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
Proper dorsal digital arteries
The proper dorsal digital arteries arise from the dorsal metacarpal arteries at the level of the metacarpophalangeal joint. They contribute to the dorsal arterial supply of the digits.
The proper dorsal digital arteries travel along the medial and lateral side of the dorsal aspect of each digit...
Article
Abductor digiti minimi muscle (hand)
The abductor digiti minimi muscle overlies the opponens digiti minimi muscle, within the hypothenar eminence, and is one of the intrinsic muscles of the hand. Occasionally an accessory abductor digiti minimi muscle of the hand is present.
Summary
origin: pisiform, pisohamate ligament, and tend...
Article
Pituitary fossa
The pituitary (hypophyseal) fossa or sella turcica is a midline, dural lined structure in the sphenoid bone, which houses the pituitary gland.
Gross anatomy
The anterior, inferior and posterior walls are bony, while the lateral walls and roof are formed by dural slings between the anterior and...
Article
Flexor digiti minimi brevis muscle (hand)
The flexor digiti minimi brevis muscle of the hand lies lateral to the abductor digiti minimi, within the hypothenar eminence, and is one of the intrinsic muscles of the hand.
Summary
origin: hook of the hamate and flexor retinaculum
insertion: proximal phalanx of 5th digit
action: flexes 5t...
Article
Infrapiriform foramen (mnemonic)
A mnemonic to remember the structures passing below the piriformis muscle in the greater sciatic foramen is:
PIN PINS or SNIP NIP
Mnemonic
P: posterior cutaneous nerve of thigh
I: inferior gluteal artery, vein and nerve
N: nerve to quadratus femoris
P: pudendal nerve
I: internal pudendal ...
Article
Persistent hypophyseal canal
Persistent hypophyseal canal, also known as the craniopharyngeal canal when larger than 1.5 mm in diameter, is a rare congenital defect characterized by communication through the central skull base between the nasopharynx and the pituitary fossa.
Terminology
There are a number of terms that r...
Article
Patent foramen ovale
A patent foramen ovale (PFO) is a normal fetal interatrial connection which can persist into adult life. This can cause stroke due to paradoxical embolus.
Terminology
Patent foramen ovale is an anatomical variant due to persistence of a normal fetal structure rather than a malformation, in con...
Article
Sesamoid ossicles of the nuchal ligament
Sesamoid ossicles of the nuchal ligament are a relatively common anatomical variant that are usually asymptomatic and most commonly occur at the C5-C6 or C6-C7 vertebral levels.
Epidemiology
They occur in ~7.5% of the population, with a male predominance of 3:1 1.
Radiographic features
Pla...
Article
Space of Poirier
The space of Poirier is an area of the palmar wrist capsule, between the radial and ulnar capsular ligaments. It lies in the interval between the capitate and lunate and has poor ligamentous support, hence is associated with perilunate dislocation/instability.
Article
Humerus
The humerus (plural: humeri) is a tubular bone of the arm that articulates proximally at the shoulder with the glenoid of the scapula, and distally at the elbow, with the radius and ulna.
Gross anatomy
Osteology
The humerus begins proximally as a rounded head and joins the greater and lesser ...
Article
Pharyngeal mucosal space
The pharyngeal (or superficial) mucosal space is a deep compartment of the head and neck, located between the fascia of the pharyngeal constrictor muscles (buccopharyngeal or visceral fascia) and the mucosal surface of the nasopharynx, oropharynx, and hypopharynx.
Terminology
Not a true anatom...
Article
Ring meniscus
A ring meniscus is a very rare anatomical variant of the lateral meniscus of the knee. The inner margin of a ring meniscus on coronal images can easily be mistaken for a bucket-handle meniscal tear displaced into the intercondylar space, so it is usually diagnosed during arthroscopy.
Article
Omohyoid muscle
The omohyoid muscle is an infrahyoid muscle of the neck that is innervated by the ansa cervicalis of the cervical plexus receiving fibers from the ventral rami of C1–C3 spinal nerves. The omohyoid is a paired, flat strap of muscle that is made up of superior and inferior bellies joined by an int...
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...
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