Spinal meningeal cysts can be classified according to a system published by Nabor et. al 2:
type I: extradural meningeal cyst without neural tissue
type Ia: extradural spinal arachnoid cyst
type Ib: sacral meningocele
type II: extradural meningeal cyst containing neural tissue, e.g. Tarlov c...
Classification system for malformations of cortical development organises a myriad of conditions into one of three major underlying groups according to the main underlying mechanism:
group I: abnormal cell proliferation or apoptosis
group II: abnormal neuronal migration
group III: abnormal co...
Classification systems for malformations of the cerebellum are varied and are constantly being revised as greater understanding of the underlying genetics and embryology of the disorders is uncovered. A classification proposed by Barkovich et al. in 2009 1 divides cerebellar malformations in two...
Classification systems for midline abnormalities of the brain and skull are varied and constantly changing as the underlying embryology and genetics are uncovered. A relatively simple and robust classification system is based on the location of abnormalities, always remembering that midline abno...
Closed reduction-internal fixation, abbreviated to CRIF, refers to the orthopaedic operative management of a fracture (or fracture-dislocation complex) where closed reduction is performed (manipulation) and internal fixation is applied, usually in the form of K-wires to stabilise the fracture.
Cochlear anomalies are a variety of congenital anomalies which, depending on the exact time at which an insult occurs during embryogenesis, may have different manifestations. Terminology is often used imprecisely leading to confusion not only among clinicians, but also in the literature.
The Cognard classification of dural arteriovenous fistulas correlates venous drainage patterns with increasingly aggressive neurological clinical course. It was first described in 1995 1 and at the time of writing (July 2016) is probably the most widely used classification system for dural arter...
The combined conduit score (CCS) is a grading scheme for the assessment of the degree of transverse-sigmoid sinus stenosis in the setting of idiopathic intracranial hypertension. The score was initially developed for ATECO MR venography 1.
Assessment is performed using maximum inten...
Complex midfacial fractures consist of multiple facial fractures that cannot be classified as any of the defined complex facial fracture (e.g. Le Fort fracture, zygomaticomaxillary complex fracture, naso-orbital-ethmoid fracture).
Congenital cardiovascular anomalies are relatively common, with an incidence of up to 1% if small muscular VSDs are included. As a group, there is a much greater frequency in syndromic infants and in those that are stillborn.
Broadly, congenital cardiovascular anomalies ...
This congenital extrahepatic portosystemic shunt classification was proposed by Morgan and Superina in 1994 1:
type 1: complete diversion of portal blood into the Inferior vena cava with congenital absence of the portal vein
1a: superior mesenteric vein and splenic vein do not join to form a c...
This congenital intrahepatic portosystemic shunt classification was proposed by Park et al. in 1990 1:
type 1: single large vessel of constant diameter connecting the right portal vein to the Inferior vena cava
type 2: localised, peripheral shunt with one or more communications in a single hep...
There are many classification systems for congenital utero-vaginal anomalies. These include:
Buttram and Gibbons classification 2
American Fertility Society (AFS) classification
Modified Rock and Adam - AFS classification
Modified Rock and Adam - AFS classification
This classification divid...
Conotruncal heart defects are a group of congenital cardiovascular anomalies. They are a leading cause symptomatic cyanotic cardiac disease diagnosed in utero.
They may account for up to a fifth of all congenital cardiac anomalies diagnosed prenatally 2.
The Cooke and Newman classification of periprosthetic hip fractures is a modification of the Bethea classification proposed several years earlier.
explosion type fracture, comminuted around the stem of the implant
the prosthesis is always loose and the fracture is inherently unstable
Coronary Artery Disease - Reporting and Data System (CAD-RADSTM) classification is proposed by the Society for Cardiovascular Computed Tomography (SCCT), the American College of Radiology (ACR), and the North American Society for Cardiovascular Imaging (NASCI), last updated in 2016.
Fractures of the coronoid process of the ulna are uncommon and often occur in association with elbow dislocation.
Fracture of the coronoid process is thought to result from elbow hyperextension with either avulsion of the brachialis tendon insertion, or shearing off by th...
The Couinaud classification (pronounced kwee-NO) is currently the most widely used system to describe functional liver anatomy. It is the preferred anatomy classification system as it divides the liver into eight independent functional units (termed segments) rather than relying on the tradition...
CT colonography reporting and data system is a method devised to standardise CT colonography reporting.
It primarily classifies abnormalities into colonic (C) and extra-colonic (E).
C0: inadequate study
C1: normal colon/benign lesion: routine screening ...
The CT severity index (CTSI) is based on findings from a CT scan with intravenous contrast to assess the severity of acute pancreatitis. The severity of computed tomography findings have been found to correlate well with clinical indices of severity.
The CTSI sums two scores:
A number of entities can present as cyanotic congenital heart disease. These can be divided into those with increased or decreased pulmonary vascularity (pulmonary plethora):
increased pulmonary vascularity
total anomalous pulmonary venous return (TAPVR) (types I and II)
transposition of the ...
Dameron-Lawrence-Bofte classification of proximal fifth metatarsal fractures divides fractures into three zones based on anatomy:
zone 1: tuberosity of 5th metatarsal
avulsion fracture of tuberosity (pseudo-jones fracture)
zone 2: meta-diaphyseal junction
zone 3: proximal dia...
The DeBakey classification, along with the Stanford classification, is used to separate aortic dissections into those that need surgical repair, and those that usually require only medical management.
The DeBakey classification divides dissections into 1-5:
type I: involves asc...
Degloving injuries can refer to a number of conditions:
degloving soft tissue injury
Morel-Lavallee lesion (closed degloving soft tissue injury)
intramuscular degloving injury
degloving bowel injury
Deltoid ligament injuries involve the deltoid ligament that forms the medial part of the ankle joint. It attaches the medial malleolus to multiple tarsal bones.
Mechanism of injury
It occurs due to eversion and/or pronation injury, or can be associated with lateral ankle fractures.
As a part of international evidence-based guidelines adopted by a collaborative effort of the American Thoracic Society (ATS), the European Respiratory Society (ERS), the Japanese Respiratory Society (JRS), and the Latin American Thoracic Association (ALAT), specific diagnostic HRCT criteria for...
Diffuse astrocytomas can be graded in according to a number of systems, the most popular being the WHO grading system. In general these grading systems focus on the presence or absence of a number of histological features 3:
Grading of diffuse axonal injury has been described histologically according to the anatomic distribution of injury, which correlated with outcome 1-3. The classification was first proposed by Adams in 1989 4 and divides diffuse axonal injury (DAI) into three grades:
grade I: involves grey-whit...
Grading of diffuse hepatic steatosis on ultrasound has been used to communicate to the clinician about the extent of fatty changes in the liver.
grade I: diffusely increased hepatic echogenicity but periportal and diaphragmatic echogenicity is still appreciable
grade II: diffusely in...
This is a basic article for medical students and other non-radiologists
Distal fibula fractures are the most common type at the ankle and are usually the result of an inversion injury with or without rotation. They are the extension of a lateral collateral ligament injury.
Duplex appendix is a rare anomaly of the appendix and is usually discovered incidentally during surgery for appendicitis.
Duplication of the vermiform appendix is extremely rare. It is found in only 1 in 25,000 patients (incidence ~0.004%) operated on for acute appendicitis. Altho...
The Eaton classification was proposed by Eaton and Malerich in 1980, and presently (time of writing, August 2016) along with Keifhaber-Stern classification, is the most widely accepted classification of volar plate avulsion injuries 1.
Knowledge of the orthopaedic Eaton classification is pract...
The Edinburgh criteria were proposed in 2018 in order to diagnose lobar intracerebral haemorrhage associated with cerebral amyloid angiopathy (CAA) 1. They can potentially be used to rule CAA-associated lobar haemorrhage either in or out, but require external validation in other patient populati...
The Elliott et al. classification system of cardiomyopathies is one of the cardiomyopathy classification systems. This was published by the European Society of Cardiology Working Group on Myocardial and Pericardial Diseases. This places emphasis on phenotypic classification 1-2.
Errors in diagnostic radiology occur for a variety of reasons related to human error, technical factors and system faults.
This classification was proposed by Renfrew et al. 5 in 1992, and at the time of writing (July 2016) remains the most widely accept...
Facial fractures are commonly caused by blunt or penetrating trauma at moderate or high levels of force. Such injuries may be sustained during a fall, physical assault, motor vehicle collision, or gunshot wound. The facial bones are thin and relatively fragile making them susceptible to injury.
The Fazekas scale is used to simply quantify the amount of white matter T2 hyperintense lesions usually attributed to chronic small vessel ischaemia, although clearly not all such lesions are due to this.
This classification was proposed by Fazekas et al. in 1987 1 and at the time of writing (l...
Fibromuscular dysplasia is classified into 5 categories according to the vessel wall layer affected:
intimal fibroplasia (1%)
medial dysplasia (70%, the commonest type)
perimedial (subadventitial) fibroplasia (15-20%)
medial hyperplasia (8-10%)
The Ficat and Arlet classification uses a combination of plain radiographs, MRI, and clinical features to stage avascular necrosis of the femoral head.
plain radiograph: normal
clinical symptoms: nil
plain radiograph: normal or minor osteopenia
The Ficat classification of osteonecrosis is based on radiographic findings. In 1985 Dr Ficat published a modified version of his initial classification in 1980:
preclinical and preradiographic
diagnosis is suspected in one hip when the other has a definite disease - this is the stage...
The Fisher scale is the initial and best known system of classifying the amount of subarachnoid haemorrhage on CT scans, and is useful in predicting the occurrence and severity of cerebral vasospasm, highest in grade 3 2.
Numerous other scales have been proposed, incorporating various paramete...
General rules and nomenclature of fractures should be understood by, and familiar to, anyone involved in the interpretation or management of fractures of the extremities. This article covers basic nomenclature of fractures.
Before the most appropriate treatment for a fr...
The Frykman classification of distal radial fractures is based on the AP appearance and encompasses the eponymous entities of Colles fracture, Smith fracture, Barton fracture, chauffeur fracture. It assesses the pattern of fractures, involvement of the radioulnar joint and presence of a distal u...
Fukuoka consensus guidelines, also referred to as the Tanaka criteria, is a classification system for intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs).
The prior international consensus guidelines (2006) were referred to as the Sendai criteria, which later ...
The Galassi classification of middle cranial fossa arachnoid cysts is used to classify arachnoid cysts in the middle cranial fossa, which account for 50-60% of all arachnoid cysts 1. Galassi et al. published this classification in 1982, and at the time of writing (June 2016), it remains the most...
The Garden classification of subcapital femoral neck fractures is the most widely used. It is simple and predicts the development of AVN 1,2. Garden described particular femoral neck and acetabular trabeculae patterns which can assist in recognising differences within this classification system...
The Gartland classification of supracondylar fractures of the humerus is based on the degree and direction of displacement, and the presence of intact cortex. It applies to extension supracondylar fractures rather than the rare flexion supracondylar fracture.
type I: undisplaced...
Gastric cancer staging is routinely performed using the TNM staging system. This article is based on the 7th edition of the TNM classification of malignant tumours.
TNM staging (7th edition)
T1a: tumour invades the lamina propria and or muscularis mucosae
T1b: tumour invades submucosa...
Gastric lymph node stations were originally divided into 16 groups proposed by the Japanese Research Society for Gastric Cancer in 1963.
The areas of stomach which drain into regional lymph nodes:
cardia and proximal lesser curvature drain into left gastric lymph nodes, then int...
The Genant classification of vertebral fractures is based on the vertebral shape, with respect to vertebral height loss involving the anterior, posterior, and/or middle vertebral body.
grade 0: normal
grade 1: mild fracture, 20% to 25% loss of height
grade 2: moderate fracture, 25% to 40% los...
Germ cell tumours are classified into two broad groups: seminoma and non-seminomatous germ cell tumours (NSGCT). The later is then divided further according to histology.
non-seminomatous germ cell tumours (NSGCT)
yolk sac tu...
Grading of germinal matrix haemorrhage has taken several forms over the years. The most commonly used system is the sonographic grading system proposed by Burstein, Papile et al.
restricted to subependymal region/germinal matrix which is seen in the caudothalamic groov...
Gilula three carpal arcs refer to the carpal alignment described on posteroanterior or anteroposterior wrist radiographs and are used to assess normal alignment of the carpus:
first arc: is a smooth curve outlining the proximal convexities of the scaphoid, lunate and triquetrum
second arc: tra...
The Glasgow Coma Scale (GCS) was developed in 1974 1 to describe the level of consciousness specifically in patients with head injury although it is now used widely as a shorthand for all manner of presentations and has generally been validated, although concerns remain about its use in certain ...
The Gleason score determines the histological grading of prostate cancer. A score of 1 to 5 is assigned to each of the two largest areas of tumour involvement in the samples obtained, based on the worst feature.
1: least aggressive
5: most aggressive
These two scores are then added together t...
The global cortical atrophy (GCA) scale, also known as the Pasquier scale, is a qualitative rating system developed to assess cerebral atrophy, especially in the context of neurodegenerative diseases. It evaluates atrophy in 13 brain regions assessed separately in each hemisphere and resulting i...
The Goldman classification of urethral injuries is a more widely accepted classification than one proposed by the American Association for the Surgery of Trauma (AAST). The Goldman classification is based on the anatomical location of the urethral injury and was initially proposed by Colapinto a...
The Goutallier classification is a classification system used to quantify the amount of fatty degeneration of the rotator cuff muscles, particularly in the context of rotator cuff tendon tears. Although originally described in shoulder CT 1, it is applicable and now most commonly used in MR. It ...
According to CT myelography, brachial plexus injuries can be classified into six types 1:
N type: normal root sleeve and nerve roots
A1 type: slightly deformed root sleeves and nerve roots as compared to unaffected site
A2 type: obliteration of the tip of root sleeves and deformed thickened n...
Gradman and Steinburg inferior vena cava aneurysm classification is one method of classing aneurysmal dilatation of the inferior vena cava, which is an uncommon finding. When present it can be often associated with other caval anomalies. Gradman and Steinburg method classifies them as 1:
The Graf method for ultrasound classification system for developmental dysplasia of the hip (DDH) in infants, combines both alpha and beta angles. There are a number of additional subdivisions, which are often not used clinically.
As a general rule, the alpha angle determines the type and in s...
The Gustilo Anderson classification, sometimes referred to as the Gustilo classification is the most widely accepted classification system of open (or compound) fractures.
The grading system is used to guide management of compound fractures, with higher grade injuries associated with higher ris...
The Gynecologic Imaging Reporting and Data System (GI-RADS) is a reporting system that was created for reporting the findings in adnexal masses based on transvaginal ultrasonography.
Findings are classified into five categories 1:
normal ovaries identified and no adn...
Hamburg classification system of vascular malformations is one of the more commonly used systems to describe the wide range of vascular malformations, largely replacing the many various eponymous syndromes traditionally used. It accounts for the underlying anatomical, histological, and pathophys...
The Harvard scoring system for rhinosinusitis is, as the name implies, a scoring system based on CT-scan assessment for grading of rhinosinusitis.
0: normal (< 2 mm mucosal thickening on any sinus wall)
1: all unilateral disease or anatomic abnormality
2: bilateral disease limited to...
LI-RADS (Liver Imaging Reporting and Data System) is both a set of standardised terminology and a classification system for imaging findings in liver lesions. The LI-RADS score for a liver lesion is an indication of its relative risk for hepatocellular carcinoma (HCC). The classification system ...
Although hepatoblastomas can be histologically classified into a variety of sub types, it is important to remember that with the possible exception of small cell undifferentiated sub type, prognosis is independent of histology when adjusted for stage gender and age 1.
E J Hinchey et al. 3 proposed a classification for acute diverticulitis, that has been variously adapted, and is useful not only in academia but also in outlining successive stages of severity.
stage 1a: phlegmon
stage 1b: diverticulitis with pericolic or mesenteric abscess
Type I: Absent or minimal femoral head changes.
A: deformity of the femoral head with intact physis.
B: deformity of the femoral head with premature physeal closure.
Type III: Pseudarthrosis of the femoral neck.
A:Complete destruction of the capital femoral epiphysis wit...
The Hunt and Hess scale describes the severity of subarachnoid haemorrhage, and is used as a predictor of survival.
asymptomatic or minimal headache and slight neck stiffness
moderate to severe headache; neck stiffness; no neurologic deficit except cranial nerve...
Hydrometra is a descriptive term that refers to a distended uterus filled with clear, non-infected fluid.
Grading systems of hydronephrosis have been devised to communicate the degree of upper collecting system dilatation. The most common system used (Society of Fetal Ultrasound, SFU) was originally designed for grading neonatal and infant hydronephrosis:
no dilatation, calyceal walls are ...
Hypertrophic cardiomyopathy (HCM) is a type of cardiomyopathy and is the leading cause of sudden death (from arrhythmias) in infants, teenagers and young adults.
Although hypertrophic cardiomyopathy can generally describe a hypertrophied and non-dilated left ventricle due to any ca...
T staging of hypopharyngeal tumours is as follows:
The hypopharynx includes the pyriform sinuses, the lateral and posterior hypopharyngeal walls, and the postcricoid region.
T1: tumour is limited to one subsite of the hypopharynx and 2 cm or less in greatest dimension
T2: tumour i...
CT scoring systems have been proposed in patients with acute respiratory distress syndrome (ARDS) to predict clinical outcomes. This scoring system was established by Ichikado et al. in 2006 2 and at the time of writing (July 2016), this is the most widely used CT scoring system.
The 2015 International Panel for NMO Diagnosis criteria are, as the name implies, a set of criteria used to diagnose neuromyelitis optic spectrum disorder (NMOSD) 1. They are based on a combination of clinical, laboratory, and neuroimaging findings.
Diagnostic criteria for NMOSD with ...
The International Ovarian Tumour Analysis (IOTA) group ultrasound rules for ovarian masses are a simple set of ultrasound findings that classify ovarian masses into benign, malignant or inconclusive masses. These rules apply to masses that are not a classical ovarian mass (e.g. corpus luteum, en...
Ishikawa classification system describes the degree of involvement of adjacent portal vein and SMV by pancreatic ductal adenocarcinoma based on calibre of the vein:
type I: normal
type II: smooth shift/displacement with normal calibre
type III: unilateral narrowing
type IV: bilateral nar...
Isomerism is a term which in general means 'mirror-image'. It is used in the context of heterotaxy and is of two types:
Mirror image of the structures on the left side of the chest along the left-right axis of the body, i.e. patients with isomeri...
The ISSVA classification of vascular anomalies is based on the initial classification published by Mulliken and Glowacki in 1982, and encompasses all vascular malformations and tumours in a framework of internationally consistent nomenclature. The classification was revised in 2014.
It is proba...
The Johansson classification of periprosthetic hip fractures was the first classification system proposed and is the simplest. It is based on the level of the fracture in relation to the prosthesis.
type I: fracture proximal to the tip of the prosthesis with the stem still in contact with the m...
The Judet and Letournel classification is the most widely used classification system for acetabular fractures.
It is based on three radiographic views (anteroposterior view, obturator oblique view and iliac oblique view) and classifies acetabular fractures into ten major fracture patterns, wh...
Kasai classification is used to describe the three main anatomical types of biliary atresia.
type I: obliteration of common bile duct (patent cystic and common hepatic duct)
IIa: obliteration of common hepatic duct (patent cystic and common bile duct), sometimes with a...
The Keifhaber-Stern classification was proposed originally by Hastings and later modified by Keifhaber and Stern in 1998. This classification, along with the Eaton classification, is the most widely accepted classification at the time of writing (August 2016) for the management of volar plate av...
The Kellgren and Lawrence system is a common method of classifying the severity of knee osteoarthritis (OA) using five grades 1. This classification was proposed by Kellgren et al. in 1957 2 and later accepted by WHO in 1961.
In applying the system, the prevalence of chronic knee pain in a post...
The Kernohan grading system for diffuse astrocytomas is no longer used, superseded by the the WHO grading system.
It was first described in 1949 and divided astrocytomas into 4 grades (I - IV) on the basis of histological features 1.
Komi classification of bile duct cysts, as stated by Komi et al, divides anomalous union of the pancreatico-bile ducts (AUPBD) into 3 types based on the angle of union of the ducts 1.
type I: union of the ducts at a right angle to each other
type Ia: without dilatation or
The Krenning score is a proposed semi-quantitative method of assessing the degree of tracer uptake on octreotide scintigraphy.
Initially designed for assessment of 111In-DTPA on planar imaging, the Krenning score is applicable to SPECT or SPECT/CT using various radiopharmaceuticals....
Kuhn classification is an anatomical classification for the subtypes of frontal cells.
type 1 (~37%): a single air cell above the agger nasi cell
type 2 (~19%): two or more air cells above the agger nasi cell
type 3 (~7%): a single large cell above the agger nasi cell that extends into the fr...
The Kuwada classification of Achilles tendon tear was proposed in 1990 4 and at the time of writing (July 2016) remains the most widely used system for describing achilles tendon rupture.
Achilles tendon tears may be grouped (according to severity of the tear and degree of retr...
The Langer Saldino syndrome or achondrogenesis type II is a sub type of achondrogenesis. It is an extremely rare fatal skeletal dysplasia.
Majority of cases are sporadic. Autosomal dominant inheritance is also another mode. There is mutation in the collagen type II gene (CO...
The Lasjaunias classification, at the time of writing (mid 2016), is one of the two commonly used systems for classifying vein of Galen malformations. It relies on dividing the entity into choroidal or mural types, depending on the number and origin of feeding arteries.
Lateral humeral condyle fractures also referred to simply as lateral condyle fractures (in the appropriate context), are relatively common elbow fractures that predominantly occur in children. They may be subtle but are hugely important to diagnose in a timely manner because if they are missed, ...