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
Optic nerve sheath diameter
Optic nerve sheath diameter has significance in the assessment of papilledema in cases of elevated intracranial pressure.
Pathology
The optic nerve sheath demonstrates changes in diameter with CSF pressure changes as there is a layer of subarachnoid space between the nerve and its sheath, whic...
Article
Myocardial mapping
Myocardial mapping or parametric mapping of the heart is one of various magnetic resonance imaging techniques, which has evolved and been increasingly used in the last decade for non-invasive tissue characterization of the myocardium 1-5. Unlike normal T1-, T2- or T2*- images, parametric mapping...
Article
Scapholunate interval
The scapholunate interval or gap is the radiographic measurement of the scapholunate joint and widening is indicative of a scapholunate ligament injury.
Measurement
The scapholunate interval should be measured between the midportion of the scaphoid and lunate on neutral PA, Moneim, PA ulnar de...
Article
Peritoneal thickening
Peritoneal thickening is a descriptive term given to describe any form of thickening of the peritoneum.
It can occur with both benign and malignant peritoneal disease. It can be classified into various subtypes based on its morphology:
smooth peritoneal thickening
peritonitis
peritoneal car...
Article
Bone age assessment
Bone age assessment is used to radiologically assess the biological and structural maturity of immature patients from their hand and wrist x-ray appearances. It forms an important part of the diagnostic and management pathway in children with growth and endocrine disorders. It is helpful in the ...
Article
Antenatal screening
Antenatal screening and diagnosis are available for a few selected genetic conditions, including trisomy 21 (Down syndrome), trisomy 18 (Edward syndrome), trisomy 13 (Patau syndrome) and neural tube defects.
For an overview of the conditions and their manifestations, please refer to the specifi...
Article
Joint effusion
A joint effusion is defined as an increased amount of fluid within the synovial compartment of a joint.
There is normally only a small amount of physiological intra-articular fluid. Abnormal fluid accumulation can result from inflammation, infection (i.e. pus) or trauma and might be exudate, tr...
Article
Left atrial enlargement
Left atrial enlargement (LAE) may result from many conditions, either congenital or acquired. It has some characteristic findings on a frontal chest radiograph. CT or MRI may also be used for diagnosis.
Clinical presentation
An enlarged left atrium can have many clinical implications, such as:...
Article
Ottawa ankle rules
The Ottawa ankle rules are a clinical decision-making strategy for determining which patients require radiographic imaging for ankle and midfoot injuries. Proper application has high (97.5%) sensitivity and reduces the need for radiographs by ~35% 1,2,4.
There are two components, assessing for...
Article
Tentorial angle
The tentorial angle is measured between a line connecting the nasion with the tuberculum sellae and the angle of the straight sinus. Normally it should measure between 27° and 52°.
Abnormalities of the posterior fossa or base of skull can alter this. For example, this angle is elevated in achon...
Article
Increased retrosternal airspace
Increased retrosternal airspace is an indicator of hyperinflation of the lungs and is usually due to emphysema.
The thickness of the space between the ascending aorta and the posterior margin of the sternum (3 cm inferior to the sternomanubrial joint) and is normally no more than 2.5 cm 1 altho...
Article
CT peritoneography
CT peritoneography is an examination used to assess difficulties with peritoneal dialysis.
Indications
Recurrent peritonitis with difficulty with fluid exchange, abdominal wall or genital soft tissue edema, localized bulging of the abdomen, and poor ultrafiltration.
Technique
Before perform...
Article
MRI of the elbow (an approach)
MRI of the elbow is a fairly frequent examination in musculoskeletal radiology practice and not quite as common in general radiological practice. This approach is an example of how to create a radiological report of an elbow MRI with coverage of the most common anatomical sites of possible patho...
Article
Gilula three carpal arcs
Gilula three carpal arcs are used in the assessment of the normal alignment of the carpus on PA wrist radiographs:
first arc: is a smooth curve outlining the proximal convexities of the scaphoid, lunate and triquetrum
second arc: traces the distal concave surfaces of the same bones
third arc:...
Article
Breast mass
Breast masses are three-dimensional space-occupying lesions in the breasts. This article provides an overview of the standard BI-RADS terminology used to describe breast masses in radiology reports and other reporting suggestions.
Radiographic features
Breast masses are described differently b...
Article
Interzygomatic line
The interzygomatic line is a commonly used reference standard for the evaluation of proptosis due to various etiologies on CT/MRI scans.
Technique
A horizontal line should be drawn between the most anterior parts of the zygomatic bones in the axial plane.
The normal distance of the interzygom...
Article
Isikoff's View
The Isikoff's view is a sonographic view which demonstrates the origins of the right and left renal arteries. It is taken in the longitudinal plane with the patient in the left lateral decubitus position 1.
Article
Cardiac segmentation model
The American Heart Association (AHA) has published the nomenclature and segmentation of the left ventricular myocardium (the cardiac segmentation model), now widely used for the description of disease-affected myocardial territories and wall function.
There are 17 segments that have a reasonabl...
Article
Gunshot injuries
Gunshot injuries are a type of penetrating trauma that often require imaging assessment, and this evaluation has both clinical relevance (assessment of organ damage, surgical planning, and prognostication), and often also forensic implications.
For a more detailed description of ballistics, see...
Article
Evaluation of recurrent bone tumors
Recurrent bone tumors are a common complication post curettage or resection.
Radiographic features
Radiographs taken pre- and postoperatively are sufficient for evaluation of recurrence based on the following features:
osteolytic changes
cortical changes
matrix mineralization (characteristi...