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.
16,900 results found
Article
Anterior angulation of the coccyx
Anterior angulation of the coccyx may be a normal variant but poses a diagnostic challenge for those considering coccygeal trauma 1.
Classification
Six types of coccyx have been described initially by Postacchini and Massobrio and later modified by Nathan et al. 2,3:
type I: the coccyx is cur...
Article
Large cell neuroendocrine carcinoma of the prostate
Large cell neuroendocrine carcinomas (LCNEC) of the prostate or prostatic large cell neuroendocrine carcinomas are very aggressive and rare high-grade neuroendocrine tumors that are usually observed in the presence of an already existing adenocarcinoma and very rarely found alone.
Epidemiology
...
Article
Salter-Harris classification
The Salter-Harris classification was proposed by Salter and Harris in 1963 1 and, at the time of writing (January 2023) remains the most widely used system for describing physeal fractures.
Classification
Conveniently the Salter-Harris types can be remembered by the mnemonic SALTR.
type I
s...
Article
Functional endoscopic sinus surgery (FESS)
Functional endoscopic sinus surgery (FESS) is a type of paranasal sinus surgery performed intranasally using a rigid endoscope. Its primary objective is to restore physiological ventilation and mucociliary transport 1.
Paranasal sinus imaging is crucial in preoperative planning and is also incr...
Article
Vertebral artery thrombosis
Vertebral artery thrombosis results in complete or partial occlusion of the vertebral artery and alteration of blood flow to the posterior cerebral circulation.
Clinical presentation
Ischemia or infarction to structures supplied by these arteries (e.g. brainstem, cerebellum, occipital lobes) m...
Article
Interstitial lung disease
Interstitial lung disease (ILD) is an umbrella term that encompasses a large number of disorders that are characterized by diffuse cellular infiltrates in a periacinar location. The spectrum of conditions included is broad, ranging from occasional self-limited inflammatory processes to severe de...
Article
Medical abbreviations and acronyms (P)
This article contains a list of commonly used medical abbreviations and acronyms that start with the letter P and may be encountered in medicine and radiology (please keep 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 - R ...
Article
Hiatus hernia
Hiatus hernias (alternative plural: herniae) occur when there is herniation of abdominal contents through the esophageal hiatus of the diaphragm into the thoracic cavity.
Epidemiology
The prevalence of hiatus hernia increases with age, with a slight female predilection.
Clinical presentation
...
Article
PET-CT indications
PET-CT is a combination of cross-sectional anatomic information provided by CT and the metabolic information provided by positron emission tomography (PET).
PET is most commonly performed with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG). Fluorine-18 (F-18) is an unstable radioisotope and has a half-...
Article
Glenoid hypoplasia
Glenoid hypoplasia, also known as glenoid dysplasia, is an uncommon congenital condition resulting from underdevelopment of inferior glenoid ossification center.
Epidemiology
Although previously considered rare, there is increasing recognition of a spectrum of glenoid hypoplasia with the incre...
Article
Cardiac calcification
Cardiac calcification is a broad term for any calcification affecting the cardiac valves, coronary arteries, aortic root, endocardium, myocardium, and/or pericardium.
Pathology
Causes of cardiac calcification are:
coronary artery disease (most common)
coronary artery aneurysms, e.g. in Kawas...
Article
Optic disc drusen
Optic disc drusen (ODD), or optic nerve head drusen or hyaline bodies, are a relatively common entity usually found incidentally on CT or on follow-up of abnormal fundoscopy.
Epidemiology
Optic disc drusen are identified radiographically in up to 0.3-3.7% of the population and are frequently b...
Article
Uterus didelphys
Uterus didelphys is a type of Müllerian duct anomaly (class III) where there is a complete duplication of uterine horns as well as duplication of the cervix, with no communication between them.
Epidemiology
Didelphic uteri account for approximately ~8% (range 5-11%) of Müllerian duct anomali...
Article
Dorsal pancreatic agenesis
Agenesis of the dorsal pancreas is an extremely rare congenital pancreatic anomaly.
While complete agenesis of the dorsal pancreas is extremely rare, partial agenesis of the dorsal pancreas is thought to be more common than ventral pancreatic agenesis 4.
Clinical presentation
While many pati...
Article
Hydrosalpinx
Hydrosalpinx is a descriptive term and refers to a fluid-filled dilatation of the fallopian tube. If the fluid is infected, i.e. pus, then it is a pyosalpinx; if bloody, then hematosalpinx.
Clinical presentation
Patients may be asymptomatic or may present with pelvic pain or infertility.
Path...
Article
Sphincter of Oddi
The sphincter of Oddi (also known as the sphincter of ampulla or choledochal sphincter) is a complex of four smooth muscle sphincters (superior and inferior sphincter choledochus [also known as Sphincter of Boyden], sphincter pancreaticus, and sphincter ampullae) within the duodenal wall. It sur...
Article
Ludwig angina
Ludwig angina, also known as Ludwig cellulitis, refers to rapidly progressive cellulitis of the floor of mouth, which is potentially life-threatening due to the risk of rapid airway compromise.
Epidemiology
Largely due to the advent of antibiotics, the condition is uncommon in present day mod...
Article
Spatial pulse length (ultrasound)
Spatial pulse length (SPL) in ultrasound imaging describes the length of time that an ultrasound pulse occupies in space. Mathematically, it is the product of the number of cycles in a pulse and the wavelength.
A shorter SPL results in higher axial resolution. The minimum distance between two ...
Article
Hidradenitis suppurativa
Hidradenitis suppurativa, also known as acne inversa, is an inflammatory skin disease of unknown cause. It has an autosomal dominant inheritance pattern, and androgen excess has been postulated 7. The disease is associated with Crohn disease and Dowling Degos disease.
Epidemiology
Up to 4% of...
Article
Hair
Hair (TA: pilus/pili) remains important physiologically and psychologically for humans. The hair shaft develops from a structure known as the hair follicle. Each hair has an arrector pili muscle and both sensory and sympathetic neural connections.
Gross anatomy
The hair shaft (TA: stipes pili)...
Unable to process the form. Check for errors and try again.