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.

908 results found
Article

Intrasinus calcification

Intrasinus calcification is a phenomenon whereby calcification is formed within the paranasal sinuses. It can occur to varying extents, therefore leading to varying degrees of attenuation on CT. Such calcification may occur either concurrently within an opacified sinus or in an aerated sinus, de...
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Intraventricular metastases

Intraventricular metastases are a very rare finding. A few intracranial tumors and some extracranial tumors metastasize to the ventricles. The most common site of intraventricular metastasis is the trigone of the lateral ventricles due to high vascularity of the choroid plexuses. The next most c...
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Intraventricular neoplasms and lesions

Intraventricular neoplasms are rare and arise from periventricular structures such as the walls of the ventricular system, the septum pellucidum and the choroid plexus. Many tumor types arise from or can bulge into the ventricular system, although there are certain lesions that are relatively re...
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Joint ankylosis (differential)

Joint ankylosis has a relatively broad differential including 1-5:   psoriatic arthritis ankylosing spondylitis chronic reactive arthritis juvenile idiopathic arthritis surgical ankylosis (arthrodesis) septic arthritis rheumatoid arthritis fluorosis ochronosis coalition, e.g. tarsal, c...
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J-shaped sella

A J-shaped sella is a variant morphology of the sella turcica, whereby the tuberculum sellae is flattened, thus forming the straight edge of the "J". The dorsum sellae remains rounded and forms the loop of the "J". Differential diagnosis Differential diagnosis for a J-shaped sella includes 1,2...
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Jugular fossa masses

Jugular fossa masses comprise a range of pathological lesions that arise from or extend into the jugular fossa in the skull base. Although not a common location for tumors it is not unusual for jugular fossa lesions to be discovered incidentally on cross-sectional imaging. Terminology Although...
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Juvenile osteoporosis

Juvenile osteoporosis refers to osteoporosis occurring in children. Pathology Etiology It can arise from a number of causes 1-4: primary conditions osteogenesis imperfecta Bruck syndrome osteoporosis pseudoglioma syndrome Ehlers-Danlos syndrome Marfan syndrome homocystinuria secondary...
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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 pseudotumor lacrimal glan...
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Lacrimal sac mass

Lacrimal sac masses are very uncommon and more commonly have a malignant (~80%) rather than benign (~20%) etiology.  Pathology Etiology inflammatory granulomatosis with polyangiitis sarcoidosis orbital pseudotumor IgG4-related disease Sjogren syndrome neoplastic epithelial tumors beni...
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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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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 paramediastinal catheter position (differential)

When a central venous catheter that is supposed to terminate in the superior vena cava or right atrium is abnormally located to the left of the mediastinum and below the level of the brachiocephalic vein, a limited differential of left paramediastinal catheter position should be considered 1: l...
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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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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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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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Lobar consolidation

Lobar consolidation is the term used to describe consolidation in one of the lobes of the lung. It infers an alveolar spread of disease and is most commonly due to pneumonia. Pathology Consolidation refers to the alveolar airspaces being filled with fluid (exudate/transudate/blood), cells (inf...
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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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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 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 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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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 years old diffuse bony sclerosis permeative process in bone pse...
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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...
Article

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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Mass-forming intrahepatic cholangiocarcinoma

Mass-forming intrahepatic cholangiocarcinomas (MF-ICC), also referred as peripheral cholangiocarcinomas, compromise one of the three recognized growth patterns of intrahepatic cholangiocarcinomas.  On imaging, these tumors usually present as large and relatively well-defined hepatic masses with...
Article

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...
Article

Maurice Reeder

Maurice "Mo" M Reeder (1933-2013) was an American radiologist who is remembered for his contributions to radiology education in the United States, in particular, the development of the radiology-pathology teaching program at the Armed Forces Institute of Pathology. Early life Maurice Merrick R...
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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 ...
Article

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...
Article

Meary's angle

Meary's angle or talus-first metatarsal angle has been used to identify the apex of deformity in patients with pes cavus and pes planus on lateral weight-bearing foot radiographs. It is the angle between a line drawn from the centers of longitudinal axes of the talus and the first metatarsal. R...
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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 or ascend to/into the head. Vascular access devices dialysis catheters peripherally inserted central catheters (PICC) ...
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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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Megaesophagus

Megaesophagus 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, ca...
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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 pseudotumor

A metal-on-metal pseudotumor, 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 pseudotumors are large focal solid or semiliquid masses around t...
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Metaphyseal blanch sign

The metaphyseal blanch sign (or 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 the ...
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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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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...
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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 duplication cyst (e.g. esophageal, bronchial) pericardial tumor primary/secondary cardiac tumor neuroge...
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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 ...
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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 ...
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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...
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Milk of calcium within a breast cyst

Milk of calcium within a breast cyst is a mammographic feature observed when there is dependent calcium layering within breast cysts. It is typically observed as "tea cup" or "crescent shaped" calcifications on a true lateral (LM or ML) view on occasionally on a MLO view. On a CC view, these cal...
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Mixed cystic and solid pituitary region mass

A mixed cystic and solid pituitary region mass has a limited differential. Differential diagnosis craniopharyngioma both papillary (more solid) and adamantinomatous (more cystic) macroadenoma cystic change / necrosis / previous hemorrhage Most other solid and enhancing pituitary region mas...
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Mixed lytic and sclerotic bone metastases

Mixed lytic and sclerotic bone metastases are seen in a number of malignancies: breast carcinoma: typically sclerotic but 25% are mixed lung carcinoma: typically lytic but 15% are mixed carcinoma of the cervix testicular tumors prostate carcinoma: typically sclerotic but 15% are mixed  gan...
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Monoarticular arthropathy

Monoarticular arthropathy can result from a number of causes: Commonest 2: gout (15-27%) septic arthritis (8-27%) osteoarthritis (5-17%) rheumatoid arthritis (RA) (11-16%) Less common 2: traumatic arthritis HADD (hydroxyapatite deposition disease) reactive arthritis 2 avascular necrosi...
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Mosaic attenuation pattern in lung

Mosaic attenuation is a descriptive term used in describing a patchwork of regions of differing pulmonary attenuation on CT imaging.  It is a non-specific finding, although is associated with the following: obstructive small airways disease: low attenuation regions are abnormal and reflect decr...
Article

Mostly/purely cystic pituitary region masses

Mostly/purely cystic pituitary region masses have a short differential. Differential diagnosis Rathke cleft cyst arachnoid cyst empty sella craniopharyngioma (adamantinomatous type): 90% have calcification  epidermoid cyst
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Moyamoya syndrome

Moyamoya syndrome, also termed the moyamoya pattern or phenomenon, is due to numerous conditions that can cause arterial occlusion of the circle of Willis, with resultant collaterals, and appearances reminiscent of moyamoya disease. These conditions include 1-4 : vessel wall abnormalities athe...
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Mucinous cystic neoplasm of the gallbladder

Mucinous cystic neoplasms of the gallbladder are extremely rare epithelial cystic tumors formed by mucin-producing cells. They are histologically similar to the other mucinous cystic tumors found elsewhere in the body. For the lesions involving the bile ducts, please refer to: biliary cystaden...
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Mucinous cystic neoplasms of the pancreas

Mucinous cystic neoplasms of the pancreas are the most common cystic neoplasm of the pancreas and include: mucinous cystadenoma of pancreas mucinous cystadenocarcinoma of pancreas intraductal papillary mucinous neoplasms (IPMN) of the pancreas: sometimes classified separately
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Mucoid impaction (lung)

Mucoid impaction, also referred to as mucus plugging, mucous plugging,  bronchial mucocele or bronchocele formation, refers to airway filling by mucoid secretions and can be obstructive or non-obstructive. It is a common pathological finding in chest imaging. Pathology Etiology Mucoid impacti...
Article

Multicentric breast cancer

A multicentric breast cancer is a term given to a breast cancer where there are two or more breast cancers separated by normal breast tissue (often taken as 5 cm of separation 4). It is related to but distinct from the term multifocal breast cancer. At a pathological level It can also mean 2 t...
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Multifocal breast cancer

Multifocal breast cancer refers to two or more individual breast cancers diagnosed at the same time within the same quadrant of the same breast 1. 
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Multilayered periosteal reaction

Multilayered periosteal reaction, also known as a lamellated or onion skin periosteal reaction, demonstrates multiple concentric parallel layers of new bone adjacent to the cortex, reminiscent of the layers on an onion. The layers are thought to be the result of periods of variable growth 2. Pa...
Article

Multiple cranial nerve thickening and enhancement

The most common causes of multiple cranial nerve thickening and enhancement include: metastasis (most common) neurofibromatosis type II lymphoma and leukemia  multiple sclerosis chronic inflammatory demyelinating polyneuropathy Lyme disease  See also cranial nerve enhancement: for comple...
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Multiple cystic neck lesions (differential)

The differential diagnosis for multiple cystic neck lesions is different to that for a solitary cystic neck mass. Differential diagnosis Cystic neck lesions are seen in: metastatic squamous cell carcinoma: older patient, M>F metastatic papillary thyroid carcinoma: usually a younger patient, ...
Article

Multiple endocrine neoplasia syndromes

Multiple endocrine neoplasia (MEN) syndromes are a collection of syndromes characterized by the presence of, as the name would suggest, multiple endocrine tumors. They are autosomal dominant in inheritance. MEN1 (Wermer syndrome) MEN2 (multiple endocrine adenomatosis) MEN2a (Sipple syndrome) ...
Article

Multiple filling defects of the ureter (differential)

Multiple filling defects within a ureter, as seen on conventional IVU or CT IVU, have a relatively small differential including: spreading or multifocal transitional cell carcinoma (TCC) vascular indentations multiple ureteral stones (steinstrasse) blood clots ureteritis cystica Stevens-Jo...
Article

Multiple intracranial calcifications

Intracranial calcifications are common in certain locations and often are of no clinical concern. The two most commonly encountered types of calcification include:  normal age-related intracranial calcifications intracranial arterial atherosclerosis Concerning calcifications are much less co...
Article

Myonecrosis

Myonecrosis is a myopathy involving infarction of skeletal muscle and can have the appearances of an intramuscular mass.  Pathology Myonecrosis has a variety of causes 1,2: idiopathic sickle cell crisis diabetic myonecrosis post-traumatic (see: calcific myonecrosis) compartment syndrome ...
Article

Narrow fetal thorax

A narrow fetal thorax on antenatal ultrasound can be present with a number of anomalies which include: achondrogenesis campomelic dysplasia homozygous achondroplasia Jarcho-Levin syndrome Jeune syndrome - asphyxiating thoracic dysplasia Russell-Silver dwarfism short rib polydactyly syndro...
Article

Narrowing of interpedicular distance

The interpedicular distance is the measurement between the pedicles on frontal/coronal imaging, which can be narrowed in a number of situations. Causes include achondroplasia 3 thanatophoric dysplasia 2 See also  widening of interpedicular distance See reference 1 for an old but interesti...
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Neonatal respiratory distress (causes)

Causes of neonatal distress can be broadly split into intrathoracic, extrathoracic and systemic: Intrathoracic Medical respiratory distress syndrome (RDS) transient tachypnea of the newborn (TTN) meconium aspiration syndrome bronchopulmonary dysplasia (BPD) patent ductus arteriosus (PDA) ...
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Neoplasms of the cauda equina (differential)

The differential diagnosis for masses of the cauda equina region is often considered separately to the remainder of the spinal cord. It is often difficult to determine whether masses in this region are intramedullary or intradural-extramedullary. Most common tumors myxopapillary ependymoma by...
Article

Nephrocalcinosis

Nephrocalcinosis, previous known as Anderson-Carr kidney or Albright calcinosis, refers to the deposition of calcium salts in the parenchyma of the kidney. It is divided into several types, with differing etiologies, based on the distribution: medullary nephrocalcinosis: 95% cortical nephrocal...
Article

Nerve root enhancement

Nerve root enhancement is phenomenon described on post contrast MRI scans that can be observed in a number of situations. Common causes post-operative states post-operative nerve root enhancement arachnoiditis leptomeningeal metastases disseminated spinal leptomeningeal metastases HIV vac...

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