Items tagged “variant”
426 results found
Article
Dromedary hump
Dromedary humps are prominent focal bulges on the lateral border of the left kidney. They are normal variants of the renal contour, caused by the splenic impression onto the superolateral left kidney.
Dromedary humps are important because they may mimic a renal mass, and as such is considered a...
Article
Ectopic pancreatic tissue
Ectopic pancreatic tissue, also known as heterotopic pancreatic tissue, refers to the presence of pancreatic tissue in the submucosal, muscularis or subserosal layers of the luminal gastrointestinal tract outside the normal confines of the pancreas and lacking any anatomic or vascular connection...
Article
Sternalis muscle
The sternalis muscle (TA: musculus sternalis 8), also known as rectus sternalis or parasternalis 7, is an uncommon chest wall accessory muscle and is of uncertain etiology and function. Its importance lies in that it should not be mistaken for a pathological lesion.
Epidemiology
Cadaveric stu...
Article
Weigert-Meyer law
The Weigert-Meyer law describes the relationship of the upper and lower renal moieties in duplicated collecting systems to their drainage inferiorly.
Weigert-Meyer law
With duplex kidney and complete ureteral duplication, the upper renal and lower renal moieties are drained by separate ureters...
Article
Circumcaval ureter
Circumcaval ureter, also known as retrocaval ureter, is a term used to describe an abnormal course of a ureter that encircles the inferior vena cava. Both of these terms are somewhat misleading, as this configuration is considered a developmental anomaly of the inferior vena cava (IVC). There ar...
Article
T-shaped uterus
T-shaped uterus refers to a specific radiographic appearance of the endometrial cavity.
Pathology
It is the most commonly associated abnormality from in utero diethylstilbestrol (DES) exposure, seen in 31% of exposed women. It is classified as a class VII Müllerian duct anomaly.
Background
D...
Case
Duplicated inferior vena cava
Published
29 Mar 2011
48% complete
MRI
Case
Accessory lateral gastrocnemius muscle
Published
12 Apr 2011
92% complete
MRI
Article
Accessory sutures
The parietal and occipital bones in particular are common regions for accessory sutures because of their multiple ossification centers.
It is important to know these anatomic variations, mainly on the head trauma image studies in children, where it could be difficult to differentiate non-depres...
Article
Hemivertebra
Hemivertebra is a type of vertebral anomaly that results from a lack of formation of one half of a vertebral body. It is a common cause of congenital scoliosis.
Epidemiology
The estimated incidence is at ~0.3 per 1000 live births 2.
Associations
Recognized associations are many and include:...
Article
Transitional vertebra
A transitional vertebra is one that has indeterminate characteristics and features of vertebrae from adjacent vertebral segments. They occur at the junction between spinal morphological segments:
atlanto-occipital junction
atlanto-occipital assimilation: complete or partial fusion of C1 and th...
Article
Lumbosacral transitional vertebra
Lumbosacral transitional vertebrae (LSTV) are a relatively common variant and can be seen in ~25% (range 15-35%) of the general population 1-3. Non-recognition of this variant and/or poor description in the report can lead to operations or procedures performed at the wrong level.
Depending on ...
Case
Onodi cells
Published
18 Jun 2011
95% complete
CT
Case
Aortic arch origin of left vertebral artery
Published
17 Jul 2011
68% complete
MRI
Article
Block vertebra
Block vertebra is a type of vertebral anomaly where there is a failure of separation of two or more adjacent vertebral bodies. It is an anatomic variant.
Pathology
In a block vertebra, there is partial or complete fusion of adjacent vertebral bodies.
Associations
hemivertebrae/absent ve...
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...
Case
Block vertebra C3/C4
Published
24 Nov 2011
57% complete
X-ray
Case
Block vertebra C3/4
Published
04 Dec 2011
85% complete
X-ray
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...