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
Transverse myelitis
Transverse myelitis, also known as acute transverse myelitis, is an inflammatory condition affecting both halves (ventral and dorsal) of the spinal cord and associated with rapidly progressive motor, sensory, and autonomic dysfunction.
MRI is the most useful imaging modality, which generally sh...
Article
Renal cell carcinoma
Renal cell carcinomas (RCC) (historically also known as hypernephroma or Grawitz tumor) are primary malignant adenocarcinomas derived from the renal tubular epithelium and are the most common malignant renal tumor. They usually occur in 50-70-year old patients and macroscopic hematuria occurs in...
Article
Uterosacral ligament
The paired uterosacral ligaments are one of the supporting structures of the uterus. Uterosacral ligaments are not infrequently affected in cases of deep infiltrating endometriosis.
Gross anatomy
The paired uterosacral ligaments are extraperitoneal structures which extend posteriorly from the ...
Article
Halo sign (chest)
The halo sign in chest imaging is a feature seen on lung window settings consisting of ground glass opacity surrounding a pulmonary nodule, mass, or consolidation. It is typically seen in angioinvasive aspergillosis.
Pathology
It is a non-specific finding which can represent partial alveolar f...
Article
Metastases to the thyroid
Metastases to the thyroid are an uncommon cause of thyroid malignancy.
Epidemiology
Metastases to the thyroid represent 1.4-3% of all malignancies 5. In autopsy series, the incidence is ~10% (range 2-24%) 1,5.
Pathology
The most common sites of primary malignancy include (note these will v...
Article
Dense hilum sign
The dense hilum sign suggests a pathological process at the hilum or in the lung anterior or posterior to the hilum. Malignancy, especially lung cancer, should be suspected. ICU patients may aspirate following extubation, typically into segment B6, overlying the hilum (B6 bronchus sign 5).
Radi...
Article
Incomplete border sign (chest)
The incomplete border sign is useful to depict an extrapulmonary mass on chest radiograph.
An extrapulmonary mass will often have an inner well-defined border and an ill-defined outer margin 1-3. This can be attributed to the inner margin being tangential to the x-ray beam and having a good inh...
Article
White epidermoid cyst
White epidermoids are a rare type of epidermoid cyst that do not follow the usual near-CSF density and signal intensity on CT and MR, respectively.
Terminology
The term “white epidermoid cyst” does not denote a variant; it represents a distinct transformation within an epidermoid cyst due to l...
Article
Sacroiliac joint
The sacroiliac joint (SIJ) is a synovial joint between ilium and the sacrum. It has little movement and its main function is to transfer weight between the axial and lower appendicular skeletons. The sacroiliac joint is a symmetrical joint (i.e. is paired) with an oblique coronal orientation and...
Article
Hickman catheter
Hickman catheters (or Hickman lines) are a type of tunneled central venous access line.
Radiographic features
Hickman catheters are typically inserted into either jugular vein, and the proximal tubing is tunneled through the subcutaneous tissues to a skin incision on the chest. The distal part...
Article
Incomplete double aortic arch
Incomplete double aortic arch is a rare vascular ring anomaly wherein a segment of the minor aortic arch, usually the left, is atretic.
Clinical presentation
As in the case of other vascular rings, this anomaly can cause 1:
stridor
wheezing
dysphagia
Some patients may reach adulthood with...
Article
Ecchordosis physaliphora
Ecchordosis physaliphora(EP) is a congenital benign hamartomatous lesion derived from notochord remnants, usually located in the retroclival prepontine region, but can be found anywhere from the skull base to the sacrum.
Terminology
There has been some controversy as to whether intradural cho...
Article
Cerebral cavernous venous malformation
Cerebral cavernous venous malformations, also commonly known as cavernous hemangiomas or cavernomas, are common cerebral vascular malformations, usually with characteristic appearances on MRI. It is the third most common cerebral vascular malformation after developmental venous anomaly and capil...
Article
Primary amenorrhea
Primary amenorrhea is defined as absence of menses by 14 years of age in the absence of growth or development of secondary sexual characteristics or absence of menses by 16 years of age regardless of the presence of normal growth and development including secondary sexual characteristics 1.
Pat...
Article
Lissencephaly-pachygyria spectrum
Lissencephaly-pachygyria spectrum describes the spectrum of diseases that cause relative smoothness of the brain surface, and includes 1:
agyria: no gyri
pachygyria: broad gyri
lissencephaly: smooth brain surface
It is a basket term for a number of congenital cortical malformations character...
Article
Muscle hernia
Muscle hernias, also known as myofascial defects, are most commonly found in the lower extremities.
Clinical presentation
Muscle hernias are typically asymptomatic, although can cause cramping sensations or pain, with or after activity. They may also present as a palpable mass, and be referred...
Article
Normal kidney size (children)
The normal size of kidneys in children follows a growth curve and is closely related to the age and size of the child. Ethnic differences have also been shown, which may be an important consideration when interpreting measurements against a reference range 4.
In infants median (normal range bet...
Article
Neuroglial cyst
Neuroglial cysts (also known as glioependymal cysts and neuroepithelial cysts) are rare, benign epithelial-lined cystic lesions that can potentially occur anywhere in the neuraxis. On imaging, they are characterized as CSF-like parenchymal cysts with smooth, rounded borders and minimal-to-no sur...
Article
Uterine dehiscence
Uterine dehiscence is usually used to refer to the process of gradual myometrial rupture without a rupture of membranes. However, the term is used synonymously with uterine rupture by some authors. It is often described in the context of a cesarean section scar where it is also termed an incisio...
Article
Ovarian cystadenofibroma
Ovarian cystadenofibromas are a relatively uncommon benign epithelial ovarian tumor where the fibrous stroma remains a dominant component of the neoplasm. As a group, they are thought to represent ~1.7 % of all benign ovarian tumors 3.
Pathology
Lesions can be bilateral in ~15% of cases. Altho...
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