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
Tarlov cyst
Tarlov cysts, also called perineural cysts, are CSF-filled dilatations of the nerve root sheath at the dorsal root ganglion (posterior nerve root sheath). These are type II spinal meningeal cysts that are, by definition, extradural but contain neural tissue.
Most Tarlov cysts are asymptomatic, ...
Article
Pelvic kidney
Pelvic kidneys, sometimes known as a sacral kidney, are kidneys that are fixed in the bony pelvis or across the spine and are an anatomic variant 1.
Epidemiology
Pelvic ectopia is seen in 1 in 2,100-3,000 autopsies. It is considered the most common form of renal ectopia 4.
Associations
Ectop...
Article
Gastrointestinal stents
Gastrointestinal (GI) stents are increasingly used to treat obstruction of the GI tract, most commonly due to malignancy.
Types of stent
esophageal stent
gastric stent
duodenal stent
enteric stent
colorectal stent
History and etymology
Somewhat surprisingly the word 'stent' is actually a...
Article
Mayer-Rokitansky-Küster-Hauser syndrome
Mayer-Rokitansky-Küster-Hauser syndrome (MRKH), also known as Müllerian aplasia, is a congenital anomaly characterized by vaginal and uterine aplasia or agenesis 9. It is usually also associated with a spectrum of other genitourinary tract abnormalities. MRKH syndrome belongs to class I Mulleria...
Article
Precalcaneal congenital fibrolipomatous hamartoma
Precalcaneal congenital fibrolipomatous hamartoma (PCFH) is a rare, benign condition characterized by the presence of asymptomatic, skin-colored, unilateral or bilateral nodules in the medial precalcaneal plantar region of the heel. It is usually first seen within the first months of life, altho...
Article
Cavernous sinus
The cavernous sinuses are paired dural venous sinuses.
Gross anatomy
The cavernous sinus is located on either side of the pituitary fossa and body of the sphenoid bone. It is most easily thought of as existing between the endosteal and meningeal layers of the dura although some additional com...
Article
Spatial resolution (CT)
Spatial resolution in CT is the ability to differentiate two adjacent objects or structures as being distinct from each other.
A high spatial resolution is important for one to discriminate between structures that are located within close proximity to each other.
Factors affecting CT spatial ...
Article
T1 black holes
T1 black holes are hypointense lesions that may be seen on T1 weighted imaging in patients with multiple sclerosis, and indicates the chronic stage with white matter destruction, axonal loss and irreversible clinical outcome.
Article
Rectovaginal fistula
Rectovaginal fistulae are a type of colovaginal fistula where there is an abnormal fistulous connection between the rectum and the vagina. It is considered the most common gastrointestinal fistula involving the female genital tract 1.
Pathology
They can occur from a number of causes that inclu...
Article
Hypoglobus
Hypoglobus refers to the inferior displacement of the globe in the orbit. It may or may not be associated with enophthalmos.
Pathology
Etiology
fracture of the orbital floor (most common)
silent sinus syndrome
orbital masses
orbital foreign bodies
thyroid ophthalmopathy
Article
Enophthalmos
Enophthalmos refers to the posterior displacement of the globe in the orbit. It implies that the globe itself is normal and is caused by either one or a combination of 1:
structural alterations in the bony orbit
orbital fat atrophy
retraction
It may or may not be associated with hypoglobus.
...
Article
Aliasing on MRI
Aliasing on MRI, also known as wrap-around, is a frequently encountered MRI artifact that occurs when the field of view (FOV) is smaller than the body part being imaged. The part of the body that lies beyond the edge of the FOV is projected onto the other side of the image 5.
This can be correc...
Article
Ultrasound-guided peripheral intravenous cannulation
Peripheral intravenous (IV) cannulation under ultrasound guidance is the placement of an IV cannula into a peripherally-located vein under the direct vision of ultrasound. This process allows the cannulation of veins that cannot be visualized or palpated without ultrasound. In trained individual...
Article
Interarterial course of the right coronary artery
Interarterial course of the right coronary artery may occur if the right coronary artery (RCA) has an aberrant origin from the left coronary sinus. The interarterial course occurs because the artery passes between the ascending aorta and the pulmonary trunk 1-3.
It is an uncommon anatomic varia...
Article
Celiac artery aneurysm
Celiac artery aneurysms are a form of visceral artery aneurysm and account for ~4% of such cases (the fourth most common visceral arterial aneurysm).
Clinical presentation
While some patients may have symptoms, they are usually asymptomatic and are incidentally discovered 10.
Pathology
Coael...
Article
Splenic artery pseudoaneurysm
Splenic artery pseudoaneurysms are rare and can arise from any portion of the splenic artery and its branches.
Clinical presentation
Unlike splenic artery true aneurysms, splenic artery pseudoaneurysms will nearly always present with symptoms 2. While their occurrence may be higher, fewer tha...
Article
Splenic artery aneurysm
Splenic artery aneurysms are the most common visceral arterial aneurysm formation as well as the third most common abdominal aneurysm (after the aorta and iliac vessels). Aneurysms are usually saccular in configuration and they can either be in the form of a true aneurysm (much more common) or a...
Article
Brown adipose tissue
Brown adipose tissue (BAT) (also known as brown fat) is one of two types of adipose tissue (the other one being white fat) important for producing thermal energy (heat, non-shivering thermogenesis), especially in the newborn. It constitutes ~5% of body mass in the newborn and tends to reduce mar...
Article
Intravenous cannula
Intravenous (IV) cannulas are small, flexible tubes inserted into a vein to deliver fluids and medications or draw blood.
This article is focused on peripheral IV cannulas.
Technique
IV cannulas can be inserted "blindly" or under ultrasound guidance 4.
Device structure
Parts of intravenous ...
Article
Non-seminomatous germ cell tumors
Non-seminomatous germ cell tumors (NSGCTs) are one of the main groups of germ cell tumors (the other being seminoma). Although they are made up of distinct histological entities, in general, they have similar radiographic appearances. They can, however, be found widely in the body, with variable...
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