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.

450 results found
Article

Spinal AVM classification

Spinal arteriovenous malformations can be classified in a number of ways: intramedullary extramedullary: 80% 1 Or into four types 2: type I: single coiled vessel (dural AV fistula) type II: intramedullary glomus AVM type III: juvenile  type IV: intradural perimedullary (AV fistula) sub t...
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Spinal cord injury

Spinal cord injury (SCI) can be traumatic or non-traumatic (i.e. neoplastic/stenosis) but the syndromes associated with spinal cord injury can be seen in all etiologies. Injury to the spinal cord can be incomplete or complete and depends upon the mechanism of injury. This is important as differ...
Article

Spinal instability neoplastic score (SINS)

The spinal instability neoplastic score (SINS) helps to assess tumor related instability of the vertebral column. It has been shown to useful in guiding the mobilization or operative management of patients with neoplastic spinal disease. Studies have reported good inter-observer agreement among...
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Spinal metastases

Spinal metastases is a vague term which can be variably taken to refer to metastatic disease to any of the following: vertebral metastases (94%) may have epidural extension intradural extramedullary metastases (5%) intramedullary metastases (1%) Each of these are discussed separately. Below...
Article

Spondylolisthesis

Spondylolisthesis denotes the slippage of one vertebra relative to the one below. Spondylolisthesis can occur anywhere but is most frequent, particularly when due to spondylolysis, at L5/S1 and to a lesser degree L4/L5.  Terminology Although etymologically it is directionless (see below) and c...
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Spondylolisthesis grading system

A commonly adopted method of grading the severity of spondylolisthesis is the Meyerding classification. It divides the superior endplate of the vertebra below into 4 quarters. The grade depends on the location of the posteroinferior corner of the vertebra above. This classification was original...
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Spondylolisthesis Wiltse classification

Spondylolisthesis can be classified according to broad etiologies as described by Wiltse in 1981 1. Typically when reporting studies with spondylolisthesis the Wiltse type is merely stated without referring to its number, whereas the grade of spondylolisthesis is explicitly stated: e.g. "Grade 1...
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SRU guidelines for assessment of thyroid nodules

The Society of Radiologists in Ultrasound (SRU) guidelines for the assessment of thyroid nodules were defined in a consensus conference statement published in 2005 focused on which thyroid nodules detected on ultrasonography should undergo fine needle aspiration. Recommendations The recommenda...
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Stahl classification of Kienböck disease

The Stahl classification of Kienböck disease, modified by Lichtman, is the most commonly used staging system and is useful in the treatment of Kienböck disease (avascular necrosis of the lunate). This system divides the disease into four stages:  stage I: normal radiograph stage II: increased...
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Stanford classification of aortic dissection

Along with the DeBakey classification, the Stanford classification is used to separate aortic dissections into those that need surgical repair, and those that usually require only medical management. The Stanford classification divides dissections by the most proximal involvement: type A: A aff...
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St. Anne-Mayo grading system of astrocytomas

The St. Anne-Mayo grading system, also known as the Daumas-Duport grading system, introduced in 1988 was for a time a popular system for grading diffuse astrocytomas but has now largely been replaced by the WHO grading system which is, however, derived from the St Anne-Mayo system and thus share...
Article

Steinberg staging of avascular necrosis

Steinberg staging of avascular necrosis of hip is a commonly used system (at the time of writing, mid-2016) similar to the Ficat and Arlet staging.  It is based on the radiographic appearance and location of lesion. It primarily differs from the other systems by quantifying the involvement of f...
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Stewart classification for proximal 5th metatarsal fractures

The Stewart classification for proximal fifth metatarsal fractures is based upon fracture location and morphology. It is divided into five types. Classification Type I extra-articular transverse or oblique fracture between base of 5th metatarsal and diaphysis (Jones fracture) Type II avulsi...
Article

Stoma

A stoma (plural stomata) is defined as an artificially created connection between two hollow organs or a hollow organ and the skin. A surgical procedure that involves the creation of a stoma carries the suffix "-ostomy".For a discussion of imaging features and potential complications, please ref...
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Subaxial cervical spine injury classification

The subaxial cervical spine injury classification (SLIC) system is a severity score for cervical spine trauma that helps in determining treatment and prognosis. Classification Injury morphology no abnormality: 0 points simple compression fracture: 1 point burst fracture: 2 points distracti...
Article

Superior vena cava obstruction (grading)

SVC obstruction can cause SVC syndrome which is the most common condition affecting this vessel. It can be secondary to extrinsic compression or intraluminal thrombosis/stenosis. Collateral pathways, with the azygos vein being the most important collateral vessel, form in response to severe narr...
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Supracondylar humeral fracture

Supracondylar humeral fractures, often simply referred to as supracondylar fractures, are a classic pediatric injury which require vigilance as imaging findings can be subtle. Epidemiology Simple supracondylar fractures are typically seen in younger children, and are uncommon in adults; 90% ar...
Article

Suzuki staging system for Moyamoya

The staging system for moyamoya disease first described by Suzuki and Takaku in their seminal 1969 article 1 is still in use today. Formally, the staging refers to findings on conventional angiography, although there are efforts to apply similar systems to MR angiography 2. Suzuki stage appears...
Article

Syrinx terminology

There are specific terms used when describing a syrinx or other cystic lesions within the spinal cord 1: hydromyelia: fluid accumulation/dilatation within the central canal, therefore, lined by ependyma syringomyelia: cavitary lesion within cord parenchyma, of any cause (there are many); locat...
Article

Tabar 5-tier grading system

The Tabar 5-tier grading system is used to classify mammographic lesions. This should not be confused with the Tabar classification of parenchymal patterns in breast imaging. It is a separate but translatable system to the BI-RADS classification system (please note that Tabar grade 3 ≠ BI-RADS 3...
Article

Talar neck fracture

Talar neck fractures extend through the thinnest cross-sectional portion of the talus, just proximal to the talar head. They represent one of the most common types of talus fracture (~30-50%), along with chip and avulsion fractures of the talus (~40-49%). These fractures are commonly associated ...
Article

Temporal bone fracture

Temporal bone fracture is usually a sequela of significant blunt head injury. In addition to potentially damage to hearing and the facial nerve, associated intracranial injuries, such as extra-axial hemorrhage, diffuse axonal injury and cerebral contusions are common. Early identification of tem...
Article

Terms used in radiology

There are numerous terms used in radiology (and clinical medicine more generally) that are worth knowing and this is a list of some of them.  General agenesis atresia artifact cyst pseudocyst dehiscence wound dehiscence diathesis dyscrasia exophytic filling defect fistula fluid col...
Article

Thoracolumbar injury classification and severity score (TLICS)

The thoracolumbar injury classification and severity score (TLICS), also sometimes known as the thoracolumbar injury severity score (TISS), was developed by the Spine Trauma Group in 2005 to overcome some of the perceived difficulties regarding the use of other thoracolumbar spinal fracture clas...
Article

Thoracolumbar spinal fracture classification systems

Thoracolumbar spinal fracture classification systems are numerous and represent attempts by various authors to create systems that allow uniform and reproducible classification and description of thoracolumbar fractures which in turn can help with treatment decision making and prognostication.  ...
Article

Three column concept of spinal fractures

The three-column concept of thoracolumbar spinal fractures (of Denis) forms the basis of a number of widely used thoracolumbar spinal fracture classification systems. Usage While the three-column concept was initially developed for classification of thoracolumbar spinal fractures, it can also ...
Article

Thrombolysis in cerebral infarction (TICI) scale

The thrombolysis in cerebral infarction (TICI) grading system was described in 2003 by Higashida et al. 1 as a tool for determining the response of thrombolytic therapy for ischemic stroke. In neurointerventional radiology it is commonly used for patients post endovascular revascularization. Lik...
Article

Thrombolysis in myocardial infarction (TIMI) risk score

The thrombolysis in myocardial infarction (TIMI) risk score is a prognostic risk stratification system that categorizes the risk of death and ischemic events in patients with unstable angina / non-ST elevation myocardial infarction and provides a basis for therapeutic decision making. It is thou...
Article

Thyroid imaging reporting and data system (TI-RADS)

Thyroid imaging reporting and data system (TI-RADS) refers to any of several risk stratification systems for thyroid lesions, usually based on ultrasound features, with a structure modelled off BI-RADS. The following article describes the initial iterations proposed by individual research groups...
Article

Tillaux fracture

Tillaux fractures are Salter-Harris III fractures through the anterolateral aspect of the distal tibial epiphysis, with variable amounts of displacement. Epidemiology It occurs in older children and adolescents when the medial aspect of the distal tibial growth plate has started to fuse. Path...
Article

Toast classification in acute ischemic stroke

The TOAST (trial of ORG 10172 in acute stroke treatment) classification denotes five sub types of ischemic stroke. large-artery atherosclerosis (embolus / thrombosis)* cardioembolism (high-risk / medium-risk)* small-vessel occlusion (lacune)* stroke of other determined etiology * stroke of ...
Article

Todani classification of bile duct cysts

The Todani classification of bile duct cysts divides choledochal cysts into five groups. Classification Type I See: type I choledochal cyst account for 80-90% of all bile duct cysts characterized by fusiform dilation of the extrahepatic bile duct a subclassification has been proposed Ia: ...
Article

Torg's classification for proximal 5th metatarsal fractures

Torg's classification of proximal fifth metatarsal fractures is based on the degree of sclerosis adjacent to the fracture on imaging at the time of presentation to determine the fracture age. Classification Type I narrow fracture line with sharp margins and no widening minimal cortical hyper...
Article

Transitional cell carcinoma grading

Transitional cell carcinomas of the urothelium are graded histologically as follows: transitional cell papilloma benign tumor, not a carcinoma but sometimes included in classification systems carcinoma in situ do not penetrate the basement membrane cells resemble those of grade II or III t...
Article

Traumatic abruptio placenta scale

The traumatic abruptio placenta scale (TAPS) was devised to stratify placental injury findings on CT. Since placental abruption is a concern in a pregnant patient who has undergone traumatic injury, CT is occasionally the first imaging modality used to evaluate the placenta. 0: normal homogeneo...
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Triplane fracture

Triplane or triplanar fractures are of the distal tibia only occurring in adolescents. As the physiological closure of the physeal plate begins medially, the lateral (open) physis is prone to this type of fracture. The name is due to the fact of the fracture expanding both in frontal and lateral...
Article

Trochanteric fracture

A trochanteric fracture is a fracture involving the greater and/or lesser trochanters of the femur. Classification Fractures in these regions can be classified as: intertrochanteric pertrochanteric: intertrochanteric, involving both trochanters subtrochanteric greater trochanteric avulsio...
Article

True hermaphroditism

True hermaphroditism is a form of disorder of gender development.  Pathology Patients with true hermaphroditism have mosaicism of 46XX and 46XY. They therefore have both ovarian and testicular tissues. Subtypes There are three forms of true hermaphroditism: unilateral true hermaphroditism ...
Article

Tuberculous spondylitis versus pyogenic spondylitis

Tuberculous spondylitis and pyogenic spondylitis are both common causes of spinal infection. Imaging findings of these 2 diseases can be challenging to distinguish, yet crucial because the treatments for these infections are particularly different 2. Radiographic features Useful distinguishing...
Article

Tuberous sclerosis (diagnostic criteria)

The tuberous sclerosis diagnostic criteria have been developed to aid the diagnosis of tuberous sclerosis and have most recently been updated in 2012 by the International Tuberous Sclerosis Complex Consensus Group (at time of writing - 2019) 1.  Criteria Genetic criteria The identification of...
Article

Tumors of muscular origin

There are a number of tumors of muscular origin, which overall are relatively uncommon, representing only 1.7% of benign soft tissue tumors, and 10.3% of malignant soft tissue tumors1.  The tumors can be divided according to the type of muscle fiber: Skeletal muscle origin benign rhabdomyoma...
Article

Tumors of the male urethra

Tumors of the male urethra are uncommon. They can be categorized both on the grounds of histology and location. Histology squamous cell carcinoma of the urethra: 80% urothelial/transitional cell carcinoma of the urethra: 15% (predominantly posterior urethra) adenocarcinoma of the urethra: 5%...
Article

Tumors of the meninges (differential)

Tumors of the meninges are a heterogeneous group of lesions which usually occur as extra-axial masses.  Although a large number of lesions that can involve meninges are scattered throughout the  WHO classification of CNS tumors, the main entities to be considered include:  meningioma and numero...
Article

Tumors of the seminal vesicles

Tumors arising primarily from the seminal vesicles are rare. Most frequently, when a mass is seen in the seminal vesicles, it represents a contiguous spread from tumors in adjacent organs, in particular, the prostate. Epithelial tumors adenocarcinoma of the seminal vesicle the most common pri...
Article

Ultrasound assessment of carotid arterial atherosclerotic disease

Ultrasound assessment of carotid arterial atherosclerotic disease has become the first choice for carotid artery stenosis screening, permitting the evaluation of both the macroscopic appearance of plaques as well as flow characteristics in the carotid artery. This article focus on internal caro...
Article

Urinary tract dilatation classification

Urinary tract dilatation (UTD) classification was a proposed unified classification of urinary tract dilatation for prenatal and postnatal care. This classification was formed with the collaborations from 8 societies (The American College of Radiology (ACR), the American Institute of Ultrasound ...
Article

Uterine biophysical profile

Uterine biophysical profile refers to assessment of uterus to produce a successful conception and implantation environment.  Uterine scoring system for reproduction (USS) The uterine scoring system for reproduction comprises the following parameters, taken in mid-cycle: 1. endometrial thickne...
Article

Vancouver classification of periprosthetic hip fractures

The Vancouver classification of periprosthetic hip fractures proposed by Duncan and Masri is the most widely used classification system. It takes into account the fracture site, the status of the femoral implant, and the quality of surrounding femoral bone stock. type A: fractures involve the t...
Article

Varicocele grading on color Doppler

Varicocele grading on color Doppler can be done variably. The most elaborate and widely-accepted grading was given by Sarteschi, as below.  For a general discussion of this condition refer to the article: varicocele. Evaluation baseline greyscale study in supine position and measure the diame...
Article

VASARI MRI feature set

The VASARI (Visually AcceSAble Rembrandt Images) MRI feature set is a system designed to enable consistent description of gliomas using a set of defined visual features and controlled vocabulary. It is the result of work by The Cancer Imaging Archive (TCIA) who publish relevant guides to use, an...
Article

Vesicoureteric reflux (grading)

Vesicoureteric reflux (VUR) grading divides vesicoureteric reflux according to the height of reflux up the ureters and degree of dilatation of the ureters: grade 1: reflux limited to the ureter grade 2: reflux up to the renal pelvis grade 3: mild dilatation of ureter and pelvicalyceal system ...
Article

Walch classification of glenoid morphology

The Walch classification of glenoid morphology is the most commonly used system describing glenohumeral pathology in primary osteoarthritis. It was initially measured on 5 mm thick slices on axial CT scans of the shoulder 1, which had mixed results for inter- and intra-observer agreement but th...
Article

Waldenström classification of Perthes disease

The Waldenström classification of Perthes disease refers to x-ray abnormalities, and represents four temporal phases of the disease. These stages have been further subdivided in the modified Elizabethtown classification 2. stage I: early asymmetric femoral epiphyseal size (smaller on the affec...
Article

Weber classification of ankle fractures

The Weber ankle fracture classification (or Danis-Weber classification) is a simple system for classification of lateral malleolar fractures, relating to the level of the fracture in relation to the ankle joint. It has a role in determining treatment.  Classification type A below the level of...
Article

Weiss classification of lateral humeral condyle fractures

The Weiss classification is one of the classification systems used for lateral humeral condyle fractures and is based on the degree of displacement measured on an internal oblique view of the elbow: type 1: <2 mm displacement type 2: 2-4 mm displacement type 3: >4 mm displacement The degree ...
Article

WFNS grading system

The WFNS (World Federation of Neurosurgical Societies) grading system uses the Glasgow Coma Scale and presence of focal neurological deficits to grade the severity of subarachnoid hemorrhage. This grading system was proposed in 1988, and this is one of the accepted systems (although not consider...
Article

Whitmore-Jewett staging system

Whitmore-Jewett staging system (also known as the Jewett staging system or ABCD system) is a staging system for prostate cancer. It was developed by the American Urological Association (AUA). Most societies (including AUA) and clinicians now advocate and use the TNM staging system. A: subclinic...
Article

WHO classification of anal canal tumors

The World Health Organization classifies anal canal neoplasms into intraepithelial neoplasms and invasive neoplasms which are further divided to epithelial and non-epithelial tumors and secondary lesions: Epithelial tumors squamous cell carcinoma of anal canal adenocarcinoma of anal canal mu...
Article

WHO classification of anal margin tumors

The WHO classification of anal margin tumors or perianal skin tumors is: intraepithelial tumors Bowen disease (precursor of squamous cell carcinoma) Paget's disease (precursor of adenocarcinoma) invasive tumors squamous cell carcinoma adenocarcinoma basal cell carcinoma  verrucous carcin...
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WHO classification of CNS tumors

The WHO classification of CNS tumors is the most widely accepted system for classifying CNS tumors and was based on the histological characteristics of the tumor. Although the most recent version of the 'blue book' is the 4th edition from 2007, an update has been released in 2016 3, which should...
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WHO classification of eye tumors

The World Health Organization (WHO) classification of eye tumors is a widely used pathologic classification system of neoplasms of the orbit. The current revision, part of the 4th edition of the WHO series, was published in 2018 and is reflected in the article below 1. Classification Tumors of...
Article

WHO classification of head and neck tumors

The World Health Organization (WHO) classification of head and neck tumors is the most widely used pathologic classification system for such disorders. The current revision, part of the 4th edition of the WHO series, was published in 2017 and is reflected in the article below 1. Classification ...
Article

WHO classification of tumors of bone

The World Health Organization (WHO) classification of bone tumors is the most widely used pathologic classification system for such disorders. The current revision, part of the 4th edition of the WHO series, was published in 2013 and is reflected in the article below 1. Classification Chondrog...
Article

WHO classification of tumors of soft tissue

The World Health Organization (WHO) classification of soft tissue tumors is the most widely used pathologic classification system for such disorders. The current revision, part of the 4th edition of the WHO series, was published in 2013 and is reflected in the article below 1. Classification A...
Article

WHO classification of tumors of the breast

The World Health Organization classification of tumors of the breast is the most widely used pathologic classification system for such disorders. The current revision, part of the 4th edition of the WHO series, was published in 2012 and is reflected in the article below 1. Classification Epith...
Article

WHO classification of tumors of hematopoietic and lymphoid tissues

The World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues is the most widely used pathologic classification system for hematolymphoid neoplasms. The current revision, known as the 4th revised edition, was published in 2016 and supersedes the 4th edition p...
Article

WHO classification of tumors of the kidney

The World Health Organization (WHO) classification of tumors of the kidney is the most commonly used pathologic classification system for such disorders. The current revision, part of the 4th edition of the WHO series, was published in 2016 as part of the WHO Classification of Tumors of the Urin...
Article

WHO classification scheme for thymic epithelial tumors

The WHO classification scheme for thymic epithelial tumors is one of many classifications systems for thymoma and related tumors, and classifies them according to histology: type a medullary thymoma spindle cell thymoma type ab: mixed thymoma type b1: lymphocyte rich predominantly cortical...
Article

WHO grading of CNS tumors

WHO (World Health Organization) grading of CNS tumors is based on histological characteristics such as cellularity, mitotic activity, pleomorphism, necrosis, and endothelial proliferation (neoangiogenesis). It is used in the WHO classification of CNS tumors.  It should be noted that at the time...
Article

WHO grading system for diffuse astrocytomas

 The WHO grading system is the most widely used system for grading diffuse astrocytomas (at the time of writing i.e. mid-2016) and is an adaptation of the now superseded St Anne-Mayo grading system (also known as the Daumas-Duport grading system).  Grade I is reserved for localized astrocytomas...
Article

WHO histological classification of benign renal neoplasms

Benign renal tumors were histologically classified according to the World Health Organization 1. This is the subset of entities in the 2016 WHO classification of renal tumors that are associated with an International Classification of Diseases for Oncology (ICD-O) behavior code of 0, indicating ...
Article

WHO histological classification of tumors of the uterine cervix

The WHO histological classification is a detailed classification of tumors of the uterine cervix. epithelial tumors squamous tumors and precursors squamous cell carcinoma, not otherwise specified - 8070/3 keratinizing - 8071/3 non-keratinizing - 8072/3 basaloid - 8083/3 verrucous - 8051/3...
Article

Wiberg classification of patella shape

Wiberg classification is a system used to describe the shape of the patella based mainly on the asymmetry between the patellar medial and lateral facets on axial views of the patella. Increasing number type indicates a larger degree of asymmetry. Classification Wiberg type 1 or a roughly symm...
Article

Winquist classification of femoral shaft fractures

The Winquist classification of femoral shaft fractures is based on fracture comminution and was proposed by Winquist in 1980. This classification is used with regards to management decision making, in determining whether a fracture requires an intramedullary nail or open reduction.  Type 0: no ...
Article

Yasargil classification of vein of Galen aneurysmal malformations

The Yasargil classification is one of the two common systems for classifying vein of Galen malformations that is currently in use at the time of writing (mid 2016).  Classification type I: small pure cisternal fistula between the vein of Galen (voG) and either the pericallosal arteries (anteri...
Article

Young and Burgess classification of pelvic ring fractures

The Young and Burgess classification is a modification of the Tile classification 1. It is the recommended 5 and most widely used classification system for pelvic ring fractures. It takes into account force type, severity, and direction, as well as injury instability. Three basic mechanistic ...
Article

Zabramski classification of cerebral cavernous malformations

The Zabramski classification of cerebral cavernomas has been proposed as a way of classifying cerebral cavernous malformations, and although not used in clinical practice it is useful in scientific publications that seek to study cavernous malformations. The classification was proposed in 1994 ...
Article

Zurich pituitary score

The Zurich pituitary score (ZPS) is a quantitative classification of pituitary adenomas based on coronal T1W magnetic resonance imaging with contrast, although the score can also be obtained with computed tomography. The ZPS is based on the ratio (R) between horizontal tumor diameter over inter...

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