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
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
Spinal vascular malformations
Spinal vascular malformations are a rare but important group of lesions that range widely in size, flow, and pathophysiology. Some, if undiagnosed and untreated, can lead to serious complications.
Although numerous classification systems exist, from the point of view of routine clinical practic...
Article
Spinal dural arteriovenous fistula
Spinal dural arteriovenous fistulas (SDAVF) are the most common type of spinal vascular malformation, accounting for ~70% of all such lesions.
This article specifically relates to spinal dural arteriovenous fistulas. For a discussion of intracranial dural arteriovenous fistulas refer to the mai...
Article
Hysterosalpingogram
A hysterosalpingogram (HSG) is a fluoroscopic examination of the uterus and the fallopian tubes, most commonly used in the investigation of infertility or recurrent spontaneous abortions.
Indications
infertility: to assess uterine morphology and tubal patency
Contraindications
pregnancy
act...
Article
Acute non-traumatic abdominal pain in pregnancy
Acute non-traumatic abdominal pain in pregnancy requires a considered imaging approach due to the increased risks of fetal demise associated with undiagnosed diseases such as perforated acute appendicitis. Ultrasound is the first-line modality due to its wide availability and ability to diagnose...
Article
Small bowel obstruction
Small bowel obstruction (SBO) refers to mechanical blockage of the transit of intestinal contents through the small bowel. CT in particular plays a key role in the diagnosis and can help identify the cause of obstruction and assess for potential complications.
Terminology
The degree of obstruc...
Article
Varicocele
Varicocele is the dilatation of the pampiniform plexus of veins, a network of many small veins found in the male spermatic cord. It is the most frequently encountered mass of the spermatic cord.
Epidemiology
The estimated incidence is at ~15% of the general male population and ~40% of subferti...
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
McCleery syndrome
McCleery syndrome is a subtype of venous thoracic outlet syndrome with symptoms resulting from compression of the subclavian vein without thrombosis (in contrast to Paget-Schroetter syndrome).
Clinical presentation
Patients with McCleery syndrome present with intermittent obstruction of the s...
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
Medulloblastoma, SHH-activated
Medulloblastoma, sonic hedgehog (SHH) activated tumors are malignant tumors of the central nervous system. They are the second most common medulloblastoma group, divided according to TP53 mutation status into TP53-wildtype and TP53-mutant that are distinct entities differing in their molecular, ...
Article
Cavernous sinus thrombosis
Cavernous sinus thrombosis (CST), the presence of thrombus in the cavernous sinus, is a rare condition, most commonly infectious in nature, and the diagnosis on imaging is not always straightforward. It has high mortality and morbidity rates.
Epidemiology
Cavernous sinus thrombosis is rare, wi...
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
Coccygeus muscle
The coccygeus muscle, also known as the ischiococcygeus muscle, is a remnant muscle of the pelvic floor.
Gross anatomy
The coccygeus is a paired muscle which is triangular in shape and overlies the sacrospinous ligament. The coccygeus lies parallel to the inferior border of the piriformis musc...
Article
IgG4-related disease
IgG4-related disease (IgG4-RD) is a systemic disease that is characterized by fibroinflammatory infiltration of various organs induced by plasma cells that express IgG4 (immunoglobulin G subclass 4).
Terminology
Since 2012, IgG4-related disease has become the preferred term 9,10. However, it h...
Article
Autoimmune pancreatitis (diagnostic criteria)
There are several sets of diagnostic criteria for autoimmune pancreatitis (AIP), with some overlap and contradictions.
Several different sets of diagnostic criteria are in use 4.
Asian 2008 AIP diagnostic criteria
both criteria I to be fulfilled
one criterion II
consistent histology
The cr...
Article
Medical abbreviations and acronyms (P)
This article contains a list of commonly used medical abbreviations and acronyms that start with the letter P and may be encountered in medicine and radiology (please keep the main list and any sublists in alphabetic order).
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R ...
Article
Left atrial appendage thrombus
Left atrial appendage thrombus is a site of intra-cardiac thrombus and refers to the presence of thrombus within the left atrial appendage.
The left atrial appendage is considered the main location of thrombus formation, predominantly in patients with non-valvular atrial fibrillation.
Radiogra...
Article
Multiple myeloma
Multiple myeloma (MM), also known by the names plasma cell myeloma and Kahler disease, is a multifocal proliferation of plasma cells based in the bone marrow. It is the most common primary malignant bone neoplasm in adults. It arises from red marrow due to the monoclonal proliferation of plasma ...
Article
Cruciate ligament dysplasia
Cruciate ligament dysplasia is a rare condition involving hypoplasia or absence of the anterior cruciate ligament (ACL) and/or the posterior cruciate ligament (PCL).
Epidemiology
The prevalence of cruciate ligament dysplasia is reported at 0.017 per 1000 live births 1,4.
Associations
The fol...