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 edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

365 results found
Article

Scoliosis (lateral bending view)

Scoliosis lateral bending views are additional scoliosis projections accompanying the standard PA/AP views with the aim of assessing the patient’s lateral range of spinal motion 1. Patient position patient erect or supine patient bending their upper body laterally (right and left) from the h...
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Scoliosis PA/AP view

The scoliosis anteroposterior (or posteroanterior) view allows for the visualization of the thoracic and lumbar vertebral bodies of interest in scoliosis and allows for the severity of lateral spinal curvature to be assessed 1. Patient position patient erect (or supine depending on protocol) ...
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Scoliosis radiography

Scoliosis radiography is useful in identifying the degree of the scoliosis curvature (major/minor or primary/compensatory curves), as well as observe its progression to determine the best method of treatment 1.   Indications Scoliosis radiographs are performed specifically when the disease is...
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Shoulder (AP glenoid view)

The shoulder AP glenoid view (also known as a "Grashey view") is an additional projection to the two view shoulder series. The projection is used to assess the integrity of the glenohumeral joint. Patient position the patient is preferably erect the midcoronal plane of the patient is parallel...
Article

Shoulder (AP view)

The shoulder AP view is a standard projection that makes up the two view shoulder series. The projection demonstrates the shoulder in its natural anatomical position allowing for adequate radiographic examination of the entire clavicle and scapula, as well as the glenohumeral, acromioclavicular ...
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Shoulder (external rotation view)

The shoulder external rotation view is an additional projection to the standard shoulder series it is often combined with the internal rotation view to visualize the entirety of the humeral head. This projection best demonstrates the greater tubercle humerus in profile. Patient position patien...
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Shoulder (Garth view)

The Garth view of the shoulder is a projection used in trauma when evaluating the glenohumeral joint for dislocations and trauma to the glenoid of the scapula; this projection is often used as a replacement to the lateral scapula view in trauma. It is an optimal projection to demonstrate Bankar...
Article

Shoulder girdle radiography

The radiography of the shoulder girdle is a commonly requested plain radiographic examination; the particular radiographic series will be dependent on the suspected pathology or injury. The extent of each series is determined by the radiography department protocols. Radiographic series shoulde...
Article

Shoulder (inferosuperior axial)

The inferosuperior axial view of the shoulder is a modified axial projection best utilized with supine patients. It is an orthogonal projection to the AP view and replaces the lateral shoulder projection. It is an appropriate projection to assess suspected dislocations, proximal humerus patholo...
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Shoulder (internal rotation view)

The shoulder internal rotation view is an additional projection to the standard shoulder series it is often combined with the external rotation view to visualize the entirety of the humeral head. This projection shows the lesser tubercle of the humerus in profile and can be used to detected susp...
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Shoulder (lateral scapula view)

The lateral scapula shoulder or Y view is part of the standard shoulder series. Orthogonal to the AP shoulder (note so is an axillary view); It is a pertinent projection to assess suspected dislocations, scapula fractures, and degenerative changes. Excellent projection to see both the coracoid ...
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Shoulder (modified transthoracic supine lateral)

The modified transthoracic supine lateral scapula is a modification of the supine lateral shoulder, used to safely image patients on spinal precautions, or patients who are unable to move; often employed in major trauma hospitals, it produces a diagnostic lateral projection of the shoulder with ...
Article

Shoulder (modified trauma axial view)

The modified trauma axial view is a supplementary projection that replaces the ‘Y view’ of the two-view shoulder series often performed in the context of trauma. It is an orthogonal view of the AP projection of the glenohumeral joint, with a higher diagnostic yield than the lateral scapular sho...
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Shoulder (outlet view)

The outlet or Neers projection of the shoulder is a specialized projection demonstrating the coracoacromial arch often utilized in the investigation of shoulder impingement 1. This projection is most commonly seen in orthopedic clinics and closely resembles a lateral scapular projection but in...
Article

Shoulder radiograph protocol

A shoulder radiograph protocol will depend on the age of the patient, and on whether the indication is because of trauma. Best practice is to have 2 orthogonal views of any bone or joint, so an AP and lateral film are obtained. The anatomy of the shoulder and the position required to acquire th...
Article

Shoulder series

The shoulder series is fundamentally composed of two orthogonal views of the glenohumeral joint including the entire scapula. The extension of the shoulder series depends on the radiography department protocols and the clinical indications for imaging. Indications Shoulder radiographs are perf...
Article

Shoulder (Stryker notch view)

The Stryker notch view is a specialized projection of the shoulder frequently used to evaluate the articulation of the glenoid and the humeral head; it is an effective projection in assessing for Hill-Sachs lesions 1. Patient position the patient is preferably erect the midcoronal plane of th...
Article

Shoulder (superior-inferior axial view)

The axial shoulder view is a supplementary projection to the lateral scapula view for obtaining orthogonal images to the AP shoulder. It is an appropriate projection to assess suspected dislocations, proximal humerus pathology, and glenohumeral articular surface abnormalities 1-3 . Patient pos...
Article

Shoulder (supine lateral view)

The supine lateral scapula view (anterior oblique AP) is a modified lateral shoulder projection often utilized in trauma imaging. Orthogonal to the AP shoulder (note so is an axillary view); It is a pertinent projection to assess suspected dislocations, scapula fractures and degenerative changes...
Article

Skeletal survey (overview)

The skeletal survey is a radiographic series performed to survey the entire skeleton (axial skeleton, upper and lower limbs) for pathology or injury. Specific projections vary depending on the clinical indication and the institution's protocol. There are various clinical indications that may wa...
Article

Skull (AP view)

The skull AP view is a nonangled AP radiograph of the skull. This view provides an overview of the entire skull rather than attempting to highlight any one region. Patient position the back of patient's head is placed against the image detector Technical factors anterior-posterior projection...
Article

Skull (Caldwell view)

The Caldwell view is a caudally angled PA radiograph of the skull, designed to better visualize the paranasal sinuses, especially the frontal sinus. Patient position the patient is seated in front of the upright detector the patient's forehead is placed against the image detector forehead an...
Article

Skull (lateral view)

The skull lateral view is a nonangled lateral radiograph of the skull. This view provides an overview of the entire skull rather than attempting to highlight any one region. Patient position the sagittal midline of the patient's head is parallel to the image detector sella turcica in profile ...
Article

Skull (PA view)

The skull PA view is a non-angled PA radiograph of the skull. This view provides an overview of the entire skull rather than attempting to highlight any one region. Patient position the patient is erect the patient's forehead is placed against the image detector allowing for the nose to be in...
Article

Skull radiography

Skull radiography is the radiological investigation of the skull vault and associated bony structures. Seldom requested in modern medicine, plain radiography of the skull is often a last resort in trauma imaging in the absence of a CT. However, it is still utilized in the setting of skeletal sur...
Article

Skull (Towne view)

The Towne view is an angled AP radiograph of the skull, used to evaluate for fractures of the skull and neoplastic changes. The projection is used to visualize the petrous part of the pyramids, the dorsum sellae and the posterior clinoid processes, which are visible in the shadow of the foramen ...
Article

Skull (Waters view)

The occipitomental (OM) or Waters view is an angled PA radiograph of the skull, with the patient gazing slightly upwards. It can be used to assess for facial fractures, as well as for acute sinusitis. Skull radiographs, in general, are rapidly becoming obsolete, being replaced by much more sensi...
Article

Spot view (mammography)

A spot view (also known as a spot compression view or focal compression view) is an additional mammographic view performed by applying the compression to a smaller area of tissue using a small compression paddle, increasing the effective pressure on that spot. This results in better tissue separ...
Article

Stenvers view

Stenvers view is a oblique radiographic projection used to demonstrate the petrous temporal bone, IAM and bony labyrinth. Fine slice multi-detector CT of the petrous bone has replaced the Stenver view due to far superior anatomic detail. It was also used to assess electrode placement following t...
Article

Step-oblique mammography

Step-oblique mammography is an accurate technique for determining whether a mammographic finding visible on multiple images on only one projection (but not elucidated using standard additional mammographic projections) represents a summation artefact or a true mass and for precisely localizing t...
Article

Sternoclavicular joint (anterior oblique views)

The anterior oblique projections of the sternoclavicular joints are complimentary to the front on PA view in the sternoclavicular joint series. The oblique positioning maneuvers the join of interest away from central structures to produce a clearer view of articulation. The side of obliquity pe...
Article

Sternoclavicular joint (PA view)

The sternoclavicular PA view is part of the plain radiographic series assessing the sternoclavicular joint. The projection produces a bilateral view of the sternoclavicular joints in the posteroanterior plane. Patient position the patient is preferably laid prone with arms resting above the he...
Article

Sternoclavicular joint (serendipity view)

The serendipity view is a specialized radiographic projection utilized in the setting of suspect dislocations of the sternoclavicular joint. The projection is seldom used in departments with functioning computed tomography, but still utilized in postoperative imaging. Patient position supine o...
Article

Sternoclavicular joint series

The sternoclavicular radiographic series is a used to evaluate sternoclavicular joint and the proximal clavicle. Imaging of the sternoclavicular joint has since been replaced by computed tomography. Indications Sternoclavicular joint radiographs are performed for a variety of indications inclu...
Article

Sternum (lateral view)

The lateral sternum view a radiographic investigation of the entire length of the sternum in profile. The view is used to query fractures or infection 1. Patient position patient is erect with the left or right side of the thorax adjacent to the image receptor patient's hands are behind their...
Article

Sternum (oblique view)

The oblique sternum view a radiographic investigation of the entire sternum often complimenting the lateral sternum projection. The view is used to query fractures or infection 1. Patient position the patient is RAO facing the upright detector; the projection is performed RAO to project the st...
Article

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Our style guide is a set of guidelines to help authors write content in a uniform way. This has become increasingly important as the number of contributors has grown. Take a look through the guide and get involved at Radiopaedia.org. general overview of Radiopaedia.org what Radiopaedia.org IS ...
Article

Systematic radiographic technical evaluation (mnemonic)

Systematic radiographic technical evaluation is an important aspect to evaluative, effective radiography. It is the process of assessing a radiographic image to ensure it meets a high level of diagnostic standard. Two mnemonics are commonly used when assessing a radiographic image: PACEMAN IMA...
Article

Talonavicular coalition

Talonavicular coalition is one of the less common subtypes of tarsal coalition, the most commons being talocalcaneal coalition and calcaneonavicular coalition. As with other forms of coalition it can be osseous, cartilaginous or fibrous. Clinical presentation Uni-or bilateral. Most patients ar...
Article

Tangential views

Tangential views are useful to differentiate intracutaneous radiopaque particles in a tattoo from intraparenchymal microcalcifications. Mammographic findings close to the skin such as masses, microcalcifications, skin dimpling or shaded areas always pose a problem of differential diagnosis. Va...
Article

Tardus parvus

Tardus parvus refers to a pattern of Doppler ultrasound spectral waveform resulting from arterial stenosis. The phenomenon is observed downstream to the site of stenosis, and is due to reduced magnitude of blood flow through the narrowed vessel during ventricular systole 7. This characteristic ...
Article

Tc-99m sestamibi

Tc-99m sestamibi (also known as sesta-methoxyisobutylisonitrile) is one of the technetium radiopharmaceuticals.  Characteristics photon energy: 140 KeV physical half-life: 6 hours normal distribution: thyroid, parathyroid, heart (myocardium) excretion: hepatobiliary and renal target organ:...
Article

Temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is the most common type of partial epilepsy, with often characteristic imaging and clinical findings. It is divided into two broad groups: medial epilepsy most common involves the mesial temporal lobe structures most frequently due to mesial temporal sclerosis l...
Article

Temporomandibular joint (axiolateral view)

The axiolateral temporomandibular view allows for visualization of the articular tubercle, mandibular condyle and fossa and is thus useful to identify structural changes and displaced fractures, as well as assess excursion and joint spaces.  Clinical indications include trauma, the presence of ...
Article

Thermoluminescent dosimeter

Thermoluminescent dosimeter (TLD) is a passive radiation detection device that is used for personal dose monitoring or to measure patient dose.  Parts plastic holder nickel-coated aluminum card with TLD discs the discs are made of a thermoluminescent material, commonly calcium sulphate doped...
Article

Thoracic spine (AP view)

The thoracic spine AP view images the thoracic spine, which consists of twelve vertebrae. It is utilized in many imaging contexts including trauma, postoperatively, and for chronic conditions.  Patient position the patient is erect or supine, depending on clinical history ideally, spinal imag...
Article

Thoracic spine (lateral view)

The thoracic spine lateral view images the thoracic spine, which consists of twelve vertebrae. It is utilized in many imaging contexts including trauma, postoperatively, and for chronic conditions. It is used in conjunction with the thoracic spine AP view to complete a thoracic spine series.  P...
Article

Thoracic spine series

The thoracic spine series is comprised of two standard projections along with a range of additional projections depending on clinical indications. The series is often utilized in the context of trauma, postoperative imaging and for chronic conditions. Radiographs of the thoracic spine are consi...
Article

Thumb (AP/PA view)

The thumb AP (anteroposterior) view is one of the standard views for assessment of the thumb. The PA (posteroanterior) view can be utilized when the patient is unable to achieve the position required for the AP view.  They are one part of the three view thumb series. There will be some magnific...
Article

Thumb (lateral view)

The thumb lateral view is an orthogonal projection of AP/PA view and helps in the localization of a foreign body in the thenar eminence, as well as providing valuable information of suspected dislocations. Patient position patient is seated alongside the table the forearm is placed on table ...
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Thumb (oblique view)

The thumb oblique view is a part of the thumb series and is particularly useful in cases with traumatic indications. Patient position patient is seated alongside the table forearm is placed on table the wrist is kept in ulnar deviation and thumb abducted fingers are kept in contact with the...
Article

Thumb series

The thumb series is comprised of a posteroanterior, oblique, and lateral projection. The posteroanterior projection is interchangeably performed anterioposter or posteroanterior depending on mobility. It examines in detail the first metacarpal and its articulations. Thumbs have a vital impact in...
Article

Tibia and fibula series

The tibia/fibula is comprised of an anteroposterior (AP), and lateral radiograph. The series is often used in emergency departments to evaluate the entirety of the tibia and fibula after trauma.  Indications The tibia/fibula radiographs are performed for a variety of indications including: tr...
Article

Tibia fibula (AP view)

The tibia fibula AP view is part of a two view series of the entire tibia, fibula, and both the knee and ankle joint.  Patient position the patient may be supine or sitting upright with their leg straighten on the table the foot is in dorsiflexion the toes will be pointing directly toward th...
Article

Tibia fibula (lateral view)

The tibia fibula lateral view is part of a two view series of the entire tibia, fibula, and both the knee and ankle joint.  Patient position the patient is in a lateral recumbent position on the table the lateral aspect of the knee and ankle joint should be in contact with the table resulting...
Article

Toes (AP view)

Toes AP view is part of a three view toe series and includes the phalanges and the toe(s) of interest and the distal half of the associated metacarpals. Patient position the patient can be either supine or be sitting upright on the table knee should be flexed so the plantar surface of the foo...
Article

Toes (oblique view)

The toes medial oblique view is part of the toe series examining the phalange and metatarsals of the foot. Patient position the patient may be supine or upright depending on comfort the affected leg must be flexed enough that the plantar aspect of the foot is resting on the image receptor th...
Article

Toes series

The toes series is comprised of an AP, AP oblique, and a lateral projection. The series is often utilized in trauma situations. It examines the entirety of the proximal middle and distal phalanges of the foot.  Indications Toe radiographs are performed for a variety of indications including 1:...
Article

Toes (sesamoid view)

The sesamoid view of the toes is a specialed view examing the sesamoid bones of the first metatarsal. Patient position the patient may be supine or sitting upright with their leg straighten on the table the foot is in dorsiflexion the toes pulled back toward the patient  Technical factors ...
Article

Tracheal bifurcation angle

The tracheal bifurcation angle can have a wide range of normal values in patients and can vary significantly in serial radiographs. It is of poor diagnostic value due to the lack of sensitivity and specificity in identifying the underlying pathology.  Terminology The interbronchial angle is th...
Article

Transcranial Doppler sonography (ultrasound)

Transcranial​ ​Doppler​ ​(TCD)​, also known as transcranial color-coded duplex sonography (TCCS) is a sonographic study of intracranial structures and blood vessels, used most commonly to identify the hemodynamic state present in the vertebrobasilar circulation and the circle of Willis.  Termin...
Article

Transesophageal echocardiography

A standard transesophageal echocardiography (TOE, or TEE in US English) is a type of ultrasound using an endoscopic transducer, which is advanced into the esophagus, offering generally superior visualization of the great vessels and posterior cardiac structures than the standard transthoracic ap...
Article

Triple-rule-out CT

Triple-rule-out CT (TRO CT) angiography may be ordered in the setting of acute chest pain to examine the thoracic aorta and the coronary and pulmonary arteries. The protocol helps exclude life-threatening causes of acute chest pain, especially if atypical, or if alternative causes to acute coron...
Article

Tucked CC views

In the standard CC views posterior tissue may be excluded from the field of view, due to the anatomical attachment to the chest wall restricting mobility of breast tissues. The tucks CC views are useful to depict lesions deep in the posterior portion of the breast, located between 10 and 2 o'clo...
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Upper limb radiography

Upper limb radiography is the radiological investigation of the shoulder girdle, humerus, ulna, radius, carpals and metacarpals of the hand. It is often utilized in the context of trauma to rule out fractures and dislocations. 
Article

Upper limb radiography (pediatric)

Upper limb radiography involves plain film imaging of the shoulder, humerus, ulna, radius, metacarpals and carpal bones in pediatric patients. Depending on the patients' age, the difficulty of the examination will vary, often requiring a specialist trained radiographer familiar with a variety of...
Article

Urinary system imaging (dual energy CT)

Dual-energy CT has a number of clinical applications in the assessment of the urinary system particularly in the realm of artefact reduction and material composition Renal stone composition Renal calculi are composed of different substances such as uric acid, calcium phosphate, calcium oxalate...
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Vascular imaging (dual energy CT)

Dual-energy CT has a variety of clinical applications in vascular imaging, due to the utilization of material decomposition and the ability to reconstruct images at a variety of energy levels. Clinical applications High kVp CT scans have lower contrast than that of lower kVp due to the K-edge ...
Article

Virtual non-contrast imaging

Virtual non-contrast imaging is an image post-processing technique used to create 'non-contrast' images of contrast-enhanced scans via the subtraction of iodine. It is an imaging technique unique to dual energy CT. Clinical applications Virtual non-contrast imaging has the potential to replac...
Article

V/Q scan

V/Q (ventilation/perfusion) scan is a scintigraphic examination of the lung that evaluates pulmonary vasculature perfusion and segmental bronchoalveolar tree ventilation. Indications diagnosis of suspected pulmonary embolism monitor pulmonary function following lung transplant provide preope...
Article

Windowing (CT)

Windowing, also known as grey-level mapping, contrast stretching, histogram modification or contrast enhancement is the process in which the CT image greyscale component of an image is manipulated via the CT numbers; doing this will change the appearance of the picture to highlight particular st...
Article

World Radiography Day

World Radiography Day (WRD) is an annual event held on November 8th to celebrate the anniversary of the discovery of x-rays by Wilhelm Roentgen, and is organized by the International Society of Radiographers and Radiological Technologists (ISRRT) 1. World Radiography Day occurs simultaneously w...
Article

Wrist (carpal bridge view)

The carpal bridge view an additional view to the three view series of the wrist and carpal bones. It is used to assess the dorsal aspect of the scaphoid, lunate and the triquetrum. Patient position the patient is seated alongside the table dorsal aspect of affected wrist is placed on the dete...
Article

Wrist (carpal tunnel view)

The carpal tunnel view is an axial projection to demonstrate the medial and lateral prominences and the concavity. It can be utilized to investigate potential hook of hamate, pisiform and trapezium factures. Patient position patient stands with the back facing the table palmar surface of hand...
Article

Wrist (clenched fist view)

The clenched fist view is an additional projection used to evaluate suspected widening of the scapholunate interval, often performed bilaterally it is a functional view that requires the patient to clench both hands.  Patient position patient is seated in front of the table  both hands are pl...
Article

Wrist (horizontal beam lateral view)

The horizontal beam lateral wrist view is a modified lateral projection when performing the three view series of the wrist and carpal bones in trauma. It is the orthogonal projection of the PA wrist without any patient movement, making it the most appropriate projection for patients in pain. Pa...
Article

Wrist (lateral view)

The lateral wrist view is part of a three view series of the wrist and carpal bones. It is the orthogonal projection of the PA wrist. Patient position patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and wrist can rest on the table abduct the hum...
Article

Wrist (oblique view)

The oblique wrist view is part of a three view series of the wrist and carpal bones. It is not generally performed in follow-up studies unless specifically requested. Patient position patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and wrist can ...
Article

Wrist (PA view)

The PA wrist view is part of a three view series of the wrist and carpal bones. Although performed PA the view can often be referred to an AP view. Patient position patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and wrist can rest on the table ...
Article

Wrist (radial deviation view)

The wrist PA radial deviation view is specialized projection employed to better demonstrate the carpal bones that lay on the ulnar aspect of the wrist. Patient position patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and wrist can rest on the tab...
Article

Wrist radiograph

Wrist radiographs are ubiquitous in the emergency departments. They are commonly performed in the pediatric and elderly populations after a fall on an outstretched hand as well as in patients after higher force trauma. Moreover, they may be performed as part of a skeletal survey looking for meta...
Article

Wrist series

The wrist series is comprised of a posteroanterior, oblique, and lateral projection. The series examines the carpal bones that are consisting of the scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate and hamate. It also examines the radiocarpal and distal radiocarpal joint al...
Article

XCCL view

An XCCL view is a supplementary mammographic view. It is a type of exaggerated cranio-caudal view. It is particularly good for imaging the lateral aspect of the breast.  It is often done when a lesion is suspected on a MLO view but cannot be seen on the CC view. In this view, the lateral aspect...
Article

XCCM view

An XCCM view is a supplementary mammographic view. It is a type of exaggerated cranio-caudal view. It is particularly good for imaging the medial portion of the breast. In this view, the medial portion of the breast is placed forward. A negative 15° tube tilt is suggested. An optimal XCCM view ...
Article

Xenon-127

Xenon-127 is a radiopharmaceutical principally used when a performing VQ scan. It is not a widely used alternative to xenon-133 with the main advantage being a higher proton energy allowing for post perfusion scanning.  photon energy: 203 KeV physical half life: 36.3 days
Article

X-ray artifacts

X-ray artifacts can present in a variety of ways including abnormal shadows noted on a radiograph or degraded image quality, and have been produced by artificial means from hardware failure, operator error and software (post-processing) artifacts.  There are common and distinct artifacts for fi...

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