Items tagged “variant”

420 results found
Article

Variant hepatic arterial anatomy

Variation in hepatic arterial anatomy is seen in 40-45% of people. Classic branching of the common hepatic artery from the celiac artery, and the proper hepatic artery into right and left hepatic arteries to supply the entire liver, is seen in 55-60% of the population.  Terminology An accessor...
Case

Azygos continuation of the inferior vena cava

 Diagnosis certain
Assoc Prof Frank Gaillard
Published 06 Feb 2009
65% complete
CT
Article

Persistent stapedial artery

The persistent stapedial artery (PSA) is an abnormal small vessel arising from the petrous portion of the internal carotid artery and crossing through the middle ear. It results from the failure of regression of the embryonic stapedial artery.  Epidemiology The prevalence is thought to range f...
Article

Duplex collecting system

A duplex collecting system, or duplicated collecting system, is one of the most common congenital renal tract abnormalities. It is characterized by an incomplete fusion of upper and lower pole moieties resulting in a variety of complete or incomplete duplications of the collecting system. While ...
Article

Duplex collecting system

A duplex collecting system, or duplicated collecting system, is one of the most common congenital renal tract abnormalities. It is characterized by an incomplete fusion of upper and lower pole moieties resulting in a variety of complete or incomplete duplications of the collecting system. While ...
Article

Intracranial arterial fenestration

Intracranial arterial fenestration refers to segmental duplication of the intracranial arteries. They may be contrasted to arterial duplication, which consists of two distinct vessels with separate origins and no downstream convergence. They are rare anomalies, felt to result from incomplete fus...
Article

Artery of Percheron

The artery of Percheron is a rare variant of the posterior cerebral circulation characterized by a solitary arterial trunk that supplies blood to the paramedian thalami and the rostral midbrain bilaterally. From the original classification of arterial patterns at the origin of the paramedian art...
Article

Persistent fetal lobulation of the kidneys

Persistent fetal lobulation is a normal variant seen occasionally in adult kidneys. It occurs when there is incomplete fusion of the developing renal lobules. Embryologically, the kidneys originate as distinct lobules that fuse as they develop and grow. Radiographic features It is often seen o...
Case

Haller cells - extensive

 Diagnosis almost certain
Assoc Prof Frank Gaillard
Published 17 Jul 2009
39% complete
CT
Article

Septate uterus

A septate uterus is a common type of congenital uterine anomaly, and it may lead to an increased rate of pregnancy loss. The main imaging differential diagnoses are arcuate uterus and bicornuate uterus. Epidemiology It is considered the commonest uterine anomaly (accounts for ~55% of such anom...
Article

Arcuate uterus

An arcuate uterus is a mildly variant shape of the uterus. It is technically one of the Müllerian duct anomalies, but is often classified as a normal variant. It is the uterine anomaly that is least commonly associated with reproductive failure. Arcuate uterus can be characterized with ultrasoun...
Article

Unicornuate uterus

A unicornuate uterus or unicornis unicollis is a type of Müllerian duct anomaly (class II) characterized by a banana-shaped uterus usually draining into a single Fallopian tube. Epidemiology This type can account for ~10% (range 6-13%) of uterine anomalies and infertility is seen in ~12.5% (ra...
Article

Müllerian duct anomalies

Müllerian duct anomalies (MDAs) are congenital abnormalities that occur when the Müllerian ducts (paramesonephric ducts) do not develop correctly. This may be as a result of complete agenesis, defective vertical or lateral fusion, or resorption failure. Epidemiology MDAs are estimated to occur...
Article

Splenunculus

Splenunculi, also known as supernumerary spleens, accessory spleens, or splenules, are small nodules of spleen that are separate from the rest of the organ.  Epidemiology They are common, seen in up to 16% of CTs of the abdomen and up to 30% of autopsies 2.  Pathology Accessory spleens are c...
Article

Splenunculus

Splenunculi, also known as supernumerary spleens, accessory spleens, or splenules, are small nodules of spleen that are separate from the rest of the organ.  Epidemiology They are common, seen in up to 16% of CTs of the abdomen and up to 30% of autopsies 2.  Pathology Accessory spleens are c...
Article

Total anomalous pulmonary venous return

Total anomalous pulmonary venous return (TAPVR) is a cyanotic congenital heart anomaly with an abnormal drainage anatomy of the entire pulmonary venous system. This contrasts with partial anomalous pulmonary venous return (PAPVR) where only part of the pulmonary venous anatomy is abnormal. In T...
Article

Heterotaxy syndrome

Heterotaxy syndrome or situs ambiguus (also commonly, but etymologically less correctly, spelled situs ambiguous) is a disturbance in the usual left-right distribution of the thoracic and abdominal organs that does not entirely correspond to the complete mirror image (situs inversus). It occurs...
Article

Renal agenesis

Renal agenesis refers to a congenital absence of one or both kidneys. If bilateral (traditionally known as the classic Potter syndrome) the condition is fatal, whereas if unilateral, patients can have a normal life expectancy.  Epidemiology Unilateral renal agenesis affects approximately 1 in ...
Article

Uterine agenesis

Uterine agenesis is the extreme of Mullerian duct anomalies (Class I) where there is a complete absence of uterine tissue above the vagina.  Epidemiology The uterine agenesis-hypoplasia spectrum accounts for ~10-15% of all Müllerian duct anomalies. Clinical presentation Clinical presentation...
Case

Azygos fissure

 Diagnosis certain
Assoc Prof Frank Gaillard
Published 10 Feb 2010
72% complete
X-ray

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