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.
16,919 results
Article
Kidneys
The kidneys are paired retroperitoneal organs that lie at the level of the T12 to L3 vertebral bodies.
Gross anatomy
Location
The kidneys are located to either side of the vertebral column in the perirenal space of the retroperitoneum, within the posterior abdominal wall. The long axis of the...
Article
Ureter
The ureter is a paired fibromuscular tube that conveys urine from the kidneys in the abdomen to the bladder in the pelvis.
Gross anatomy
The ureter is 25-30 cm long and has three parts:
abdominal ureter: from the renal pelvis to the pelvic brim
pelvic ureter: from the pelvic brim to the bla...
Article
Reticuloendothelial system
The reticuloendothelial system (RES) comprises a number of tissues:
spleen
bone marrow
liver Kupffer cells
Article
Extrapyramidal system
The extrapyramidal system is the part of the motor system involved in modulation and regulation of movement. As its name suggests, it is distinct from the motor fibers that are relayed through the pyramids of the medulla oblongata (corticospinal and corticobulbar tracts).
Although the extrapyra...
Article
Adrenal hyperplasia
Adrenal hyperplasia refers to non-malignant growth (enlargement) of the adrenal glands.
Secondary adrenal cortical hyperplasia (i.e., ACTH-dependent, Cushing Disease) is more common and most often due to ACTH producing pituitary tumors. More rarely, it is caused by ACTH-producing small cell lu...
Article
Cesarean section scar diverticulum
Cesarean section scar diverticulum is a form of outpouching located in the anterior lower uterine cavity at the site of a cesarean section scar.
There is some similarity with the term cesarean scar niche.
Clinical presentation
mostly asymptomatic
postmenstrual spotting
Radiographic feature...
Article
Ovarian fibroma
Ovarian fibromas are benign ovarian tumors of sex cord/stromal origin. Although fibromas account for ~4% of all ovarian neoplasms, they are the most common sex cord ovarian tumors.
Epidemiology
Fibromas occur at all ages but are most frequently seen in middle-aged women.
Associations
They ar...
Article
Deauville five-point scale
The Deauville five-point scale (Deauville 5PS) is an internationally-recommended scale for routine clinical reporting and clinical trials using FDG PET-CT in the initial staging and assessment of treatment response in Hodgkin lymphoma (HL) and certain types of non-Hodgkin lymphomas (NHL).
Incl...
Article
Hemorrhagic ovarian cyst
Hemorrhagic ovarian cysts usually result from hemorrhage into a corpus luteum or other functional cyst. Radiographic features are variable depending on the age of the hemorrhage. They typically resolve within 8 weeks.
Clinical presentation
Patients may present with sudden-onset pelvic pain, p...
Article
Ovarian fibrothecoma
Ovarian fibrothecomas comprise tumors in the spectrum of ovarian sex cord / stromal tumors where there are components of both an ovarian fibroma and an ovarian thecoma.
Epidemiology
Most occur in adult women, with ~66% in postmenopausal women. Although they account for ~1% of all ovarian tumo...
Article
Lesser palatine nerves
The lesser palatine nerves (or posterior palatine nerves) are a group of 2 to 3 nerves (usually 2 nerves) that arise off the maxillary division of the trigeminal nerve and contributes to the pterygopalatine ganglion.
Gross anatomy
The lesser palatine nerves divide off the maxillary division ju...
Article
Greater palatine nerve
The greater palatine nerve, also known as the anterior palatine nerve, is a branch of the maxillary division of the trigeminal nerve and contributes to the pterygopalatine ganglion.
Gross anatomy
The greater palatine nerve divides off the maxillary division just after emerging from the foramen...
Article
Dorsal dermal sinus
Dorsal dermal sinus is an epithelium-lined tract from the skin to the spinal cord, cauda equina, or arachnoid as in a form of spinal dysraphism.
Clinical presentation
A dorsal dermal sinus manifests as a small dimple or pinpoint ostium, which is often associated with an area of hyperpigmented...
Article
Spinal cord
The spinal cord is the part of the central nervous system found within the vertebral column's spinal canal. The cord extends from the corticomedullary junction at the foramen magnum of the skull down to the tip of the conus medullaris within the lumbar cistern. It is lined by the spinal pia mate...
Article
Aicardi-Goutières syndrome
Aicardi-Goutières syndrome is a rare hereditary neurodegenerative disease which usually presents in early infancy as a systemic and central nervous system inflammatory syndrome characterized by hepatosplenomegaly, vasculopathy and encephalopathy. Many of the features are similar to congenital TO...
Article
Cervical canal stenosis
Cervical canal stenosis is a general term that refers to the abnormal narrowing of the cervical spinal canal that compromises the nerve root and/or spinal cord resulting in radiculopathy and/or compressive myelopathy. The most common cause of cervical spinal canal stenosis is age-related degener...
Article
Lumbar canal stenosis
Lumbar canal stenosis is a general term that refers to the pathological narrowing of the spinal canal, nerve root canals and/or the intervertebral foramina in the lumbar spine 1-4,6,7,9,10.
Epidemiology
Lumbar canal stenosis is common, especially among individuals over 60 years old, and its pr...
Article
Spinal stenosis
Spinal stenosis is a condition in which a portion of the spinal canal narrows to the point at which it can exert pressure on the nerves that travel through the spine.
Spinal stenosis is not to be confused with foraminal stenosis, which is the narrowing of the foramina with subsequent compressio...
Article
Midbrain
The midbrain, or mesencephalon (plural: mesencephala or mesencephalons), is the most rostral part of the brainstem and sits above the pons and is adjoined rostrally to the thalamus. During development, the midbrain forms from the middle of three vesicles that arise from the neural tube.
When vi...
Article
Pons
The pons (TA: pons; plural: pontes 3), a.k.a. pons Varolii, is the middle portion of the three contiguous parts of the brainstem, sitting above the medulla and below the midbrain. It acts as a relay between the cerebellum and cerebral hemispheres.
Gross anatomy
The pons has a bulbous shape an...
Unable to process the form. Check for errors and try again.