clear cells with abundant gr...
Article
Acquired tracheo-esophageal fistula
An acquired tracheo-esophageal fistula refers to a pathological communication between the trachea and esophagus due to a secondary cause.
Pathology
Acquired causes of tracheo-esophageal fistulae can be divided into those that are related to malignancy (common) and those from other causes (unco...
Article
Acral fibromyxoma
Acral fibromyxomas, also known as superficial acral fibromyxomas or digital fibromyxomas are benign mesenchymal proliferations prone to recurrence usually found in the subungual and periungual sites of the digits.
Terminology
The term 'cellular digital fibroma' is not recommended 1,2.
Epidemi...
Article
Active surveillance
Active surveillance describes a management option aiming at close monitoring of a specific stage in disease and minimizing adverse treatment-related effects without compromising survival at the same time. Curative or definite treatment is intended and offered upon deterioration or explicit patie...
Article
Acute abdominal pain
Acute abdominal pain is a common acute presentation in clinical practice. It encompasses a very broad range of possible etiologies and diagnoses, and imaging is routinely employed as the primary investigative tool in its modern management.
Terminology
A subgroup of patients with acute abdomina...
Article
Acute airspace opacification with lymphadenopathy (differential)
Acute airspace opacification with lymphadenopathy is a subset of the differential diagnosis for generalized airspace opacification and includes:
post-obstructive causes (usually chronic, but 'new' changes can occur)
primary lung cancer
pulmonary metastases
lymphoma/leukemia
infection
prim...
Article
Acute lymphoblastic leukemia
Acute lymphoblastic leukemia (ALL) is a malignant disorder of the bone marrow characterized by the proliferation of the lymphoid progenitor cells, typically of the B cell lineage.
Epidemiology
Acute lymphoblastic leukemia is the commonest form of childhood leukemia, accounting for ~80% of pedi...
Article
Acute myeloid leukemia
Acute myeloid leukemia (AML), also referred to as acute myelogenous leukemia, is a hematological malignancy characterized by the abnormal clonal proliferation of immature myeloid precursors (myeloblasts) or poorly differentiated cells of the hematopoietic system. It primary infiltrates the bone ...
Article
Adenocarcinoma in situ, minimally invasive adenocarcinoma and invasive adenocarcinoma of lung
Adenocarcinoma in situ, minimally invasive adenocarcinoma and invasive adenocarcinoma of the lung have replaced the now-defunct term bronchoalveolar carcinoma (BAC).
In 2011 the International Association for the Study of Lung Cancer (IASLC) and several other societies jointly revised the classi...
Article
Adenocarcinoma in situ of the lung
Adenocarcinomas in situ (AIS) of the lung refer to a relatively new entity which falls under the spectrum of pre-invasive lesions of the lungs. This entity partly replaces the noninvasive end of the previous term bronchoalveolar carcinoma. Adenocarcinoma in situ is defined as a localized adenoca...
Article
Adenocarcinoma of the lacrimal glands
Adenocarcinoma of the lacrimal glands is rare, with few cases reported in the literature since it was first described in 1996 1. Primary adenocarcinoma of the lacrimal gland is extremely rare; only 9 cases have been reported in the literature 1,2. It can be classified into high- and low-grade ma...
Article
Adenocarcinoma of the lung
Adenocarcinoma of the lung is the most common histologic type of lung cancer. Grouped under the non-small cell carcinomas of the lung, it is a malignant tumor with glandular differentiation or mucin production expressing in different patterns and degrees of differentiation.
This article brings...
Article
Adenocarcinoma of the prostate with neuroendocrine differentiation
Adenocarcinoma of the prostate with neuroendocrine differentiation is a malignant neuroendocrine tumor of the prostate which only differs from acinar or ductal adenocarcinoma on immunohistochemistry staining.
Diagnosis
The diagnosis of adenocarcinoma of the prostate with neuroendocrine differe...
Article
Adenocarcinoma of the seminal vesicle
Adenocarcinomas of the seminal vesicles are the most common malignant primary neoplasm of the seminal vesicles.
Epidemiology
Primary adenocarcinomas of the seminal vesicles are very rare 1,2 and can be observed at a wide age range 2.
Diagnosis
Diagnostic criteria
The following modified diag...
Article
Adenocarcinoma (urinary bladder)
Adenocarcinoma of the urinary bladder is rare and accounts for only ~1% of all bladder cancers (90% are transitional cell carcinomas).
Pathology
Metaplasia of urinary bladder induced by chronic irritation or infection can lead to adenocarcinoma. Pathological types of adenocarcinoma of the urin...
Article
Adenoid cystic carcinoma
Adenoid cystic carcinomas are a rare histological subtype of adenocarcinoma.
Pathology
Adenoid cystic carcinomas are generally considered low grade 4. The tumors have a notable tendency for perineural spread.
Location
They have a wide distribution and mainly occur in relation to the airways,...