Items tagged “refs”
2,972 results found
Article
MacEwen triangle
The MacEwen triangle (also called the suprameatal triangle or mastoid fossa) is a surgical landmark on the surface of the temporal bone just superior to the external auditory canal used to locate the level of the mastoid antrum.
Three lines form the triangle:
superior: inferior temporal line/s...
Article
Malignant vascular tumors
Malignant vascular tumors are rare, accounting for <1% of all sarcomas.
Pathology
intermediate grade
hemangioendothelioma
Kaposi sarcoma
high grade
hemangiopericytoma
angiosarcoma
Article
Malleus
The malleus (plural: mallei) is the most lateral middle ear ossicle, located between the tympanic membrane and the incus.
Gross anatomy
The malleus has a head, neck, and three distinct processes (manubrium (handle), anterior and lateral processes).
The head is oval in shape, and articulates p...
Article
Mammography
Mammography is a dedicated radiographic technique for imaging the breast, and the resultant images are known as mammograms.
Types of mammography
In general terms, there are two types of mammography: screening and diagnostic.
Mammography differs significantly in many respects from the rest of ...
Article
Megalencephaly
Megalencephaly is a disorder characterized by an abnormally large brain. It is primarily a proliferative disorder of embryonic origin. It may involve all or part of the cerebral hemispheres and can be bilateral or unilateral. It is often associated with polymicrogyria or agyria.
Terminology
...
Article
Congenital spinal meningocele
Congenital spinal meningoceles are developmental anomalies of meningothelial elements displaced into the skin and subcutaneous tissues.
Please refer to the meningocele article for a broad overview of all types of this condition.
Pathology
It is a defect of the neural tube, an embryonic struc...
Article
Middle ear effusion
Middle ear effusions are frequent in children due to prominent adenoids and horizontal Eustachian tubes. These do not require imaging and can be treated expectantly / medically / surgically with tympanostomy tubes. Eustachian tube dysfunction is the accepted etiology, with resorption of air and ...
Article
Middle ear granulation tissue
Development of granulation tissue in the middle ear cavity is a generalized response to injury/inflammation, chronic otomastoiditis. It can either be typical or go down the pathway of becoming a cholesterol granuloma.
Radiographic features
Typical granulation tissue is common, more so than cho...
Article
Middle lobe bronchiectasis
Middle lobe bronchiectasis is an imaging an imaging descriptor when bronchiectasis is confined to the middle lobe. When it (predominantly) involves the middle lobe it is sometimes is termed right middle lobe predominant (RMLP) bronchiectasis 2.
Middle lobe bronchiectasis may be seen in:
non-tu...
Article
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 and ...
Article
Muscles of the tongue
The muscles of the tongue are divided into 2 groups each comprising 4 muscles. They are classified as intrinsic (to the tongue) and extrinsic muscles. They allow for the complex movements of the tongue and are all innervated by the hypoglossal nerve (CN XII) except one:
intrinsic muscles of th...
Article
Myelitis
Myelitis is a collective term simply referring to any inflammation of the spinal cord. It is a form of myelopathy.
The two major sub types include:
leukomyelitis
multiple sclerosis
ADEM
transverse myelitis
ideopathic transverse myelitis
secondary transverse myelitis: viral, neurosyphilis ...
Article
Myoepithelioma
Myoepitheliomas and malignant myoepitheliomas were considered a variant of pleomorphic adenomas until 1991. However, these are also found in the breast and bronchus and have gained recognition as separate entities 1.
Epidemiology
They account for <1% of salivary gland tumors, and only rarely u...
Article
Myokymia
Myokymia refers to an involuntary undulating movement of muscle 1.
The term is employed in a number of clinical contexts 1-3:
eyelid myokymia: pathogenesis is not well understood
extra-ocular muscle myokymia: pathogenesis is not well understood
inferior oblique myokymia (rare)
superior obli...
Article
Midline nasal region lesions
A variety of congenital midface anomalies occur in children. Although rare, these disorders are clinically important because of their potential for connection to the central nervous system. Lesions presenting as a midline nasal mass include:
nasal glioma
nasal encephalocele
nasal dermoid cyst...
Article
Nephrocalcinosis
Nephrocalcinosis, previously 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 nephroc...
Article
Nerve to stapedius
The nerve to stapedius arises from the facial nerve to supply the stapedius muscle. The branch is given off in the facial nerve's mastoid segment, as it passes posterior to the pyramidal process.
Damage to this branch with resulting paralysis of stapedius leads to hypersensitivity to loud noise...
Article
Nottingham classification
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...
Article
Nutmeg liver
A nutmeg liver appearance is due to a perfusion abnormality of the liver usually as result of hepatic venous congestion. When hepatic veins are congested, contrast is prevented from diffusing through the liver in a normal manner. This results in a mottled pattern of contrast enhancement in the a...
Article
Oculomotor nerve palsy
Oculomotor nerve palsies, or third nerve palsies, result in weakness of the muscles supplied by the oculomotor nerve, namely the superior rectus, inferior rectus, medial rectus, inferior oblique, and levator palpebrae superioris muscles.
Terminology
If the pupil is normal-sized and reactive to...