Items tagged “reference needed”

103 results found

Extraocular muscle involvement in thyroid associated orbitopathy (mnemonic)

A mnemonic to remember the order in which extraocular muscles are involved in thyroid-associated orbitopathy (TAO) is: I'M SLOw Mnemonic I: inferior rectus M: medial rectus S: superior rectus L: lateral rectus O: obliques muscles (superior oblique and inferior oblique) There is some deba...

Linear scleroderma

Linear scleroderma, also known as scleroderma en coup de saber, is a very focal form of scleroderma classically characterized by a linear band of atrophy involving the frontal or frontoparietal scalp and subjacent thinned calvaria associated with ipsilateral focal brain abnormalities.  In the b...

Nodular filling defects of duodenum (differential)

Nodular filling defects due to mucosal lesions in the duodenum are due to a number of processes. For a differential list which includes non-mucosal lesions see duodenal filling defects. The differential diagnosis for mucosal lesions includes:  heterotopic gastric mucosa 1-2 mm clustered onl...


The increased globe size or macrophthalmia may have many differentials: buphthalmos (congenital glaucoma) axial myopia macrophthalmus in neurofibromatosis type 1 (NF1) connective tissue disorders: Marfan syndrome, Ehlers-Danlos syndrome Focal enlargement: staphyloma coloboma See also mi...

Littre hernia

Littre hernias are hernias (alternative plural: herniae) containing a Meckel diverticulum, and are also known as persistent omphalomesenteric duct hernias. They are most frequently encountered in the inguinal region. Radiographic features CT blind-ending tubular structure arising from antimes...

Accordion sign (colon)

The accordion sign (also known as concertina sign) is seen on CT of the abdomen and refers to the similarity between the thickened edematous wall of pseudomembranous colitis and the folds of an accordion. This appearance is the result of hyperemic enhancing mucosa stretched over markedly thicken...

Tc-99m DTPA

Tc-99m DTPA (diethylene-triamine-pentaacetate) is one of the technetium radiopharmaceuticals used in renal imaging and primarily used to measure the glomerular filtration rate (GFR). Characteristics photon energy: 140 KeV physical half-life: 6 hours biological half-life: 2.5 hours normal di...

Mesenteric lymph nodes

In the premultidetector CT era, mesenteric lymph nodes (often shortened to mesenteric nodes) were only really appreciated when enlarged. Following the advent of routine volume acquisition CT (and especially coronal reformats) lymph nodes in the mesentery are commonly seen in normal individuals, ...

MRI physics

The physics of MRI are complicated and much harder to understand than those underpinning image generation in plain radiography, CT or ultrasound.  What follows is a very abbreviated, 'broad strokes' description of the process. Essentially, the process can be broken down into four parts: prepar...

Pantaloon hernia

A pantaloon hernia (or "Saddlebag" hernia) is defined as any combination of two adjacent hernia sacs of the femoral or inguinal region (direct or indirect inguinal hernias (alternative plural: herniae)) on the same side.2 Thus, examples include: femoral with direct hernias, femoral with indirect...

Hybrid imaging

Hybrid imaging refers to the fusion of two (or more) imaging modalities to form a new technique. By combining the innate advantages of the fused imaging technologies synergistically, usually a new and more powerful modality comes into being. Some hybrid imaging modalities are synergistic solely...

Space charge

Space charge refers to the collection of electrons which are emitted from the metal surface, after the application of tube current, at a short distance away from the metal surface. These electrons collect and form a cloud of negative charge around the metal surface. This space charge repels and...

Jewelry artifacts

It is common to see jewelry artifacts on imaging examinations, most commonly plain radiographs, although also on other modalities, where they can produce unhelpful artifacts that may obscure important structures and preclude confident diagnostic evaluation 1. These include: body piercings in m...

Radiology training for chiropractic radiologists in the United States of America

Radiology training for chiropractic radiologists in the United States of America includes a minimum of 3 years of residency after obtaining a Doctor of Chiropractic degree (DC), which is largely focused on musculoskeletal (MSK) radiology. A small number of chiropractic radiologists pursue a one ...


Microbubbles are intravenous contrast agents used in contrast-enhanced ultrasound. Microbubble contrast agent is different to the agitated saline contrast agent often used in echocardiographic studies. Microbubbles consist of a gas surrounded by a lipid, lipopolymer, or polymer shell. They rang...


Telecanthus (rare plural: telecanthi) represents an increased intercanthal distance. It is often used interchangeably with hypertelorism, referring to increased distance between the eyes. Causes and associations trauma: naso-orbitoethmoidal (NOE) fractures ethnic variation acquired sinus an...

Courvoisier sign (hepatobiliary)

Courvoisier sign or Courvoisier-Terrier sign states that in a patient with painless jaundice and an enlarged gallbladder (or right upper quadrant mass), the cause is unlikely to be gallstones and therefore presumes the cause to be an obstructing pancreatic or biliary neoplasm until proven otherw...


Cholecystectomies are one of the most common surgical procedures performed. Evidence of a cholecystectomy is often seen on imaging procedures with surgical clips in the gallbladder fossa and radiologists should be aware of possible complications.  Indications cholelithiasis cholecystitis gal...

Sciatic hernia

Sciatic hernias (alternative plural: herniae) are a rare type of pelvic floor hernia, which occur through either the greater or lesser sciatic foramina. The hernias can contain variable structures. See also curlicue ureter sign

Aberrant right subclavian and left vertebral arteries

 Diagnosis certain
Dr Hani Makky Al Salam
Published 11 Mar 2017
98% complete