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.

78 results found
Article

Cardinal ligament

The cardinal ligaments, also known as transverse cervical ligaments or Mackenrodt ligaments, are paired structures that act to support the pelvic organs of the female pelvis. These along with the uterosacral and pubocervical ligaments, provide support to prevent pelvic organ prolapse 1.  Gross ...
Article

Ovary size and volume

Ovary size and volume is frequently determined with ultrasound. The volume estimate is calculated by the formula for an ellipsoid, where D1, D2, and D3 are the three axial measurements: D1 x D2 x D3 x 0.52 The normal, adult, non-pregnant, mean ovary volume of women who are not postmenopausal i...
Article

Subseptate uterus

A subseptate uterus is a mild form congenital uterine anomaly (often considered as a normal variant) where there is a presence of a partial septum within the uterus not extending to the cervix and with the central point of the septum at an acute (<90°) angle. The external uterine contour is unif...
Article

Urogenital diaphragm

The urogenital diaphragm is an incorrect historic term describing a structure or structures in the perineum. The term is still in occasional use despite not appearing in Terminologia Anatomica. Most descriptions of the diaphragm relate to a discoid space between the superficial and deep fasciae...
Article

Ectopic ovary

Ectopic ovaries are a rare ovarian abnormality. Supernumerary ovaries contain normal ovarian tissue in an ectopic location with a ligamentous attachment 1. Epidemiology  A few of the etiological explanations of ectopic ovary include embryologic origin, post-inflammatory implantation of ovarian...
Article

Adnexa (female pelvis)

The adnexa, or more formally the adnexa uteri, and also known as the uterine appendages, is a collective term for the: ovaries fallopian tubes broad ligaments Some texts also include the associated blood vessels, nerves and other supporting tissues in the definition. It is interesting to not...
Article

Viscera

The viscera (singular: viscus) refers to all the internal organs within the major cavities of the thorax, abdomen and pelvis. Therefore it does not include organs of the CNS, head and neck or musculoskeletal compartments nor does it encompass non-internal organs (e.g. the skin) 1. Splanchnology...
Article

Suspensory ligament of the ovary

The suspensory ligament of the ovary is a thin fold of the parietal peritoneum which attaches to the lateral margin of the ovary and extends to the lateral pelvic sidewall. It is also referred to as the infundibulopelvic ligament 1,2. It should not to be confused with the ovarian ligament which ...
Article

Chevron sign (endopelvic fascial defect)

The chevron sign refers to the appearance caused on axial pelvic MR images by posterior drooping of the posterolateral wall(s) of the upper third of the vagina, due to loss of integrity of the lateral level 1 endopelvic fascia.
Article

Endopelvic fascia

The endopelvic fascia is the enveloping connective tissue network for the pelvic viscera, suspending, supporting and fusing the pelvic organs to the arcus tendineus fasciae pelvis, which itself inserts onto the pelvic sidewalls and pubic bones. The major anterior component is the pubovesical li...
Article

H and M lines (pelvic floor)

The H and M lines are reference lines for the pelvic floor on imaging studies and help detect and grade pelvic floor prolapse on defecography studies. The H line is drawn from the inferior margin of the pubic symphysis to the posterior aspect of the anorectal junction, and represents the diamet...
Article

Pubococcygeal line

The pubococcygeal line (PCL) is a reference line for the pelvic floor on imaging studies and helps detect and grade pelvic floor prolapse in defecography studies. It is defined as a line that joins the inferior border of the symphysis pubis to the final coccygeal joint and it is drawn in a midli...
Article

Ampulla (disambiguation)

Ampulla (plural: ampullae) is an anatomical term used for tubular structures with a short segmental bulbous dilatation: ampulla (fallopian tube) ampulla (lacrimal system) ampulla (esophagus): a.k.a. phrenic ampulla ampulla (rectum) ampulla (semicircular ducts) ampulla (spleen) ampulla of ...
Article

Clitoris

The clitoris (plural: clitorides), the female homologue of the penis, and part of the female reproductive system, is situated at the anterior aspect of the labia minora. The clitoris, like the penis, is formed of a body and glans, formed respectively from the crura of the clitoris and the bulbs ...
Article

Bulbs of the vestibule

The bulbs of the vestibule (also known as the vestibular, vestibulovaginal or clitoral bulbs) are conglomerations of erectile soft tissue, collectively homologous to the bulb of the penis. However unlike in the male, the developing bulb is bisected by the vaginal opening to form two halves. The...
Article

Vaginal opening

The vaginal opening, is also known as the introitus (plural: introituses), vaginal orifice, or ostium vaginae (plural: ostia vaginarum) (TA) . Gross anatomy The entrance to the vagina lies in the vestibule of the vulva in the median plane. It has an anteroposterior orientation and is partially...
Article

Inguinal lymph nodes

The inguinal lymph nodes (often shortened to the inguinal nodes) are a major group of lymph nodes in the lymphatic system. They are the major drainage pathway of the lower limbs, genitals, dorsal perineum and the inferior most aspect of the anterior abdominal wall. Inguinal lymph nodes larger th...
Article

Agenesis (general)

The biological/medical term agenesis (plural: ageneses) refers to failure of an organ to grow or develop during the embryological period. Examples include: appendiceal agenesis cerebellar agenesis corpus callosum agenesis dental agenesis (anodontia) diaphragmatic agenesis dorsal pancreati...
Article

Uterine venous plexus

The uterine venous plexus is a network of veins surrounding the uterus and has extensive anastomoses with the vaginal venous plexus inferiorly and ovarian venous plexuses laterally. Gross anatomy The uterine venous plexus lies along the lateral aspects and superior angles of the uterus within ...
Article

Uterosacral ligament

The paired uterosacral ligaments are one of the supporting structures of the uterus. Uterosacral ligaments are not infrequently affected in cases of deep infiltrating endometriosis. Gross anatomy The paired uterosacral ligaments are extraperitoneal structures which extend posteriorly from the ...
Article

Round ligament of the uterus

The round ligament is one of the supporting structures of the uterus. It has a function in uterine anteflexion. Embryology It is part of the embryologic remnant of the gubernaculum. Gross anatomy It is a rope-like fibromuscular band which extends from the anterolateral aspect of the uterus a...
Article

Fallopian (disambiguation)

The eponym Fallopian may refer to: Fallopian canal (facial nerve canal) Fallopian tube (uterine duct) Fallopian ligament (inguinal ligament) History and etymology It is named after Gabriele Falloppio (also known by his Latin name Fallopius), Italian anatomist (1523-1562).
Article

Isthmus (disambiguation)

Isthmus (plural: isthmi) is an anatomical term and refers to a slender structure joining two larger components. Some of these uses of the word isthmus are now rarely used or only seen in older texts and articles: isthmus (aorta) isthmus (auditory tube) isthmus (auricle of the ear) isthmus (c...
Article

Labeled imaging anatomy cases

This article lists a series of labeled imaging anatomy cases by body region and modality. Brain CT head: non-contrast axial CT head: non-contrast coronal CT head: non-contrast sagittal CT head: angiogram axial CT head: angiogram coronal CT head: angiogram sagittal CT head: venogram axial...
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.
Article

Hymen

The hymen (plural: hymens) is a thin fold of mucous membrane which extends across the vaginal opening, usually with some form of internal defect, which permits the free passage of normal menses.  It usually ruptures during coitus with the remnants, usually in the form of small tags of tissue ar...
Article

Frenulum (disambiguation)

Frenulum (plural: frenula) is an anatomical term and refers to a small fold of soft tissue that checks the movement of an anatomical part. frenulum (clitoris) frenulum (ileocecal valve) frenulum (labia minora) frenulum (penis) frenulum (tongue) History and etymology Frenulum derives from ...
Article

Labia minora

The labia minora (singular: labium minus) are small glabrous cutaneous folds lying between and just superior to the labia majora. At their posterior margin the labia may be conjoined by a thin cutaneous fold of skin, the frenulum of the labia (also known as the fourchette or posterior commissure...
Article

Labia majora

The labia majora (singular: labium majus) form the anteroinferior most part of the vulva, they are continuous with the mons pubis anteriorly and the perineum posteriorly. The labia are apposed in the midline forming the, externally-visible, pudendal cleft.  Gross anatomy The labia majora have ...
Article

Paraurethral duct

The paraurethral ducts (or Skene ducts) drain the paraurethral glands of the female urethra. There is one duct, draining each gland, on each side, just proximal to the external urethral meatus. History and etymology  Skene ducts are named after the Scottish-American gynecologist Alexander John...
Article

Mons pubis

The mons pubis (plural: montes pubis) refers to the rounded protuberant skin-covered soft tissue overlying the symphysis pubis (in both sexes). It is most prominent in adult females. In females it forms the most superior part of the vulva and it is also called the mons Veneris (plural: montes V...
Article

Vulva

The vulva (plurals: vulvas or vulvae), also known as the pudendum, (plural: pudenda) is the collective term given to the female external genitalia. The vulva consists of the: mons pubis labia majora labia minora clitoris bulbs of the vestibule vestibule of the vulva vaginal opening hyme...
Article

Endometrium

The endometrium refers to the inner lining of the uterine lumen, composed of endometrial glands surrounded by loose highly cellular connective tissue. Gross anatomy Layers In women of reproductive age, the endometrium is composed of two layers: stratum basale (basal layer): describes the de...
Article

Vestibule (disambiguation)

A vestibule is an anatomical term and refers to a small cavity at the proximal end of a tube. It may refer to: vestibule (aorta) vestibule (ear) vestibule (larynx) vestibule (mouth) vestibule (nose) vestibule (esophagus) vestibule (vulva) History and etymology Vestibule derives ultimate...
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...
Article

Fallopian tube segments (mnemonic)

A useful mnemonic to remember the order of the five segments of the fallopian tube, from lateral to medial, the direction an ovum would pass following ovulation, is: Four INches Across IS IMpossible Four inches (10 cm) is the approximate length of the fallopian tube. ​Mnemonic F: fimbriae I...
Article

Fornix (disambiguation)

The term fornix (plural: fornices) is used for anatomical structures in multiple organ systems that all share an arch-like morphology: fornix (brain) fornix (eye) fornix (lacrimal) fornix (pharynx) fornix (renal) fornix (stomach) fornix (vagina) History and etymology Fornix is Latin for...
Article

Fornix (vagina)

The fornices are superior recesses of the vagina formed by the protrusion of the cervix into the vaginal vault. There is a large posterior fornix and a smaller anterior fornix with two small lateral fornices.  History and etymology Fornix is Latin for 'arch'.
Article

Bartholin glands

The Bartholin glands, also known as the greater vestibular glands (or vulvovaginal glands) are paired pea-sized structures, lying on either side of the vaginal opening, and are homologous to the bulbourethral (Cowper) glands in the male. They form part of the vulva. Gross anatomy These glands ...
Article

Internal iliac lymph nodes

The internal iliac lymph nodes (often shortened to internal iliac nodes) are the lymph nodes found adjacent to the internal iliac artery and its branches and drain the regions supplied by these vessels. This encompasses a large area from the genitalia anteriorly, the psoas muscle posteriorly and...
Article

Gonadal artery

The gonadal arteries are the paired primary vascular supply to the ovaries in the female and the testes in the male. As the anatomy of the gonadal arteries differs substantially between the sexes, they are covered separately: ovarian arteries testicular arteries
Article

Broad ligament

The broad ligaments (TA: ligamentum latum uteri or plica lata uteri 4) are the paired lateral folds of the parietal peritoneum which reflect over the upper genital tract in females. Gross anatomy The broad ligament extends from the lateral aspect of the uterus to the lateral pelvic wall and ca...
Article

Anatomy curriculum

The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists. General anatomy Neuroanatomy Head and neck anatomy Thoracic anatomy Abdominal and pelvic anatomy Spinal anat...
Article

Superficial perineal pouch

The superficial perineal pouch is an anatomic space below the perineal membrane in the urogenital triangle of the perineum. Gross anatomy The superficial perineal pouch is inferior (superficial) to the perineal membrane in the urogenital triangle, anterior to the transverse line between the is...
Article

Deep perineal pouch

The deep perineal pouch is an anatomic space superior (deep) to the perineal membrane in the urogenital triangle of the perineum, anterior to the transverse line between the ischial tuberosities. Gross anatomy The deep perineal pouch is above (deep to) the perineal membrane in the urogenital t...
Article

Perineum

The perineum is a diamond-shaped region below the pelvic diaphragm and is divided by an imaginary line drawn between the ischial tuberosities into anteriorly the urogenital triangle and posteriorly the anal triangle. Gross anatomy The perineum is bounded by the pubis anteriorly, the ischial tu...
Article

Deep inguinal lymph nodes

The deep inguinal lymph nodes (often shortened to the deep inguinal nodes) form a subgroup of the inguinal lymph node group, and are located within the femoral sheath, medial to the femoral vein. They receive afferent lymphatic drainage from the deep lymphatics of the distal lower extremity and ...
Article

Cervical plicae palmatae

Cervical plicae palmatae are normal folds seen on the anterior and posterior walls of the cervical canal. They are often described as longitudinal ridges or oblique elevation. Sometimes they are identified on MRI, and one must make sure not to misinterpret this finding as abnormal. Studies repo...
Article

Corpus albicans

The corpus albicans is a fibrous scar that results from the involution of the corpus luteum if fertilisation does not occur. When seen on ultrasound, it is a small, lobulated echogenic intra-ovarian lesion.  History and etymology It is Latin for "whitening body", after the white appearance of ...
Article

Female reproductive system

The female reproductive system (or tract) comprises the vulva, vagina, uterus, uterine tubes and ovaries. It can be imaged using a wide range of imaging modalities but ultrasound and MRI are most useful. 
Article

Abdominal and pelvic anatomy

Abdominal and pelvic anatomy encompasses the anatomy of all structures of the abdominal and pelvic cavities. This anatomy section promotes the use of the Terminologia Anatomica, the international standard of anatomical nomenclature. 
Article

Adnexa (disambiguation)

Adnexa (single/plural) is a general term that refers to the accessory structures of an organ. Adnexa have been described in relation to: cutaneous/skin adnexa hair follicles, sweat glands, nails adnexa mastoidea structures in the mastoid (posterior) wall of the middle ear, e.g. mastoid antr...
Article

Levator ani muscle

The levator ani muscle, also known as the muscular pelvic diaphragm, is the musculotendinous sheet that forms the majority of the pelvic floor, supports the pelvic viscera, and aids in urinary and fecal evacuation as well as maintaining continence. Gross anatomy The levator ani has three main ...
Article

Retroverted uterus

A retroverted uterus is a normal variation of female pelvic anatomy in which the body of the uterus is tilted backwards (usually leans forward, i.e. anteverted) on itself to match the isthmus of the neck and lower uterine segment. There are variable grades of uterine retroversion. Epidemiology ...
Article

Broad ligament contents (mnemonic)

A mnemonic for the contents of the broad ligament is: BROAD Mnemonic B: bundle (ovarian neurovascular bundle) R: round ligament O: ovarian ligament A: artifacts (vestigial structures) D: duct (oviduct)
Article

Dominant ovarian follicle

A dominant ovarian follicle refers to the follicle that enlarges to release an ovum during a menstural cycle. Usually approximately 10 Graafian follicles begin to mature where one becomes a dominant follicle and the rest become atretic ovarian follicles. After release of the ovum the remainder o...
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

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

Ovarian follicle

An ovarian follicle (also known as a Graafian follicle in its mature state) is the basic unit of female reproductive biology and is composed of roughly spherical aggregations of cells and contains a single oocyte. Gross anatomy An ovarian follicle can be initiated to grow and develop, culminat...
Article

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...
Article

Persistent right umbilical vein

A persistent right umbilical vein (PRUV) is an uncommon vascular anomaly which is often detected in utero. Epidemiology The estimated prevalence is ~2 per 1000 births 1,2. Pathology In the normal situation, the right umbilical vein begins to obliterate in the ~4th week of gestation and disap...
Article

Canal of Nuck

The canal of Nuck is an abnormal patent pouch of parietal peritoneum extending anteriorly from the round ligament of the uterus into the labia majora through the inguinal ring into the inguinal canal. Incomplete obliteration of this canal is known as a patent processus vaginalis and can result i...
Article

Parametrium

The parametrium is a band of fibrous tissue that separates the supravaginal portion of the cervix from the bladder. It extends on to its sides and laterally between the layers of the broad ligaments. The uterine artery and ovarian ligament are located in the parametrium. The parametrium is imp...
Article

Corpus luteum

The corpus luteum (plural: corpora lutea) is a temporary endocrine structure involved in ovulation and early pregnancy. During ovulation, the primary follicle forms the secondary follicle and subsequently the mature vesicular follicle. At ovulation the follicle ruptures expelling the ovum into...
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...
Article

Müllerian duct

The Müllerian ducts (or paramesonephric ducts) are paired ducts of mesodermal origin in the embryo. They run laterally down the side of the urogenital ridge and terminate at the Müllerian eminence in the primitive urogenital sinus. In the female, they will develop to form the uterine tubes, ute...
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

Abdominal surface anatomy

Abdominal surface anatomy can be described when viewed from in front of the abdomen in 2 ways: divided into 9 regions by two vertical and two horizontal imaginary planes divided into 4 quadrants by single vertical and horizontal imaginary planes These regions and quadrants are of clinical imp...
Article

Ovarian tumors

Ovarian tumors are relatively common and account for ~6% of female malignancies. This article focuses on the general classification of ovarian tumors. For specific tumor features, please refer to the relevant subarticles. Pathology Subtypes Primary ovarian tumors Surface epithelial-stromal o...
Article

Ovarian artery

The ovarian artery is a paired structure and is the main gonadal artery in females. Gross anatomy Origin The ovarian artery arises anterolaterally from the aorta just inferior to the renal arteries and superior to the inferior mesenteric artery (between L2 and L3). Course Descends caudally ...
Article

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 ...
Article

Pelvis

The term pelvis (plural: pelvises or pelves) can refer to either the bony pelvis or the pelvic cavity. Bony pelvis The bony pelvis is formed by the sacrum and coccyx and a pair of hip bones ("ossa coxae"), which are part of the appendicular skeleton. Its primary function is the transmission of...
Article

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 6-8 cm in length, extending posterosuperior from the vestibule through the urogenital diaphragm to the...
Article

Uterus

The uterus is an extraperitoneal 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. It measures about 7.5 cm in length, 5 cm wide at its upper part, and nearly 2.5 cm in thickness in adults....
Article

Cervix

The cervix or uterine cervix is the lower constricted segment of the uterus providing the passage between the uterus proper and the vagina.  Gross anatomy The cervix is somewhat conical in shape, with its truncated apex directed posteriorly and inferiorly. The inferior aspect of the cervix pro...
Article

Ovary

The ovaries (TA: ovarium 9) are paired female gonads of the reproductive and endocrine systems. They lie within the ovarian fossa on the posterior wall of the true pelvis and form part of the adnexa.  Gross anatomy The ovaries are firm and ovoid in shape and measure approximately 1.5-3.0 cm × ...
Article

Fallopian tube

The fallopian tube (TA: tuba uterina 8), also known as the uterine 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...
Article

Bicornuate uterus

A bicornuate uterus is a type of uterine duplication anomaly. It can be classified as a class IV Mullerian duct anomaly. Epidemiology Overall, congenital uterine anomalies occur in ~1.5% of females (range 0.1-3%). Bicornuate uteri are thought to represent ~25% (range 10-39%) of Mullerian duct ...

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.