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.

Create new article

470 results found

Skull (lateral view)

The skull lateral view is a non-angled lateral radiograph of the skull. This view provides an overview of the entire skull rather than attempting to highlight any one region. Indications This projection is used to evaluate for skull fractures, in addition to neoplastic changes and Paget diseas...

Skull (AP view)

The skull anteroposterior (AP) view is a non-angled radiograph of the skull. This view provides an overview of the entire skull rather than attempting to highlight any one region. Indications This examination is able to assess for medial and lateral displacements of skull fractures, in additio...

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. Indications This projection is often done as a series, it is useful to demonstrate the greater tub...

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. Indications This projection shows the lesser tubercle of the humerus in profile and can be used t...

Skull (PA view)

The skull posteroanterior (PA) view is a non-angled radiograph of the skull. This view provides an overview of the entire skull rather than attempting to highlight any one region. Indications This examination is able to assess for medial and lateral displacements of skull fractures, in additio...

Anatomical position

The anatomical position, also known as standard anatomical position, is the consistent position of the human body in which positional reference is made for anatomical nomenclature. It is not reliant on whether the patient is standing, supine, prone, sitting, etc. The position is defined as if t...

Temporal bone (modified Stenvers view)

The modified Stenvers view is an oblique radiographic projection used to demonstrate the petrous temporal bone, internal acoustic meatus and bony labyrinth. It is performed as a posteroanterior (PA) projection to minimize radiation to the orbits. This view has succeeded the Stenvers view, which ...

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...

Developer solution

Developer solution is used in the darkroom for developing (i.e. converting latent image to visible image) x-ray films used in conventional (screen film) radiography. Components developer: hydroquinone (for high contrast) + Metol or phenidone (for low contrast) the developer itself gets oxidis...

Cassette

Cassettes are rigid holders used in conventional and computed radiography (CR) for the screen film system and imaging plate respectively. The back side of the cassette has rubber or felt for adequate contact between the screen film system or with the imaging plate. The front of the cassette is...

Pöschl projection

Pöschl projection is used in imaging the temporal bone. The plane of projection is perpendicular to the long axis of the temporal bone. In the Pöschl projection the temporal bone is imaged from its anteromedial to posterolateral aspects. See also Stenvers view

Peroral pneumocolon

Peroral pneumocolon is a technique that can be used during a small bowel follow through (SBFT) to better visualize the ascending colon and terminal ileum. Procedure The goal of a peroral pneumocolon is to create a double contrast study (oral contrast and gas) of the ascending colon and termina...

Shoulder (AP glenoid view)

The shoulder AP glenoid view also known as a true AP or 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. Indications The glenoid view is an ideal projection to inspect the glenoid rim, the g...

Skull (Caldwell view)

The Caldwell view is a caudally angled radiograph, with its posteroanterior projection allowing for minimal radiation to the orbits. This view may be used in imaging of the skull or facial bones depending on the clinical indications. Indications This view aids in visualizing the paranasal sinu...

Elbow (supracondylar AP view)

AP view for supracondylar aspect of humerus may be taken to look for supracondylar fracture. Patient position patient stands facing the x-ray tube with the posterior aspect of arm in contact with cassette (placed on a vertical stand) X-ray beam features a horizontal beam is employed centere...

Humerus (AP view)

The AP view of the humerus is part of the humerus series and is usually taken in a standing position. However, it can also be obtained in a supine position. The projection demonstrates the humerus in its natural anatomical position allowing for adequate radiographic examination of the entire hu...

Humeral neck (AP view)

AP view for neck of humerus is taken to look for fracture in the neck of humerus. Patient position patient can stand or lay down facing the X-ray tube the dorsal aspect of shoulder of the affected side is kept in contact with the cassette (placed on a vertical stand) X-ray beam features a ...

General radiography article structure

There are two main types of general radiography articles that require a different set of subheadings as the usual epidemiology, clinical presentation, pathology, etc. are not relevant. Radiographic series These articles describe the set of projections that make up a series that might be reques...

Scaphoid series

The scaphoid series is comprised of posteroanterior, oblique, lateral and angled posteroanterior projections. The series examines the carpal bones focussed mainly on the scaphoid. It also examines the radiocarpal and distal radioulnar joints along with the distal radius and ulna. Scaphoid fractu...

Dual energy CT

Dual energy CT, also known as spectral CT, is a computed tomography technique that uses two separate x-ray photon energy spectra, allowing the interrogation of materials that have different attenuation properties at different energies. Whereas conventional single energy CT produces a single imag...

Humerus series

The humerus series is usually used for the detection of traumatic injury to the shaft of the humerus. Indications Humerus radiographs are performed for a variety of indications including: trauma bony tenderness at the glenohumeral joint/region restriction of abduction suspected disloca...

Elbow (lateral view)

The lateral elbow view is part of the two view elbow series, examining the distal humerus, proximal radius and ulna. It is deceptively one of the more technically demanding projections in radiography 1-3. The projection is the orthogonal view of the AP elbow allowing for examination of the ulna...

Elbow (AP view)

The elbow AP view is part of the two view elbow series, examining the distal humerus, proximal radius and ulna. The projection demonstrates the elbow joint in its natural anatomical position allowing for adequate radiographic examination of the articulations of the elbow including the radiohum...

Elbow series

The elbow series is a set of radiographs taken to investigate elbow joint pathology, often in the context of trauma. It usually comprises an AP and lateral projection, although other non-standard, modified projections are utilized for specific indications. Indications Elbow x-rays are indicate...

Forearm (lateral view)

Forearm lateral view is one of two standard projections in the forearm series to assess the radius and ulna. Indications This view allows for the assessment of suspected dislocations or fractures and localizing foreign bodies within the forearm. Patient position patient is seated alongside t...

Forearm (AP view)

The forearm AP view is one of two standard projections in the forearm series to assess the radius and ulna. Indications This view demonstrates the elbow joint in its natural anatomical position allowing for assessment of suspected dislocations or fractures and localizing foreign bodies within ...

Forearm series

The forearm series is comprised of an anteroposterior and lateral projection. The series examines the entire radius and ulna including articulations distally and proximal. Typically requested for midshaft injuries, the forearm series is not a 'two-for-one' projection of the wrist and the elbow j...

Temporal bone (Stenvers view)

Stenvers view is an oblique radiographic projection used to demonstrate the petrous temporal bone, internal acoustic meatus, 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 electrod...

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. Indications The lateral wrist radiograph is requested for myriad reasons including but not limited to trauma, suspected infective processes, injuries the distal...

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. Indications The PA wrist radiograph is requested for myriad reasons including but not limited to trauma, suspected infective processes, injuries t...

Scaphoid (lateral view)

The scaphoid lateral view is part of a four view series of the scaphoid, wrist and surrounding carpal bones. It is a complementary projection to the PA view demonstrating the scaphoid in the orthogonal plane. Patient position patient is seated alongside the table the affected arm if possible ...

Scaphoid (PA ulnar deviation view)

The posteroanterior ulnar deviation scaphoid view is part of a four view series of the scaphoid, wrist and surrounding carpal bones. Although performed PA, the view can often be referred to as an AP view. The view is performed with the wrist in ulnar deviation to free the scaphoid from bony supe...

Digital radiography

Digital radiography is based on the use of discrete values in comparison to conventional radiography which uses analog/continuous values. It removes the requirement of dark room procedures. Digital radiography does not use cassettes. It uses direct or indirect flat panel detectors or charge cou...

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 radioulnar joint alo...

Thumb (lateral view)

The thumb lateral view is an orthogonal projection of AP/PA view. Indications As with all thumb radiographs, this is a view requested for a number of reasons including trauma, suspected inflammatory process or foreign body (to name a few). This particular view helps in the localization of a fo...

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 magnifica...

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...

Fingers (lateral view)

Finger lateral view is a standard projection for radiographic assessment of the fingers; it is one of three views of the finger series. it is divided into: lateral index and middle fingers lateral of ring and little fingers Indications The lateral projection is an ideal projection to assess ...

Finger (PA view)

Finger PA view is a standard projection for radiographic assessment of the fingers; it is one of three views of the finger series. Indications This projection is best to access the joint spaces and distal, middle and proximal phalanx in the AP plane. It is not advisable to only obtain one vie...

Finger series

The finger series is comprised, conventionally of a posteroanterior, oblique and a lateral view. The series examines in detail the distal, middle and proximal phalanx as well as the interphalangeal, metacarpophalangeal and carpometacarpal joints. Note: the thumb (first digit) reviewed under th...

Hand (ball-catcher view)

The ball-catcher view, Nørgaard projection, or posterior oblique view of both hands is an additional projection of the routine hand series. Indications The ball-catcher view is typically undertaken to assess for erosive arthropathies such as rheumatoid arthritis. It often complements the bilat...

Hand (lateral view)

The lateral hand view is an orthogonal view taken along with the PA view of the hand. Indications The lateral hand view is requested for diagnosing a variety of clinical indications such as rheumatoid arthritis, osteoarthritis, suspected fracture or dislocation and localizing foreign bodies. ...

Hand (bilateral PA view)

The bilateral PA view is merely a single film that includes both hands, side by side. Indications This view often complements the ball-catcher view and is performed almost exclusively to examine for evidence of rheumatological disorders (e.g. rheumatoid arthritis, osteoarthritis, psoriatic ar...

Hand (oblique view)

The hand oblique view is part of a two view series metacarpals, phalanges, carpal bones and distal radial ulnar joint. Indications The oblique hand view is requested for diagnosing a variety of clinical indications such as rheumatoid arthritis, osteoarthritis, suspected fracture or dislocatio...

Hand (PA view)

The Hand PA view is part of a two view series metacarpals, phalanges, carpal bones and distal radial ulnar joint. Indications The PA hand view is requested for diagnosing a variety of clinical indications such as rheumatoid arthritis, osteoarthritis, suspected fracture or dislocation and loca...

Hand series

The hand series consists of posteroanterior, oblique, and lateral projections. Although additional radiographs can be taken for specific indications. The series primarily examines the radiocarpal and distal radioulnar joints, the carpals, metacarpals, and phalanges. Indications Hand x-rays ar...

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.

Radiographic positioning terminology

Radiographic positioning terminology is used routinely to describe the position of the patient for taking various radiographs. Standard nomenclature is employed with respect to the anatomic position. Terminology Basic terms of relations anterior is towards the front of the body (Latin: before...

Ankle radiograph (an approach)

Ankle radiographs are frequently performed in emergency departments, usually, after trauma, the radiographic series is comprised of three views: an anteroposterior, mortise, and a lateral. They may be performed to assess degenerative or inflammatory arthritis as well as to look for the sequela o...

Wrist radiograph

Wrist radiographs are ubiquitous in 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 metaboli...

Inferomedial superolateral oblique projection

Inferomedial superolateral oblique projection is useful for stereotactic biopsy positioning. This projection allows access to the inferior aspect of the breast to achieve shortest skin to abnormality distance. It is also useful in the nonconforming patient. Technique Rotate C arm to about 125°...

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...

Caudal cranial projection

Caudal cranial projection is an additional trouble shooting view. Technique invert the C arm as for a CC projection step the patient forward and have her bend excessively forward at the waist to ensure that the abdomen does not encroach in the x ray field place the image receptor above the b...

Elevated craniocaudal projection

Elevated craniocaudal projection is an additional trouble shooting view. Technique direct beam superiorly to inferiroly face patient towards unit, feet forward lean patient inward, relaxing the shoulders bring inferior aspect of breast onto the image receptor pull breast outward and forwar...

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 artifact or a true mass and for precisely localizing t...

Lateral view

The lateral view is an additional view obtained at virtually every diagnostic evaluation. A lateral view may be obtained as a mediolateral view (ML) or lateromedial view (LM) view depending on where the imaging tube and detector are located. Technique for an ML view, the tube emitting the x-ra...

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...

Pediatric hip (frog leg lateral view)

The frog leg lateral view is a special radiograph of the pelvis to evaluate the hip. Some departments will perform this routinely instead of the AP pelvis view to reduce exposure and maintain high diagnostic accuracy 1. Indications Bilateral examination allows for better visualization of the ...

Foot (weight-bearing lateral view)

The weight-bearing lateral foot radiograph is important in the assessment of foot alignment and the diagnosis of abnormalities that cause malalignment and foot pain. Nonweightbearing views (e.g. lateral foot) would be inadequate for the assessment of alignment as the bones of the feet are not in...

Foot (weight-bearing dorsoplantar view)

The weight-bearing dorsoplantar foot radiograph is a specialized projection of the foot. Nonweightbearing views (e.g. DP foot) are inadequate for the assessment of alignment because the bones of the feet are not in a functional position. Indications This view is key to the assessment of foot a...

Osteonecrosis of the humeral head

Osteonecrosis of the humeral head, also known as Haas disease, is considered the second most common location for osteonecrosis (following the hip). Clinical presentation Insidious onset of pain poorly localized and usually severe night and rest. The range of motion is initially preserved. In ...

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...

Bullseye view

The bullseye view is designed for better evaluation of lesion located in retroareolar area. In this view, the nipple-areola complex are directed upward or downward on the detector surface to visualize the areolar and periareolar region en face, allowing characterization of lesions in this area.

Rolled CC view

Given that the rolled projections can be performed from any standard projection, the most commonly used is certainly the cranio-caudal one. A rolled CC view It's performed to locate a lesion only visible in the cranio-caudal view, or when overlapped tissues in the standard view can simulate or...

Maquet view

A maquet view is a type of radiographic projection of the lower limbs. They are a well established method of determining the axial alignment of the lower limb in the coronal plane and are of particular use in assessment of total knee replacements. Radiographic assessment Construct the weight ...

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 ...

Craniocaudal view

The craniocaudal view (CC view), along with the MLO view, is one of the two standard projections in a screening mammography. It must show the medial part as well as the external lateral portion of the breast as much as possible. A correctly performed CC projection may show the pectoral muscle o...

Magnification view (mammography)

A magnification view in mammography is performed to evaluate and count microcalcifications and its extension (as well the assessment of the borders and the tissue structures of a suspicious area or a mass) by using a magnification device which brings the breast away from the film plate and close...

Axillary view

An axillary view (also known as a "Cleopatra view“) is a type of supplementary mammographic view. It is an exaggerated craniocaudal view for better imaging of the lateral portion of the breast to the axillary tail. This projection is performed whenever we want to show a lesion seen only in the a...

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...

Mediolateral view

The mediolateral (ML) view is a supplementary mammographic view and shows less breast tissue and pectoral muscle than the mediolateral oblique view (MLO view). Technique The tube is rotated 90 degrees and the lateral aspect of the chest wall is along the bucky edge. The height is at the level ...

Cleavage view

A cleavage view (also called "valley view") is a mammogram view that depicts the posteromedial portion of both breasts (the “valley” between the two breasts) by placing them on the cassette at the same time and pulling them anteriorly. Manual technical factors should be used. A cleavage view ...

Contrast media extravasation

Contrast media extravasation (CMEV) refers to the leakage of intravenously-administered contrast media from the normal intravascular compartment into surrounding soft tissues; it is a well-known complication of contrast-enhanced CT. It can also occur in MRI, but the complications are rare given ...

Tc-99m sestamibi

Tc-99m sestamibi (sestamibi is a shortening of sesta-methoxyisobutylisonitrile) is one of the technetium radiopharmaceuticals. Characteristics photon energy: 140 KeV physical half-life: 6 hours lipophilic cation normal distribution: thyroid, parathyroid, heart (myocardium) e...

Modulation transfer function

The modulation transfer function (MTF) describes the ability of a detector to retain the contrast of an object. It measures how much spatial frequency is transferred from the object to an image 8. MTF = output signal amplitude / input signal amplitude Discussion On the radiogram, objects havi...

Double spot compression view

A double spot compression view is obtained by focal compression of both sides of the breast to produce higher spatial and contrast resolution. This is made possible due to the increased amount of breast thinning and a significant decreased incidence of blurring because of decreased exposure time...

Contrast-enhanced mammography

There are 2 types of contrast-enhanced mammography examination – temporal subtraction and dual-energy. Initial work in the early 2000s used temporal subtraction, but artefacts due to patient movement during prolonged compression limited its diagnostic usefulness. Travieso et al produced a usef...

Reversed CC view

The reversed CC view is an additional view. It is useful for the study of breasts with surgical scars in the lower quadrants. The ability to see the scar through the compressor paddle offers to the mammographer the possibility to flatten it properly, reducing the formation of scar folds as well ...

Late mediolateral view

A late mediolateral projection is an additional view that can be used whenever,in the presence of rounded calcifications of probable intracystic nature, the standard ML view does not allow the recognition of the characteristic tea cups appearance due to the density of milk of calcium. A second ...

Eklund technique

Eklund modified compression technique is a technique which can be used for patients with augmented or reconstructed breasts post mastectomy. Technique It consists of posterosuperior displacement of the implants simultaneously to an anterior traction of the breast, pushing the implants towards...

Lateromedial oblique view

A lateral-medial oblique (LMO) view is a type of supplementary mammographic view. The advantage of performing the lateromedial view is to depict lesions located far medio-posteriorly visible on the CC view only, or to depict palpable lesions in the inner quadrant not seen on mammography. This...

Mediolateral oblique view

The mediolateral oblique (MLO) view is one of the two standard mammographic views, alongside the craniocaudal (CC) view. It is the most important projection as it allows depiction of most breast tissue. Adequacy The representation of the pectoral muscle on the MLO view is a key component in...

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...

Frontal oblique approach mammography

Background Mammographic technique is very important to obtain diagnostic mammograms, to reduce the number of false negatives and to increase the sensitivity of the procedure. As widely noted in literature, most breast pathology occurs in the upper outer quadrant and is very important that this ...

Digital breast tomosynthesis

Digital breast tomosynthesis (DBT) is an imaging technique that allows a volumetric reconstruction of the whole breast from a finite number of low-dose two-dimensional projections obtained by different X-ray tube angles, with a geometric principle very similar to that applied in stratigraphic te...

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...

Lateromedial view

The lateromedial view (or LM view) is a supplementary mammographic view where the bucky is placed up against the sternum and the and film is taken in a true lateral projection. This view allows the medial breast to be closest to the film. This view allows the medial breast to be more carefully e...

Mammography views

There are numerous mammography views that can broadly be split into two groups standard views supplementary views - additional information or problem solving Standard views Standard views are bilateral craniocaudal (CC) and mediolateral oblique (MLO) views, which comprise routine screening ...

Chest radiograph

The chest radiograph (also known as the chest x-ray or CXR) is anecdotally thought to be the most frequently-performed radiological investigation globally although no published data is known to corroborate this. UK government statistical data from the NHS in England and Wales shows that the ches...

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...

Whole-body CT (protocol)

CT polytrauma/multitrauma, also called trauma CT, whole body CT (WBCT) or panscan, is an increasingly used investigation in patients with multiple injuries sustained after significant trauma. The majority of the evidence regarding whole-body CT is, understandably, retrospective. There is some e...

Bone scintigraphy

Bone scintigraphy (a.k.a. bone scans) is a nuclear medicine (scintigraphic) study that makes use of technetium-99m (commonly Tc-99m-methylene diphosphonate (MDP)) as the active agent 2. About 50% of the injected dose will be absorbed by the bones after 2 to 6 hours 2. The study has three phases...

MRI pulse sequence abbreviations

This article contains a list of commonly and less commonly used MRI pulse sequence abbreviations and their meaning. If available, an explanation is included in a separate article. image weighting T1 T2 T2*: T2 star PD: proton density DWI: diffusion-weighted imaging and ADC: apparent diff...

Filtered (1)Done (clear)

+Systems

×Article Sections

+Sort By

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

Unable to process the form. Check for errors and try again.

Thank you for updating your details.