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.

More than 200 results
Article

Urethral calculus

Urethral calculi are an uncommon type of urolithiasis, accounting for ~1% of all urinary tract stones. Epidemiology They almost all occur in males 2 with two peak incidences - one in childhood and the other at 40 years 3. Clinical presentation Most commonly acute lower urinary tract symptoms...
Article

Abnormal renal rotation

Abnormal renal rotation, also known as renal malrotation, refers to an anatomical variation in the position of the kidneys, in particular to anomalous orientation of the renal hilum. It may occur unilaterally or bilaterally. It is almost always an asymptomatic incidental finding. Epidemiology ...
Article

Diabetic embryopathy

Diabetic embryopathy refers to a spectrum of fetal anomalies that precipitate when the mother has background diabetes mellitus. The fetus may develop many of the fetal conditions associated with maternal diabetes although strictly speaking the anomalies should only include those that start in th...
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Pituitary region masses

Pituitary region masses include lesions in the sella turcica, suprasellar cistern, parasellar region include cavernous sinuses, and basisphenoid/clivus. Several mnemonics have been popularized, including SATCHMO. A more comprehensive list includes the following, along with differentiating featu...
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Portal vein thrombosis

Portal vein thrombosis may be seen in a variety of clinical contexts, and when acute can be a life-threatening condition. It is a major cause of non-cirrhotic presinusoidal portal hypertension. Portal vein thrombus may be either bland and/or malignant (i.e. tumor thrombus), and it is a critical ...
Article

Horseshoe kidney

Horseshoe kidneys are the most common type of renal fusion anomaly. They render the kidneys susceptible to trauma and are an independent risk factor for the development of renal calculi and transitional cell carcinoma of the renal pelvis. Epidemiology Horseshoe kidneys are found in approximate...
Article

Congenital renal anomalies

Congenital renal anomalies comprise of vast spectrum of pathologies and include: renal agenesis renal dysgenesis congenital renal hypoplasia congenital megacalyectasis congenital cystic renal disease infantile polycystic renal disease: autosomal recessive polycystic kidney disease (ARPKD):...
Article

Bicuspid aortic valve

Bicuspid aortic valve (BAV) refers to a spectrum of deformed aortic valves with two functional leaflets or cusps which are often unequal in size. They are most often congenital while an acquired bicuspid valve occurs when there is fibrous fusion between the right and left cusps of a pre-existin...
Article

Gout

Gout is a crystal arthropathy due to deposition of monosodium urate crystals in and around the joints. Epidemiology Typically occurs in those above 40 years. There is a strong male predilection of 20:1, with this predilection more pronounced in younger and middle-aged adults. In the elderly, t...
Article

Crossed fused renal ectopia

Crossed fused renal ectopia refers to an anomaly where the kidneys are fused and located on the same side of the midline. Epidemiology The estimated incidence is around 1 out of 1000 births 1. There is a recognized male predilection with a 2:1 male to female ratio. More than 90% of crossed ren...
Article

Accessory and cavitated uterine mass

Accessory and cavitated uterine mass (ACUM), also known as non-communicating accessory uterine cavity or cystic adenomyoma, is a rare uterine anomaly comprised of an accessory uterus-like mass in the uterus along the wall but with no communication to the main uterus. Clinical presentation This...
Article

MSK pelvis protocol (MRI)

The MRI pelvis protocol encompasses a set of MRI sequences for the routine assessment of the pelvis. Note: This article aims to frame a general concept of an MRI protocol for the assessment of the pelvis in the setting of suspected musculoskeletal pathology. Protocol specifics will vary dependi...
Article

Perianal fistula

Perianal fistula (or fistula-in-ano) (plural: fistulae or fistulas) is the presence of a fistulous tract across/between/adjacent to the anal sphincters and is usually an inflammatory condition 1. Epidemiology Incidence is estimated at ~1:10,000 2, with a recognized male predilection of 2-4:1. ...
Article

Urethral stricture

Urethral strictures are relatively common and typically occur either in the setting of trauma or infection. Epidemiology The demographics of the affected population is dictated by the etiology, but in general, it is safe to say that adult males make up the vast majority of cases. Clinical pre...
Article

External adenomyosis

External adenomyosis is a subtype of uterine adenomyosis which involves the outer part of the uterus disrupting the serosa yet not affecting the junctional zone. This type of adenomyosis is quite always associated with deep pelvic endometriosis which is likely the progenitor of this type of aden...
Article

Neurosyphilis

Neurosyphilis results from infection of the central nervous system by the spirochete Treponema pallidum, subspecies pallidum. The disease has a heterogeneous spectrum of early and late manifestations. For a general discussion, and for links to other system-specific manifestations, please refer ...
Article

Alanine peak

Alanine is one of the compounds examined in MR spectroscopy. It resonates at 1.48 ppm chemical shift. It may be elevated in meningiomas 1.
Article

MR spectroscopy

The technique of magnetic resonance spectroscopy (usually shortened to MR spectroscopy or MRS) allows tissue to be interrogated for the presence and concentration of various metabolites. Grossman and Yousem said "If you need this to help you, go back to page 1; everything except Canavan (disease...
Article

Mandibular fossa

The mandibular fossa or glenoid fossa is the smooth concave articular surface located in the inferolateral aspect of temporal bone 1. It is anteriorly formed by the squamous part of temporal bone, which constitutes the superior articular part of temporomandibular joint. Posteriorly, it is formed...
Article

Condylar process of the mandible

The condylar process, also called the condyloid process, is the process on the mandible that articulates with the disk of the temporomandibular joint (TMJ). Gross anatomy The mandibular condylar process consists of two portions: condyle ​presents an articular surface for articulation with th...
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