USG in normal menstrual cycle

The changes in the internal uterine lining of the uterus - the endometrium - during the menstrual cycle is termed the uterine cycle of menstruation

These changes occur in response to the hormones estrogen and progesterone secreted by the ovaries during the ovarian cycle of menstruatio -

Endometrial thickness is a commonly measured parameter on routine gynaecological ultrasound and MR imaging

The appearance as well as the thickness of the endometrium will depend on whether the patient is of reproductive age or post-menopausal and if of reproductive age at what point in the menstrual cycle they are examined

The changes in the internal uterine lining of the uterus - the endometrium - during the menstrual cycle is termed the uterine cycle of menstruation

These changes occur in response to the hormones estrogen and progesterone secreted by the ovaries during the ovarian cycle of menstruatio -

Endometrial thickness is a commonly measured parameter on routine gynaecological ultrasound and MR imaging

The appearance as well as the thickness of the endometrium will depend on whether the patient is of reproductive age or post-menopausal and if of reproductive age at what point in the menstrual cycle they are examined

Endometrial thickness is a commonly measured parameter on routine gynaecological ultrasound and MR imaging

The appearance as well as the thickness of the endometrium will depend on whether the patient is of reproductive age or post-menopausal and if of reproductive age at what point in the menstrual cycle they are examined

The endometrium should be measured in the long axis or sagittal plane

The measurement is of the thickest echogenic area from one basal endometrial interface across the endometrial canal to the other basal surface

Care should be taken not to include the hypoechoicmyometrium in this measurement

Premenopausal In premenopausal patients

there is significant variation at different stages of the menstrual cycle

during menstruation 2-4 mm early proliferative phase (day 6-

14) 4-8 mm late proliferative-pre ovulatory

phase up to 11 mm secretory phase 7-16 mm following dilatation and

curettage or spontaneous abortion lt5 mm if it is thicker consider retained products of conception

Premenopausal In premenopausal patients

there is significant variation at different stages of the menstrual cycle

during menstruation 2-4 mm early proliferative phase (day 6-

14) 4-8 mm late proliferative-pre ovulatory

phase up to 11 mm secretory phase 7-16 mm following dilatation and

curettage or spontaneous abortion lt5 mm if it is thicker consider retained products of conception

At birth the uterus is similar in size to the cervix (23ndash46 cm) and the endometrium generally appears as a thin echogenic line

Approximately one-fourth of neonates will have fluid collections within the endometrial cavity

Once puberty is reached the appearance of the endometriumbegins to approximate that seen in adulthood and varies with the stage of the menstrual cycle

Postmenopausal EM Will depend on the whether or

not there is a history of vaginal bleeding and on the use of hormonal therapy tamoxifen

Homogeneous smooth endometria measuring 5 mm or less are considered within the normal range with or without hormonal replacement therapy

if on tamoxifen 3 lt6 mm (although ~50 of those receiving tamoxifen have been reported to have a thickness of gt8 mm 7)

in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used

The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent

A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)

During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness

Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)

At this time the endometrium is disorganized and chaotic and only about 1mm thick

In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content

in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer

There is thorough transmission and posterior acoustic enhancement noted

Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding

And thus starts the next menstrual cycle

Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment

Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1

During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

Postmenopausal EM Will depend on the whether or

not there is a history of vaginal bleeding and on the use of hormonal therapy tamoxifen

Homogeneous smooth endometria measuring 5 mm or less are considered within the normal range with or without hormonal replacement therapy

if on tamoxifen 3 lt6 mm (although ~50 of those receiving tamoxifen have been reported to have a thickness of gt8 mm 7)

in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used

The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent

A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)

During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness

Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)

At this time the endometrium is disorganized and chaotic and only about 1mm thick

In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content

in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer

There is thorough transmission and posterior acoustic enhancement noted

Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding

And thus starts the next menstrual cycle

Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment

Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1

During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

in a patient undergoing hormonal replacement therapy may vary up to 3 mm if cyclic estrogen and progestin therapy is being used

The endometrium will appear thickest prior to progestin exposure and thinnest after the progestin phase Imaging should be performed at the beginning or end of a cycle of treatment when the endometrium will be at its thinnest and any pathologic thickening will be most prominent

A patient undergoing unopposed estrogen therapy with endometrial thickening exceeding 8 mm should be considered for biopsy whereas patients receiving progesterone in addition to estrogen can be rescanned at the beginning or end of the following cycle to determine if there has been a change in endometrial thickness (22)

During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness

Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)

At this time the endometrium is disorganized and chaotic and only about 1mm thick

In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content

in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer

There is thorough transmission and posterior acoustic enhancement noted

Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding

And thus starts the next menstrual cycle

Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment

Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1

During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

During menstruation the endometriumappears as a thin echogenic line 1ndash4 mm in thickness

Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)

At this time the endometrium is disorganized and chaotic and only about 1mm thick

In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content

in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer

There is thorough transmission and posterior acoustic enhancement noted

Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding

And thus starts the next menstrual cycle

Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment

Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1

During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

Once the menstrual bleeding stops there is a short duration of about 48 hours when the endometrium rests and repairs itself (resting phase)

At this time the endometrium is disorganized and chaotic and only about 1mm thick

In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content

in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer

There is thorough transmission and posterior acoustic enhancement noted

Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding

And thus starts the next menstrual cycle

Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment

Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1

During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

In the late proliferative (periovulatory) phase the endometrium develops a multilayered appearance with an echogenic basal layer and hypoechoic inner functional layer separated by a thin echogenicmedian layer arising from the central interface or luminal content

in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer

There is thorough transmission and posterior acoustic enhancement noted

Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding

And thus starts the next menstrual cycle

Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment

Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1

During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

in the secretory phase it is at its thickest and becomes uniformly echogenic as the functional layer becomes oedematous and isoechoic to the basal layer

There is thorough transmission and posterior acoustic enhancement noted

Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding

And thus starts the next menstrual cycle

Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment

Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1

During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

Endometrial growth stops from the 22nd day of the cycle as the corpus luteumdegenerates Then it starts to shrink and then necrosis occurs with shedding of the endometrial lining and bleeding

And thus starts the next menstrual cycle

Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment

Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1

During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

Journey to ovulation begins during late lutealphase of prior menstrual cycle when certain 2-5 mm sized healthy follicles form a population from which dominant follicles is to be selected for next cycle This process is called recruitment

Usual number of such follicles may be 3-11 which goes on decreasing with advancing age1

During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

During Day 1-5 of the menstrual cycle a second process of follicular selection begins when among all recruited follicles certain growing follicles of size 5-10 mm are selected while rest of the follicles regress or become atretic

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

During Day 5-7 of the menstrual cycle a process of dominance begins when a certain follicle of 10 mm size takes the control and becomes dominant

This also suppresses the growth of the rest of the selected follicles and in a way is destined to ovulate

This follicle starts growing at rate of 2-3 mm a day and reaches 17-27 mm size just prior to ovulation

One important learning point in this regard is largest follicle on day 3 of the cycle may or may not be a dominant follicle in the end Process of dominance begins late when suddenly a certain underdog follicle starts growing faster and suppresses others to become dominant

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

Almost nearing ovulation rapid follicle growth takes place and follicle starts protruding from the ovarian cortex attains a crenated border and it literally explodes to release the ovum along with some antral fluid

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

Ovulation is determined by

following sonographic signs follicle suddenly disappears

or regresses in size irregular margins intra-follicular echoes Follicle

suddenly becomes more echogenic

free fluid in the pouch of Douglas

increased perifollicular blood flow velocities on doppler

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

At ovulation the follicle ruptures expelling the ovum into the fallopian tube

The remnants of the follicle are called the corpus luteum and ranges from 2-5 cm As it matures it involutes

The corpus luteum produces oestrogenand progesterone maintaining optimum conditions for implantation if the ovum is fertilised

if fertilised the corpus luteumcontinues to produce these hormones and maximises the chance of implantation into the endometrium it reaches a maximum size at ~10 weeks and finally resolves at around 16-20 weeks

not fertilised the corpus luteuminvolutes and turns into a corpus albicans by around 2 weeks

The corpus luteum is an endocrine gland responsible for helping to regulate the menstrual cycle and support early pregnancy

Cells of the preovulatory follicle wall contribute to the formation of the corpus luteum by structural and functional transformation that begins just prior to follicle rupture

Perifollicular capillaries fenestrate the basal lamina of the follicle wall the basal lamina breaks down and luteal cells arise from theca internaand granulosa cells66

Neoangiogenesis of the corpus luteum facilitates its endocrine gland activity

diffusely thick wall peripheral vascularity lt3 cm possible crenulated contour If the cyst has been present for

some time with complicating haemorrhage a fine internal lace like echo-pattern may be seen

Colour Doppler interrogation show either no vascularity within the cyst or at times show low resistance blood flow around the cyst also known as hypervascular ring of fire

Degradation of vascular flow accompanies luteolysis the regression of the corpus luteum in the late luteal phase of each menstrual cycle in the absence of conception

Following luteal regression the corpus albicans may be visualized until the time of subsequent ovulation

Corpus albicans are typically visualized as hyperechoic structures within the ovary and they may occasionally appear to be more pronounced owing to the presence of surrounding follicles

Failure of ovulation and development of ldquocysticrdquo follicle

The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure

Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst

No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity

The follicular fluid remains clearhypoechoic

Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture

This results in retention of the oocytecumulus complex is within the lumen of the LUF

The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue

There is also a hazy indistinct border between the follicle fluid and the follicle wall

In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent

Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation

Menstrual flow does occur but menses are often lighter than usual

The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH

Failure of ovulation and development of ldquocysticrdquo follicle

The follicle typically grows larger than the mean preovulatory follicle diameter of 23 mm thin atreticfollicle walls are observed and small flecks of particulate matter are frequently seen in the lumen or aggregated at the side of the structure

Infertility can also be associated with growth of a dominant follicle beyond a preovulatory diameter and subsequent formation of a large anovulatory follicle cyst

No luteinization of the follicle wall occurs and the follicle wall is thin and displays marked hyperechocity

The follicular fluid remains clearhypoechoic

Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture

This results in retention of the oocytecumulus complex is within the lumen of the LUF

The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue

There is also a hazy indistinct border between the follicle fluid and the follicle wall

In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent

Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation

Menstrual flow does occur but menses are often lighter than usual

The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH

Following release of the preovulatory surge of LH the preovulatory-size dominant follicle fails to rupture

This results in retention of the oocytecumulus complex is within the lumen of the LUF

The follicle wall thickens and attains gray scale and vascular features similar to luteal tissue

There is also a hazy indistinct border between the follicle fluid and the follicle wall

In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent

Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation

Menstrual flow does occur but menses are often lighter than usual

The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH

In addition the point of follicle rupture a characteristic that distinguishes the LUF from a cystic corpus luteum is absent

Typically the mid-luteal progesterone concentration and basal body temperatures are lower than would be anticipated following normal ovulation

Menstrual flow does occur but menses are often lighter than usual

The mechanism for the formation of the LUF is uncertain and may include an ill-timed or attenuated release of the surge of LH or may be due to a defect in the follicle that makes it unresponsive to a normal LH surge such as aberrant or reduced receptors for LH