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.
14,938 results found
Article
Ankle series
The ankle series is comprised of an anteroposterior (AP), mortise and lateral radiograph. The series is often used in emergency departments to evaluate the distal tibia, distal fibula, and the talus; forming the ankle joint.
See approach to an ankle series.
Indications
Ankle radiographs are p...
Article
Ankle (stress view)
The AP stress view of the ankle is a highly specialized view used to assess the integrity of the syndesmosis and deltoid ligament. It can be performed one of two ways, with gravity or via manual external rotation.
Indications
In intermediate ankle injuries that have no syndesmotic widening on...
Article
Ankle x-ray (summary)
This is a basic article for medical students and other non-radiologists
An ankle x-ray, also known as ankle series or ankle radiograph, is a set of two x-rays of the ankle joint. It is performed to look for evidence of injury (or pathology) affecting the ankle, often after trauma.
Reference ar...
Article
Ankylosing spondylitis
Ankylosing spondylitis (less commonly known as Bechterew disease or Marie Strümpell disease) is a seronegative spondyloarthropathy, which results in fusion (ankylosis) of the spine and sacroiliac (SI) joints, although involvement is also seen in large and small joints.
Epidemiology
Traditional...
Article
Ankylosing spondylitis (cardiovascular manifestations)
Cardiovascular manifestations of ankylosing spondylitis may affect around 2-10% of all patients with ankylosing spondylitis. Cardiac complications include:
left ventricular dysfunction: considered on of the commonest findings 3
aortic root dilatation: also a relatively frequent finding 3
righ...
Article
Ankylosing spondylitis (thoracic manifestations)
Thoracic manifestations of ankylosing spondylitis can be varied. For a general discussion of the condition refer to the parent article on ankylosing spondylitis.
It can affect the tracheobronchial tree and the lung parenchyma, and the disease spectrum includes:
upper lobe fibrocystic changes -...
Article
Anlage
An anlage in biology refers to the primordial precursor of a tissue or organ, which is still recognisable as a collection of cells that will form that specific tissue.
The term is commonly used in medicine to refer to organs, such as the pancreas, when one is describing anatomical variants and ...
Article
Ann Arbor staging system
The Ann Arbor staging system was the landmark lymphoma staging classification system for both Hodgkin lymphoma and non-Hodgkin lymphoma. It is named after the town of Ann Arbor in the US state of Michigan where the Committee on Hodgkin's Disease Staging Classification met in 1971 to agree on it....
Article
Annular fissure
Annular fissures are a degenerative deficiency of one or more layers that make up the annulus fibrosus of the intervertebral disc.
Terminology
Many authors prefer the term annular fissure over annular tear, as the latter seems to imply acute injury 1,2. In the setting of severe trauma with di...
Article
Annular ligament (disambiguation)
The annular ligament can refer to:
annular ligament of the stapes
annular ligament of the proximal radio-ulnar joint
Article
Annular pancreas
Annular pancreas is a morphological anomaly that results in pancreatic tissue completely or incompletely encircling the duodenum. This condition can cause duodenal obstruction and is therefore important to recognize, as radiologists are frequently the first to make the diagnosis.
Epidemiology
...
Article
Annuloaortic ectasia
Annuloaortic ectasia refers to a proximal dilatation of the aortic root at the level of the aortic annulus, which is the same level as the sinus of Valsalva.
Pathology
Annuloaortic ectasia occurs with connective tissue diseases such as Marfan disease and Ehlers-Danlos syndrome. It is a cystic ...
Article
Annulus fibrosus
The annulus fibrosus (plural: annuli fibrosi) surrounds the nucleus pulposus and together they form the intervertebral disc.
Gross anatomy
The annulus comprises 15 to 20 collagenous (type I) laminae which run obliquely from the edge of one vertebra down to the edge of the vertebra below. The d...
Article
Annulus fibrosus calcification
Annulus fibrosus calcification is a form of intervertebral disc calcification where the peripheral annular portion (annulus fibrosus) can get calcified. This may occur in isolation or in conjunction with other sites of disc calcification. It could involve any portion of the spine. Some suggest t...
Article
Annulus of Zinn contents (mnemonic)
A mnemonic to remember the contents of the tendinous ring (also known as the annulus of Zinn) from superior to inferior is:
One Canal, Several Orbital Nerves In One Annulus
Mnemonic:
OC: optic canal
SO: superior division of oculomotor nerve
N: nasociliary nerve
IO: inferior division of ocu...
Article
Anode angle
The anode angle refers to the angle the target surface of the anode sits at in relation to the vertical.
Most x-ray tubes have an anode angle of 12-15 degrees but greater or lesser angles can also be used depending on the application. The degree of angulation of the anode affects the effective...
Article
Anode heel effect
Anode heel effect refers to the lower field intensity towards the anode in comparison to the cathode due to lower x-ray emissions from the target material at angles perpendicular to the electron beam.
Basic concept
The conversion of the electron beam into x-rays doesn’t simply occur at the sur...
Article
Anode (x-ray tube)
The anode (or anticathode) is the component of the x-ray tube where x-rays are produced. It is a piece of metal, shaped in the form of a bevelled disk with a diameter between 55 and 100 mm, and thickness of 7 mm, connected to the positive side of the electrical circuit. The anode converts the en...
Article
Anomalous aortic origin of coronary artery
Anomalous aortic origin of coronary artery (AAOCA) refers to a congenital coronary artery anomaly in which a coronary arteries arises from a different coronary sinus.
Terminology
Anomalous origin of the coronary artery arising from the opposite sinus (ACOAS) is a narrower definition and refers...
Article
Anomalous course of coronary arteries
Anomalous course of a coronary artery is a type of congenital coronary artery anomaly. It may represent a benign and incidental finding, but rarely it is a malignant course predisposing patients to life-threatening myocardial ischemia or arrhythmias, depending on where the artery runs.
Clinica...
Article
Anomalous insertion of the medial meniscus
Anomalous insertion of the medial meniscus (AIMM) is an anatomical variation of the insertion of the anterior root of the medial meniscus.
Terminology
Defined as a congenital variation in the insertion of the anterior root of the medial meniscus onto the anterior cruciate ligament (ACL). The...
Article
Anomalous left coronary artery from the pulmonary artery
Anomalous left coronary artery from the pulmonary artery (ALCAPA), also known as Bland-White-Garland syndrome (BWG), is a rare congenital coronary artery anomaly and is considered one of the most severe of such anomalies.
There are two forms, based on onset of disease, each of which has differe...
Article
Anomalous pancreaticobiliary junction
An anomalous pancreaticobiliary junction, also known as pancreaticobiliary maljunction, describes the abnormal junction of the pancreatic duct and common bile duct that occurs outside the duodenal wall to form a long common channel (>15 mm).
Epidemiology
It is more common in Asia and eastern c...
Article
Anomalous systemic arterial supply to normal lung
Anomalous systemic arterial supply to normal lung is an anatomical variant in which a portion of the lung (usually a basal segment) is supplied by a systemic vessel without a distinct pulmonary sequestration.
Terminology
It was traditionally (perhaps inappropriately since not a true sequestrat...
Article
Anomaly detection
Anomaly detection uses a large number of normal examples to train an algorithm which detects what is normal (based on the training examples) and what is not normal. Anomaly detection has features of both supervised and unsupervised learning, and is applicable to Radiology as it’s important to di...
Article
Anophthalmia
Anophthalmia refers to a complete absence of ocular development. It is often considered to represent the most severe form of microphthalmia.
Pathology
It can occur in three different situations:
primary anophthalmia: complete absence of eye tissue due to a failure of the part of the brain tha...
Article
Anorectal disease (summary)
This is a basic article for medical students and other non-radiologists
Anorectal disease is a group of conditions that affect the anus and rectum. The most common conditions in this group include hemorrhoids, anal fissures, anorectal abscess and anal fistula.
Reference article
This is a summ...
Article
Anorexia nervosa
Anorexia nervosa is a psychiatric disorder characterized by distorted self-perception of body weight leading to starvation, obsession with remaining underweight, and an excessive fear of gaining weight. One in five patients with anorexia dies due to complications of the disease.
Epidemiology
T...
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Anorexia nervosa (CNS manifestations)
The CNS manifestations of anorexia nervosa are common but varied with most of the imaging features non-specific in their own right.
For a general discussion, and for links to other system specific manifestations, please refer to the article on anorexia nervosa.
Epidemiology
Studies have iden...
Article
Anosmia
Anosmia (also known as anosphresia or olfactory anesthesia) is the complete absence of the sense of smell.
Terminology
In addition to anosmia, there is also hyposmia (a.k.a. microsmia or olfactory hypoesthesia) representing a diminished sense of smell and parosmia (a.k.a. dysosmia or paraosmi...
Article
ANOVA
ANOVA (ANalysis Of VAriance) is a statistical technique commonly seen in radiology research.
ANOVA analyzes are conceptually similar to the student t-test, but involve comparison of multiple groups at once. The alternative to an ANOVA would be multiple head-to-head t-tests, but this would likel...
Article
Anoxic brain injury
Anoxic brain injury, also known as global hypoxic-ischemic injury, is seen in all age groups (from antenatal to the elderly) as a result of numerous etiologies. The pattern of injury depends on a number of factors including:
age of the patient (brain maturity)
neonatal hypoxic-ischemic encepha...
Article
Ansa cervicalis
The ansa cervicalis (or ansa hypoglossi, an archaic synonym) is a component of the cervical plexus which gives muscular branches to the geniohyoid muscle of the suprahyoid group and most of the infrahyoid (strap) muscles (excluding the thyrohyoid muscle).
It lies within the carotid triangle, s...
Article
Ansa pancreatica
The ansa pancreatica is a rare type of anatomical variation of the pancreatic duct. It is a communication between the main pancreatic duct (of Wirsung) and the accessory pancreatic duct (of Santorini). Recently, the ansa pancreatica has been considered as a predisposing factor in patients with i...
Article
Anteater nose sign (foot)
The anteater nose sign refers to an anterior tubular elongation of the superior calcaneus which approaches or overlaps the navicular on a lateral radiograph of the foot. This fancifully resembles the nose of an anteater and is indicative of calcaneonavicular coalition 1,2.
History and etymolog...
Article
Antegrade ureteric stent
Antegrade ureteric stents are performed under fluoroscopic guidance, typically by an interventional radiologist or urologist. It is performed via percutaneous access from the kidney. It is usually performed using the access from a prior percutaneous nephrostomy, a so-called two-step procedure, a...
Article
Antenatal features of Down syndrome
Antenatal screening of Down syndrome (and other less common aneuploidies) should be available as a routine component of antenatal care. It allows families to either adjust to the idea of having a child with the condition or to consider termination of pregnancy.
For a general description of Down...
Article
Antenatal screening
Antenatal screening and diagnosis are currently available for a few selected genetic conditions, including trisomy 21 (Down syndrome), trisomy 18 (Edward syndrome), trisomy 13 (Patau syndrome) and neural tube defects.
For an overview of the conditions and their manifestations, please refer to t...
Article
Antenatal soft markers on ultrasound
Antenatal soft ultrasound markers are fetal sonographic findings that are generally not abnormalities as such but are indicative of an increased age adjusted risk of an underlying fetal aneuploidic or some non chromosomal abnormalities.
Most of the described features do not constitute a structu...
Article
Antepartum hemorrhage
Antepartum hemorrhage (APH) refers to vaginal bleeding during the second half of pregnancy (> 20 weeks gestation). APH may occur in varying degrees from mild to severe, with concomitant risk to mother and baby and potential to result in severe maternal/fetal compromise, including death.
Epidemi...
Article
Anterior abdominal wall
The anterior abdominal wall forms the anterior limit of the abdominal viscera and is defined superiorly by the xiphoid process of the sternum and costal cartilages and inferiorly by the iliac crest and pubic bones of the pelvis.
Gross anatomy
In general, the anterior abdominal wall has nine la...
Article
Anterior abdominal wall hernia
Anterior (or ventral) abdominal wall hernias (herniae also used) are a subgroup of abdominal wall herniae that are differentiated by the location of the hernia.
epigastric hernia
incisional hernia
port site hernia
interparietal hernia
parastomal hernia
paraumbilical hernia
Spigelian hern...
Article
Anterior angulation of the coccyx
Anterior angulation of the coccyx may be a normal variant but poses a diagnostic challenge for those considering coccygeal trauma.
Classification
Four types of coccyx have been described:
type I: the coccyx is curved slightly forward, with its apex pointing caudally (~70%)
type II: the coccy...
Article
Anterior ankle impingement syndrome
Anterior ankle impingement (AAI) syndrome is the result of chronic repetitive trauma with impingement of the anterior tibia against the talus.
Epidemiology
Common in soccer players and ballet dancers 1.
Clinical presentation
Clinical features of anterior ankle impingement syndrome include pa...
Article
Anterior ankle tendons (mnemonic)
A mnemonic that refers to the order of the anterior ankle tendons around the ankle is:
Tom Hates Dick
The mnemonic can be used to remember the order of the tendons from medial to lateral as they pass under the extensor retinaculum of the ankle.
Mnemonic
T: tibialis anterior
H: extensor hal...
Article
Anterior atlanto-occipital membrane
The anterior atlanto-occipital membrane is a thin membrane that joins the upper border of the anterior arch of the atlas (C1) to the anterior inferior surface of the foramen magnum. It is a continuation of the anterior longitudinal ligament above the C1 level. It is immediately posterior to the ...
Article
Anterior bronchus sign
The anterior bronchus sign refers to the appearance of the anterior segmental bronchus of the upper lobes as seen on a frontal chest radiograph.
Gross anatomy
The anterior segment bronchus of the upper lobes courses anteriorly and laterally. When the orientation is predominantly anteriorly the...
Article
Anterior cardiac veins
The anterior cardiac veins are a group of parallel coronary veins that course over the anterior surface of the right ventricle, draining it and entering directly into the right atrium. They may occasionally drain into the small cardiac vein.
Article
Anterior cardinal veins
The anterior cardinal veins are paired transient embryologic venous vessels which deliver venous return to the heart starting at about 4 weeks of gestation 1.
Embryogenesis
The anterior cardinal veins begin their embryological development as symmetric venous channels draining blood from the cr...
Article
Anterior center-edge angle
The anterior center-edge angle, also known as the vertical-center-anterior (VCA) angle, is a radiographic measurement of the anterior coverage of the femoral head by the acetabulum. It is used in assessing acetabular dysplasia and pincer type of femoroacetabular impingement.
Radiographic featur...
Article
Anterior cerebral artery
The anterior cerebral artery (ACA) along with the middle cerebral artery (MCA) forms at the termination of the internal carotid artery (ICA). It is the smaller of the two, and arches anteromedially to pass anterior to the genu of the corpus callosum, dividing as it does so into its two major bra...
Article
Anterior cerebral artery (ACA) infarct
Anterior cerebral artery (ACA) territory infarcts are much less common than either middle or posterior cerebral artery territory infarcts.
Epidemiology
ACA territory infarcts are rare, comprising ~2% of ischemic strokes 1,2.
Clinical presentation
ACA stroke syndrome presents as 1-3:
dysarth...
Article
Anterior cervical angle
The anterior cervical angle is a novel ultrasound parameter that is being used as a predictor of spontaneous preterm birth.
Measurement
The angle between the uterine wall and the cervical canal is measured during the first and the second trimester by a transvaginal ultrasound. It is measured u...
Article
Anterior cervical discectomy and fusion (ACDF)
Anterior cervical discectomy and fusion (ACDF) is a commonly performed spinal fusion procedure for the decompression of the cervical cord due to disc protrusions and posteriorly projecting osteophytes.
It is not to be confused with an ACDA (anterior cervical disc arthroplasty).
Technique
The ...
Article
Anterior cervical space
The anterior cervical space is a small infrahyoid compartment of the head and neck. It is a fat containing space and is not enclosed by fascia 1.
Gross anatomy
Contents
areolar fat
Relations
posterior: carotid space
medial: visceral space
superior: submandibular space
Related pathology
...
Article
Anterior chest wall protocol (MRI)
The MRI anterior chest wall protocol encompasses a set of MRI sequences for the routine assessment of the sternoclavicular joints and/or the anterior chest wall.
Note: This article aims to frame a general concept of an MRI protocol for the assessment of sternoclavicular joints and/or the anteri...
Article
Anterior choroidal artery
The anterior choroidal artery (AChA) supplies several crucial anatomical structures of the brain important for vision and motor control. Identification of AChA is important because of its strategic and extensive area of supply as well as large variations in the territorial distribution.
Gross a...
Article
Anterior choroidal artery syndrome
Anterior choroidal artery syndrome is a rare entity characterized by the triad of
hemiplegia
hemianaesthesia and
contralateral hemianopia
This occurs as a result of cerebral infarction in the anterior choroidal artery territory.
The syndrome may also be associated with neuropsychological di...
Article
Anterior cingulate cortex
The anterior cingulate cortex (ACC), previously known as the precingulate, is a region of the brain surrounding the anterior corpus callosum. It is involved in the limbic system and the prefrontal cortex.
Summary
location: it is located superior to the anterior corpus callosum, more specifical...
Article
Anterior circulation
The anterior circulation is the blood supply to the anterior portion of the brain, including most of the supratentorial structures excluding the occipital lobes.
The anterior circulation is supplied by the internal carotid arteries which each divide into two the large terminal branches, the ant...
Article
Anterior commissure
The anterior commissure (AC) is a transversely oriented commissural white matter tract that connects the two cerebral hemispheres along the midline. It is a very important anatomical landmark that connects different parts of the limbic system on both sides and plays a role in the interhemispheri...
Article
Anterior commissure of the larynx
The anterior commissure of the larynx is the anterior junction point of the true vocal cords. It is bounded anteriorly by the thyroid cartilage and is part of the laryngeal glottis.
Article
Anterior commissure - posterior commissure line
The anterior commissure - posterior commissure line (AC-PC line), also known as the bicommissural line, has been adopted as a convenient standard by the neuroimaging community, and in most instances is the reference plane for axial imaging in everyday scanning. The creation of a standard image p...
Article
Anterior communicating artery
The anterior communicating artery (ACOM) arises from the anterior cerebral artery and acts as an anastomosis between the left and right anterior cerebral circulation. Approximately 4 mm in length, it demarcates the junction between the A1 and A2 segments of the anterior cerebral artery.
Branche...
Article
Anterior compartment of the arm
The anterior compartment of the arm is one of the two compartments of the arm.
A sheath of deep fascia surrounds the arm, the brachial fascia. Two intermuscular septa (medial and lateral) extend from it to attach to the humerus at the medial condylar ridge and lateral supracondylar ridge, respe...
Article
Anterior compartment of the forearm
The forearm is divided into the anterior compartment and the posterior compartment by the deep fascia, lateral intermuscular septum and the interosseous membrane between the ulna and radius.
Muscles
The eight muscles located in the anterior compartment of the forearm can be divided into three...
Article
Anterior compartment of the leg
The anterior compartment of the leg is one of the four compartments in the leg between the knee and foot. Muscles within this compartment primarily produce ankle dorsiflexion and toe extension.
The leg is separated into anterior, lateral, superficial posterior and deep posterior compartments by...
Article
Anterior compartment of the thigh
The anterior compartment of the thigh is one of the three compartments in the thigh. Muscles within this compartment primarily produce hip flexion and knee extension.
The thigh is separated into anterior, posterior and medial (adductor) compartments by intermuscular septa and surrounded by the ...
Article
Anterior condylar confluence
The anterior condylar confluence is an extracranial venous structure at the base of skull that communicates extensively with regional veins and dural venous sinuses.
It is located immediately anterior to the hypoglossal canal and medial to the jugular vein, just inferior to the jugular bulb an...
Article
Anterior corticospinal tract
The anterior corticospinal tract is formed at the level of the of the medullary pyramids, where the majority (90%) of descending corticospinal tract fibers decussate to form the lateral corticospinal tract. The majority of the remaining non-decussating 10% of fibers form the much smaller anterio...
Article
Anterior cranial fossa
The anterior cranial fossa constitutes the floor of the cranial vault which houses the frontal lobes of the brain.
Gross anatomy
Structures present in the midline of the anterior cranial fossa from anterior to posterior are:
groove for superior sagittal sinus
groove for anterior meningeal v...
Article
Anterior cruciate ligament
Anterior cruciate ligament (ACL) is one of the two cruciate ligaments that stabilize the knee joint.
Gross anatomy
The ACL arises from the anteromedial aspect of the intercondylar area on the tibial plateau and passes upwards and backwards to attach to the posteromedial aspect of the lateral ...
Article
Anterior cruciate ligament avulsion fracture
Anterior cruciate ligament (ACL) avulsion fracture or tibial eminence avulsion fracture is a type of avulsion fracture of the knee. This typically involves separation of the tibial attachment of the ACL to variable degrees. Separation at the femoral attachment is rare 5.
Epidemiology
It is mor...
Article
Anterior cruciate ligament ganglion cyst
Anterior cruciate ligament (ACL) ganglion cysts, commonly referred to simply as ACL cysts, along with ganglion cysts arising from the alar folds that cover the infrapatellar fat pad, make up the vast majority of intra-articular ganglion cysts of the knee.
Epidemiology
Anterior cruciate ligamen...
Article
Anterior cruciate ligament graft impingement
Anterior cruciate ligament graft impingement is a complication of an anterior cruciate ligament (ACL) reconstruction and usually associated with a decreased range of motion.
Epidemiology
Associations
Anterior cruciate ligament graft impingement is associated with improper tunnel placement and...
Article
Anterior cruciate ligament graft stretching
Anterior cruciate ligament graft stretching or graft elongation refers to a clinical scenario of increased knee laxity in the setting of intact graft fibers and can occur as a complication of anterior cruciate ligament reconstruction.
Epidemiology
Anterior cruciate ligament (ACL) graft stretch...
Article
Anterior cruciate ligament graft tear
Anterior cruciate ligament graft tears can occur as complications of anterior cruciate ligament reconstruction or as a consequence of a traumatic reinjury.
Epidemiology
An anterior cruciate ligament reinjury occurs in about 7% of patients with an anterior cruciate ligament reconstruction 1.
R...
Article
Anterior cruciate ligament mucoid degeneration
Anterior cruciate ligament (ACL) mucoid degeneration, along with tears and anterior cruciate ligament ganglion cysts, is a relatively common cause of increased signal within the anterior cruciate ligament (ACL). The appearance can mimic acute or chronic interstitial partial tears of the ACL. How...
Article
Anterior cruciate ligament reconstruction
Anterior cruciate ligament (ACL) reconstruction is a common procedure post ACL tear. It aims to reduce knee joint instability and thus prevent any further meniscal and/or cartilage damage.
Procedure
There are numerous surgical techniques for ACL reconstruction 1-3:
autograft reconstruction
...
Article
Anterior cruciate ligament reconstruction complications (overview)
Anterior cruciate ligament (ACL) reconstruction complications are common, occurring in 10-25% of patients.
Clinical presentation
Patients with complications of ACL reconstruction can present with decreased range of motion (impingement or arthrofibrosis) and/or laxity (graft rupture or stretchi...
Article
Anterior cruciate ligament tear
Anterior cruciate ligament (ACL) tears are the most common knee ligament injury encountered in radiology and orthopedic practice.
Clinical presentation
Patients typically present with symptoms of knee instability, usually after acute trauma. The following signs and symptoms are common:
poppi...
Article
Anterior dislocation of the hip
Anterior hip dislocation is much less common than a posterior hip dislocation. It constitutes only 5-18% of all hip dislocations.
Pathology
While the posterior dislocation is often associated with fractures, the anterior dislocation is mostly an isolated injury 1.
Subtypes
It can be classifi...
Article
Anterior division of the mandibular nerve
The anterior division of the mandibular division of the trigeminal nerve has four branches, which are all motor branches except one. The four branches are:
deep temporal nerves
lateral pterygoid nerves
masseteric nerve
buccal nerve
Article
Anterior epitympanic recess
The anterior epitympanic recess, also known as the supratubal recess, is a small discrete space in the epitympanum anterior to the malleus. It is separated from the epitympanum proper by the cog.
Article
Anterior ethmoidal artery
The anterior ethmoid artery is a branch of the ophthalmic artery. It supplies the anterior and middle ethmoidal sinuses, frontal sinus, the lateral nasal wall and the nasal septum (see nasal cavity).
Gross anatomy
It traverses the anterior ethmoidal foramen with the anterior ethmoidal nerve (w...
Article
Anterior ethmoidal foramen
The anterior ethmoid foramen is a small opening in the ethmoid bone. It is the anatomical border of anterior and posterior ethmoid air cells. It transmits the anterior ethmoidal artery, vein and nerve.
The anterior ethmoid foramen is situated 25 mm away from the lacrimal crest, 12 mm anterior t...
Article
Anterior ethmoidal nerve
The anterior ethmoidal nerve is an extraconal branch of the nasociliary nerve, a branch of the ophthalmic division of the trigeminal nerve. Some authors describe it as either the terminal branch or a direct continuation of the nasociliary nerve. It branches off distal to the infratrochlear nerv...
Article
Anterior ethmoidal notch
The anterior ethmoidal notch contains the anterior ethmoidal artery and has significant rates of anatomic variation that put the artery during functional endoscopic sinus surgery (FESS).
Gross anatomy
The anterior ethmoidal notch lies in the medial wall of the superomedial orbit, adjacent to t...
Article
Anterior fontanelle
The anterior or frontal fontanelle is the diamond-shaped soft membranous gap (fontanelle) at the junction of the coronal and sagittal sutures. It persists until approximately 18-24 months after birth, after which it is known as the bregma. The precise timing of the anterior fontanelle closure is...
Article
Anterior fontanelle inclusion cyst
Anterior fontanelle inclusion cysts, also commonly referred to as congenital dermoid inclusion cysts, are cystic lesions overlying the anterior fontanelle without communication with the underlying intracranial compartment.
Terminology
Although the term congenital dermoid inclusion cyst is mor...
Article
Anterior glenolabral injuries
Anterior glenolabral injuries are common in the setting of anterior shoulder dislocation and comprise a number of closely related entities:
Bankart lesion
bony Bankart lesion
anterior labroligamentous periosteal sleeve avulsion (ALPSA)
Perthes lesion
glenolabral articular disruption (GLAD)
...
Article
Anterior hip pain
Causes of anterior hip pain include:
osteoarthritis
synovitis including
pigmented villonodular synovitis (PVNS)
synovial osteochondromatosis
inflammatory arthropathy (e.g. rheumatoid arthritis)
iliopsoas bursitis
ganglion cyst
synovial cyst
muscle tear
malignancy
inguinal adenopathy
...
Article
Anterior horn syndrome
Anterior horn syndrome is a fairly generic term used to refer to flaccid paralysis and areflexia due to involvement of the anterior grey matter horns of the spinal cord. Sensation is typically preserved.
Causes of anterior horn syndrome include:
anterior spinal artery ischemia
poliomyeliti...