Items tagged “variant”
200 results found
Article
Transverse vaginal septum
Transverse vaginal (transvaginal) septum (TVS) is a type of rare congenital uterovaginal anomaly (class II under the Rock and Adam classification).
Epidemiology
It is rare with a frequency of 1 in 70,000 females.
Clinical presentation
In the case of a complete septum, patients commonly prese...
Article
Congenital utero-vaginal anomalies
There are many classification systems for congenital utero-vaginal anomalies. These include:
Buttram and Gibbons classification 2
American Fertility Society (AFS) classification
Modified Rock and Adam - AFS classification
Modified Rock and Adam - AFS classification
This classification divid...
Article
Bicuspid aortic valve
Bicuspid aortic valve (BAV) refers to a spectrum of deformed aortic valves with two functional leaflets or cusps which are often unequal in size.
They are most often congenital while an acquired bicuspid valve occurs when there is fibrous fusion between the right and left cusps of a pre-existin...
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
Mesiodens
A mesiodens (plural: mesiodentes) is the most common supernumerary tooth and is located in the palatal midline between the two maxillary central incisors.
Epidemiology
It is rare with an estimated prevalence of ~1% (range 0.09 to 2.2%) 3. There is an increased male predilection with a M:F rati...
Article
Meckel diverticulum
Meckel diverticulum is a congenital intestinal diverticulum due to fibrous degeneration of the umbilical end of the omphalomesenteric (vitelline) duct that occurs around the distal ileum. It is considered the most common structural congenital anomaly of the gastrointestinal tract.
Epidemiology
...
Article
Circumaortic left renal vein
Circumaortic left renal vein, also known as circumaortic renal collar is an anomaly of left renal vein when a supernumerary or accessory left renal vein passes posterior to the aorta, apart from the normal renal vein passing anterior to the aorta. This anomaly is potentially hazardous, if unreco...
Article
Retroaortic left renal vein
Retroaortic left renal vein (RLRV) is a normal anatomical variant where the left renal vein is located between the aorta and the vertebra and drains into the inferior vena cava.
Its recognition is important in order to avoid complications during retroperitoneal surgery or interventional procedu...
Article
Renal vein anomalies
There are several variations in renal venous anatomy. Some of these are specific to the left renal vein.
Left renal vein anomalies are generally classified into four types 2:
type I
the ventral preaortic limb of the left renal vein is obliterated, but the dorsal retroaortic limb persists and...
Article
Empty sella
An empty sella, also known as an empty pituitary fossa, refers to the appearance of the sella turcica when the pituitary gland appears shrunken or invisible and CSF fills the space instead. It is commonly an incidental finding of no clinical significance, but there exists a well-established asso...
Article
Ectopic posterior pituitary
An ectopic posterior pituitary reflects a disruption of normal embryogenesis of the posterior pituitary and is one of the more common causes of pituitary dwarfism. Although it can be an isolated abnormality, numerous other congenital central nervous system malformations have been identified. Whe...
Article
Lunotriquetral coalition
A lunotriquetral coalition, also known as lunotriquetral fusion or synostosis, is a type of carpal coalition and represents a congenital lack of separation of the lunate and triquetral bones of the carpus.
Terminology
The term coalition is preferred over fusion for congenital coalitions, as d...
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 1.
Classification
Six types of coccyx have been described 2,3:
type I: the coccyx is curved slightly forward, with its apex pointing caudally (~70%)
type II: the ...
Article
Duplication of inferior vena cava
Duplication of the inferior vena cava is a relatively rare but well described vascular anomaly. This caval abnormality had an increased association with renal anomalies like crossed fused ectopia or circumaortic renal collar 1,2.
Epidemiology
The incidence of inferior vena cava duplication is ...
Article
Accessory ossicle of the anterior arch of the atlas
The accessory ossicle of the anterior arch of the atlas is a normal variant and is best appreciated on a lateral cervical/sagittal study. It is observed as a circular and corticated osseous density that articulates with the inferior aspect of the anterior arch of the atlas.
It is not associate...
Article
Metopic suture
The metopic suture (also known as the frontal, interfrontal, or median frontal suture) is a vertical fibrous joint that divides the two halves of the frontal bone and is present in a newborn.
Persistent metopic sutures can be misdiagnosed as vertical skull fractures, therefore it is important t...
Article
Partial anomalous pulmonary venous return
Partial anomalous pulmonary venous return (PAPVR), also known as partial anomalous pulmonary venous connection (PAPVC), is a rare congenital cardiovascular condition in which some of the pulmonary veins, but not all, drain into the systemic circulation rather than in the left atrium.
Epidemiolo...
Article
Sprengel deformity
Sprengel deformity, or congenital elevation of the scapula, is a complex deformity of the shoulder and is the most common congenital shoulder abnormality. An initial diagnosis can often be made on radiographs, but CT or MRI is often necessary to evaluate the details of the abnormality.
Epidemio...
Article
Foramen tympanicum
The foramen tympanicum (plural: foramina tympanica), also known as foramen of Huschke, is an anatomical variation in the external acoustic canal (EAC), where a bony defect connects the EAC to the temporomandibular joint (TMJ).
Epidemiology
Various studies have reported on the occurrence of a f...
Article
Loop-to-loop colon
The loop-to-loop colon describes an abnormal colonic course associated with the absence of the left kidney from the renal fossa.
The transverse colon extends to the lateral margin of the abdominal wall and the descending colon courses medially to fill the renal fossa, resulting in a "looped" c...
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