Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

1,140 results found
Article

Lacrimal gland masses

Lacrimal gland masses​ can be classified into two broad groups - inflammatory (~50%) and neoplastic, either lymphoma (25%) or salivary gland type tumors (~25%).  Pathology Inflammatory sarcoidosis affects ~25% of patients with systemic disease orbital inflammatory pseudotumour lacrimal gla...
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Large for dates uterus

A large for date uterus is a clinical observation based on uterine fundal height, which may result in referral for ultrasound assessment, usually in mid to late pregnancy.    Causes include: incorrect dates constitutionally large fetus multiple pregnancy fetal macrosomia polyhydramnios ut...
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Large joint dislocation

Large joint dislocation is a not uncommon presentation to emergency rooms. Described in order of comonality: shoulder dislocation elbow dislocation posterior dislocation of the hip knee dislocation
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Large unilateral pleural effusion

When a pleural effusion is large and unilateral, concern for an underlying abnormality should be raised. Causes include: tumor bronchogenic carcinoma mesothelioma pleural metastases lymphoma pleural lymphoma primary effusion lymphoma infection parapneumonic effusion empyema extension ...
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Laryngeal cyst

Laryngeal cysts can occur in any part of the larynx, but are more frequent in supraglottic locations, such as the epiglottis and vallecula. The prevalence of each location varies on different studies.  Epidemiology The laryngeal cysts represent a rare group, about 5%, of benign laryngeal lesio...
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Lateral epicondyle fracture

Lateral epicondyle fractures are rare epicondylar fractures. They are much rarer than medial epicondyle fractures and represent avulsion of the lateral epicondyle. They are usually seen in the setting of other injuries 1-3.  Epidemiology Incidence typically peaks in the pediatric age group (6-...
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Leadless cardiac pacemaker

Leadless cardiac pacemakers are a recently introduced type of cardiac conduction device. These pacemakers are self-contained right ventricular single-chamber pacemakers that are implanted percutaneously via a femoral approach 1-3. There are currently two leadless cardiac pacemakers on the market...
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Lead poisoning

Lead poisoning or plumbism is a multisystem condition due to the way in which lead interferes with the function of virtually every organ system. Plumbism most severely manifests due to its devastating effects on the CNS, but it also has important deleterious consequences on the skeletal, renal, ...
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Left atrial line

The left atrial (LA) line monitors LA pressure and is indicative of left ventricular function, preload and afterload. The LA line enters from the left superior vein and exits the far side of the chest. The LA line is a single lumen catheter unlike the right atrial line, which is double lumen. N...
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Left lower lobe collapse

Left lower lobe collapse has distinctive features, and can be readily identified on frontal chest radiographs, provided attention is paid to the normal cardiomediastinal contours. However, the shadow cast by the heart does make it more difficult to see than the right lower lobe collapse. Some o...
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Left lower lobe consolidation

Left lower lobe consolidation refers to consolidation in part (incomplete) or all (complete) of the left lower lobe. Pathology Consolidation refers to the alveolar airspaces being filled with fluid (exudate/transudate/blood), cells (inflammatory), tissue, or other material. The list of causes...
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Left paramediastinal catheter position (differential)

When a central venous catheter that is supposed to project over the superior vena cava is abnormally located to the left of the mediastinum a limited differential of left paramediastinal catheter position should be considered 1: located within a vein left sided superior vena cava left interna...
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Left upper lobe collapse

Left upper lobe collapse has distinctive features but can be challenging to identify on chest radiographs by the uninitiated. Hence it is a classic chest radiograph case for radiology fellowships exams. For a general discussion refer to the article on lobar collapse. Radiographic features Pla...
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Left upper lobe consolidation

Left upper lobe consolidation refers to consolidation in part (incomplete) or all (complete) of the left upper lobe. Pathology Consolidation refers to the alveolar airspaces being filled with fluid (exudate/transudate/blood), cells (inflammatory), tissue, or other material. The list of causes...
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Leg bowing in children

Leg bowing in children is common and often developmental. Differential diagnosis The differential includes: developmental bowing exaggeration of normal age-related angulation changes at the knee neonates and infants normally have varus angulation that gradually corrects within 6 months of w...
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Leiomyoma

Leiomyoma is a benign smooth muscle (myometrial) tumor, most commonly found in the uterus.  Classification Leiomyoma is classified by location: uterine leiomyoma cervical leiomyoma leiomyoma of the urinary bladder urethral leiomyoma solitary cutaneous leiomyoma vascular leiomyoma (angiol...
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Leptomeningeal enhancement

Leptomeningeal enhancement refers to a diffuse or focal gyriform or serpentine enhancement that can be seen in the following conditions: Diffuse meningitis pyogenic meningitis viral meningitis tuberculous meningitis (can also be focal) CNS cryptococcal infection coccidioidal meningitis (c...
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Lesions of the corpus callosum (differential)

Lesions of the corpus callosum are uncommon and arise from multiple different etiologies. The lesions can be classified according to underlying pathophysiology 4-6. Congenital agenesis of the corpus callosum enlarged perivascular spaces tubonodular pericallosal lipoma: associated with dysgen...
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Leukemia

Leukemia is a hematological neoplasm characterized by the overproduction of immature (blasts) or abnormally differentiated cells of the hematopoietic system in the bone marrow that often, but not always, extends into the peripheral blood.  This article aims to provide an overview of leukemia as...
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Leukocoria

Leukocoria (also spelled as leucocoria or leukokoria) refers to an abnormal white reflection from the retina of the eye. Despite its color, the reflection is related to the familiar red-eye effect. Usually, when a light is shone through the iris, the retina appears red to the observer. In leukoc...
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Leukodystrophies

The leukodystrophies are a heterogeneous group of disorders that primarily affect the white matter of the central nervous system. They are particularly encountered in childhood as many are genetically determined and represent abnormalities in white matter metabolism. A number of leukodystrophies...
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Linear atelectasis

Linear atelectasis refers to a focal area of subsegmental atelectasis that has a linear shape. Depending on its shape, it is also known as plate, discoid or band atelectasis. Linear atelectasis may appear to be horizontal, oblique or perpendicular and is very common. It usually occurs as a conse...
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Linitis plastica

Linitis plastica is a descriptive term usually referring to the appearance of the stomach, although the rectum can also be described this way. The appearance is said to be reminiscent of an old leather water-bottle. Pathology The underlying cause is usually a scirrhous adenocarcinoma with diff...
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Littre hernia

Littre hernia is a hernia containing a Meckel diverticulum. Also known as a persistent omphalomesenteric duct hernia. It is most frequently encountered in the inguinal region. Radiographic features CT blind-ending tubular structure arising from antimesenteric border of small bowel and extendi...
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Liver lesions

Liver lesions represent a heterogeneous group of pathology ranging from solitary benign lesions to multiple metastases from a variety of primary tumors. Liver lesions may be infiltrative or have mass effect, be solitary or multiple, benign or malignant. Assessment of liver lesions takes into c...
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Liver lesions (pediatric)

Pediatric liver lesions are a heterogeneous group that include infiltrative lesions and those that demonstrate mass effect. Moreover, they may be solitary or multiple, benign or malignant: benign liver tumors malignant liver tumors Epidemiology There are differing frequencies of both benign ...
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Liver trauma

The liver is one of the most frequently damaged organs in blunt trauma, and liver trauma is associated with a significant mortality rate. Epidemiology In blunt abdominal trauma, the liver is injured ~5% (range 1-10%) of the time 1,3. Clinical presentation Patients can present with right uppe...
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Liver tumors

Liver tumors, like tumors of any organ, can be classified as primary or secondary. Metastases Liver metastases are by far the most common hepatic malignancy, with many of the most common primaries readily seeding to the liver. This is especially the case with gastrointestinal tract tumors, due...
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Lobar consolidation

Lobar consolidation is the term used to describe consolidation in one of the lobes of the lung. It infers a alveolar spead of disease and is most commonly due to pneumonia. Pathology Consolidation refers to the alveolar airspaces being filled with fluid (exudate/transudate/blood), cells (infla...
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Lobar lung collapse

Lobar collapse refers to the collapse of an entire lobe of the lung. As such it is a subtype of atelectasis (collapse is not entirely synonymous with atelectasis, which is a more generic term for 'incomplete expansion').  Individual lobes of the lung may collapse due to obstruction of the supply...
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Localized pulmonary hemorrhage

Localized pulmonary hemorrhage is a descriptive term for a pulmonary hemorrhage restricted to a particular focal region of the lung. It can range from involving a small focus of hemorrhage to a whole lobe. Pathology Etiology Focal pulmonary hemorrhage can occur from a number of causes: pulmo...
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Locked facet joint

Locked facet joint is a type of facet joint dislocation that results from jumping of the inferior articular process over the superior articular process of the vertebra below and becomes locked in the position. It can be unilateral or bilateral. Radiographic features Plain radiograph The tip ...
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Long bone metaphyseal cupping (differential)

Long bone metaphyseal cupping is most likely due to the local oligaemia from thrombosis in the terminal epiphyseal arteries to the epiphyseal plate, induced by prolonged regional immobilization 7.  The differential diagnosis of long bone metaphyseal cupping includes:  Common normal variant r...
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Longitudinally extensive spinal cord lesion

Longitudinally extensive spinal cord lesions (LESCL), also known as longitudinally extensive transverse myelitis (LETM), represent extensive involvement of the spinal cord, with abnormal T2 signal traversing at least three vertebral body segments in length. Differential diagnosis They are typi...
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Longitudinal temporal bone fractures

Longitudinal temporal bone fractures are petrous temporal bone fractures that occur parallel to the long axis of the petrous temporal bone. Although more current classifications of the extent of temporal bone fractures focus on the integrity of the otic capsule rather than the fracture orientati...
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Longitudinal versus transverse petrous temporal bone fracture

Petrous temporal bone fractures are classically divided into longitudinal, transverse or mixed fracture patterns depending on the direction of fracture plane with respect to the long axis of the petrous temporal bone. Some features may aid in distinguishing them.                 Longitudinal pe...
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Loss of intervertebral disc space (differential)

Loss of intervertebral disc space can be due to a variety of causes: degenerative disc disease of the spine: most common cause trauma diskitis neuropathic spondyloarthropathy dialysis related spondyloarthropathy ankylosing spondylitis ochronosis crystal deposition diseases sarcoidosis ...
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Lower abdominal / pelvic calcification

Causes of calcifications in the lower abdomen and pelvis include: vascular calcifications atherosclerosis aneurysms phleboliths urogenital uterine fibroid ovarian dermoid prostatic calcification seminal vesicle and ductus deferens calcification bladder stones gallstones dropped stone...
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Lower extremity fractures

There are a vast range of lower extremity fractures. Below are listed several of such fractures of the lower limb. Many have eponyms. Pelvis and femur pelvic fractures anterior inferior iliac spine avulsion injury Duverney fracture Malgaigne fracture proximal femoral fractures bisphosphon...
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Lower gastrointestinal bleeding (differential)

Lower gastrointestinal bleeding usually occurs distal to the ligament of Treitz, and has a wide differential diagnosis: diverticular disease enterocolitis infective Crohn’s disease ulcerative colitis ischemic colitis vascular malformation vascular ectasia angiodysplasia arteriovenous m...
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Low signal intensity renal parenchyma

There are relatively few causes of low signal intensity renal parenchyma. Causes include: hemolysis paroxysmal nocturnal hemoglobinuria mechanical: malfunctioning prosthetic cardiac valve sickle cell disease infection hemorrhagic fever with renal syndrome (HFRS) vascular disease acute re...
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Lunate dislocation

Lunate dislocations are an uncommon traumatic wrist injury that require prompt management and surgical repair. The lunate is displaced and rotated volarly. The rest of the carpal bones are in a normal anatomic position in relation to the radius. These should not be confused with perilunate disl...
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Lung atelectasis

Lung atelectasis refers to collapse or incomplete expansion of pulmonary parenchyma. Note that the term "atelectasis" is typically used when there is partial collapse, whereas the term "collapsed lung" is typically reserved for when the entire lung is totally collapsed. Classification Atelecta...
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Lymphangitic carcinomatosis (mnemonic)

A mnemonic for the causes of lymphangitic carcinomatosis is: Certain Cancers Spread By Plugging The Lymphatics Mnemonic C: cervix C: colon S: stomach B: breast P: prostate and pancreas T: thyroid L: larynx and lung
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Lymph node imaging

Lymph node imaging is a useful technique, aiding the clinician in determining whether nodes are benign or malignant. Multiple modalities are used for the assessment and characterization of lymph nodes, each with its advantages and drawbacks. Modalities Ultrasound size  number shape echotex...
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Lytic bone metastases

Lytic bone metastases are due to a variety of primary tumors, and are more common than sclerotic metastases (although many may occasionally have mixed lytic and sclerotic components). They include 1: thyroid cancer renal cell cancer adrenal gland carcinoma and pheochromocytoma uterine carcin...
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Lytic skull lesion

Lytic skull lesions have a relatively wide differential that can be narrowed, by considering if there are more than one lesion and whether the mandible is involved. Pathology Causes lytic skeletal metastases multiple myeloma epidermoid - scalloped border with a sclerotic rim eosinophilic g...
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Macrophthalmia

The increased globe size or macrophthalmia may have many differentials: buphthalmos (congenital glaucoma) axial myopia macrophthalmus in neurofibromatosis type 1 (NF1) connective tissue disorders: Marfan syndrome, Ehlers-Danlos syndrome Focal enlargement: staphyloma coloboma See also mi...
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Main differentials in musculoskeletal imaging

Here is a list of some of the most useful differential diagnoses in musculoskeletal imaging. By process 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 pseudopermeat...
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Male breast disease

Male breast disease includes a wide spectrum of conditions. Many conditions and entities that affect the female breast may also affect the male breast.  Pathology Malignant male breast cancer lymphoma dermatofibrosarcoma Benign gynecomastia pseudogynecomastia: fat deposition within the b...
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Malignant liver tumors (pediatric)

Pediatric malignant liver tumors are rare, some of which occur only in children but that are similar to those that occur in adults. Epidemiology Malignant liver tumors account for ~1% of pediatric malignancies 2. Pathology Broadly, any malignant liver mass can be defined as a metastasis or p...
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Malignant neoplasms involving the uterus

Malignant neoplasms involving the uterus account for a significant proportion of all female cancers. They can be classified as: endometrial carcinoma : commonest: >90% of all uterine malignancies endometrioid carcinoma of the uterus: commonest histological type, ~80% papillary serous carcino...
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Malignant esophageal neoplasms

Malignant esophageal neoplasms are much more common than benign esophageal neoplasms, especially if the patient is symptomatic.  Pathology esophageal carcinoma (90%) esophageal squamous cell carcinoma (SCC) esophageal spindle cell carcinoma esophageal adenocarcinoma esophageal neuroendocri...
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Malignant vs benign gastric ulcer (barium)

Barium meal has been frequently used to differentiate malignant and benign gastric ulcers: Features suggesting benign gastric ulcer outpouching of ulcer crater beyond the gastric contour (exoluminal) smooth rounded and deep ulcer crater smooth ulcer mound smooth gastric folds that reach the...
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Mandibular lesions

Mandibular lesions are myriad and common. The presence of teeth results in lesions that are specific to the mandible (and maxilla) and a useful classification that defines them as odontogenic or non-odontogenic. While it may often not be possible to make a diagnosis on imaging alone, this classi...
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Mandibular periostitis

There are many causes for mandibular periostitis: Langerhans cell histiocytosis malignancy (both primary and metastatic) necrosis, e.g. radiation osteonecrosis osteomyelitis pyogenic Garre's sclerosing osteomyelitis actinomycosis (uncommon) syphilis (uncommon) tuberculosis (uncommon) r...
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March fracture

March fractures are a name subtype of fatigue/stress fracture. They occur due to repeated concentrated trauma to a normal bone, classically the 2nd metatarsal of the foot but can occur in other weight-bearing bones of the lower limb and pelvis. Radiographic features Please see the article on s...
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Masses arising from the foramen of Monro (differential)

The differential diagnosis of masses arising from the foramen of Monro can be approached depending on the age of the patient. Pediatric choroid plexus papilloma craniopharyngioma germinoma glioma Langerhans cell histiocytosis neurofibromatosis pilocytic astrocytoma subependymal giant ce...
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Masticatory muscle hypertrophy

Masticatory muscle hypertrophy or commonly presenting as temporalis and masseter muscles hypertrophy is a rare disease that affects muscles of mastication and results in "pseudo-masses". Commonly seen in anxious individuals with "bruxism" and in chronic gum chewing 1.  It sometimes gives a "thr...
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Mastitis

Mastitis refers to inflammation of the breast parenchyma, of which there are a number of subtypes: acute mastitis puerperal mastitis: occurs usually from infection with Staphylococcus during lactation non-puerperal mastitis: not related to lactation, and occurs usually in older women plasma ...
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Mastoid air cell opacification

Mastoid air cell opacification can occur in a number of situations and can include a spectrum of inflammatory, neoplastic, vascular, fibro-osseous, and traumatic changes. They include otomastoiditis acute otomastoiditis chronic otomastoiditis radiation 3 trauma tumors primary tumors pla...
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Maydl hernia

Maydl hernias are defined as the presence of two small bowel loops within a single hernial sac, that is, there are two efferent and two afferent loops of bowel, forming a "W" shape. This type of hernia is more prone to strangulation and necrosis. The intervening intra-abdominal loop is also at ...
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McBurney point

McBurney point is defined as a point that lies one-third of the distance laterally on a line drawn from the umbilicus to the right anterior superior iliac spine. Classically, it corresponds to the location of the base of the appendix 1. Clinically, McBurney point is relevant for the elicitation...
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McRae line

McRae line is a radiographic line drawn on a lateral skull radiograph or midsagittal section of CT or MRI, joining the basion and opisthion. Normal position of the tip of dens is 5mm below this line. If the tip of the dens migrates above this line it indicates the presence of basilar invaginati...
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Meary's angle

Meary's angle or lateral talo-first metatarsal angle has been used to identify the apex of deformity in patients with pes cavus and pes planus on lateral weightbearing foot radiographs. It is the angle between a line drawn from the centers of longitudinal axes of the talus and the first metatars...
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Meckel cave lesions (differential)

Meckel cave lesions are numerous. The aim of this article is to list them in an easy way for revision and assessment of differential diagnosis.  Neoplastic Meckel cave tumors account for only 0.5% of all intracranial tumors. The most common histologies include: trigeminal schwannoma: most com...
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Medial epicondyle fracture

Medial epicondyle fractures represent almost all epicondyle fractures and occur when there is avulsion of the medial epicondyle. They are typically seen in children, and can be challenging to identify. Failure to diagnose these injuries can lead to significant long term disability.  Epidemiolog...
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Medial epicondylitis

Medial epicondylitis (also known as golfer's elbow) is an angiofibroblastic tendinosis of the common flexor- pronator tendon group of the elbow. Epidemiology It is less common than lateral epicondylitis. As with lateral epicondylitis, it typically occurs in the 4th to 5th decades of life. Ther...
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Mediastinal lymph node enlargement

Mediastinal lymph node enlargement can occur from a wide range of pathologies. It may occur on its own or in association with other lung pathology. Terminology Although mediastinal lymphadenopathy is used interchangeably - by some - with "mediastinal lymph node enlargement", they are not synon...
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Mediastinal mass

Mediastinal mass may be caused by a wide variety of neoplastic and non-neoplastic pathologies. It is helpful to identify the location of the mass since this significantly reduces the breadth of the differential diagnosis.  There are four conceptual compartments of the mediastinum which are larg...
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Mediastinal widening (differential)

The differential diagnoses for mediastinal widening include: traumatic aortic injury vascular anomalies unfolded aorta double SVC aberrant right subclavian artery azygos continuation of the IVC pneumomediastinum lung atelectasis pulmonary masses abutting the mediastinum mediastinal ly...
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Medical devices in the abdomen and pelvis

Medical devices in the abdomen and pelvis are important to be recognized, just like medical devices of the chest. Often we ignore these devices, considering them to be incidental and non-pathological, however it is essential to be aware of potential complications. Gastrointestinal tubes stomac...
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Medical devices in the neck

Medical devices in the neck are regularly observed by radiologists on plain film and CT reporting. They include devices which pass through the neck into the chest and stomach. Vascular access devices dialysis catheters peripherally inserted central catheters (PICC) central venous catheters ...
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Medical devices in the thorax

Medical devices in the thorax are regularly observed by radiologists when reviewing radiographs and CTs. Extrathoracic devices tubing, clamps, syringes lying on or under the patient rubber sheets, foam mattresses, clothing, hair braids, nipple piercings etc. may also be visible These devices...
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Medullary nephrocalcinosis

Renal medullary nephrocalcinosis is the commonest form of nephrocalcinosis and refers to the deposition of calcium salts in the medulla of the kidney. Due to the concentrating effects of the loops of Henle, and the biochemical milieu of the medulla, compared to the cortex, it is 20 times more co...
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Mega esophagus

Mega esophagus or diffuse esophageal dilatation can be caused by a variety of conditions.  Pathology Etiology Some of the more common causes are given below 1-3: esophageal dysmotility achalasia Chagas disease scleroderma distal obstruction malignant stricture, e.g. esophageal cancer, c...
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Meningeal enhancement

Meningeal enhancement is a generic term related to the enhancement of the membranes that envelop the brain and spinal cord. Due the anatomical features, this enhancement can be divided in two subtypes: leptomeningeal enhancement (pial or pial-arachnoid enhancement) pachymeningeal enhancement (...
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Meningocele

Meningoceles are protrusions of the meninges through a defect or weak point in the skull or spine, usually involving the soft tissues beneath the surface of the skin. They are typically categorized into congenital, iatrogenic (e.g. following a craniotomy, sinus surgery, or as a laminectomy compl...
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Metachronous breast cancer

Metachronous breast cancers are two breast cancers that occur in either breast in two different time periods. Treatment and prognosis The survival rate of women with metachronous breast cancers diagnosed within 2 years of the original primary is worse than those with unilateral disease 4.
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Metal-on-metal pseudotumour

A metal-on-metal pseudotumour, also known as aseptic lymphocyte-dominant vasculitis-associated lesion (ALVAL), is a mass-forming tissue reaction around a metal-on-metal hip or knee replacement. Clinical presentation Metal-on-metal pseudotumours are large focal solid or semiliquid masses around...
Article

Metaphyseal blanch sign

The metaphyseal blanch sign (a.k.a. metaphyseal blanch sign of Steel) is one of the signs seen on AP views of the adolescent hip indicating posterior displacement of the capital epiphysis. It is a crescent-shaped area of increased density, that overlies the metaphysis adjacent to the physis on ...
Article

Metaphyseal fracture

Metaphyseal fractures are fractures that involve the metaphysis of tubular bones. They may occur in pediatric or adult patients. Examples of metaphyseal fractures: adults surgical neck of humerus fracture distal radial fracture transtrochanteric fracture children distal radial buckle frac...
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Metaphyseal lesions

The differential diagnosis for metaphyseal lesions includes: osteomyelitis metastases non-ossifying fibroma enchondroma aneurysmal bone cyst simple bone cyst chondromyxoid fibroma chondrosarcoma cortical desmoid giant cell tumor desmoplastic fibroma intraosseous lipoma osteosarcoma ...
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Metastatic intramammary lymph node

A metastatic intramammary lymph node refers to an intramammary lymph node involved with metastatic or malignant disease. Radiographic features Breast ultrasound Sonographic features that suggest metastatic involvement include 4: disappearance or loss of central echogenic hilar region marked...
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Metatarsalgia

The term metatarsalgia refers to pain in the region of the metatarsophalangeal joints. It is a frequent presenting complaint in the foot.  Pathology Etiology Common causes include 1,2: interdigital (Morton) neuroma Freiberg infraction stress fractures involving the foot intermetatarsal bu...
Article

Midcarpal dislocation

Midcarpal (central carpal) dislocation describes an injury where there is dislocation of the capitate from the lunate, and subluxation of the lunate from the radius. This term is somewhat confusing because some authors use "midcarpal dislocation" to refer generally to perilunate and lunate dislo...
Article

Middle ear tumors

There are a range of middle ear tumors, which are more likely to be benign than malignant.  Pathology The three most common middle ear tumors are (not in any particular order as there are differences in the literature) 1-3:  glomus tympanicum paraganglioma congenital cholesteatoma middle ea...
Article

Middle mediastinal mass

The differential diagnosis for a middle mediastinal mass includes 1-3: lymphadenopathy aneurysm, e.g. aortic, pulmonary artery, bronchial artery congenital cyst pericardial cyst foregut duplications cyst (e.g. esophageal, bronchial) pericardial tumor primary/secondary cardiac tumor neuro...
Article

Midline neck mass

Midline neck masses have a relatively narrow differential, as few structures are present in the midline. Dividing the causes according to structure of origin is a useful schema. lymph node(s): Delphian node(s) inflammatory adenopathy malignancy thyroid gland thyroglossal duct cyst thyroid ...
Article

Midline shift

One of the most important indicators of increased intracranial pressure due to mass effect is midline shift. Pathology Any intra-axial or extra-axial lesion (tumor, hemorrhage, abscess, etc) has the potential to exert mass effect on the brain parenchyma and cause lateral shift of the midline s...
Article

Miliary opacities (lungs)

The term miliary opacities refers to innumerable, small 1-4 mm pulmonary nodules scattered throughout the lungs. It is useful to divide these patients into those who are febrile and those who are not. Additionally, some miliary opacities are very dense, narrowing the differential - see multiple...
Article

Milking effect

Milking effect phenomenon is a pathognomonic angiographic finding in myocardial bridging of coronary arteries. Systolic compression of coronary vessels with partial or complete decompression during diastole is described as milking effect. Its significance lies in:  increased risk of thrombus fo...
Article

Milk of calcium (disambiguation)

The term milk of calcium (MOC) is given to dependent, sedimented calcification within a cystic structure or hollow organ. This sort of colloidal calcium suspension layering can occur in various regions: renal: milk of calcium in renal cyst (most common) breast: milk of calcium in breast cyst ...

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