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.
16,896 results found
Article
Bronchiectasis
Bronchiectasis (plural: bronchiectases) is defined as an irreversible abnormal dilatation of the bronchial tree. It has a variety of underlying causes, with a common etiology of chronic inflammation. High-resolution CT is the most accurate modality for diagnosis.
Epidemiology
As there are many...
Article
Ultrasound (introduction)
Ultrasound (US) is an imaging technology that uses high-frequency sound waves to characterize tissue. It is a useful and flexible modality in medical imaging and often provides an additional or unique characterization of tissues when compared to other modalities such as conventional radiography ...
Article
Harmonic imaging
Harmonic imaging is a technique in ultrasonography that provides images of better quality as compared with conventional ultrasound technique.
Physics
Harmonic imaging exploits non-linear propagation of ultrasound through the body tissues. The high pressure portion of the wave travels faster th...
Article
Contrast-enhanced ultrasound
Contrast-enhanced ultrasound (CEUS) involves the administration of intravenous contrast agents consisting of microbubbles/nanobubbles of gas.
Clinical applications
liver
hepatic metastasis
cystadenoma/cystadenocarcinoma
cholangiocarcinoma
hepatocellular carcinoma
hepatic adenoma
focal no...
Article
Scleritis
Scleritis refers to inflammation of the sclera. It has a wide range of causes.
Epidemiology
It can affect any age group but usually those between ages 30 and 50 years. There is a recognized increased female predilection (F:M of ~2:1).
Pathology
Information on the pathogenesis of scleritis is...
Article
Sniff test
The fluoroscopic sniff test is a useful addition to diaphragm fluoroscopy and is used to evaluate diaphragmatic contraction and excursion in patients with suspected phrenic nerve palsy or paralysis, breathing difficulties following stroke or recent elevation of a hemidiaphragm on chest radiograp...
Article
Retinoblastoma
Retinoblastomas are the most common intraocular neoplasm found in childhood and with modern treatment modalities, are, in most cases, curable.
On imaging, they are generally characterized by a heterogeneous retinal mass with calcifications, necrotic components and increased vascularization on D...
Article
Ocular metastasis
Ocular metastases, also termed uveal metastases, are the most common intraocular malignant tumors, and are probably underdiagnosed 1. Ocular metastases need to be distinguished from extraocular metastasis, a quite different group of tumors.
This article will discuss metastatic lesions affecting...
Article
Diaphragmatic paralysis
Diaphragmatic paralysis, diaphragmatic paresis or diaphragmatic palsy may be first suspected when a newly elevated hemidiaphragm is seen on a chest radiograph. Bilateral paralysis is much more serious but often overlooked with an average delay of 2 years to diagnosis.
Clinical presentation
The...
Article
Posterior vitreous detachment
Posterior vitreous detachment (PVD), also known as hyaloid detachment, occurs when the retinal layer and vitreous body/posterior hyaloid membrane dissociate, with an intervening fluid collection forming in the subhyaloid space.
Epidemiology
It is thought to be a common consequence of aging, oc...
Article
Intracranial lipoma
Intracranial lipomas are not tumors as such, but rather a result of abnormal differentiation of embryologic meninx primitiva. They are frequently associated with abnormal development of adjacent structures.
Terminology
The term intracranial lipoma is used somewhat loosely. The broadest usage w...
Article
Retinal detachment
Retinal detachment is a detachment of the neurosensory retina from the underlying pigmented choroid. Apposition of the retinal pigmented epithelium to the overlying retina is essential for normal retinal function.
Terminology
There are numerous subtypes of retinal detachment 5:
rhegmatogenous...
Article
Choroid plexus lipoma
Choroid plexus lipomas are uncommon and like other intracranial lipomas are usually found incidentally at the trigones of the lateral ventricles when imaging is obtained for other indications.
Terminology
Some of the literature refers to the extension of tubulonodular pericallosal lipoma into ...
Article
Choroidal detachment
Choroidal detachment is a detachment of the choroid from the underlying sclera due to the accumulation of fluid in the suprachoroidal space, generally due to increased intraocular pressure (IOP), as observed in some settings:
choroidal effusion
transudative: trauma
exudative: fluid accumulati...
Article
Endophthalmitis
Endophthalmitis (plural: endophthalmitides) is a potentially sight-threatening condition that involves intraocular inflammation of any cause. It is distinguished from panophthalmitis in that it does not extend beyond the sclera. It is either infectious or non-infectious in etiology, but in clini...
Article
Ectopia lentis
Ectopia lentis refers to subluxation or dislocation of the lens of the eye secondary to dysfunction or disruption of zonular fibers. It is most commonly due to trauma. The commonest atraumatic etiologies are Marfan syndrome and homocystinuria.
Pathology
Etiology
trauma
systemic and syndromic...
Article
Globe rupture
Globe rupture is an ophthalmologic emergency. A ruptured globe or an open-globe injury must be assessed in any patient who has suffered orbital trauma because open-globe injuries are a major cause of blindness.
In blunt trauma, ruptures are most common just posterior to the insertions of the re...
Article
Medical abbreviations and acronyms (I)
This article contains a list of commonly used medical abbreviations and acronyms that start with the letter I and may be encountered in medicine and radiology (please keep both the main list and any sublists in alphabetic order).
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q...
Article
Sjögren syndrome
Sjögren syndrome, or Sjögren disease, is an autoimmune condition of the exocrine glands that produce tears and saliva.
Epidemiology
Sjögren syndrome is the second most common autoimmune disorder after rheumatoid arthritis. There is a recognized female predilection with F:M ratio of ~9:1. Patie...
Article
Inclusion body myositis
Inclusion body myositis (IBM) is a type of inflammatory myositis. It is often considered is the most common acquired myopathy in patients older than 50 years.
Epidemiology
Inclusion body myositis tends to present in older individuals 4, often after the age of 50 years, although the disease may...
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