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
Nasal cavity
The nasal cavity, also known as the nasal fossa, forms part of the upper respiratory tract.
Terminology
Somewhat confusingly, the nasal cavity may refer to either the space either side of the nasal septum or the two spaces combined. So for the same individual one can correctly refer to their s...
Article
Rectal prolapse
A rectal prolapse is a form of pelvic organ prolapse and refers to the prolapse of the rectum into the anal canal. They can involve the entire wall of the rectum or only the mucosal layer.
Epidemiology
Rectal prolapse in Western populations is more common in females (M:F 1:4). In women, it is ...
Article
Lumbar epidural gas
Lumbar epidural gas is a rare phenomenon where gas locules are observed within the spinal canal of the lumbar spine. It can arise from a number of factors:
due to regional degenerative disc disease with or without dorsal epidural disc migration: thought to be from gas leaking from the disc spac...
Article
CNS embryonal tumor with PLAGL amplification
CNS embryonal tumor with PLAGL amplification is a recently identified pediatric brain tumor found in both the supratentorial and infratentorial brain defined by amplification of the PLAGL1 or PLAGL2 genes. Given its histological overlap with other embryonal CNS tumors, it was previously misclass...
Article
Indirect inguinal hernia
Indirect inguinal hernias (alternative plural: herniae), a type of groin herniation, are the most common type of abdominal hernia.
Epidemiology
It is five times more common than a direct inguinal hernia, and is seven times more frequent in males, due to the persistence of the processus vaginal...
Article
Anterior cruciate ligament reconstruction
Anterior cruciate ligament (ACL) reconstruction is a common procedure post ACL tear. It 's aim is to rebuild the anatomy and function of the native ACL and reduce knee joint instability, thus it will prevent any further meniscal and/or cartilage damage.
Procedure
There are numerous surgical t...
Article
Emphysematous cystitis
Emphysematous cystitis refers to a gas-forming infection of the bladder wall.
Epidemiology
The condition is rare and usually confined to certain patient subgroups. Median age affected is 66 years. More common in women, 2:1 F:M 9.
Risk factors
Risk factors include:
diabetes mellitus
conside...
Article
Pelvic organ prolapse
Pelvic organ prolapse refers to a pathological downward herniation of various pelvic organ structures into or through the perineum. It usually results from pelvic floor weakness by impairment of various ligaments, fasciae, and muscles that support the pelvic organs.
In its most severe form, it ...
Article
Shading sign (endometrioma)
Shading sign is an MRI finding typically seen in an endometrioma. It may also be seen with some endometrioid tumors (e.g. endometrioid carcinoma of the ovary) and uncommonly other blood-containing lesions (e.g. hemorrhagic corpus luteum cysts).
The sign describes lesions that are hyperintense o...
Article
T2 dark spot sign (endometrioma)
T2 dark spot sign is an MRI appearance of endometriomas as a result of chronic hemorrhage. The sign is useful in differentiating a solitary endometrioma from a functional hemorrhagic ovarian cyst, as both might show high T1 signal with T2 shading.
The sign describes a focal T2 hypointense nodu...
Article
Mushroom cap sign (endometriosis)
The mushroom cap sign is one of the important signs of deep rectosigmoid endometriosis on T2-weighted MRI sequences. It is highly specific for submucosal involvement of the rectosigmoid colon and can be useful for differentiating endometriosis from other infiltrating lesions, such as malignancie...
Article
Obturator externus muscle
The obturator externus is a flat, triangular muscle, which covers the outer surface of the anterior wall of the pelvis.
Summary
Origin: external surface of obturator membrane and adjacent bone (inferior pubic ramus and the ramus of the ischium)
Insertion: trochanteric fossa of femur
Blood su...
Article
Mesothelioma
Mesothelioma is an aggressive malignant tumor of mesothelium and 90% of tumors arise from the pleura.
This article is about the pleural form of the disease, other locations include 17:
peritoneal mesothelioma (~10%)
pericardial mesothelioma (<1%)
cystic/multicystic mesothelioma
tunica vagi...
Article
Cryptogenic organizing pneumonia
Cryptogenic organizing pneumonia (COP) is a disease of unknown etiology characterized on imaging by multifocal ground glass opacifications and/or consolidation. A wide variety of infectious as well as noninfectious causes may result in a similar histologic pattern.
Terminology
Organizing pneum...
Article
Myometrial cysts
Myometrial cysts are cysts seen in the myometrium and these can be differentiated appropriately based on location and sonological or Doppler features. Most commonly they are benign 2.
Pathology
Etiology
They can arise from variable etiology and include 1,2:
adenomyosis
most often seen at t...
Article
Enchondromatosis
Enchondromatosis, also known as Ollier disease (see Terminology section), is a non-hereditary, sporadic, skeletal disorder characterized by multiple enchondromas principally located in the metaphyseal regions.
Terminology
Some authors make a distinction between Ollier disease and enchondromato...
Article
Coronoid process fracture
Fractures of the coronoid process of the ulna are uncommon and often occur in association with elbow dislocation.
Pathology
Mechanism
Fracture of the coronoid process is thought to result from elbow hyperextension with either avulsion of the brachialis tendon insertion or shearing off by the...
Article
Hyoid bone
The hyoid bone is a midline "U or horseshoe-shaped" bone that serves as a structural anchor in the mid-neck. It is the only bone in the human body that does not directly articulate with another bone (other than sesamoids). It is a place of convergence of multiple small neck muscles that permit t...
Article
Muscular attachments of the hyoid bone (mnemonic)
A handy mnemonic to recall the muscle attachments of the hyoid bone. The first sentence is for six muscles attaching superiorly, the second sentence is for three muscles attaching inferiorly. Both sentences are in order from lateral to medial:
Christopher, He Didn't See Girls Much. That's Obvio...
Article
Renal artery aneurysm
Renal artery aneurysms (RAA) are the second most common visceral aneurysms (15-22%), the most common being splenic artery aneurysms (60%).
Epidemiology
Renal artery aneurysms occur in ~0.1% of the population 6,8,10. They are more common in females 6. The median age at diagnosis is 50 years 8....
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