Esophageal atresia is closely related to tracheo-esophageal fistula and can be divided into1:
type A: isolated esophageal atresia (8%)
type B: proximal fistula with distal atresia (1%)
type C: proximal atresia with distal fistula (85%)
type D: double fistula with intervening atresia (1%)
The term off-ended is used by some orthopedic surgeons and radiologists to describe a long bone fracture that is displaced by more than the width of the bone. An off-ended fracture is often shortened due to muscle contraction.
Oligoprogression is an increasingly recognized concept in oncology, denoting a state where after an initially successfully systemic therapy of disseminated metastases, a single or very few lesions display further progression.
A key difference between the related concepts of oligom...
Open book pelvic injuries are most often the result of high-energy trauma and are associated with significant morbidity and mortality due to associated vascular injuries.
Open book pelvic injuries result from an anteroposterior compression injury to the pelvis and result in a combin...
Organ Procurement and Transplantation Network (OPTN) is the unified transplantation network in the United States and runs under the administration of United Network for Organ Sharing (UNOS). OPTN classification is the part of the imaging policy of UNOS that consists of in order to determine the ...
Orthoroentgenogram is a radiographic study used to evaluate anatomic leg length and calculate leg-length discrepancies. This study utilizes a long ruler placed on the film, and three radiographs including bilateral hips, knees and ankles.
Similar studies used to evaluate true leg length include...
Osteoarthritis of the hip can be graded according to severity on imaging.
Conventional radiograph grading
grade 0: normal
grade 1: possible joint space narrowing and subtle osteophytes
grade 2: definite joint space narrowing, defined osteophytes and some sclerosis, especially in the acetabul...
Osteochondral injury staging system for MRI attempts to grade the stability and severity of osteochondral injury and is used to plan management.
injury limited to articular cartilage
MRI findings: subchondral edema
x-ray findings: none
cartilage injury with associated subc...
Osteochondritis dissecans can be classified at surgery into 4 stages:
lesion in continuity with the host bone
covered by intact cartilage
stable on probing
partial discontinuity of the lesion from the host bone
unstable on probing
fragment not dislocat...
The several forms of osteogenesis imperfecta (OI) have been classified, representing wide variation in appearance and severity, and clinical features vary widely not only between types but within types.
Osteogenesis imperfecta was initially classified by type according to a sche...
The ovarian-adnexal reporting and data system (O-RADS) is an ultrasound risk stratification and management system for the evaluation of ovarian and other adnexal masses.
These recommendations function have been published to guide the management of "average-risk patients without acute symptoms" ...
Ovarian cysts are commonly encountered in gynecological imaging, and vary widely in etiology, from physiologic, to complex benign, to neoplastic.
Small cystic ovarian structures should be considered normal ovarian follicles unless the patient is pre-pubertal, post-menopausal, pregnan...
Overall visual assessment of coronary artery calcification is a simple scoring system for risk assessment of coronary heart disease mortality by an overall "gestalt" of none, mild, moderate or heavy coronary artery calcification. It is comparable to the Agatston score but has the advantage of be...
Pediatric mediastinal masses are the most common chest masses in children, with the anterior mediastinum being the most common site 1.
As in adults, mediastinal masses are classified depending on anatomical sites:
anterior mediastinal masses
middle mediastinal masses
posterior mediastinal ma...
This classification system based on the embryology and anatomy of the nasal cavity, nasofrontal region, and nasolacrimal apparatus as well as anomalies associated with craniofacial syndromes.2
choanal atresia and stenosis
pyriform aperture stenosis
Palmer classification for triangular fibrocartilage complex (TFCC) abnormalities is based on the cause, location and degree of injury 1:
Class 1 - traumatic injury
a: central perforation of the triangular fibrocartilage (TFC) disc proper
b: ulnar avulsion with or without distal ulnar fracture...
Palmini classification of focal cortical dysplasia published in 2004 was one of the leading classification systems used for focal cortical dysplasia, recently replaced by a newer classification; Blumcke classification of focal cortical dysplasia.
Unfortunately, as is the case with many classif...
A number of pancreatic injury grading systems have been proposed.
American Association for the Surgery of Trauma (AAST)
grade 1: hematoma with minor contusion/laceration but without duct injury
grade 2: major contusion/laceration but without duct injury
grade 3: distal lacer...
Pandystrophies are neurological diseases that demonstrate both white and grey-matter involvement, as opposed to leukodystrophies (dominated by white matter involvement) or poliodystrophies (dominated by grey matter involvement).
Most metabolic diseases with central nervous system involvement fa...
Parenchymal patterns in breast imaging influence mammographic screening sensitivity and is related to the risk of breast cancer. This article describes the historical classifications of breast density. See the main article on breast density for the currently accepted BI-RADS descriptors.
Harrington criteria can be used to predict which long bone skeletal metastases are at high risk of pathological fracture and should undergo prophylactic internal fixation. It preceded the Mirels classification for impending pathological fracture but has not been validated and its use is debated....
Mirels classification is a system used to predict the highest risk of pathological fracture among long bones affected by metastases, and is based on site, location, matrix and/or presence of pain.
involving <1/3 of bone diameter
The Patte classification describes the amount of supraspinatus tendon retraction in a complete tear of the rotator cuff of the shoulder, and is applied on sequences in the frontal plane 1:
stage 1: proximal stump near the bony insertion
stage 2: proximal stump is at the level of the humeral he...
Patterns of normal bone marrow distribution in the spine have been described by Ricci 1. They apply to patients from the age of 6 months.
There are four patterns of normal red and yellow bone marrow distribution, with great variability not only between patients, but between respe...
Recognizing patterns of sinonasal obstruction is useful to help localize the area of pathology and narrow the differential diagnosis.
Babbel et al described five pattern of sinonasal obstruction 1, which are readily apparent on CT:
The penetration-aspiration scale (PAS) is a means of grading the severity of penetration or aspiration observed in a videofluoroscopic swallow study and is widely used 2.
The term aspiration is used for material that passes inferior to the level of the vocal folds. If material enters the larynx...
A simple grading system for penile fracture has been developed but it is not widely used or validated nor recognized by relevant urological surgical societies. Regardless, this system which relies on ultrasound assessment of the tunica albugenia, corpora of the penis, urethra and other fascia 1 ...
Perianal disease (also known as anorectal disease) is the collective name given to a group of diseases that primarily affect the anal canal +/- rectum. The disease spectrum ranges from the typically benign, e.g. hemorrhoids, to the more potentially more serious, e.g. perianal fistula 1-3.
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 inferior to the fovea capitis, a small fracture not involving the weightbearing surface
type II: fracture ext...
The PISAPED criteria for the diagnosis of pulmonary embolus indicate the presence or absence of pulmonary emboli based on findings on perfusion scintigraphy (only the Q portion of the V/Q scan) in combination with chest radiography. The criteria were validated in the Prospective Investigative St...
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...
Poliodystrophies are neurological disease dominated by grey-matter involvement as opposed to leukodystrophies (dominated by white matter involvement) or pandystrophies (both white and grey matter involved).
The poliodystrophy group are defined by predominant grey matter involvement, but some de...
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 characterized 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) is a structured reporting scheme for multiparametric prostate MRI in the evaluation of suspected prostate cancer in treatment naive prostate glands. This article reflects version 2.1, published in 2019 and developed by an internationally repre...
The PSA density (PSAD), is a calculation performed at diagnosis and is the serum PSA level (ng/mL) divided by the volume of the prostate gland (mL)1. Prostate volume is calculated from TRUS measurements2,3.
Alternatively, PSAD may be calculated using MRI measurements3 of prostate volumes or le...
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 edema 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 inter...
Pulmonary sarcoidosis may be classified on a chest radiograph into 5 stages (Scadding criteria) 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
Ranson criteria are useful in assessing prognosis in early acute pancreatitis. The more of the criteria are met the higher the mortality. Ranson criteria are assessed both at admission and at 48 hours.
age: >55 years
white blood count: >16 000/mL
blood glucose level: >...
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...
The RCR Breast Group (RCRBG), a working group formed by the Royal College of Radiologists (RCR) in the United Kingdom, published their standardized classification for breast imaging findings in 2009 1. The fourth edition was published in November 2019 2. This 5-point scale is used to classify t...
Response Evaluation Criteria In Solid Tumors (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 measurable...
The RENAL nephrometry scoring system was developed to categorize renal masses into low, intermediate and high complexity, based on cross-sectional imaging findings. Its purpose is to aid in decision making, patient counseling, surgical planning, and patient follow-up, as well as academic reporti...
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 from 2012 is an international multidisciplinary classification of the severity of acute pancreatitis, updating the 1992 Atlanta classification.
The worldwide consensus aims for an internationally agreed-upon classification of acute pancre...
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 tumors 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 CA...
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 classifica...
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 oriented through the epiphysis to the physis where it will take a horizontal orientation extending to the edge of the physis.
The Salter-Thompson classification of Perthes disease simplifies the Catterall classification into two 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
group B: i...
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...
The Schenck classification is categorizing knee dislocation based on the pattern of ligament tears. The four major ligamentous stabilizers are the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL) and the lateral collateral ligament (LCL) compl...
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 tumors are a subtype of ovarian tumors and account for 8-10% of all ovarian tumors. They arise from two groups of cells in the ovary:
primitive sex cords: coelomic epithelium
The group of tumors includes
ovarian fibroma-thecoma spectrum
Short limb skeletal dysplasias are skeletal dysplasias which are characterized by limb shortening
Rhizomelic (proximal limb shortening)
particularly type II
Shoulder impingement describes a group of conditions characterized by the entrapment of musculoskeletal soft tissue within the shoulder, which primarily results in pain. The catching of the affected structures may be structural and/or functional in etiology 2.
The commonest form of shoulder imp...
The shunt-dependency in symptomatic aneurysmal subarachnoid hemorrhage (SDASH) score is a harmonized score for the prediction of hydrocephalus requiring shunting after subarachnoid hemorrhage. The tool is employed in the acute phase to predict which patients will require shunting, rather than to...
The Siewert-Stein classification of esophageal adenocarcinoma classes these tumors 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 e...
The Simpson grade of meningioma resection was described in 1957 and correlated the degree of surgical resection completeness 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) are...
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:
There are several described single-phase CT angiography collateral scores for evaluating the status of collateral vessels in acute ischemic stroke. These scores have been shown to be reliable predictors of clinical outcomes and eligibility for mechanical thrombectomy (endovascular clot retrieval...
Situs classification (plural: sitūs) 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 the normal configuration
situs ambiguus (heterotaxy): an intermediate configuration with ...
Situs solitus (rare plural: sitūs soliti) 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 a...
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...
A small for dates fetus can result from a number of factors
structural anomalies (syndromes)
fetal Warfarin syndrome
hydantoin embryopathy (Dilantin TM)
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...