Articles
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16,868 results found
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 ...
Article
Ultrasound assessment of carotid arterial atherosclerotic disease
Ultrasound assessment of carotid arterial atherosclerotic disease has become the first choice for carotid artery stenosis screening, permitting the evaluation of both the macroscopic appearance of plaques and flow characteristics in the carotid artery.
This article focuses on internal carotid a...
Article
Mycetoma (soft-tissue)
Mycetoma refers to a chronic and progressively destructive granulomatous disease within the soft tissues. The defining clinical triad comprises of a:
localized mass-like soft tissue injury
with draining sinuses
that discharge grains of contagious material
It is one of the "neglected tropical...
Article
Diffuse leptomeningeal glioneuronal tumor
Diffuse leptomeningeal glioneuronal tumor (previously known as disseminated oligodendroglial-like leptomeningeal tumor of childhood) is a rare tumor of the central nervous system. It typically presents with hydrocephalus secondary to prominent leptomeningeal enhancement, often without a readily ...
Article
Anterior vertebral body tether (AVBT)
Anterior vertebral body tethering (AVBT) is a fusionless technique for treating and managing idiopathic scoliosis in skeletally immature patients to reduce the typical side effects of rigid posterior fusion (such as loss of spinal motion and risks adjacent segment degeneration later in life) 1,3...
Article
Effman Classification of urethral duplication
The Effman classification is a widely used system classifying several distinct types of urethral duplication.
Usage
The Effman classification is the most commonly used 3, which is considered the most complete classification from a clinical and functional point of view 4, but it is only based ...
Article
Usual interstitial pneumonia
Usual interstitial pneumonia (UIP) is a histopathologic and radiologic pattern of interstitial lung disease, which is the hallmark pattern for idiopathic pulmonary fibrosis (IPF).
On imaging, usual interstitial pneumonia usually presents with a lung volume loss and an apicobasal gradient of pe...
Article
Classification system for midline abnormalities of the brain and skull
Classification systems for midline abnormalities of the brain and skull are varied and constantly changing as the underlying embryology and genetics are uncovered.
Classification
A relatively simple and robust classification system is based on the location of abnormalities, proposed by Nuñez ...