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.

544 results found
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Surgical haemostatic material

Surgical haemostatic material is used to control bleeding intraoperatively and is hence frequently voluntarily left in the operative bed, not to be confused with a gossypiboma which is foreign material left by mistake. It can mimic an abscess on imaging studies. Various types are available, the ...
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Syndactyly

Syndactyly refers to a congenital fusion of two or more digits. It may be confined to soft tissue (soft tissue syndactyly / simple syndactyly) or may involve bone (bony syndactyly / complex syndactyly). Epidemiology The overall estimated incidence is at ~1 per 2,500 to 5,000 live births 6,8. T...
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T2 dark spot sign

T2 dark spot sign is an MRI appearance of endometriomas seen as a result of chronic haemorrhage. The sign is useful in differentiating a solitary endometrioma from a functional haemorrhagic ovarian cyst, as both might show high T1 signal with T2 shading.  The T2 dark spot, described in the sign...
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Tamoxifen-associated endometrial changes

Tamoxifen has pro-oestrogenic effects on the endometrium and thus is associated with an increased prevalence of: endometrial polyps: occurs in ~8-36% of women in treated 8 endometrial hyperplasia: occurs in ~1-20% of women treated ref cystic endometrial atrophy endometrial carcinoma Epidemi...
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Teratoma

Teratomas are germ cell tumours that arise from ectopic pluripotent stem cells that fail to migrate from yolk sac endoderm to the urogenital ridge during embryogenesis. By definition, they contain elements from all three embryological layers: endoderm, mesoderm and ectoderm although frequently, ...
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Theca lutein cyst

Theca lutein cysts (TLC), also known as hyperreactio luteinalis (HL), are a type of functional ovarian cysts. They are typically multiple and seen bilaterally. Pathology They are thought to originate due to excessive amounts of circulating gonadotrophins such as beta-hCG. Hyperplasia of the th...
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Thoracic endometriosis

Thoracic endometriosis is an uncommon location for endometriosis and the main cause of catamenial pneumothorax.  Epidemiology Most often occurs in the third and fourth decades of life 3. Clinical presentation Symptoms may include: catamenial pleuritic chest pain catamenial haemoptysis: whe...
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Tip of the iceberg sign (ovarian dermoid cyst)

Tip of the iceberg sign refers to one of the characteristic appearances of an ovarian dermoid cyst. If there are echogenic cyst contents of sebum and hair, they cause marked posterior acoustic attenuation so that only the superficial part of the cyst is seen. Just like an iceberg, you may only b...
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Trachelectomy

Trachelectomy (sometimes known as a cervicectomy) refers to the removal of the uterine cervix.  It is sometimes performed as a uterine-sparing surgery for certain cases with cervical malignancy 2-3. When it is performed with the curative intent it is often termed a radical trachelectomy and is ...
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Transient abnormal myelopoiesis

Transient abnormal myelopoiesis (TAM) is a phenomenon that can happen in the fetuses or neonates with trisomy 21. The condition can mimic leukaemia. Epidemiology The estimated incidence is at ~10% of newborns with trisomy 21 3. Radiographic features Antenatal ultrasound In the context of kn...
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Transient physiological myometrial contraction

Transient myometrial contraction is a physiological phenomenon which may mimic focal adenomyosis Radiographic features It appears as focal low signal intensity bulge/region of the myometrium which may disappear on subsequent images or at cine MR imaging.   Differential diagnosis focal adenom...
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Transverse cerebellar diameter

In obstetric imaging, the fetal transverse cerebellar diameter (TCD) is often measured as an additional fetal biometric parameter. It is measured as the maximal diameter between the cerebellar hemispheres on an axial scan. The value of the transverse cerebellar diameter in mm's is considered rou...
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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...
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Triploidy

Triploidy is a rare lethal chromosomal (aneupliodic) abnormality caused by the presence of an entire extra chromosomal set.  Epidemiology It is considered the 3rd commonest fatal chromosomal anomaly 7. While it is thought to affect as much as 1-2% of conceptions, the vast majority are thought ...
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Trisomies

Trisomies are chromosomal anomalies which usually occur due to non-disjunction. The vast majority of affected fetuses being spontaneously aborted, often very early during gestation. Only three are compatible with extra-uterine life (T13, T18, T21), and only one beyond early infancy (T21). In or...
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Trisomy 22

Trisomy 22 is an aneuploidic chromosomal anomaly which is usually fatal unless in mosaic forms. Pathology Variants Duplication of the short arm (p) and a small section of the long arm (q) of chromosome 22 can give result to the cat-eye syndrome - Schmidt-Fraccaro syndrome. Radiographic featu...
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True hermaphroditism

True hermaphroditism is a form of disorder of gender development.  Pathology Patients with true hermaphroditism have mosaicism of 46XX and 46XY. They therefore have both ovarian and testicular tissues. Subtypes There are three forms of true hermaphroditism: unilateral true hermaphroditism ...
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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...
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Tubal ectopic pregnancy

Tubal ectopic pregnancy (or adnexal ectopic pregnancy) is the most common location of an ectopic pregnancy. Epidemiology It is the most common type of ectopic by far, accounting for 93-97% of cases. Pathology Although the fallopian tube has many anatomical parts, for the purposes of ectopic ...
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Tubal ring sign

Tubal ring sign, also referred to as bagel sign or blob sign, one of the ultrasound signs of a tubal ectopic. It comprises of an echogenic ring which surrounds an unruptured ectopic pregnancy. It is said to have a 95% positive predictive value (PPV) for ectopic pregnancy. Differential diagnosis...
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Tuberculosis (fallopian tube)

Tuberculosis of the fallopian tube is one of the most common sites of tuberculous pelvic inflammatory disease.  Clinical presentation Many patients may be asymptomatic, with the disease being discovered during the workup for infertility.  Signs and symptoms are often vague and can include acut...
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Tuberculous pelvic inflammatory disease

Tuberculous pelvic inflammatory disease refers to pelvic inflammatory disease due to Mycobacterium tuberculosis. Epidemiology Genital tract involvement may be present in ~1.5% of cases of those affected with tuberculosis 4. Pathology Infection almost always results from spread from an extrag...
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Tubo-ovarian abscess

Tubo-ovarian abscesses are one of the late complications of pelvic inflammatory disease. Epidemiology Risk factors Risk factors include 15: previous diagnosis of pelvic inflammatory disease 16 presence of intrauterine device multiple sexual partners diabetes mellitus immunocompromised st...
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Tunnel cluster

Tunnel cluster (TC) is a type of Nabothian cyst characterised by complex multicystic dilatation of the endocervical glands. Epidemiology Tunnel cluster is found in ~8% of adult women, 40% of whom are pregnant, almost exclusively multigravid women, and older than 30 years. Clinical presentatio...
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Turner syndrome

Turner syndrome, also known as 45XO or 45X, is the most common of the sex chromosome abnormalities in females.  Epidemiology The incidence is estimated at 1:2000-5000 of live births, although the in utero rate is much higher (1-2% of conceptions) due to a significant proportion of fetuses with...
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Ultrasound guided percutaneous drainage

Ultrasound guided percutaneous drainage is one form of image guided procedure, allowing minimally invasive treatment of collections that are accessible by ultrasound study. It has several advantages and disadvantages over CT, which include: Advantages is a dynamic study, allowing greater prec...
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Umbilical venous dilatation

Umbilical venous dilatation is a rare entity and often tends to occur as an isolated finding 4. Dilatation of the umbilical vein can arise from a number of pathologies: umbilical venous varix (UVV): particularly if focal fetal hydrops: a focal dilatation due to an umbilical venous varix with...
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Undifferentiated carcinoma of the endometrium

Undifferentiated carcinoma of the endometrium is rare histological subtype of endometrial cancer. It is considered a high grade carcinoma, carries a poor prognosis and is often under-recognised 1. Epidemiology It is thought to represent approximately 1-9% of endometrial cancers 1,6. Pathology...
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Undifferentiated carcinoma of the ovary

An undifferentiated carcinoma of the ovary is a rare type of ovarian epithelial tumour. They account for ~ 4% of ovarian cancer 2. Pathology With these tumours, cellular differentiation is not sufficient for the tumour to be categorised into serous, mucinous or other specified subtypes. Pure u...
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Unicornuate uterus

A unicornuate uterus or unicornis unicollis is a type of Müllerian duct anomaly (class II) characterised 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...
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Urethral agenesis

Urethral agenesis (or urethral atresia) refers to a situation where there is a congenital absence of the urethra.  It can be a cause of fetal obstructive uropathy. Pathology Associations prune belly syndrome 5 bladder agenesis 2 Radiographic features Antenatal ultrasound May show a dilate...
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Urethral diverticulum

Urethral diverticula, or urethroceles, are focal outpouchings of the urethra. They should not be confused with a ureterocele of the distal ureter. Epidemiology Urethral diverticula occur far more frequently in women than in men and are estimated to occur in 1-6% of women, especially those with...
Article

Urogenital triangle

The urogenital triangle forms the anterior half of the diamond-shaped perineum. The triangle's corners are defined by the pubis symphysis anteriorly and the ischial tuberosities anterolaterally. The anterolateral borders are the ischiopubic rami and the posterior border is the transverse perinea...
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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...
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Uterine arteriovenous malformation

Uterine arteriovenous malformations (UAVM) result from formation of multiple arteriovenous fistulous communications within the uterus without an intervening capillary network. Clinical presentation Presentation can vary. UAVMs can cause life-threatening massive bleeding in young women. Bleedin...
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Uterine artery

The uterine artery is seen bilaterally and is a branch of the anterior division of the internal iliac artery. Gross anatomy Course It runs medially in the pelvis, within the base of the broad ligament, to the outer surface of the uterus. From lateral to medial it has a descending, transverse ...
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Uterine artery embolisation

Uterine artery embolisation (UAE) is an interventional radiological technique to occlude the arterial supply to the uterus and is performed for various reasons. History Uterine artery embolisation has been practised for more than 20 years for controlling haemorrhage following delivery / aborti...
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Uterine artery embolisation: MRI assessment

Uterine artery embolisation (UAE) is used as an alternative to hysterectomy in selected patients and MRI assessment is key in allowing not only pre-procedure assessment but also assessing post-procedural outcome.   For a general discussion of the underlying condition refer to the article on ute...
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Uterine artery flow notching

Uterine artery flow notching refers to phenomenon observed in uterine arterial Doppler ultrasound assessment. Pathology Associations The presence of notching after 22 weeks is associated with several other conditions including adverse pregnancy outcomes. These include pregnancy induced hyper...
Article

Uterine artery pseudoaneurysm

Uterine artery pseudoaneurysm (UAP) is a rare cause of secondary postpartum haemorrhage.  Clinical presentation UAP usually presents as delayed (secondary) postpartum haemorrhage, that is per vaginal bleeding which occurs more than 24 hours and up to 6 weeks postpartum. However, some reported ...
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Uterine biophysical profile

Uterine biophysical profile refers to assessment of uterus to produce a successful conception and implantation environment.  Uterine scoring system for reproduction (USS) The uterine scoring system for reproduction comprises the following parameters, taken in mid-cycle: 1. endometrial thickne...
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Uterine choriocarcinoma

Uterine choriocarcinomas are one of the commonest choriocarcinomas and are often associated with gestational trophoblastic disease (GTD).  Epidemiology These tumours typically occur in women of childbearing age as a gestational choriocarcinoma. Most such cases present within one year of an ant...
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Uterine dehiscence

Uterine dehiscence is, usually, used to refer to the process of gradual myometrial rupture without a rupture of membranes. However, the term is used synonymously with uterine rupture by some authors. It is often described in the context of C-section scar where it is also termed an incisional deh...
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Uterine duplication anomalies

Uterine duplication anomalies are a group of Müllerian duct anomalies where fusion of the Müllerian duct associated structures fail to some degree: uterus didelphys: class III bicornuate uterus: class IV (second commonest duplication anomaly) septate uterus: class V (commonest duplication ano...
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Uterine enlargement (differential)

Uterine enlargement can occur in a number of situations from both diffuse and focal processes. These include:  gestation related events normal intrauterine pregnancy molar pregnancy - gestational trophoblastic disease  postpartum uterus - still larger than usual hormonal causes exogenous h...
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Uterine leiomyoma

Uterine leiomyomas, also referred as uterine fibroids, are benign tumours of myometrial origin and are the most common solid benign uterine neoplasms. Commonly an incidental finding on imaging, they rarely cause a diagnostic dilemma. There are various medical, surgical and interventional treatme...
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Uterine leiomyosarcoma

Uterine leiomyosarcomas are malignant uterine tumours that arises from the myometrium. The uterus is the commonest location for a leiomyosarcoma. Epidemiology Typically present in women in the 6th decade. They account for up to one-third of uterine sarcomas but only ~8% of all uterine cancers ...
Article

Uterine lipoleiomyoma

Uterine lipoleiomyomas result from degeneration of smooth muscle cells in an ordinary leiomyoma and represent a rare benign tumour of the uterus 1. Epidemiology Lipoleiomyomas have a reported incidence of 0.03-0.20% and are typically found in postmenopausal patients with typical uterine leiomy...
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Uterine lymphoma

Uterine lymphoma refers to involvement of the uterus with lymphoma. Some authors also place lymphoma of the uterine cervix under this group. Epidemiology It is rare condition with initial uterine involvement occurring in only 1% of patients with lymphoma 3. However, uterine involvement is more...
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Uterine perforation

Uterine perforation represents a serious complication that can occur as a result of any type of intrauterine procedure or implantation. Some authors use the term uterine rupture synonymously with the term uterine perforation. Pathology Causes IUCD insertion: IUCD related uterine perforation ...
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Uterine rupture

Uterine rupture is a rare but nevertheless potentially catastrophic complication that can occur in pregnancy.  Epidemiology The incidence rate in pregnancy is at 0.05% 6.   Clinical presentation Uterine rupture is usually an acute presentation with haemodynamic instability and abdominal disc...
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Uterine sarcoma

Uterine sarcoma is a malignant uterine tumour thats is composed of part or all sarcomatous (mesodermal) elements. They however account for a minority of all uterine malignancies (1-6% 3-4).  Pathology Classification They can be broadly classified as pure or mixed 4: mixed malignant mixed Mu...
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Uterine smooth muscle tumours of uncertain malignant potential

Uterine smooth muscle tumours of uncertain malignant potential (STUMP) is a recently defined entity by the World Health Organisation for a heterogeneous group of uterine smooth muscle tumours that cannot be histologically diagnosed as unequivocally benign or malignant 1. See also malignant neo...
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Uterine tube

The uterine tube, also known as the Fallopian tube or less commonly the oviduct, is a paired hollow tube that bridges between each ovary and the uterus and functions to convey the mature ovum from the former to the latter. If conception occurs, it normally does so within the tube. It can be affe...
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Uterus

The uterus is a hollow, thick-walled, muscular organ of the female reproductive tract that lies in the lesser pelvis.   Gross anatomy The uterus has an inverted pear shape. In the adult, it measures about 7.5 cm in length, 5 cm wide at its upper part, and nearly 2.5 cm in thickness. It weighs ...
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Uterus didelphys

Uterus didelphys is a type of Müllerian duct anomaly (class III) where there is a complete duplication of uterine horns as well as duplication of the cervix, with no communication between them.   Epidemiology Didelphic uteri account for approximately ~8% (range 5-11%) of Müllerian duct anomali...
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VACTERL association

VACTERL is an acronym that describes a non-random constellation of congenital anomalies. It is not a true syndrome as such and is equivalent to the VATER anomaly. Epidemiology The estimated incidence is 1 in 10,000-40,000 births 3. Pathology The acronym VACTERL derives from: V: vertebral an...
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VACTERL-H association

The VACTERL-H association is a rare non-random association which bears the features of the standard VACTERL association with added fetal hydrocephalus. Unlike the standard VACTERL association which is sporadic, the VACTERL-H is hereditary with both X-linked 3 and autosomal recessive 2 inheritan...
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Vagina

The vagina is a midline fibromuscular tubular organ positioned in the female perineum extending superiorly from the vulva, to the cervix and uterus in the pelvis.  Gross anatomy The vagina is 8-10 cm in length, extending posterosuperior from the vestibule through the urogenital diaphragm to th...
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Vaginal atresia

Vaginal atresia refers to a spectrum of anomalies comprising of failure to form a part or all of the vagina.   Epidemiology It is considered the second most common cause of primary amenorrhea. The estimated  Incidence is at ~ 2 in 10000 women. Clinical presentation The most common symptom...
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Vaginal cancer (staging)

The staging of primary vaginal cancer covers for all histological sub types and is as follows FIGO staging system stage 0: carcinoma in situ stage I: tumour confined to vagina stage II: invasion of paravaginal tissues but no extension beyond pelvic side walls stage III: extension to pelvic ...
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Vaginal cuff

The vaginal cuff is the remnant tissue after a hysterectomy. The cuff may be evaluated for tumor recurrence (often with ultrasound) if the uterus was removed for cervical or endometrial carcinoma. Radiographic findings The appearance of the cuff depends on what type of hysterectomy was perform...
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Vaginal leiomyoma

Vaginal leiomyomas are an extremely rare entity and fall under extra-uterine pelvic leiomyomas.  Epidemiology They are extremely rare with only ~ 300 cases reported in literature 3. Pathology It may occur anywhere along the vaginal canal and is usually localized, mobile, non-tender, and circ...
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Vaginal lymphoma

Vaginal lymphoma can refer to: secondary involvement of the vagina (secondary vaginal lymphoma) from widespread generalised lymphoma relatively commoner usually comprises of diffuse large cell B non-Hodgkin's lymphoma (DLBCL) 2 primary vaginal lymphoma much rarer
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Vaginal pessary

A vaginal pessary is a device inserted into the vagina which can either be mechanical or pharmaceutical. A mechanical pessary is most commonly used to treat uterine prolapse. It is also used to treat stress urinary incontinence, a retroverted uterus, cystocoele and rectocoele. A bewildering arr...
Article

Vaginal stenosis

Vaginal stenosis refers to a narrowing of the vagina, it can be congenital or acquired. Pathology Causes Acquired causes include scarring from prior pelvic irradiation - brachytherapy Radiographic features General Depending on the site of stenosis and state of menstruation there can be a...
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Valsalva manoeuvre

The Valsalva manoeuvre is the forced expiration of air against a closed airway, resulting in increased intra-abdominal, intrathoracic and pharyngeal pressure. It can be performed against a closed glottis or by one closing the mouth and pinching the nose while forcibly exhaling. It is commonly u...
Article

Vascular Ehlers Danlos syndrome

Vascular Ehlers-Danlos syndrome (EDS) or type IV Ehlers-Danlos syndrome (EDS 4) is the most malignant form of Ehlers-Danlos syndrome. This form is often accompanied by neurovascular complications secondary to vessel dissections and/or aneurysms. Epidemiology Vascular EDS represents about 4% of...
Article

Venetian blind artifact (uterus)

The Venetian blind artifact (shadows) is a sonographic finding that is typically associated with adenomyosis but can also occur in uterine fibroids. The Venetian-blind artifact associated with adenomyosis is typically "thin" whereas when associated with uterine fibroids, there are also edge shad...
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Vesicovaginal fistula

Vesicovaginal fistulas are abnormal fistulous connections between the urinary bladder and vagina, resulting in an involuntary discharge of urine through the vagina. Epidemiology The overall incidence of vesicovaginal fistula is unknown but was reported to be 2.11 per 100 births in Nigeria 1. ...
Article

Vesicovaginal reflux

Vesicovaginal reflux is a well-known entity rarely encountered by radiologists. It is a behavioural disorder, a type of dysfunctional elimination syndrome commonly encountered in pre-pubertal girls. It is defined as reflux of urine into the vaginal vault either in supine or upright position duri...
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Vestibule (disambiguation)

A vestibule is an anatomical term and refers to a small cavity at the proximal end of a tube. vestibule (aorta) vestibule (ear) vestibule (larynx) vestibule (mouth) vestibule (nose) vestibule (oesophagus) vestibule (vulva) History and etymology Vestibule derives ultimately from the Lati...
Article

Vestibule of the vulva

The vestibule of the vulva (vestibule of the vagina in some texts 2) is the area between the labia minora, and posterior to the glans of the clitoris. It marks the boundary between the vagina and the vulva. The urethra, vagina and the greater vestibular glands open out into the vestibule.
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Vulva

The vulva (or pudendum) is the collective term given to the female external genitalia. The vulva consists of the: mons pubis labia majora labia minora clitoris vestibular bulbs vestibule of the vulva vaginal opening hymen Bartholin glands Radiographic features Individual component st...
Article

Vulval cancer (staging)

Staging of vulval cancer is the FIGO staging system and is as follows: stage 0: carcinoma in situ (pre-invasive); corresponds to Tis stage I: tumour <2cm (greatest dimension) and confined to vulva/perineum; corresponds to T1 stage Ia: stromal invasion by <1mm Stage Ib: stromal invasion by >1...
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Vulval neoplasms

Vulval neoplasms are rare and mostly seen in an elderly female patients. Squamous cell carcinoma is most common malignancy of the vulva which only 30% of them are associated with oncogenic HPV viruses. Pathology Squamous neoplastic lesions  Premalignant  classic vulvar intraepithelial neopla...
Article

Whirlpool sign (mesentery)

The whirlpool sign of the mesentery, also known as the whirl sign, is seen when the bowel rotates around its mesentery leading to whirls of the mesenteric vessels.  Terminology The term whirlpool sign is used in other contexts: see whirlpool sign (disambiguation). Radiographic features It is...
Article

Whirlpool sign (ovarian torsion)

The whirlpool sign or whirl sign of ovarian torsion is characterised by the appearances of a twisted ovarian pedicle seen on US or even on CT.  Terminology The term whirlpool sign is used in other contexts: see whirlpool sign (disambiguation).
Article

WHO histological classification of tumours of the uterine cervix

The WHO histological classification is a detailed classification of tumours of the uterine cervix. epithelial tumours squamous tumours and precursors squamous cell carcinoma, not otherwise specified - 8070/3 keratinizing - 8071/3 non-keratinizing - 8072/3 basaloid - 8083/3 verrucous - 805...

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