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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.

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Elbow (external oblique view)

The elbow external oblique view is an additional projection of the elbow often used to better demonstrate the radial head free from superposition. Patient position patient is seated alongside the table the fully extended arm and forearm, in a supinated position, are kept in contact with the t...

Elbow (inferosuperior view)

The inferior-superior elbow view is a modified elbow projection for patients in acute flexion greater than 90 degrees, it is also an additional projection to better demonstrate the olecranon process.It is comprised of two views demonstrating the distal humerus and proximal forearm structures Pa...

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 (medial oblique view)

The elbow medial oblique view is a specialized projection, utilized to demonstrate both the coronoid process in profile and the olecranon process sitting within the olecranon fossa of the humerus. Patient position the patient is seated alongside the table fully extended arm and forearm, in a ...

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...

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...

Endovascular aneurysm sealing system (EVAS)

Endovascular aneurysm sealing system (EVAS) was developed with the intention to expand beyond the anatomic limitations of endovascular aneurysm repair (EVAR) devices, as well as to decrease the rates of re-intervention secondary to graft migration and type II endoleaks. EVAS was designed by End...

Facial bones (reverse Waters)

The acanthioparietal or reverse water's view modified Water's view used in trauma. 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 sensitive CT scans. Patient position the ...

Femoral torsion analysis

Femoral torsion analysis is used to assess the alignment of a femur post surgery. If one side has been operated on it can be compared to the non-operated side. Method Superimpose axial images of: femoral heads the neck of femurs femoral condyles Draw a line from the center of the femoral h...

Finger (oblique view)

Finger oblique view is a standard projection for radiographic assessment of the fingers. It is not required for follow-up studies for 'query Foreign Body' unless specifically requested. Patient position patient is seated alongside the table (similar to a projection of hand) from a pronated po...

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. Patient position patient is seated alongside the table (similar to the projection of hand) palmar aspect of pronated hand is placed over detector and extended fi...

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...

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 Patient position Lateral of index and middle fingers patient seated...

Flat panel CT

Flat panel computed tomography (FPCT), otherwise, know as flat panel volume tomography are multidetector computed tomography scanners that utilize a large area detector rather than a fixed array of detectors 1,3. Flat panels have a significantly wider z-axis area coverage that can cover larger ...

Foot (dorsoplantar view)

The dorsoplantar view is part of a three view series examining the phalanges, metatarsals and tarsal bones that make up 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 o...

Foot (lateral view)

The lateral projection is part of the three view series examining the phalanges, metatarsals and tarsal bones that make up the foot. The lateral projection additionally examines the talocrural joint. Patient position the patient may be supine or upright depending on comfort the affected le...

Foot (medial oblique view)

The medial oblique projection is part of the three view series examining the phalanges, metatarsals and tarsal bones that make up 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...

Foot series

The foot series is comprised of a dorsoplantar (DP), medial oblique, and a lateral projection. The series is often utilized in emergency departments after trauma or sports related injuries 2,4. See: approach to foot series. Indications Foot radiographs are performed for a variety of indicatio...

Foot (weightbearing dorsiplantar view)

The weightbearing dorsiplantar foot radiograph is a specialized projection of the foot. It is key to the assessment of foot alignment and the diagnosis of abnormalities that cause malalignment and foot pain. Nonweightbearing views (e.g. DP foot) are inadequate for the assessment of alignment be...

Foot (weightbearing lateral)

The weightbearing 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. oblique foot radiograph) are inadequate for the assessment of alignment because the bones of the feet ...

Forearm (AP view)

Forearm AP view is a standard projection to assess radius and ulna. Patient position patient is seated alongside the table forearm is supinated, and its dorsal surface is kept in contact with the cassette with extension at the elbow joint both elbow joint and wrist joints are also kept in co...

Forearm (lateral view)

Forearm lateral view is a standard projection to assess radius and ulna. Patient position patient is seated alongside the table elbow is flexed to 90 degrees and the medial aspect of the wrist, forearm and elbow joint are placed in contact with the detector shoulder, elbow and wrist should b...

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 mid shaft injuries, the forearm series is not a 'two-for-one' projection of the wrist and the elbow ...

Fowler-Philip angle

The Fowler-Philip angle reflects the relation of the inferior calcaneus to the posterior calcaneus. Measurement It is an angle measured on the lateral view of a loaded foot; formed between 2 lines: a line tangent to the posterosuperior border of the calcaneus and the calcaneal tuberosity. a ...

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 ...

Gage sign

Gage sign is a V-shaped lucent defect at the lateral portion of the epiphysis and/or adjacent metaphysis. It is pathognomonic for Legg-Calve-Perthes disease. It may occur early in the disease and is one of the five indicators of a worse prognosis, which are: Gage sign calcification lateral t...

General radiography curriculum

The general radiography section covers in detail the various clinical presentations that require specific plain radiographic investigation, the anatomy covered, and how it is displayed via the chosen view. It outlines standard and modified radiographic technique to accommodate for a wide range o...

Grid cutoff

Grid cutoff is an unwanted absorption of x-rays via an x-ray grid, observed when a grid is employed incorrectly, most often seen with parallel grids. The term cutoff stems from the phenomenon in which the primary x-ray beam is 'cut off' by grid lines, leading to an overall decrease in optical de...

Gymnast wrist

Gymnast wrist is a term that used to describe variety of chronic overuse injuries of the wrist in gymnasts with immature skeleton. Gymnast wrist is a combined of osseous and ligamentous injury and usually manifests as a chronic Salter-Harris type I fracture of the distal radial physis on radiogr...

Hand (ball-catcher view)

The Nørgaard projection is also known as the ball-catcher view or posterior oblique view of both hands. It is an additional projection of the routine hand series. The ball-catcher view is often done to investigate signs of rheumatoid arthritis. Patient position patient may be seated alongside...

Hand (bilateral PA view)

The bilateral PA view often compliments the ball-catcher view. It is often done to investigate signs of rheumatoid arthritis and osteoarthritis. Patient position patient may be seated alongside or facing the table both hands are pronated with their palmer surfaces placed on the detector Tec...

Hand (lateral view)

The lateral hand view is an orthogonal view taken along with the PA view of the hand. Often an additional projection, the lateral view is used primarily to assess for foreign bodies and/or displacement of fractures/dislocations. Patient position patient is seated alongside the table hand is e...

Hand (oblique view)

The hand oblique view is part of a two view series metacarpals, phalanges, carpal bones and distal radial ulnar joint. Patient position patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and hand can rest on the table the hand is rotated externall...

Hand (PA view)

The Hand PA view is part of a two view series metacarpals, phalanges, carpal bones and distal radial ulnar joint. Patient position patient is seated alongside the table the affected arm if possible is flexed at 90° so the arm and hand can rest on the table the affected hand is placed, palm ...

Hand series

The hand series consists of a posteroanterior and oblique projection, 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 are indicate...

Hip (AP view)

The AP hip is part of a radiographic series examining the anatomy of the hip joint and proximal femur. Patient position patient is supine lower limbs are internally rotated 15-25° from the hip (do not attempt this if a fracture is suspected) Technical factors AP projection centring point ...

Hip (Clements-Nakayama view)

The Clements-Nakayama view of the hip is a highly specialized lateral projection utilized on patients with bilateral femoral fractures, or patients unable to mobilize due to postoperative requirements. When performed correctly the projection can yield images of a high diagnostic quality comparab...

Hip (Dunn view)

The Dunn view is a radiographic projection of the hip that demonstrates and examines the hip joint, femoral head, acetabulum, and particularly the relationship of the femoral head and acetabulum. The Dunn view is the preferred projection to aid and diagnose femoroacetabular impingement (FAI) du...

Hip (frog leg lateral view)

The frog leg lateral view is a special radiographic of the pelvis to evaluate the hip. Bilateral examination allows for better visualization of the hip joints and femoral neck, and therefore is an important view in the assessment of: slipped capital femoral epiphysis Perthes disease Patient ...

Hip (horizontal beam lateral view)

The horizontal beam lateral hip radiograph or shoot through hip is the in the purist terms the orthogonal view of the neck of the femur to the AP projection 1,3. The projection is used to assess the neck of the femur in profile during the investigation of a suspected neck of femur fracture 2. ...

Hip (Von Rosen view)

The Von Rosen view is a radiographic projection of the hip that demonstrates the relationship between the femoral head and the acetabulum. The von Rosen view is used in the diagnosis of developmental dysplasia of the hip in pediatric patients. This view forces dislocation of the affected hip(s)...

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 ...

Humerus (AP view)

AP view of the humerus is part of the humerus series and is usually taken in 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 humerus ...

Humerus (lateral view)

Lateral view of the humerus is part of the humerus series and is usually taken in standing position. However, it can also be taken in the supine position. The projection demonstrates the humerus in the lateral position allowing for adequate radiographic examination of the entire humerus and its...

Humerus radiographic series

The humerus series is comprised of an AP and lateral radiograph, utilized primarily in trauma, but also in the evaluation of bone tumors. Indications trauma: fracture neck of humerus / shaft of humerus fractures bone tumor detection Projections The two standard projections allows two views ...

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...

Humerus (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 centred...

Iliofemoral line

The Iliofemoral line is traced on an AP pelvis projection. It is a curvilinear line, along the outer surface of the ilium, through the superior acetabular rim and the femoral neck. It should be bilaterally symmetrical. Asymmetry may be the result of congenital dysplasia, slipped femoral capital...

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°...

Intercristal line

The intercristal line (also known as Jacobys’s Line or Tuffier’s Line) is a horizontal line drawn across the highest points of both the iliac crests in an anteroposterior (AP) lumbar radiography 1,2 Intercristal line most often intersects the body of the L4 or its inferior endplate in men and t...

Intraosseous pseudomeningocele

An intraosseous pseudomeningocele is an intradiploic CSF collection communicating with the subarachnoid space. Epidemiology Intraosseous pseudomeningoceles are rare sequelae of a skull fractures of traumatic or iatrogenic ethology occurring in infants and young children. They can be seen in an...

Iodinated contrast-induced thyrotoxicosis

Iodinated contrast-induced thyrotoxicosis is rare and may occur in patients with pre-existing thyroid disease and through complications of thyrotoxicosis (e.g. cardiac arrhythmia) may be fatal. Patients with a normal thyroid gland are unaffected. Patients with existing thyrotoxicosis should no...

Iodinated contrast media

Iodinated contrast media are contrast agents that contain iodine atoms used for x-ray-based imaging modalities such as computed tomography (CT), although they are also used in fluoroscopy, angiography and venography, and even occasionally, plain radiography. Although the intravenous route of adm...

Iterative reconstruction (CT)

Iterative reconstruction refers to an image reconstruction algorithm used in CT that begins with an image assumption, and compares it to real time measured values while making constant adjustments until the two are in agreement. Computer technology limited early scanners in their ability to per...

Knee (AP view)

The Knee AP view is a standard projection to assess the knee joint, distal femur, proximal tibia and fibula and the patella. Patient position patient is supine on the table with the knee and ankle joint in contact with the table leg is extended ensure the knee is not rotated Technical fact...

Knee (AP weight-bearing view)

The Knee AP weight-bearing view is a specialized projection to assess the knee joint, distal femur, proximal tibia and fibula and the patella. Often used in the context of orthopedic appointments to obtain images of the knees in their natural anatomical position. This view is often used to ass...

Knee (Beclere method intercondylar view)

The Beclere method intercondylar view is an additional projection of the knee, used to better examine the tibial plateau and femoral intercondylar spaces. It is anecdotally known as a 'notch view' Patient position patient is supine on the table with the knee flexed 40 degrees image receptor ...

Knee (horizontal beam lateral view)

The horizontal beam lateral view (cross-table lateral) is an orthogonal view to the AP view of the knee. It is the ideal projection to assess for lipohemarthrosis in a joint effusion, and requires little to no patient movement; hence, it is the lateral projection of choice for acute knee injurie...

Knee (oblique view)

The Knee oblique view is an additional projection requested to examine the knee joint in greater detail, often in the absence of a CT scanner. The view is comprised of both an internal and external oblique. Patient position patient is supine on the table with the knee and ankle joint in contac...

Knee (Rosenberg view)

The Rosenberg view of the knees is a specialized series often used to detect early signs of osteoarthritis. It should be the initial study for any patient with a suspicion of knee osteoarthritis. It consists of a PA radiograph with weight bearing and 45 degrees of knee flexion. It is more sensi...

Knee series

The knee series is a set of radiographs taken to investigate knee joint pathology, often in the context of trauma. It usually comprises an AP and lateral projection, although other non-standard, modified projections can be used for specific indications. See also knee radiograph (an approach). ...

Knee (skyline Laurin view)

The knee skyline Laurin view is an inferior-superior projection of the patella. It is one of many different methods to obtain an axial projection of the patella. This projection is best suited to patients able to maintain a semi-recumbent position on the examination table. Patient position the...

Knee (skyline Merchant view)

The knee skyline Merchant view is a superior-inferior projection of the patella it is one of many different methods to obtain an axial projection of the patella. This is an ideal projection for patients that are better suited in the supine postion. Patient position patient is supine on the tab...

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 ...

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...

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...

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...

Lipiodol

Lipiodol® (also known as ethiodized oil) is an oil-based iodinated contrast medium that was historically used for myelography and hysterosalpingography. It was later superseded by newer, less hazardous, agents, and now is used primarily as a therapeutic agent. Guerbet is now the sole manufacture...

Lower limb radiography

Lower limb radiography is the radiological investigation of the pelvis, hip joint, femur, knee joint, tibia, fibula, ankle joint, tarsal bones of the foot and metatarsals. It is often utilized in the context of trauma to rule out fractures and dislocations.

Lumbar spine (AP/PA view)

The lumbar spine AP view images the lumbar spine which consists of five 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 imaging sho...

Lumbar spine (flexion and extension views)

The lumbar spine flexion and extension views images the lumbar spine which consists of five vertebrae. They are specialized projection, assessing for instability of the lumbar spine often in the context of spondylolisthesis. Patient position the patient is positioned erect: ideally, spinal i...

Lumbar spine (lateral view)

The lumbar spine lateral view images the lumbar spine which consists of five vertebrae. It is utilized in many imaging contexts including trauma, postoperatively, and for chronic conditions. Patient position the patient is positioned erect, supine or lateral recumbent, depending on clinical h...

Lumbar spine (oblique view)

The lumbar spine oblique view is used to visualize the articular facets and pars interarticularis of the lumbar spine. Patient position the radiographs can be performed with the patient in the erect or supine position erect two radiographs performed with patient at RAO 35-45° and LAO 35-4...

Lumbar spine series

The lumbar 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 such as ankylosing spondylosis. Lumbar spine x...

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...

Mammography

Mammography is a dedicated radiographic technique for imaging the breast. Types of mammography In general terms, there are two types of mammography: screening and diagnostic. Mammography differs significantly in many respects from the rest of diagnostic imaging. Screening mammography In ge...

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 ...

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 ...

Mediolateral oblique view

The mediolateral oblique (MLO) view is one of standard mammographic views. It is the most important projection as it allows to depict most breast tissue. Adequacy The representation of the pectoral muscle on the MLO view is a key component in assessing the adequacy of patient positioning and ...

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 ...

Modified Stenvers view

The modified Stenvers view is an oblique radiographic projection used to demonstrate the petrous temporal bone, IAM and bony labyrinth. It is primarily used to assess electrode placement following the insertion of a cochlear implant. Specifically it assesses the: integrity, positioning, and dep...

Motion artifact

Motion artifact is a patient-based artifact that occurs with voluntary or involuntary patient movement during image acquisition. Misregistration artifacts, which appear as blurring, streaking, or shading, are caused by patient movement during a CT scan. Blurring also occurs with patient moveme...

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. spin echo sequences (SE) T1: T1 weighted IR: inversion recovery T2 : T2 weighted RARE: rapid acquisition with r...

Neonatal abdominal radiograph (supine view)

AP supine radiograph for neonates is a mobile examination performed on the neonatal unit. It can be taken as a standalone projection or as part of a series including a left lateral decubitus x-ray in cases of suspected perforation. Patient position the patient is supine, lying on their back i...

Neonate chest (supine view)

The supine chest view of the neonatal patient is a common radiographic examination when examining preterm patients 1. Although not overall technically demanding, the radiographer should allocate time to ensure little to no repeats are required. Research surrounding the technical evaluation and ...

Noise (computed tomography)

Noise in computed tomography is an unwanted change in pixel values in an otherwise homogenous image. Often, noise is defined loosely as, the grainy appearance on cross-sectional imaging; more often than not, this is quantum mottle. Noise in CT is measured via the signal to noise ratio (SNR); c...

Normal brain imaging examples

This article lists examples of normal imaging of the brain and surrounding structures, divided by modality and protocol. CT CT (routine) example 1: C- axial, coronal, sagittal example 2: C- axial, coronal, sagittal & axial bone example 3: C- axial, C+ axial, coronal, sagittal example 4: C-...

Normal breast imaging examples

This article lists examples of normal imaging of the breast and surrounding structures, divided by region and modality. Breast Mammography MLO and CC (standard mammographic views) labelled example unlabelled example lateral: example needed compression: example needed cleavage view: examp...

Normal chest imaging examples

This article lists examples of normal imaging of the chest and surrounding structures, divided by modality. Plain radiographs Adult examples chest radiograph PA adult male example 1 example 2: with inverted windows example 3 PA adult female example 1 example 2 example 3: with labels ...

Normal gastrointestinal tract imaging examples

This article lists examples of normal imaging of the gastrointestinal tract and surrounding structures, divided by modality. Plain radiograph example 1: abdominal film example 2: erect and supine example 3, example 4: pediatric example 5: young adult male Barium studies example 1, example...

Normal genitourinary tract imaging examples

This article lists examples of normal imaging of the genitourinary tract and surrounding structures, divided by modality. Kidneys Plain radiograph KUB: example 1 abdominal x-ray: example 1 Intravenous Urogram (IVU) / Intravenous Pyelogram (IVP) IVU: example 1 Ultrasound renal ultrasound:...

Normal head and neck imaging examples

This article lists examples of normal imaging of the head and neck and surrounding structures, divided by region and modality. Neck For normal spinal imaging, please see: normal spinal imaging Plain radiographs soft tissue: example 1, example 2, example 3 CT soft tissue contrast: example ...

Normal hepatobiliary imaging examples

This article lists examples of normal imaging of the liver and biliary tree and surrounding structures, divided by region and modality. Liver Plain radiographs liver silhouette: example Ultrasound liver ultrasound example 1 with shear wave elastography liver Doppler ultrasound: example ne...

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