Peripheral arterial disease (PAD) is a common and debilitating condition.
The age-adjusted prevalence of peripheral arterial disease is ~12% 3.
Atherosclerosis is the leading cause of occlusive arterial disease of the extremities in patients over 40 years of age with t...
Several classification systems have been proposed for periprosthetic fractures of the hip:
American Academy of Orthopedic Surgeons (AAOS) classification
Cooke and Newman (modified Bethea) classification
Vancouver classification: most widely used
There are several periurethral cystic lesions. These include:
female genitourinary tract:
Gartner duct cyst
epidermal inclusion cyst of the vagina
Skene duct cyst
Bartholin gland cyst
endometrial cyst of perineal-vulval-vaginal region
male genitourinary trac...
One of the methods used for grading of periventricular leukomalacia based on sonographic appearances is as:
grade 1: areas of increased periventricular echogenicity without any cyst formation persisting for more than 7 days
grade 2: the echogenicity has resolved into small periventricular cyst...
The peroneal tubercle (also known as the peroneal trochlea) is one of the two bony projections or protuberances that may be seen on the lateral aspect of the calcaneus, the other one being the retrotrochlear eminence.
The peroneal tubercle is present immediately inferior to the fibular malleolu...
PGMI (Perfect, Good, Moderate, Inadequate) is a method of evaluation of clinical image quality in mammography developed by the United Kingdom Mammography Trainers Group with the support of the Royal College of Radiographers, aimed to ensure the maintenance of a high standard of mammography in Br...
There are several drugs which are useful for evaluation of nuclear studies for respective systems. These drugs play an important role in monitoring the physiological changes and aiding in diagnosis .
Drugs used are
metoclopramide and erythromycin in gastrointestinal scintigraphy; used for gast...
Piedmont fractures have been variably defined in the literature. Many suggest that Piedmont fractures are synonymous with Galeazzi fractures. That is a fracture of the radius at the middle and distal third with associated disruption of the distal radioulnar joint.
The initial report about the s...
Pipkin classification is the most commonly used classification for femoral head fractures, which are uncommon but are associated with hip dislocations.
type I: fracture distal to the fovea capitis, a small fracture not involving the weightbearing surface
type II: fracture proxi...
Placental grading (Grannum classification) refers to an ultrasound grading system of the placenta based on its maturity. This primarily affects the extent of calcifications. In some countries, the use of placental grading has fallen out of obstetric practice due to a weak correlation with advers...
Poliovirus is the causative agent involved in poliomyelitis. It is a single-stranded RNA virus and one of the smallest significantly described viruses:
group: group IV
species: enterovirus C
Polymicrogyria is one of many malformations of cortical development (see classification system for cortical malformations), and along with grey matter heterotopias, falls under a bewildering group of conditions characterised by abnormalities both in migration of neurons to the cortex and abnorma...
The posterior atrophy score, a.k.a. Koedam score, has been developed to enable visual assessment of parietal atrophy on MRI, and is useful in the assessment of patients with possible dementia, especially atypical or early onset Alzheimer's disease (see: neurodegenerative MRI brain: an approach) ...
Preinvasive lesions for lung adenocarcinoma are a category of small non-invasive lung lesions which are closely related to adenocarcinoma of the lung. They may represent a spectrum of premalignant to low-grade malignant lesions.
The category includes two types of lesions:
atypical adenomatous ...
PI-RADS (Prostate Imaging Reporting and Data System) refers to a structured reporting scheme for evaluating the prostate for prostate cancer. It is designed to be used in a pre-therapy patient.
The original PI-RADS score was annotated, revised and published as the second version, PI-RADS v2 6, ...
A pulmonary arterial stenosis can be classified into several types 1,2:
type I: involving main pulmonary artery
type II: involving bifurcation
type III: multiple peripheral stenoses
type IV: central and peripheral stenoses
congenital pulmonary stenosis
There are numerous causes of pulmonary hypertension, and thus not surprisingly there have been many classification systems.
In 2003, the 3rd World Symposium on PAH met in Venice and produced an updated classification system (this has been further revised in the Dana Point classification of pulm...
The classification system for pulmonary hypertension was revised at the 4th World Symposium on Pulmonary Hypertension held in Dana Point, California, in 2008 1.
This system is as follows:
group 1: pulmonary arterial hypertension
1.1: idiopathic pulmonary arterial hypertension
1.2: heritable ...
In 2013, the 5th World Symposium on pulmonary hypertension took place in Nice, France and modified the classification system for pulmonary hypertension.
The modified system divides pulmonary hypertension into five groups:
group 1: pulmonary arterial hypertension (disorders of the pulmonary ar...
Pulmonary nodules are small, rounded opacities within the pulmonary interstitium. Pulmonary nodules are common and, as the spatial resolution of CT scanners has increased, detection of smaller and smaller nodules has occurred, which are more often an incidental finding.
One grading system on pulmonary oedema based on chest radiograph appearances and pulmonary capillary wedge pressure (PCWP) is as follows:
grade 0: normal chest radiograph, PCWP 8-12 mmHg
grade 1: shows evidence of upper lobe diversion on a chest radiograph, PCWP 13-18 mmHg
grade 2: shows inte...
Pulmonary sarcoidosis may be classified on a chest radiograph into 5 stages 1-2:
stage 0: normal chest radiograph
5-10% of patients at presentation
stage I: hilar or mediastinal nodal enlargement only
45-65% of patients at presentation
60% go onto a complete resolution
stage II: nodal enla...
Ranson's criteria are useful in assessing prognosis in early acute pancreatitis. The more of the criteria are met the higher the mortality. Ranson's criteria are assessed both at admission and at 48 hours.
age: >55 years
white blood count: >16 000/mm
blood glucose leve...
RASopathies are a class of developmental disorders caused by germline mutations in genes that encode for components or regulators of the Ras/mitogen-activated protein kinase (MAPK) pathway.
As a group, RASopathies represent one of the most common malformation syndromes, with an in...
The Raymond–Roy occlusion classification (RROC) is an angiographic classification scheme for grading the occlusion of endovascularly treated intracranial aneurysms 1. It is also known as the Raymond class, Montreal scale or the Raymond Montreal scale.
class I: complete obliteration
class II: r...
work in progress - Fran/Derek
UK interpretation/system to guide investigation (2008)
Response Evaluation Criteria In Solid Tumours (RECIST) was updated to version 1.1 in 2009.
For both RECIST 1.0 and 1.1, the requirement for measurable disease at baseline depends on the endpoints of the clinical trial.
The fundamental concept common to both versions of RECIST is that measurabl...
A retropulsed fragment is any vertebral fracture fragment that is displaced into the spinal canal, thereby potentially causing spinal cord injury.
They usually arise from the vertebral body with or without a portion of the pedicle, and are displaced posteriorly, hence the prefix 'retro'.
The retrotrochlear eminence is located posterior to the peroneal tubercle and the peroneal tendons.
It is one of two bony projections or protuberances that may be seen arising from the lateral wall of the calcaneum, the other being the peroneal tubercle.
It is seen to be prominent in individua...
The Revised Atlanta classification of acute pancreatitis is an international multidisciplinary classification of the severity of acute pancreatitis, updating the 1992 Atlanta classification. It was initially revised in 2012 and then further updated in 2016 6.
The worldwide consensus aims for an...
Following months of preparation, experts in the field of vasculitis from 12 different countries proposed an update to the 1994 International Chapel Hill Consensus Conference nomenclature of vasculitides. This 2012 update at the time of writing (mid-2016) remains the most widely used system for d...
Riseborough and Radin classification of intercondylar fractures of the humerus can be used to classify this injury, which is the result of direct trauma to the olecranon as it is driven as a wedge between the humeral condyles. Four types of fractures can be identified:
type I: no displacement ...
The risk of malignancy index (RMI) in ovarian tumours is a validated clinical tool used for risk stratification of ovarian lesions, to guide further management 1-3.
The score incorporates the patient's menopausal status (M), ultrasound features of the lesion (U), and the serum C...
The Risser classification is used to grade skeletal maturity based on the level of ossification and fusion of the iliac crest apophyses. It is primarily in planning corrective surgery for scoliosis.
stage 0: no ossification center at the level of iliac crest apophysis
stage 1: ...
The Rockwood classification (1998) is the most common classification system in use for acromioclavicular joint injuries 3. This well known 6-type system is a modification of the earlier 3-class classification system described by Allman (1967) 2 and Tossy (1963).
It takes into account not only t...
One method of grading rotator cuff tears on MRI is as follows:
grade 0: normal
grade I: increased T2 signal with normal morphology
grade II: increased T2 signal with abnormal morphology (thickening, or irregularity of the tendon)
grade III: defined tear (e.g. partial or full thickness, compl...
The Rotterdam CT score of traumatic brain injury is a relatively recently described classification aimed at improving prognostic evaluation of patients admitted with acute traumatic brain injuries.
It was published in 2006 1 and is gaining in popularity. Along with the Marshall classification ...
The Roy-Camille classification of fractures of the odontoid process of C2 depends on the direction of the fracture line 1.
The level of fracture line as described by the Anderson and D’Alonzo classification, is not predictive of the degree of instability or the risk of non-union. This classific...
Sacroiliitis grading can be achieved using plain radiographs according to the New York criteria 4.
grade 0: normal
grade I: some blurring of the joint margins - suspicious
grade II: minimal sclerosis with some erosion
definite sclerosis on both sides of joint 5
The Salter-Harris classification was proposed by Salter and Harris in 1963 1 and at the time of writing (June 2016) remains the most widely used system for describing physeal fractures.
Conveniently the Salter-Harris types can be remembered by the mnemonic SALTR.
Salter-Harris type II fractures are the most common type of physeal fractures that occur in children. There is a fracture that extends through the physis and into a portion of the metaphysis. A triangular metaphyseal fragment, otherwise known as the Thurston Holland fragment, will be left intact...
Salter-Harris type III fractures are an uncommon, intraarticular fracture physeal fractures that occur in children.
The fracture line is often obliquely orientated through the epiphysis to the physis where it will take a horizontal orientation extending to the edge of the physis.
Salter-Thompson classification for Legg-Calve-Perthes disease simplifies the Catterall classification into 2 groups. Based on the radiographic crescent sign, we can distinguish:
group a: including Catteral groups I and II, where the crescent sign involves less than 50% of the femoral head.
The Sanders classification system is used to assess intraarticular calcaneal fractures, which are those involving the posterior facet of the calcaneus. This classification is based on the number of intraarticular fracture lines and their location on semicoronal CT images. This classification is ...
Sarcopenia can be defined as significant loss of muscle function as a result of decreased muscle bulk. The definition was originally restricted to elderly individuals only, however many use it for people of any age.
A direct evaluation of muscle mass on imaging can be performed. Conversely, a r...
Schatzker classification system is one method of classifying tibial plateau fractures.
Increase in type number denotes increasing severity, reflecting an increase in energy imparted to the bone at the time of injury and also an increasingly worse prognosis 1. The most common fracture of the tib...
Scheuermann disease, also known as juvenile kyphosis, juvenile discogenic disease 11, or vertebral epiphysitis, is a common condition which results in kyphosis of the thoracic or thoracolumbar spine. The diagnosis is usually made on plain film.
occurs in ~5% (range 0.4-8%) of the ...
Sex cord / stromal ovarian tumours are a subtype of ovarian tumours and account for 8-10% of all ovarian tumours. They arise from two groups of cells in the ovary:
primitive sex cords: coelomic epithelium
The group of tumours includes
ovarian fibroma-thecoma spectrum
Short limb skeletal dysplasias are skeletal dysplasias which are characterised by limb shortening
Rhizomelic (proximal limb shortening)
particularly type II
The shunt-dependency in symptomatic aneurysmal subarachnoid haemorrhage (SDASH) score is a harmonized score for the prediction of hydrocephalus requiring shunting after subarachnoid haemorrhage. The tool is employed in the acute phase to predict which patients will require shunting, rather than ...
The Siewert-Stein classification of oesophageal adenocarcinoma classes these tumours according to their relationship to anatomical landmarks 1. It was initially proposed by Siewert et al in 1996, becoming widely used in predicting lymph node spread and directing optimal management. As of the 7th...
The Simpson grade of meningioma resection was described in 1957 and correlated the degree of surgical resection completeness with with symptomatic recurrence 1.
Although the type of resection still plays a part in the likelihood of symptomatic recurrence, other factors (such as the MIB-1 index...
The Singh index is a classification system for bone density of the femoral neck based on the visibility of the trabecular types that can be seen in the femoral neck.
Trabecular types in proximal femur
Five trabecular types can be present in the proximal part of the femur:
Situs classification can be a daunting topic, but it falls into three main groups :
situs solitus: the normal configuration of thoracic and abdominal organs
situs inversus: mirror image of normal
situs ambiguus: an intermediate configuration with duplication (isomerism)
Situs is best thought...
Situs solitus refers to the normal position of the thoracic and abdominal organs.
On plain radiograph, careful attention should be directed at the location of the aortic arch, gastric fundus, cardiac apex, pulmonary fissures and the branching pattern of ...
A small for dates fetus can result from a number of factors
structural anomalies (syndromes)
fetal Warfarin syndrome
hydantoin embryopathy (Dilantin TM)
The WHO 2002 classification of soft tissue tumours is as follows:
This, however, has been revised under the 2013 WHO tissue tumour classification system 4.
lipomatosis of nerve 8850/0
In typical Scheuermann disease of the thoracic spine the Sorensen criteria are met when three or more consecutive vertebrae are wedged by 5 degrees or more 1.
The Spetzler-Martin arteriovenous malformation (AVM) grading system allocates points for various features of intracranial arteriovenous malformations to give a grade between 1 and 5. Grade 6 is used to describe inoperable lesions. The score correlates with operative outcome.
size of ni...
Spinal arteriovenous malformations can be classified in a number of ways:
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)
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 aetiologies.
Injury to the spinal cord can be incomplete or complete and depends upon the mechanism of injury. This is important as diffe...
The spinal instability neoplastic score (SINS) helps to assess tumour related instability of the vertebral column. It has been shown to useful in guiding the mobilisation or operative management of patients with neoplastic spinal disease.
Studies have reported good inter-observer agreement amon...
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%)
intramedually metastases (1%)
Each of these are discussed separately. Below ...
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.
Although etymologically it is directionless (see below) and c...
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...
Spondylolisthesis can be classified according to broad aetiologies 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 ...
Squamous cell carcinomas (SCC) of the head and neck are common, being the sixth most common cancer. They can have a cutaneous or mucosal origin. As such there is a wide array of clinical and radiographic manifestations, and are separated into:
squamous cell carcinoma of the skin of the head and...
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...
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...
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...
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...
The Stewart classification for proximal fifth metatarsal fractures is based upon fracture location and morphology. It is divided into five types.
extra-articular transverse or oblique fracture between base of 5th metatarsal and diaphysis (jones fracture)
Grading of SUFE (slipped upper femoral epiphysis) can be made on both AP and true lateral projections.
On an AP radiograph a line along the superior margin of the femoral neck (line of Klein) should intersect the lateral corner of the epiphysis.
As the epiphysis slips, the metaphysis can be d...
SVC obstruction can cause SVC syndrome which is the most common condition affecting this vessel. It can be secondary to an extrinsic compression or intraluminal thrombosis/stenosis. Collateral pathways, with the azygos vein being the most important collateral vessel, form in response to severe n...
Supracondylar humeral fractures, often simply referred to as supracondylar fractures, are a classic paediatric injury which require vigilance as imaging findings can be subtle.
Simple supracondylar fractures are typically seen in younger children, and are uncommon in adults; 90% a...
The staging system for moyamoya disease first described by Suzuki and Takaku in their seminal 1969 article1 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 t...
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...
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...
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 ...
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 haemorrhage, diffuse axonal injury and cerebral contusions are common. Early identification of te...
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.
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...
The two most commonly currently used thoracolumbar spinal fracture classification systems are the AO classification and the TLICS although a number of other classification systems have been proposed over the years 1. Each has benefits and drawbacks and each incorporates various features in an at...
The three column concept of thoracolumbar spinal fractures was initially devised by Francis Denis and presently CT is mandatory for an accurate classification.
While initially developed for classification of thoracolumbar spinal fractures, it can also be applied to the lower cervical spine 3 as...
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 ischaemic stroke. In neurointerventional radiology it is commonly used for patients post endovascular revascularisation. Li...
The thrombolysis in myocardial infarction (TIMI) risk score is a prognostic risk stratification system that categorises the risk of death and ischemic events in patients with unstable angina / NSTEMI and provides a basis for therapeutic decision making. It is thought to have potential to improve...
TI-RADS is a risk stratification system for classifying thyroid lesions and was recently recognized in an American College of Radiology (ACR) white paper1. Its use is being advocated similar to BI-RADS category for breast lesions.
In 2017, a white paper2 was released by the ACR committee on th...
Tillaux fractures are Salter-Harris III fractures through the anterolateral aspect of the distal tibial epiphysis, with variable amounts of displacement.
It occurs in older children and adolescents when the medial aspect of the distal tibial growth plate has started to fuse.
The TOAST (trial of ORG 10172 in acute stroke treatment) classification denotes five sub types of ischaemic stroke.
large-artery atherosclerosis (embolus / thrombosis)*
cardioembolism (high-risk / medium-risk)*
small-vessel occlusion (lacune)*
stroke of other determined aetiology *
The Todani classification of bile duct cysts divides choledochal cysts into five groups.
See: type I choledochal cyst
account for 80-90% of all bile duct cysts
characterised by fusiform dilation of the extrahepatic bile duct
a subclassification has been proposed
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.
narrow fracture line with sharp margins and no widening
minimal cortical hyper...
Transitional cell carcinomas of the urothelium are graded histologically as follows:
transitional cell papilloma
benign tumour, 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 ...
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...