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.
495 results found
Article
20° oblique projection
20° oblique projection is a troubleshooting projection used in mammography, especially in young women and in follow-up patients.
Technique
The C-arm is turned approximately 20° for a superomedial-inferolateral oblique. With the patient's feet pointing towards the unit and her torso turned slig...
Article
3D fast spin echo (MRI sequence)
3D fast spin-echo sequences are MRI pulse sequences that are able to rapidly image relatively large volumes of tissue with high resolution whilst retaining many of the advantages of fast spin-echo sequences.
They are able to create the same weightings as traditional 2D sequences (i.e., T1, T2,...
Article
Abdomen (AP supine view)
The AP supine abdominal radiograph can be performed as a standalone projection or as part of an acute abdominal series, depending on the clinical question posed, local protocol and the availability of other imaging modalities.
Indications
This view is useful in assessing abdominal pathologies,...
Article
Abdomen (dorsal decubitus view)
The dorsal decubitus view is a supplementary projection often replacing the lateral decubitus view in the context of an unstable patient who is unable to roll nor stand. Used to identify free intraperitoneal gas (pneumoperitoneum). It can be performed when the patient is unable to be transferred...
Article
Abdomen (KUB view)
The kidneys, ureters, bladder (KUB) radiograph is optimized for assessment of the urogenital system, and should not be confused with the AP supine abdomen view. However, in cases where the patient may have both gastrointestinal and urogenital abnormalities, all pathologies will still be reported...
Article
Abdomen (lateral decubitus view)
The lateral decubitus abdominal radiograph is used to identify free intraperitoneal gas (pneumoperitoneum). It can be performed when the patient is unable to be transferred to, or other imaging modalities (e.g. CT) are not available. The most useful position for detecting free intraperitoneal ai...
Article
Abdomen (oblique view)
AP oblique supine radiograph is a projection often used in barium studies and foreign body localization.
Indications
This view is normally performed when localizing foreign bodies or lines within the abdominal cavity. Additionally, the oblique abdominal series can be utilized in the assessment...
Article
Abdomen (PA erect view)
The PA erect abdominal radiograph is often obtained in conjunction with the AP supine abdominal view in the acute abdominal series of radiographs.
The erect abdominal radiograph has virtually disappeared from clinical practice in the United Kingdom, with studies dating back to the 1980s affirmi...
Article
Abdomen (PA prone view)
The PA prone radiograph is rarely performed and is often utilized when a patient is unable to lay supine. The projection is adequate for the examination of the abdominal cavity, however, not as practical for the renal structures due to magnification.
Indications
This view is useful in visualiz...
Article
Abdomen radiograph (pediatric)
The abdomen radiograph is a commonly requested examination in the pediatric patient. Children that present for abdominal x-rays are often very unwell, therefore specialized techniques and appropriate communication are essential for gaining the child's cooperation.
Indications
Performing abdom...
Article
Abdominal imaging (dual-energy CT)
The role of dual energy CT is becoming increasingly more prevalent abdominal imaging due to the availability of scanners and increasing field of research.
Acute bowel ischemia
The addition of iodine maps and 40-keV monoenergetic images to standard single energy CT images was found to increase ...
Article
Abdominal radiography
Abdominal radiography can be useful in many settings. Before the advent of CT, it was a primary means of investigating gastrointestinal pathology and often allowed indirect evaluation of other abdominal viscera.
Indications
Although abdominal radiography has lower sensitivity and specificity t...
Article
ABER position
The ABER position relates to MR arthrography of the shoulder joint and is a mnemonic for ABduction and External Rotation.
In this position, labral tears are made conspicuous by tightening the inferior glenohumeral labroligamentous complex (which are also the most important glenohumeral ligament...
Article
Acromioclavicular joint (AP view)
The acromioclavicular AP view is a single projection assessing the patency of the acromioclavicular joint.
See also, acromioclavicular joint injuries.
Indications
The AP view of the acromioclavicular joint is often requested when the referrer either knows about or highly suspects an acromiocl...
Article
Acromioclavicular joint (AP weight-bearing view)
The acromioclavicular joint AP weight-bearing view, often performed together with the normal non-weight-bearing AP view, helps in ruling out joint displacement when it is suspected but not confirmed on the frontal image.
Indications
This view is used in the assessment of possible acromioclavic...
Article
Acromioclavicular joint series
The acromioclavicular (AC) joint radiographic series is used to evaluate the acromioclavicular joint and the distal clavicle.
Indications
AC radiographs are performed for a variety of indications including:
shoulder trauma
direct blows to the shoulder region
following a fall onto ...
Article
Acute abdominal series
The acute abdominal series is a common set of abdominal radiographs obtained to evaluate bowel gas.
Indications
The acute series is used for a variety of indications including:
determine the amount of bowel gas, with possible bowel distention
assess air-fluid levels
query pneumoper...
Article
ADIR position
The ADIR (ADduction and Internal Rotation) position relates to MR arthrography of the shoulder joint.
When added to a neutral-position shoulder protocol, MR arthrography in the ADIR position facilitates the diagnosis of labroligamentous lesions in patients with recurrent shoulder dislocations, ...
Article
Air gap technique
The air gap technique is a radiographic technique that improves image contrast resolution through reducing the amount of scattered radiation that reaches the image detector. In select situations, this technique can be used instead of an antiscatter grid as the primary scatter reduction method in...
Article
Air gap technique (general radiography)
The utilization of the air gap technique in general radiography is limited due to the need for equipment facilitation to create the air gap when it is not inherent in the standard technique.
Horizontal-beam lateral hip
There are many different methods of performing the horizontal beam lateral ...
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