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.
16,879 results found
Article
Notch sign (primary CNS lymphoma)
The notch sign refers to an abnormally deep depression at the tumor margin in contrast-enhanced MRI in primary CNS lymphoma 1. It is not an uncommon sign in primary CNS lymphoma and can be seen in both immunocompetent and immunocompromised patients. It suggests an irregular growth pattern as wel...
Article
Meynert's commissure
Meynert’s commissure, also known as dorsal supraoptic commissure, is one of three white matter tracts that comprise the supraoptic commissure 1,2. The remaining two tracts that comprise the supraoptic commissure are Gudden’s commissure (ventral supraoptic decussation) and the anterior hypothalam...
Article
Voriconazole-induced periostitis
Voriconazole-induced periostitis is similar to fluorosis and is most likely due to the high fluoride content in the drug. The side-effect is related to the dose and duration of treatment and resolves rapidly after drug cessation 1.
Epidemiology
Voriconazole-induced periostitis primarily occurs...
Article
X-marks-the-spot sign (large bowel volvulus)
The X-marks-the-spot sign of large bowel volvulus refers to the crossing loops of the bowel at the site of the transition. It has been reported to improve diagnostic confidence in detecting cecal and sigmoid volvulus. This is in contrast to the split-wall sign which indicates partial obstruction...
Article
Perineum
The perineum is a diamond-shaped region below the pelvic diaphragm and is divided by an imaginary line drawn between the ischial tuberosities into anteriorly the urogenital triangle and posteriorly the anal triangle.
Gross anatomy
The perineum is bounded by the pubis anteriorly, the ischial tu...
Article
COACH syndrome
The acronym COACH describes a syndrome associated with:
C: cerebellar vermis defect (Joubert syndrome)
O: oligophrenia
A: ataxia
C: coloboma
H: hepatic fibrosis
Epidemiology
COACH syndrome is considered extremely rare.
Associations
The association with infantile polycystic kidney diseas...
Article
Acute flaccid paralysis
Acute flaccid paralysis is a syndrome resulting from a wide array of underlying conditions. The features are of a fairly rapidly progressing lower motor neuron pattern weakness with potential involvement not only of the limbs but also of muscles of the pharynx, trunk and diaphragm 1.
Historica...
Article
Rocking-horse phenomenon
Rocking-horse phenomenon occurs in total shoulder arthroplasty when there is an abnormal glenoid version angle positioning that causes glenoid component failure.
The glenoid component is stable when the load applied by the humeral head is centered, whereas anterior or posterior translation of ...
Article
Deep artery of the penis
The deep artery of the penis, also known as cavernosal artery, is one of the two terminal branches of the internal pudendal artery.
Gross anatomy
Origin
The internal pudendal artery bifurcates terminally into the deep artery of the penis and the dorsal artery of the penis at the anterior marg...
Article
Birbeck granules
Birbeck granules refer to unusual rod-shaped structures specific to Langerhans cells. Their origin and function remain undetermined. Langerin is a crucial component within Birbeck granules.
History and etymology
Birbeck granules were first described by Michael S Birbeck in 1961 3.
Related pat...
Article
Ovary size and volume
Ovary size and volume is frequently determined with ultrasound. The volume estimate is calculated by the formula for an ellipsoid, where D1, D2, and D3 are the three axial measurements:
D1 x D2 x D3 x 0.52
The normal, adult, non-pregnant, mean ovary volume of women who are not postmenopausal i...
Article
Egyptian eye sign
"Egyptian eye sign" or "sonographic eye sign" refers to the normal appearance of great saphenous vein on ultrasound, in transverse view 1,2.
Ultrasound examination of the great saphenous vein shows echogenic fascia surrounding it, with the saphenous fascia superiorly and the muscular fascia inf...
Article
Mechanical index
The mechanical index (MI) is an attempt to measure part of an ultrasound beam's bioeffects. The mechanical index is found on most ultrasound display screens, along with the thermal index.
Mechanical index is proportional to an ultrasound beam's peak negative pressure (or peak rarefaction pressu...
Article
Renal sinus lipomatosis
Renal sinus lipomatosis refers to a condition where there is excessive renal sinus fat replacement.
Pathology
Renal sinus lipomatosis results from renal parenchymal atrophy, inflammation, calculous disease, aging 1, or exogenous or endogenous steroids. There is usually no or rarely little mass...
Article
Doge cap sign (pneumoperitoneum)
The doge cap sign, also referred to as Morison pouch sign, is a radiographic sign of pneumoperitoneum. It presents as a triangular-shaped (although may also be crescentic or semicircular) gas lucency, usually bound by the 11th rib in the right upper quadrant on abdominal radiographs due to air i...
Article
Dorsal artery of the penis
The dorsal artery of the penis is one of the two terminal branches of the internal pudendal artery.
Gross anatomy
Origin
The internal pudendal artery bifurcates into the deep artery of the penis and the dorsal artery of the penis at the anterior margin of the perineal membrane 1.
Terminatio...
Article
Epidural spinal cord compression scale
The epidural spinal cord compression (ESCC) scale, sometimes known eponymously as the Bilsky scale, is used to assess the degree to which vertebral body metastasis compromises the spinal canal and whether cord compression is present. It may serve as a guide as to when intervention (radiotherapy ...
Article
Wolffian duct
The Wolffian duct (also known as the mesonephric duct) is one of the paired embryogenic tubules that drain the primitive kidney (mesonephros) to the cloaca. It also gives off a lateral branch forming the ureteric bud. In both the male and the female, the Wolffian duct develops into the trigone o...
Article
Poliomyelitis-like syndrome
Poliomyelitis-like syndrome, or polio-like paralysis, is an uncommon form of myelitis that presents similar to polio, due to non-poliovirus pathologies which selectively involve the anterior horn cells of the spinal cord and result in an anterior horn syndrome. Although it usually has an infecti...
Article
Testicular dislocation
Testicular dislocation is a rare condition in which a testis is dislocated from its normal position within the scrotum to another location, most commonly the superficial inguinal pouch.
Epidemiology
The condition mainly occurs in younger men with a mean age of 25 years 2.
Clinical presentatio...
Unable to process the form. Check for errors and try again.