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 continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
More than 200 results
Article
Reticuloendothelial system
The reticuloendothelial system (RES) comprises a number of tissues:
spleen
bone marrow
liver Kupffer cells
Article
Interthalamic adhesion
The interthalamic adhesion, or massa intermedia, is a small variably present non-neural connection between the medial apposing surfaces of the two thalami that passes through the third ventricle7. It is not a commissure as once thought, as it does not contain neurons; instead, it is composed of ...
Article
Circle of Willis
The circle of Willis (COW) or circulus arteriosus is an arterial polygon (heptagon) formed as the internal carotid and vertebral systems anastomose around the optic chiasm and infundibulum of the pituitary stalk in the suprasellar cistern. This communicating pathway allows equalization of blood-...
Article
Conoid tubercle
The conoid tubercle also known as the coracoid tuberosity (not to be confused with the coracoid process of the scapula) is a bony prominence on the inferior surface of the lateral third of the clavicle.
It marks the insertion of the conoid ligament (which along with the trapezoid ligament) for...
Article
Os odontoideum
Os odontoideum (plural: ossa odontoidea) is an anatomic variant of the odontoid process of C2 and needs to be differentiated from persistent ossiculum terminale and from a type 2 odontoid fracture. It can be associated with atlantoaxial instability.
Although it was originally thought to be a c...
Article
Aortic arch
The aortic arch represents the direct continuation of the ascending aorta and represents a key area for a review of normal variant anatomy and a wide range of pathological processes that range from congenital anomalies to traumatic injury.
Summary
origin: continuation of the ascending aorta at...
Article
Accessory left atrial appendage
An accessory left atrial appendage is a frequent fortuitous finding in cardiac imaging, encountered in ~10% of patients. They are more often seen as a small diverticular structure projecting from the right upper side of the left atrial wall.
Differential diagnosis
it must not be confused with ...
Article
Lateral talocalcaneal angle
The lateral talocalcaneal angle is one of the angles that can be measured for the assessment of pes planus and pes cavus and assessment of hindfoot deformity.
Measurement
The lateral talocalcaneal angle is drawn on a weight-bearing lateral foot radiograph. There are two ways that it has been d...
Article
Internal oblique muscle
The internal oblique muscle is one of the muscles that form the anterior abdominal wall. Inferiorly, it contributes towards the formation of the inguinal ligament.
Summary
origin: originates along the whole length of the lumbar fascia, from the anterior two-thirds of the intermediate line of t...
Article
Transversus abdominis muscle
The transversus abdominis muscle, named according to the direction of its muscle fibers, is one of the flat muscles that form the anterior abdominal wall. It is deep to the internal oblique muscle and ends in the anterior aponeurosis, which ultimately blends with the linea alba.
Summary
origi...
Article
External oblique muscle
The external oblique muscle is one of the muscles that forms the anterior abdominal wall. Its free inferior border forms the inguinal ligament, and its aponeurotic part contributes to the anterior wall of the inguinal canal.
Summary
origin: outer surface of the shaft of the lower eight ribs 3...
Article
Focal fatty deposits in bone marrow
Focal fatty deposits, also known as marrow islands or replacements in the bone marrow, are well-defined focal fat islands within the bone marrow of the spine or other parts of the axial skeleton 1,2.
Epidemiology
Common in older individuals, related to age but not to sex.
Associations
Focal ...
Article
External ear
The external ear (or outer ear) comprises the auricle (or pinna), the external auditory meatus, and the tympanic membrane ("eardrum"). The auricle concentrates and amplifies sound waves and funnels them through the outer acoustic pore into the external auditory meatus to the tympanic membrane.
...
Article
Superior vermian vein
The superior vermian vein is formed in the midline over the superior aspect of the cerebellar vermis (over the anterior lobe) by multiple tributaries draining not just the subjacent vermis but also the adjacent cerebellar hemispheres. These tributaries most often coalesce into a single trunk ove...
Article
Facial nerve
The facial nerve is the seventh (CN VII) cranial nerve and comprises two roots, a motor root and a smaller mixed sensory, taste and parasympathetic root, known as nervus intermedius, which join together within the temporal bone (TA: nervus facialis or nervus cranialis VII).
The facial nerve has...
Article
Canalis basilaris medianus
The canalis basilaris medianus (median basal canal), also known as clival canal, median clival canal, or inferior median clival canal, refers to a number of anatomic variant midline canals in the clivus, typically involving the basioccipital portion.
Gross anatomy
These canals are generally we...
Article
Modiolus (mouth)
The modiolus (plural: modioli), also known as the modiolus anguli oris or commissural modiolus, is a small fibromuscular structure at the corner of the mouth where fibers from multiple facial muscles converge, and helps coordinate the action of these muscles.
Gross anatomy
The convergence of t...
Article
Cervical rib
Cervical ribs are supernumerary or accessory ribs arising from the seventh cervical vertebra. They occur in ~0.5% of the population, are usually bilateral, but often asymmetric 2, and are more common in females.
Related pathology
Although cervical ribs are usually asymptomatic, they are the mo...
Article
Ductus deferens
The ductus deferens (plural: ductus deferentes), formerly known as the vas deferens (plural: vasa deferentia), forms part of the male internal genitalia where it transports sperm from the epididymis to the ejaculatory duct.
Terminology
In modern anatomic nomenclature, it is no longer referred ...
Article
Azygos vein
The azygos vein is a unilateral vessel that ascends in the thorax to the right of the vertebral column, carrying deoxygenated blood from the posterior chest and abdominal walls. It forms part of the azygos venous system.
Terminology
The spelling azygous when referring to the vein is incorrect,...
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