The Lodwick classification is a system for describing the margins of a lucent/lytic bone lesion. The terms used in the description suggest the level of concern for an aggressive, and possibly malignant, process.
type 1: geographic
1A: thin, sclerotic margin
1B: distinct, well-...
LR2 cirrhosis-associated nodules are defined as "probably benign" according to the LI-RADS classification system. They are a common finding in a cirrhotic liver and do not need to be mentioned in the report.
The nodule must demonstrate all of the following:
The Lugano classification recommends two methods of visualization for standing lymphoma:
Computer tomography (CT)
Positron emission tomography–computed tomography (PET/CT)
Response Assessment on CT
CT uses for the standing of all types of lymphoma (if CT is performed for tumor size measure...
Several classification systems exist for the lunate morphology 1, 2.
The lunate classification proposed by Veigas et al. is arguably the most relevant 3:
type I lunates: single distal articular facet for the capitate
type II lunates: additional distal articular facet medially...
The Lund-Mackay score is a widely used method for radiologic staging of chronic rhinosinusitis 1.
When reading a CT scan of the paranasal sinuses and ostiomeatal complex, the reader assigns each sinus a score of:
0 (no abnormality)
1 (partial opacification) or
2 (complete opacification)
The IASLC (International Association for the Study of Lung Cancer) 8th edition lung cancer staging system was introduced in 2016 and supersedes the IASLC 7th edition.
T: primary tumour
Tx: primary tumour cannot be assessed or tumour proven by the presence of malignant cells in spu...
Lung-RADSTM (or lung imaging reporting and data system) is a classification proposed to aid with findings in low dose CT screening exams for lung cancer. The goal of the classification system is to standardize follow-up and management decisions. The system is similar to the Fleischner criteria b...
Lymph nodes in the neck have been divided into seven levels, generally for the purpose of squamous cell carcinoma staging. This system is not inclusive of several important groups, however, such as the supraclavicular, parotid, retropharyngeal space, and occipital nodes.
The Magerl classification of thoracolumbar spinal fractures is based on the three column concept by Denis, and the McAfee classification. It relies exclusively on CT findings.
A: compression injuries
A1: impaction fractures
A1.1: endplate impaction
A1.2: wedge impaction
The magnetic resonance imaging in multiple sclerosis (MAGNIMS), which is a European collaborative research network, published in 2016 new recommendations to upgrade the imaging diagnosis criteria for multiple sclerosis (MS). These came as a consensus, based on evidence-based and expert opinions ...
Here is a list of some of the most useful differential diagnoses in musculoskeletal imaging.
lucent/lytic bone lesions (FEGNOMASHIC)
multiple lucent/lytic bone lesions
benign lytic bone lesions in patients under 30
diffuse bony sclerosis
permeative process in bone
The Markowitz and Manson classification system categorises fractures of the naso-orbitoethmoid (NOE) complex as follows 1:
type I - in which the medial canthal tendon is intact and connected to a single large fracture fragment
type II - the fracture is comminuted, and the medial canthal tendon...
The Marshall classification of traumatic brain injury is a CT scan derived metric using only a few features and has been shown to predict outcome in patients with traumatic brain injury.
This system was first published in 1992 1 building on findings from a large cohort of head injury cases des...
The Mason classification is used to classify radial head fractures and is useful when assessing further treatment options 1-2.
type I: non-displaced radial head fractures (or small marginal fractures), also known as a "chisel" fracture
type II: partial articular fractures with displacement (>2...
Mayfield classification of carpal instability, also known as perilunate instability classification (carpal dislocations), describes carpal ligament injuries.
Instability has been divided into four stages 1-2:
stage I: scapholunate dissociation (rotatory subluxation of the scaphoid)
Mayo classification of scaphoid fractures divides them into three types according to the anatomic location of the fracture line:
Fractures of the distal third are further divided into distal articular surface and distal tubercle fractures:
McAfee classification of acute traumatic spinal injuries is based on the three column concept of the spine. CT is needed for accurate assessment.
wedge compression: isolated anterior column compression
stable burst: anterior and middle column compression but posterior column i...
The McDonald's criteria are MRI criteria used in the diagnosis of multiple sclerosis and were initially described in 2001 and revised in 2005. Since these initial revisions, the criteria has been revised again in 2010 and 2017.
Below are the previously used criteria, which should no longer be e...
McDonald diagnostic criteria 2010 were MRI criteria used in the diagnosis of multiple sclerosis. They were introduced in 2001, revised in 2005, 2010 (the focus of this article) and in 2016 (by MAGNIMS) 1. The latest revision was in 2017 2.
Below are the previously used criteria, which should no...
McDonald diagnostic criteria for multiple sclerosis are clinical, radiographic, and laboratory criteria used in the diagnosis of multiple sclerosis. They were originally introduced in 2001 1, revised in 2005 2, 2010 3, 2016 (by MAGNIMS) 4 and most recently in 2017 5. The 2017 revision is the foc...
The McGill Thyroid Nodule Score (MTNS) is a scoring system developed to estimate the risk of malignancy of thyroid nodules.1
The MTNS is based on 22 parameters:
eight clinical or laboratory parameters
gender (male): 1 point
age (>45 years old): 1 point
palpable nodule (prese...
Meandering main pancreatic duct (MMPD) comprises of a reverse Z-type and loop-type of pancreatic ducts.
These ductal variants are found in ERCP and MRCP studies. The exact incidence is not known.
Increased incidence of meandering pancreatic duct has been reported in patients with idiopathic re...
Medial collateral ligament (MCL) injuries are graded into three groups on MRI, much in the same way as many other ligaments:
grade 1: (minor sprain) high signal is seen medial (superficial) to the ligament, which looks normal
grade 2: (severe sprain or partial tear) high signal is seen medial ...
The medial temporal lobe atrophy (MTA) score is useful in distinguishing patients with mild cognitive impairment and Alzheimer disease from those without impairment 2 is helpful in the assessment of patients with possible dementia (see neurodegenerative MRI brain - an approach).
The International Thymic Malignancy Interest Group (ITMIG) classification of mediastinal compartments was developed to reflect a division of the mediastinum based on cross-sectional imaging. It was in part an effort to consolidate prior discrepant classification systems in use by different medic...
The MELD score (Model for End-stage Liver Disease) is a classification used to grade liver dysfunction in preparation for liver transplantation. It is an estimate of 3 month mortality.
The components of the score are:
serum creatinine (mg/dl)
if dialysis twice in last week, then bilirubin is ...
The metaphyseal-diaphyseal angle (of Drennan) is an important measurement used to distinguish between tibia vara (Blount disease) and physiological bowleg.
This angle is measured by drawing a line along the long axis of the tibia, creating a perpendicular to this line, and drawing another line...
Microtia refers to a small pinna of the ear, when is it completely absent it is termed anotia.
The estimated incidence at around 1:9000 live births. It is more common in males and there is a recognised right sided predilection.
Microtia can be associated ...
The Milch classification is one of the classificaiton systems that can be used for lateral humeral condyle fractures and splits these fractures into two groups depending on their relationship with the trochlear groove:
type I: fracture passes lateral to the trochlear groove
type II: fracture p...
Mitchell classification of avascular necrosis is based on MRI signal characteristics within the centre of the lesion on T1 and T2-weighted images.
The lesion is classified into four stages with stage A representing early disease and stage D representing late disease. However, th...
Modality is the term used in radiology to refer to one form of imaging e.g. CT scanning. It is often used in the plural form, e.g. various modalities can be employed to evaluate this liver lesion.
More generally, in clinical medicine, the term modality is used for different types of procedures ...
The modified CT severity index is an extension of the original CT severity index (CTSI) was developed by Balthazar and colleagues in 1994 for distinguishing mild, moderate and severe forms of acute pancreatitis.
The original CT severity index has been followed internationally and has been very ...
The modified Fisher scale is a method for grading subarachnoid haemorrhage (SAH) seen on non-contrast CT. It was developed from the original Fisher scale which was modified to account for patients with thick cisternal blood and concomitant intraventricular (IVH) or intraparenchymal haemorrhage.
The modified Memphis criteria are a set of screening criteria for blunt cerebrovascular injury (BCVI) in trauma. The presence of one or more of these criteria makes necessary a complementary CTA or DSA study to exclude a BCVI.
The screening protocol criteria for BCVI are:
base of skull fractur...
The modified Noyes grading of chondromalacia was published in 2009 and is divided into four grades by MRI, typically using fat saturated proton density sequences. The original Noyes grading system was based on arthroscopic findings.
grade 0: normal cartilage
grade 1: increased ...
The modified Outerbridge grading of chondromalacia is divided into four grades by MRI, typically using fat saturated proton density sequences. This grading system was originally devised for arthroscopy initially for assessment of chondromalacia patella, but then modified and extended for all cho...
The modified Rankin scale or is a commonly used to quantify functional outcome in individuals who suffer a neurological event. The scale was initially described by Rankin in 1957 to assess the outcome of cerebrovascular accidents 1. It has subsequently been modified 2,3 and has been used in a wi...
The modified Ringertz grading system has historically been one of the more frequently used grading systems for diffuse astrocytomas, but has not essentially been replaced by the WHO grading system.
Unlike the WHO grading system and St Anne-Mayo grading system (also known as the Dumas-Duport gra...
The modified treatment in cerebral infarction (mTICI) score was developed from the original Thrombolysis in Cerebral Infarction (TICI) scale by a consensus group in 2013 1. The recommendations included a name change to better reflect the increasing use of endovascular therapy for stroke, and sim...
Disc degeneration can be graded on MRI T2 spin-echo weighted images using a grading system proposed by Pfirrmann 1. This classification is not used on routine spine reports, being more important for research purposes.
grade I: disc is homogeneous with bright hyperintense white signal intensity ...
MRI grading system for abnormal high meniscal signal intensity was reported by Lotysch et al. MR grades 1, 2 and 3 have been used:
grade 1: small focal area of hyperintensity, no extension to the articular surface
grade 2: linear areas of hyperintensity, no extension to the articular surface
Mucinous neoplasms of the appendix are epithelial tumours of the appendix that produce mucin. According to a panel of specialists consensus published in 2016, a new nomenclature and classification for the appendiceal mucinous neoplasms based on their histologic type and biologic behaviour has be...
Mueller Weiss syndrome refers to a spontaneous adult onset osteonecrosis of the tarsal navicular. This syndrome is multifactorial and related to chronic loading on a suboptimally ossified navicular bone which is susceptible to central osteonecrosis due to its centripetal blood supply. It is dist...
The Müllerian duct anomaly classification is a seven point system that can be used to describe a number of embryonic Müllerian duct anomalies:
class I: uterine agenesis / uterine hypoplasia
a: vaginal (uterus: normal / variety of abnormal forms)
Myeloproliferative disorders (MPDs) are a diverse group of conditions that are characterised by the overproduction of red cells, white cells and/or platelets in bone marrow. There are numerous conditions considered in this group but the most common are:
There are several types of neck dissections which can classified as follows:
Radical neck dissection
Radical neck dissection is considered to be the standard basic procedure for cervical lymphadenectomy. All other procedures represent one or more alterations of this procedure. The dissection i...
Necrotising enterocolitis (NEC) can be staged into three groups, helping to guide appropriate treatment. In general, stage I and II are managed medically whereas stage III is managed surgically.
lethargy, temperature instability, apnoea, bradycardia
emesis, abdominal d...
The Neer classification of proximal humeral fractures is probably the most frequently used along with the AO classification of proximal humeral fractures. Even if an exact knowledge of this classification system is beyond the everyday use of many radiologists, the terminology and factors which i...
Nerve injury classification describes the various features of nerve injury on MRI with respect to pathological events.
grade I: there is increased T2/STIR signal in the nerve, however the muscle appears normal
grade II: increased T2/STIR signal in ne...
Neuroendocrine tumours (NETs) represent a wide spectrum of disease. They consist of a large heterogeneous group of malignancies that are derived from embryonic neural crest tissue found in various organ such as the hypothalamus, pituitary gland, thyroid gland, adrenal medulla, and gastrointestin...
Non-Hodgkin lymphoma (NHL) is a catch-all term for lymphomas that are not of the Hodgkin subtype. It is a heterogeneous group of malignancies in terms of histology, clinical presentation, and prognosis.
See 2008 WHO classification for further information on subtypes.
Non-specific interstitial pneumonia (NSIP) is the second most common morphological and pathological pattern of the interstitial lung diseases. NSIP has two main subtypes:
fibrotic type: most common, having a more dismal outcome
cellular type: less common, but carries a much better prognosis du...
Bone marrow signal of the clivus changes predictably with age and is well assessed with midline T1 non-fat-saturated, non-contrast images. As is seen in the rest of the body the proportion of yellow (fatty) marrow increases with age. Knowledge of these changes allows diagnosis of the abnormal cl...
The Nottingham classification is used at the end of work up of a breast lesion to help guide management.
A = malignant
lesion needs surgical excision regardless of biopsy result
B = indeterminate
will accept a benign biopsy result, but only if it is congruent with imaging, i.e. a well circum...
Occipital condylar fractures result from high-energy blunt trauma and is a specific and localized type of basilar skull fracture.
The exact incidence of these fractures is unknown but are reported to occur in 3-4% patients with moderate-severe traumatic brain injuries 3.
Odontoid process fracture, also known as the peg or dens fracture, occurs where there is a fracture through the odontoid process of C2.
The mechanism of injury is variable, and can occur both during flexion or extension with or without compression 5.
There are two cl...
Oesophageal atresia is closely related to tracheo-oesophageal fistula and can be divided into1:
type A: isolated oesophageal 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%)
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...
T staging of oral cavity tumours is as follows:
The anterior border of the oral cavity is the junction of the skin and vermilionborder of the lip. The posterior border is formed by the junction of the hard and soft palates superiorly, the circumvallate papillae inferiorly, and the ...
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 ...
T staging of oropharyngeal tumours is as follows:
The oropharynx includes the base of the tongue, the inferior surface of the soft palate and uvula, the anterior and posterior tonsillar pillars, the glossotonsillar sulci, the pharyngeal tonsils, and the lateral and posterior pharyng...
Orthoroentgenogram is a radiographic study used to evaluate anatomic leg length and calculate leg-length discrepancies. This study utilises 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...
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 oedema
x-ray findings: none
cartilage injury with associated sub...
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.
OI was initially classified by type according to a scheme developed by Dr Da...
Ovarian cysts are commonly encountered in gynaecological imaging, and vary widely in aetiology, 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, pregnant, or the...
Paediatric 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 m...
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
b: ulnar avulsion with or without distal ulnar fracture
may involve the proximal or distal lamina (foveal...
A number of pancreatic injury grading systems have been proposed.
American Association for the Surgery of Trauma (AAST)
grade 1: haematoma with minor contusion/laceration but without duct injury
grade 2: major contusion/laceration but without duct injury
grade 3: distal lace...
Mammographic density is considered a risk factor for breast cancer, and parenchymal patterns in breast imaging are important in the way in which the effects mammographic screening sensitivity. Women with high-risk density patterns should be screened more frequently and/or with additional views p...
Harrington criteria can be used to predict which skeletal metastases are at high risk of pathological fracture and should undergo prophylactic internal fixation. It preceded the Mirel classification for impending pathological fracture but has not been validated and its use is debated.
Mirel classification is a system used to predict the highest risk of pathological fracture among bones affected by metastases.
involving <1/3 of bone diameter
involving 1/3-2/3 of bone diameter
Recognising patterns of sinonasal obstruction is useful to help localise 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:
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
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/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 malleolus, lying in between the two t...
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 a 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 adverse ...
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
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) ...
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...