Articles
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16,923 results
Article
Split scar sign (rectal cancer response assessment)
The split scar sign has been described as a feature on rectal cancer MRI studies acquired following chemoradiotherapy. It is characterized by a high specificity and positive predictive value for a complete response 1. In a meta-analysis that observed an average complete response rate of 38%, the...
Article
Rectal cancer protocol (MRI)
MRI protocol for rectal cancer is a group of MRI sequences put together for imaging staging of primary tumors of the rectum and assessment of response following neoadjuvant therapy. Modified versions of the protocol may also be used for the assessment of local recurrence.
Note: This article is ...
Article
Aneurysmal bone cyst
Aneurysmal bone cysts (ABC) are benign expansile osteoclastic giant cell-rich bony neoplasms, composed of numerous blood-filled channels and cystic spaces 1.
ABC accounts for the 'A' in the popular mnemonic for lucent bone lesions FEGNOMASHIC.
Terminology
The terms 'giant cell reparative gran...
Article
Progressive ataxia and palatal tremor
Progressive ataxia and palatal tremor (PAPT) is a rare sporadic or familial syndrome characterized by symptomatic palatal tremor/myoclonus and progressive cerebellar ataxia, usually in the setting of bilateral hypertrophic olivary degeneration without an identifiable causative lesion to the tria...
Article
Scleroderma (musculoskeletal manifestations)
Musculoskeletal manifestations of scleroderma are common although variable and are a major contributor to morbidity 7.
For a general discussion of scleroderma, please refer to the parent article: scleroderma.
Epidemiology
Symptomatic joints are present in ~40% (range 12-65%) of patients when ...
Article
Popcorn-like calcification of the breast
Popcorn-like calcification of the breast is the classical description for the calcification seen in involuting fibroadenomas, which, as the name suggests, have a popcorn-like appearance.
If the calcifications in a fibroadenoma are small and abundant, they might resemble malignant-type calcific...
Article
Nasal dermoid cyst
Nasal dermoids (or nasal dermoid sinus cysts) are the most common congenital midline nasal lesion typically presenting in early childhood.
Epidemiology
Nasal dermoids are rare and account for only 4-12% of all dermoid cysts of the head and neck, far less common than angular dermoids 1,2. They ...
Article
Phakomatoses
The phakomatoses (also known as neurocutaneous syndromes) are a heterogeneous group of disorders most characterized by the involvement of structures that arise from the embryonic ectoderm (thus central nervous system, skin, and eyes), although other systems may also be involved.
Pathology
As a...
Article
Intraconal orbital lesions
Intraconal orbital lesions are broadly divided into two main groups; those with or without involvement of the optic nerves.
Lesions with optic nerve involvement:
optic nerve glioma
optic nerve meningioma
optic neuritis
pseudotumor
lymphoma and leukemia
intracranial hypertension
retinobla...
Article
Mastectomy
Mastectomy is a surgical treatment for breast cancer in which the entire breast tissue is removed through a surgical procedure as opposed to a wide local excision. Sometimes, adjacent structures, such as lymph nodes, are removed to prevent recurrence or metastasis. In some cases, mastectomy is d...
Article
Neurocranium
The neurocranium (plural: neurocrania) is the name given to the portion of the skull that encloses the brain. It comprises the skull base and the skull vault. The neurocranium and facial bones (viscerocranium) together form the skull.
Article
Cranial vault
The cranial vault, also known as the skull vault, skullcap or calvaria, is the cranial space that encases and protects the brain together with the base of the skull. The cranial vault and the base of skull together form the neurocranium.
Gross anatomy
The cranial vault consists of the followin...
Article
Amputation (generic)
The term amputation refers to the disconnection of all or part of a limb from the body. Specifically, amputation is defined as the removal of the structure through a bone. This is in contrast to disarticulation, which is the removal of the structure through a joint.
When due to trauma, traumati...
Article
Petrous part of temporal bone
The petrous part of the temporal bone, also known as the petrous temporal bone (PTB), forms the part of skull base between the sphenoid and occipital bones.
Gross anatomy
The petrous temporal bone has a pyramidal shape with an apex and a base as well as three surfaces and angles:
apex (petro...
Article
Base of the skull
The base of the skull (or skull base) forms the floor of the cranial cavity and separates the brain from the structures of the neck and face. The skull base and vault collectively form the neurocranium.
Gross anatomy
The base of the skull is a bony diaphragm composed of a number of bones - fro...
Article
Middle ear
The middle ear or middle ear cavity, also known as tympanic cavity or tympanum (plural: tympanums/tympana), is an air-filled chamber in the petrous part of the temporal bone. It is separated from the external ear by the tympanic membrane, and from the inner ear by the medial wall of the tympanic...
Article
Cerebrospinal fluid
Cerebrospinal fluid (CSF) is the clear liquid that surrounds and bathes the brain and spinal cord.
Physiology
Production
Cerebrospinal fluid is produced by the epithelium of the choroid plexus within the ventricular system and flows in the direction from the lateral ventricles to the third ve...
Article
Lateral ventricle
The lateral ventricles are paired CSF-filled spaces in the cerebrum and part of the ventricular system of the brain. They are larger than the third or fourth ventricles but can be asymmetrical. Each has five divisions, including three horns that project into the lobe after which they are named:
...
Article
Central nervous system
The central nervous system (CNS) is the part of the nervous system that includes the brain and spinal cord.
Gross anatomy
The main components of the CNS are the brain and spinal cord. In addition, the CNS includes the optic nerves (cranial nerve II), retinas, olfactory nerves (cranial nerve I)...
Article
Axial skeleton
The axial skeleton is the central portion of the bony skeleton comprising the head, neck and trunk (80 bones in total). It has many functions including housing and protecting the central nervous system as well as the organs of the chest, abdomen and pelvis. It enables movement and supports the u...