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.

16,914 results
Article

Chipmunk sign (brainstem)

The chipmunk sign refers to the MRI appearance of the medulla in some patients with leukodystrophies, particularly Alexander disease. The same appearance has been described in adult polyglucosan body disease, vanishing white matter disease, Pelizaeus-Merzbacher disease, 4H syndrome, and adult-on...
Article

Mild malformation of cortical development with oligodendroglial hyperplasia and epilepsy (MOGHE)

Mild malformation of cortical development with oligodendroglial hyperplasia and epilepsy (MOGHE) is a histopathological entity primarily associated with drug-resistant frontal lobe epilepsy. MOGHE is characterized by a distinct histological phenotype that includes blurred gray-white matter bound...
Article

Modified Dallas discographic classification of intervertebral disc radial tears

The modified Dallas classification describes the discography appearance of radial annular tears of the intervertebral disc. Classification grade 0: contrast remains in the nucleus pulposus grade 1: contrast leaks into the inner 1/3 of the annulus fibrosus grade 2: contrast leaks into the mid...
Article

Anterior superior aortic recess

The anterior superior aortic recess is one of the variable invaginations of the superior aortic recess and is located anterior to the ascending aorta (mostly towards the left) 1-4. It can sometimes include aortopulmonary window region 1. Clinical importance It may occasionally mimic mediastina...
Article

Sinonasal glomangiopericytoma

Glomangiopericytomas (GPC), also known as sinonasal-type hemangiopericytomas, are rare vascular tumors that typically arise in the nasal cavity and paranasal sinuses characterized by a perivascular myoid pattern 1. Terminology  Glomangiopericytomas (GPCs) are often referred to as sinonasal hem...
Article

Mesenteric cyst

Mesenteric cysts are a very rare cause of abdominal pain and have a wide range of underlying causes.  Terminology The term "mesenteric cyst" is considered a descriptive of the location and gross appearance of "any cyst" arising in the mesentery 8. Epidemiology Mesenteric cysts are rare, with...
Article

Basilar invagination

Basilar invagination, also called basilar impression, is a congenital or acquired craniocervical junction abnormality where the tip of the odontoid process projects above the foramen magnum.  Terminology The following terms are often used interchangeably because they describe upwards migration...
Article

Airway foreign bodies in children

Airway foreign bodies in children are potentially fatal, which is why immediate recognition is important. Unfortunately, delayed diagnosis is common. Epidemiology Children under the age of four years have an increased risk of foreign body (FB) aspiration, with a slight male predominance 1.  C...
Article

Mycetoma (soft-tissue)

Mycetoma refers to a chronic and progressively destructive granulomatous disease within the soft tissues. The defining clinical triad comprises of a: localized mass-like soft tissue injury with draining sinuses that discharge grains of contagious material It is one of the "neglected tropical...
Article

Xanthogranulomatous pyelonephritis

Xanthogranulomatous pyelonephritis (XGP) is a rare form of chronic pyelonephritis and represents a chronic granulomatous disease resulting in a non-functioning kidney. Radiographic features are usually specific. Epidemiology Xanthogranulomatous pyelonephritis is seen essentially in all age gro...
Article

Fat-containing renal lesions

There are numerous fat-containing renal lesions, including: renal angiomyolipoma renal cell carcinoma (often has calcifications when contains macroscopic fat) Wilms tumor (most common pediatric renal mass) renal oncocytoma renal or perirenal lipoma/liposarcoma Non-mass lesions may also occ...
Article

Acromioclavicular joint injury

Acromioclavicular joint injuries, commonly shortened to ACJ injuries, are characterized by damage to the acromioclavicular joint and surrounding structures. Almost invariably traumatic in etiology, they range in severity from a mild sprain to complete disruption. Epidemiology Acromioclavicular...
Article

Post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder (PTLD), also referred as post-transplant lymphoproliferation disorder, represents a variety of conditions ranging from lymphoid hyperplasia to malignancy, included in the WHO classification of haematolymphoid tumors under "lymphoid proliferations and ...
Article

Erdheim-Chester disease

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell, non-familial multisystemic histiocytosis, with widespread manifestations and of highly variable severity. The most common presenting symptom is bone pain. Epidemiology Erdheim-Chester disease is a rare, non-inherited disease of middl...
Article

Perinephric myxoid pseudotumor of fat

Perinephric myxoid pseudotumor of fat is a very rare, benign, and slowly growing tumor, which can mimic renal cysts, retroperitoneal cystic tumors and liposarcomas alike. Due to its rarity and overlapping imaging appearance the diagnosis is almost always made by histopathological analysis.  Eti...
Article

Hepatic angiosarcoma

Hepatic angiosarcoma is a rare malignancy, but is still the third most common primary liver tumor. They have a variable appearance on both CT and MRI, reflecting the pleomorphic histological nature. Prognosis is very poor, with survival uncommon beyond one year from diagnosis.  Terminology Hep...
Article

Cyst of the ligamentum flavum

Cysts of the ligamentum flavum, also known as flaval cysts, are classified as degenerative spinal cysts 1, which arise from the ligamentum flavum. Epidemiology Cysts of the ligamentum flavum do not show any gender predilection (M=F) and are most commonly found in the middle-aged and elderly 1....
Article

Knee series

The knee series is a set of radiographs taken to investigate knee joint pathology, often in the context of trauma. It usually comprises an AP and lateral projection, although other non-standard, modified projections can be used for specific indications. See also knee radiograph (an approach). ...
Article

Knee radiograph (an approach)

Knee radiographs are common and often a quick and easy diagnostic exam in the emergency setting. An efficient approach to them requires a good understanding of anatomy with review strategies to ensure an accurate diagnosis. Systematic review Choosing a search strategy and utilizing it consiste...
Article

Amastia

Amastia is a rare congenital condition characterized by the absence of breast tissue, nipple and areola. This may occur unilaterally or bilaterally. Pathology During embryological development, breasts first appear as ectoderm ridges during the 6th week of gestation. This ridge grows thicker an...

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.