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Shannon and MegHCCS Radiography lectureNormal anatomy & physiology ofThe female pelvisUltrasound of the female pelvisTwo approaches are used to evaluate the female pelvis sonographically: transabdominal and transvaginal.The transabdominal approach:Requires a full urinary bladder.Uses a 3.5-5 MHz transducer.Offers a wider field of view for general screening.The transvaginal approach:Performed with an empty bladder.Uses a higher frequency transducer, typically 7.5-10 MHz.Offers a more detailed study but is limited in its field of view and depth of penetration. A complete pelvic examination should consist of a transabominal scan followed by a transvaginal examination.External LandmarksThe Bony PelvisThe Pelvic Cavity and PeritoneumPELVIC LANDMARKSExternal landmarksThe external genitalia in the female, also known as the vulva or pudendum, consist of the mons pubis, labia majora, labia minora, clitoris, urethral opening, and vestibule of the vagina.The vagina itself is the part of the female genitalia that forms a canal from the orifice through the vestibule to the uterine cervix. It is behind the bladder and in front of the rectum.These external structures are important to recognize when using translabial and transvaginal scanning techniquies.External landmarks The mons pubis is a pad of fatty tissue and thick skin that overlies the symphisis pubis and is covered by pubic hair after puberty.External landmarks The labia are folds of skin at the opening of the vagina. The labia majora is the thicker external folds. The labia menora is the thin folds of skin between the labia majora.External landmarks The clitoris is located anterior to the urethra and is usually partially hidden between the labia major.External landmarks Posterior to the clitoris, the urethral opening and vestibule of the vagina can be normally identified between the labia minora. The most posterior orifice is the anus.The bony pelvisThe bony pelvis consists of four bones: two innominate (coxal) bones, the sacrum, and the coccyx.The Ileopectineal Line is an imaginary line that dissects the pelvis, dividing it obliquely into two anatomical compartments.Pelvis Major (False Pelvis) – above pelvic brim; communicates with the abdominal cavityPelvis Minor (True Pelvis) – below pelvic brim; considered to be the Pelvic CavityThe Abdominal WallMuscles of the False PelvisMuscles of the True PelvisMUSCLESOF THE PELVISThe abdominal wall These muscles extend from the xiphoid process to the symphysis pubis. Rectus abdominis, external oblique, internal oblique, transversus abdominis.Muscles of the false pelvis Include the psoas major and iliacus muscles, which form the pelvic side wall.The psoas major muscles join with the iliacus muscles to form the iliopsoas muscles, which do not enter the true pelvis.Muscles of the true pelvisInclude the piriformis muscles, obturator internus muscles, and muscles of the pelvic diaphragm.The piriformis muscles form the posterolateral wall.The obturator internus muscles form the anterolateral pelvic side wall.The pelvic diaphragm is formed by the levator ani and coccygeus muscles to make up the pelvic floor.Muscles of the true pelvisBladder&ureters The ureters are the two tubes that carry urine inferiorly from the kidneys to the urinary bladder. The urinary bladder is located in the anterior portion of the pelvic cavity. The function of the bladder is to collect and store urine until it empties through the urethra.Vagina The vagina is a collapsed muscular tube that extends upward and backward, from the external genitalia to the cervix of the uterus. It lies posterior to the urinary bladder and urethra, and anterior to the rectum. It is the passageway for menstruation and is extended during sexual intercourse and childbirth.Normal AnatomyEndometriumUterine LigamentsP
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Normal anatomy & physiology of The female pelvis
Normal anatomy & physiology ofThe female pelvisPresentation by Meg Sullivan & Shannon WrightCHAPTER 39Two approaches are used to evaluate the female pelvis sonographically: transabdominal and transvaginal.
The transabdominal approach:Requires a full urinary bladder.Uses a 3.5-5 MHz transducer.Offers a wider field of view for general screening.
The transvaginal approach:Performed with an empty bladder.Uses a higher frequency transducer, typically 7.5-10 MHz.Offers a more detailed study but is limited in its field of view and depth of penetration.
A complete pelvic examination should consist of a transabominal scan followed by a transvaginal examination.Ultrasound of the female pelvisPELVIC LANDMARKSExternal Landmarks
The Bony Pelvis
The Pelvic Cavity and PeritoneumThe external genitalia in the female, also known as the vulva or pudendum, consist of the mons pubis, labia majora, labia minora, clitoris, urethral opening, and vestibule of the vagina.
The vagina itself is the part of the female genitalia that forms a canal from the orifice through the vestibule to the uterine cervix. It is behind the bladder and in front of the rectum.
These external structures are important to recognize when using translabial and transvaginal scanning techniquies.External landmarks
The mons pubis is a pad of fatty tissue and thick skin that overlies the symphisis pubis and is covered by pubic hair after puberty.External landmarks
The labia are folds of skin at the opening of the vagina. The labia majora is the thicker external folds. The labia menora is the thin folds of skin between the labia majora.External landmarks
The clitoris is located anterior to the urethra and is usually partially hidden between the labia major.External landmarks
Posterior to the clitoris, the urethral opening and vestibule of the vagina can be normally identified between the labia minora. The most posterior orifice is the anus.External landmarksThe bony pelvis consists of four bones: two innominate (coxal) bones, the sacrum, and the coccyx.
The Ileopectineal Line is an imaginary line that dissects the pelvis, dividing it obliquely into two anatomical compartments.
Pelvis Major (False Pelvis) above pelvic brim; communicates with the abdominal cavity
Pelvis Minor (True Pelvis) below pelvic brim; considered to be the Pelvic Cavity
The bony pelvisMUSCLESOF THE PELVISThe Abdominal Wall
Muscles of the False Pelvis
Muscles of the True Pelvis
These muscles extend from the xiphoid process to the symphysis pubis.
Rectus abdominis, external oblique, internal oblique, transversus abdominis.The abdominal wall Include the psoas major and iliacus muscles, which form the pelvic side wall.
The psoas major muscles join with the iliacus muscles to form the iliopsoas muscles, which do not enter the true pelvis.
Muscles of the false pelvisInclude the piriformis muscles, obturator internus muscles, and muscles of the pelvic diaphragm.
The piriformis muscles form the posterolateral wall.
The obturator internus muscles form the anterolateral pelvic side wall.
The pelvic diaphragm is formed by the levator ani and coccygeus muscles to make up the pelvic floor.Muscles of the true pelvis
Muscles of the true pelvis The ureters are the two tubes that carry urine inferiorly from the kidneys to the urinary bladder.
The urinary bladder is located in the anterior portion of the pelvic cavity.
The function of the bladder is to collect and store urine until it empties through the urethra.Bladder&ureterschange layout to "title slide" The vagina is a collapsed muscular tube that extends upward and backward, from the external genitalia to the cervix of the uterus.
It lies posterior to the urinary bladder and urethra, and anterior to the rectum.
It is the passageway for menstruation and is extended during sexual intercourse and childbirth.Vagina
change layout to "title slide"UTERUSNormal Anatomy
Endometrium
Uterine Ligaments
Positions The uterus is a pear-shaped organ that consists of a fundus, body, and cervix.
Size varies with age and parity; 6-8 cm in length and 3-5 cm in anteroposterior and transverse dimensions.
The uterine cavity is a potential space for fluid accumulation, allowing for dynamic changes during menstrual cycle and pregnancy.Normal anatomy
UTERUS At the lateral borders of the fundus (widest, most superior portion) are the cornua, where the fallopian tubes enter the uterine cavity.
The body (corpus) lies between the fundus and the cervix and is the largest portion of the uterus.
The cervix is the lower cylindrical portion that projects into the vaginal canal.Normal anatomy
UTERUS The uterine wall consists of 3 histologic layers:
The serosa or perimetrium, is the external layer.
The myometrium is the muscular middle layer (thickest).
The endometrium is a mucous membrane lining the glandular tissue.Normal anatomy
UTERUS The endometrium changes dynamically in response to the cyclic hormonal flux of ovulation.
It varies in sonographic appearance and histologic structure.
Two primary layers:
Superficial functional layer: consisting of glands and stroma (supporting tissue) that sheds with menses.
Basal layer: the thin layer of the ends of endometrial glands that regenerates new endometrium after menses.endometriumUTERUS The uterus is supported in its midline position by paired broad ligaments, round ligaments, uterosacral ligaments, and cardinal ligaments.
Uterine ligaments
Broad Ligaments are a double fold of peritoneum that drape over the fallopian tubes, uterus, and ovaries.
Extend from the lateral sides of the uterus to the side wall of the pelvis.
Contain uterine blood vessels and nerves.
Mesosalpinx: upper fold that encloses fallopian tube.
Mesovarium: posterior portion that encloses the ovary.Uterine ligaments
Round ligaments are fibrous cords that occur in front of and below the fallopian tubes between the layers of the broad ligament.
These two cords commence on each side of the superior aspect of the uterus, course upward and lateral to the inguinal canal and insert into the labia majora.
Helps hold the uterine fundus and body in a forward position.Uterine ligaments
The cervix is the only portion of the uterus that is firmly supported.
It is fixed in position by the cardinal ligaments (continuation of broad ligaments) and the uterosacral ligaments.Uterine ligaments
Although variable, the average uterus position is considered to be anteverted and anteflexed.
It is not unusual to see a uterus that has variations of version and flexion.
Abnormal dropping of the uterus (uterine prolapse) occurs if the uterine ligaments and pelvic floor muscles are weak.
The uterus may also tilt to the right (dextro) or left (levo) of the midline.
Filling of the bladder will affect uterine position; a full bladder will tip the average anteverted, anteflexed uterus backward.Positions of the uterus Anteversion
Most common position
The cervical canal forms a 90-degree or smaller angle with the vaginal canal.Positions of the uterus
Anteflexion
The body and fundus of the uterus are curved forward upon the cervix.Positions of the uterus
Retroflexion
The uterine fundus or body curves backward upon the cervix.Positions of the uterus
Retroversion
The cervical canal forms an angle less than 90-degrees with the vaginal canal.
In multiparous females, the entire uterus may tip backward rather than forward.Positions of the uterus
Retroversion with retroflexion
The entire uterus is tilted backward with the fundus and body folded posteriorly upon the cervix.Positions of the uterus
The fallopian tubes are oviducts that are coiled, muscular tubes that open into the peritoneal cavity and their lateral end.
Approximately 10-12 cm in length;1-4 mm in diameter.
Four anatomic portions:
Infundibulum Ampulla Isthmus Interstitial
Fimbriae: fringe-like extensions which move over the ovary, directing the ovum into the fallopian tube after ovulation.FALLOPIANTUBESchange layout Infundibulum
Wide trumpet-shaped lateral portion
Contains fimbriaeFallopian tubes
Ampulla
Longest and most coiled portion of the fallopian tube
Area in which fertilization of the ovum most often occursFallopian tubes
Isthmus
Medial segment of the fallopian tubeFallopian tubes
Interstitial
Segment that passes through the uterine cornua
Narrowest segment of the fallopian tubeFallopian tubes
Position & Size
Normal Anatomy
Ovarian LigamentsovariesovariesPosition & Size Almond-shaped structures Measure approximately 3 cm long Lie in ovarian fossa, posterior to the uterus Dual blood supply:ovarian arteryuterine artery The ovarian vein drains blood into IVC on the right, and into the renal vein on the left.ovariesNormal Anatomy Outer cortexConsists of follicles in various developmental stagesTunica albuginea: dense covering connective tissue of cortexGerminal epithelium: thin layer of cells surrounding tunica albuginea Central medullaConnective tissue containing blood, nerves, lymphatic vessels, and some smooth muscle at the region of the hilum Ovaries produce the reproductive cell, the ovum Two steroidal hormones:Estrogen secreted by the folliclesProgesterone secreted by the corpus luteumResponsible for producing and maintaining secondary gender characteristics and for preparing the uterus for implantation of a fertilized ovum and for development of the mammory glands in the female.
ovariesOvarian Ligaments Supported medially by the ovarian ligaments. Originate bilaterally at the cornua of the uterus Supported laterally by the suspensory (infundibulopelvic) ligaments. Extend from infundibulum of the fallopain tube and ovary to the sidewall of the pelvis The ovaries are also attached to the posterior aspect of the broad ligament by a fold of peritoneum called the mesovarium.PELVIC VASCULATUREPelvic vasculatureVesselLocationExternal iliac arteriesMedial psoas borderExternal iliac veinsMedial and posterior to arteriesInternal iliac arteriesPosterior to ureters & ovariesInternal iliac veinsPosterior to arteriesUterine arteries & veinsBetween layers of broad ligaments, lateral to uterusArcuate arteriesArclike arteries that encircle uterus in outer third of myometriumRadial arteriesBranches of arcuate arteries that extend from myometrium to base of endometriumStraight & Spiral arteriesBranches of radial arteries that supply zona basalis of endometriumOvarian arteriesBranch laterally off aorta, run within suspensory ligaments and anastomose with uterine arteriesOvarian veinsRight vein drains into IVC directly; left drains into left renal veinPelvic vasculature
Pelvic vasculature
PHYSIOLOGYThe Menstrual Cycle
Follicular Development & Ovulation
Endometrial Changes
Abnormal Menstrual CyclesThe Menstrual cyclePHYSIOLOGYReproductive years begin with onset and end with cessation of menses
Menses: periodic flow of blood & cellular debris that occurs during menstruationAverage length: ~ 28 daysRegulated by hypothalamusDependent on cyclic release of estrogen & progesterone from ovaries
Menstruation: days 1 4 of the menstrual cycle
Menstrual StatusPremenarche pre-puberty; before onset of mensesMenarche post-puberty; menses occurs every 28 daysMenopause - cessation of mensesFollicular development & ovulationDevelopment of ovarian follicles monthly release of an ovum (ovulation)
PHYSIOLOGYOvulatory Cycle: cyclic release of estrogen & progesterone from ovariesLasts ~28 daysDetermines course of menstrual cycleOccurs in 2 phases Follicular and Luteal
Follicular development & ovulationPHYSIOLOGYFSH stimulates follicular development
Follicles secrete increasing amounts of estrogen as they grow
One follicle, the graafian follicle, reaches maturity
High estrogen levels trigger pituitary LH secretion
LH triggers ovulation on about day 14
Graafian follicle ruptures, releasing an ovum
Follicular PhaseDays 1-14 first day of menstruation through ovulationFollicular development & ovulationPHYSIOLOGYLuteal PhaseDays 15-28 corresponds to secretory phase of menstrual cycle
Ruptured follicle cells form corpus luteum (luteinization)
Corpus luteum secretes progesterone
Progesterone stimulates endometrial growth
Corpus luteum degenerates (9-11 days after ovulation)
Progesterone declines
Menstruation occurs; cycle begins againFollicular development & ovulationPHYSIOLOGYEndometrial changesPHYSIOLOGYVarying levels of EE & P endometrial change
Endometrial Cycle: characteristic changes in endometrium
Changes occur during menstrual cycle
Determined by hormonal changes during ovulatory cycle
Endometrial changesPHYSIOLOGY
3 phases of endometrial cycle:MenstrualProliferativeSecretoryEndometrial changesMenstruationDays 1-4Declining P spiral arteriole constrictionDecreased blood to endometrium ischemia & shedding of zona functionalisPHYSIOLOGY
Endometrial changesProliferative PhaseDays 5-14 corresponds to follicular phase of ovarian cycleThin endometriumOvarian follicles develop; estrogen increasesUterine lining regenerates & thickensOvulation on day 14PHYSIOLOGY
Endometrial changesSecretory PhaseDays 15-28 corresponds to luteal phase of ovarian cycleRuptured follicle becomes corpus luteumCorpus luteum secretes progesteroneEndometrium thickensIf no pregnancy, estrogen and progesterone decreaseMenses on day 28PHYSIOLOGY
PhaseSonographic Appearance of EndometriumMenstrualVarying levels of fluid & debris
Thickness decreasesProliferativeEarly: thin echogenic line
Mid-Phase: thickens to 4-8 mm; hypoechoic with three line sign
Before ovulation: 6-10 mm; becomes isoechoic with myometriumSecretory7-10 mm (thickest dimension)
Echogenic; three line appearance blurredEndometrial changesPHYSIOLOGYabnormal Menstrual cyclesMenorrhagia: Abnormally heavy or long periods
Oligomenorrhea: Menstrual cycles prolonged >35 days
Polymenorrhea: Menstrual cycles with interval
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