Items tagged “stub”
1,310 results found
Article
Minimally invasive adenocarcinoma of the lung
Minimally invasive adenocarcinoma (MIA) of the lung is a relatively new category in the classification of adenocarcinoma of the lung. Lesions that fall into this category refer to small solitary adenocarcinomas <3 cm (i.e. <30 mm) with either pure lepidic growth or predominant lepidic growth wit...
Article
Sacral nerve plexus - posterior components (mnemonic)
A mnemonic to remember the posterior components of the sacral plexus is:
Crime Scene InvestiGation
Mnemonic
C: common peroneal nerve
S: superior gluteal nerve
I: inferior gluteal nerve
Article
MRI electronics and data processing
As an introduction to the electronics and data processing of the MRI scanner, a schematic diagram has been provided (figure 1).
Starting from the right hand side, we have the computer that directs all of the action in the MRI acquisition and acquires and processes the data. The computer tells t...
Article
Ginkgo leaf sign (subcutaneous emphysema)
The ginkgo leaf sign of the chest, also referred to as the ginkgo leaf sign of subcutaneous emphysema, is a radiographic appearance seen with extensive subcutaneous emphysema of the chest wall. Gas outlines the fibers of the pectoralis major muscle and creates a branching pattern that resembles ...
Article
Acquisition time
The time of acquisition for a conventional spin echo or gradient echo sequence is the product of the repetition time, phase encoding steps, and number of averages (TR x phase steps x NEX).
For example, with a one-second TR, 128 phase steps, and two averages, we would get an acquisition time of...
Article
Arc of Buhler aneurysm
An Arc of Buhler aneurysm is a rare pathology that can occur in an arc of Buhler. It can occur in association with stenoses of celiac axis. This is considered a true aneurysm. Transcatheter embolization has been successfully tried as the management technique.
Differential diagnosis
On imaging ...
Article
Ovarian lesions with T2 hypointensity
A hypointense ovarian lesion on T2 weighted MRI is usually a sign of benignity. The low signal is considered to be due to fibrosis and blood products 1.
Lesions that can give this appearance include 1:
endometrioma
Brenner tumor
ovarian fibroma
ovarian fibrothecoma
ovarian cystadenofibrom...
Article
Oxycephaly
Oxycephaly (also known as turricephaly) is the most severe of the craniosynostoses and results from the premature closure of all sutures.
Characterized by a tower-like skull which may be associated with:
8th cranial nerve lesion
optic nerve compression
mental deficiency
syndactyly
Article
Chamberlain line
Chamberlain line is a line joining the back of hard palate with the opisthion on a lateral view of the craniocervical junction.
Significance
It helps to recognize basilar invagination which is said to be present if the tip of the dens is >3 mm above this line.
McGregor developed a modificatio...
Article
Nasion
The nasion (also known as bridge of the nose) is the midline bony depression between the eyes where the frontal and two nasal bones meet, just below the glabella.
It is one of the skull landmarks: craniometric points for radiological or anthropological skull measurement.
Article
Left colic flexure
Left colic flexure (or splenic flexure) is the bend in the large intestine in the left upper quadrant of the abdomen as the transverse colon continues as the descending colon. The phrenicocolic ligament attaches the splenic flexure to the left hemidiaphragm. It lies more cranial than the right c...
Article
Trethowan sign
The Trethowan sign is used to diagnose slipped capital femoral epiphysis (also called slipped upper femoral epiphysis). In this sign, the line of Klein passes above the femoral head 1.
It is best seen on the frontal projection 2. On the AP view of a normal hip, the Klein line intersects a small...
Article
Starry sky appearance (ultrasound)
A starry sky appearance, also known as a centrilobular pattern 7, refers to a sonographic appearance of the liver parenchyma with bright echogenic dots throughout a background of decreased liver parenchymal echogenicity. Although usually associated with acute hepatitis, this sign has been found ...
Article
Monro-Kellie hypothesis
Monro-Kellie hypothesis is a pressure-volume relationship that aims to keep a dynamic equilibrium among the essential non-compressible components inside the rigid compartment of the skull 1-3.
The average intracranial volume in the adult is around 1700 mL, composed of brain tissue (~1400 mL), ...
Article
McGregor line
The McGregor line is a modification of the Chamberlain line and is used in the evaluation of basilar invagination when the opisthion is not identified on plain radiographs.
It refers to a line connecting posterior edge of the hard palate to the most caudal point of the occipital curve. If the t...
Article
Coloenteric fistula
A coloenteric fistula is a type of gastrointestinal fistulation wherein there is abnormal communication between the colon and the small bowel.
Pathology
Etiology
It can occur from a number of causes which include:
Crohn disease - considered one of the commonest causes
colorectal car...
Article
Geographic skull
A geographic skull is a radiographic appearance which is seen in eosinophilic granuloma (EG) and characterized by destructive lytic bone lesions, the edges of which may be bevelled, scalloped or confluent.
See also
geographic appearance
Article
Thumb sign (epiglottitis)
The thumb sign in epiglottitis is a manifestation of an edematous and enlarged epiglottis which is seen on lateral soft-tissue radiograph of the neck, and it suggests a diagnosis of acute infectious epiglottitis. This is the radiographic corollary of the omega sign 1-3.
See also
Thumb sign is ...
Article
Urethra
The urethra is the terminal segment of the genitourinary system. Because of vastly different anatomy between the sexes, male and female urethras are discussed separately:
female urethra
male urethra
NB: At present (2020) there is no standardized universal terminology for the post-operative ur...
Article
Pseudotumor of the calcaneus
Pseudotumor of the calcaneus is a normal variation of the trabecular pattern of the calcaneus on plain radiography secondary to atrophic trabeculae.
This condition is one of the skeletal "do not touch" lesions which can mimic a tumor-like (e.g. calcaneal lipoma) or a cyst-like (e.g. calcaneal s...
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