Wednesday, 8 January 2020

ABC of Transvaginal Sonography (TVS) as it is called.-Ovarian imaging


Tips of ovarian imaging in nonpreg state? How & what to interpret ovaries in TVS as you look into the USG screen?? : To use highest frequency probe and keep on moving the probe in side to side direction, up-downwards, angular-i.e. to fornices:-
Q.1: What is the Expected Shape, location and orientation of normal ovaries?? Ans:-The normal ovary is ellipsoid in shape and is variable in both location and orientation depending upon the age and parity of the patient as well as the degree of bladder distention. In the nulliparous adult female the ovaries  are situated in the ovarian fossa which is adjacent to the lateral pelvic side wall and is bounded by the obliterated umbilical artery anteriorly the ureter and internal iliac anteriorly posteriorly and the external iliac vein superiorly . But the inferior aspect of the ovary is slightly smaller than the superior or tubal aspect and is bound to the uterine cornea by the ovarian ligament which lies within the broad ligament. The lateral surface of the ovary is in contact with the parietal peritoneum lining the ovarian fossa and most of the medial surface is covered by the fallopian tube. The anterior border of the ovary is attached to the mesovarium through which the vascular channels and nerves pass into the ovarian hilum.
Q.2:-How best to calculate ovarian volume?? The concept of prolate ellipse: - Ovarian volume is calculated by measuring the ovary in three dimensions on two orthogonal planes and using the formula for the prolate ellipse.

Q3: Does ovarian size vary with age?? Oh yes. Ovarian size depends upon age menstrual status pregnancy status body habitus and phase of the menstrual cycle.
Q. 4:-What is the mean Ov volume of ovary(each) in premenosal  women?? In premenopausal women the mean ovarian volume is 9.8 ml.
Q. 5:-What happens in normal menst cycles –day wise volume changes of ovaries as follicles increase due to increase of Liq Follicle & repeated  mitois if Granulosa   cells?? With the highest volumes found in the preovulatory phase and the lowest volumes in the luteal phase Normal ovarian  volume decreases  after the age of 30 years .

Q. 6:-Age wise changes in volume of ovaries: - In one large study mean ovarian volume significantly decreased in each decade up to age 60 years measuring 6.6 ml in women under 30 years of age 6.1 ml in women 30 to 39 year old, 4.8 ml at ages 40 to 49 years 2.6 ml at ages 50 to 59 years 1.98 ml at ages 60 to 69 years and 1.85 ml over age 70 years.

Q. 7:-Height of the woman concerned & ovarian size? The authors found a statistically significant increased ovarian size in tall women but no relationship to weight despite the small size of the postmenopausal ovary the majority are detectable by TVS. 
Q. 8:-How does developing and immature follicles look like in TVS-====it is like anechoic unilocular with clear margins cysts?   The normal ovary in women of reproductive age has a variable appearance over the course of the menstrual cycle. Developing and immature follicles can be seen throughout the entire menstrual cycle and appear as anechoic unilocular sharply marinated cysts measuring from 2 to 9 mm

Q. 9:-Size of the DF & on which day? By days 8 to 12 of the menstrual cycle one or more dominant follicles will grow to a diameter of approximately 20 to 25 mm and then rupture at ovulation releasing the oocyte.
Q. 10 :-In what %of normally menst woman we can image a second but nondominat follicle? Up to 80% of patients have a second non dominant follicle that becomes almost as large as the dominant follicle, but admittedly slightly less than D F.

Q. 11 :-How best to recognize preovulatory dominant follicle in a TVS if you are alone?? The preovulatory dominant follicle may have a slightly complex appearance with the oocyte and its supporting structures appearing as a ring like structure within the follicle.
Q. 12. How do U, my dear members differentiate a CL from a DF?? Ans: 1) Cellular hypertrophy 2) Vacuolization of the cyst wall... We know that following ovulation the corpus luteum evolves from the remnant of the mature follicle. We are aware of that.
Q. 13. What else?? But we should remember that there is a dynamic process of cellular hypertrophy and increased vacuolization of the cyst wall. Therefore a corpus luteum is typically visible in the secretory phase of the menstrual cycle and in the first few weeks of early pregnancy...

Q. 14 What are the characteristic features on sonographic imaging?? Ans:- the corpus luteum typically has a relatively thick homogeneously echogenic wall the inner margin of which may be slightly irregular with a crenulated appearance On color Doppler  the wall of the corpus  luteum often demonstrates a circumferential ring of arterial flow with a low resistance spectral Doppler waveform  Internal  echoes are common reflecting variable amounts of internal hemorrhage that occurred at the time of ovulation and occasionally a corpus luteum may be filled with homogenous low level echoes mimicking a solid mass However there is usually evidence of enhanced through transmission because of the fluid content and there will be no central vascularity
Q. 15 What is the size of CL?? Ans: Typically the corpus luteum is under 3.0 cm in maximal dimension but rarely may it become larger.

Q. 16. Is corpus albicans sonographically imagable?? Ans: No, never .If pregnancy does not occur the corpus luteum gradually involutes and atrophies to become the corpus albicans which is typically not sonographically identifiable

Q.17 Relevance of Small echogenic foci measuring 1 to 3 mm may be noted in the periphery of otherwise normal appearing ovaries?? No relevance. No concern.  In approximately half of women undergoing TVS particularly in the perimenopausal age group. These foci often demonstrate ring down artifact and are a benign finding. What is the source or etiology?? These are due likely related to the presence of tiny cysts possibly cholesterol or hemosiderin deposition and less likely tiny calcifications. These tiny echogenic foci may come and go underneath the surface epithelium and should not raise concerns or result in follow up imaging.
Q.18:- In the postmenopausal patient ovarian size decreased correlating with hormonal status and length of time since menopause?? Ans: probably yes, the mean postmenopausal ovarian volumes have been reported to range from 1.2 to 5.8 ml with an ovarian volume of greater than 8 ml considered abnormal in all cases.

Q. 19:-What is the significance if ovarian sixe is bigger than other? Ans:-Some authors have suggested that a unilateral ovarian size twice   that of the opposite side regardless of the size should also be considered abnormal even though folliculogenesis has ceased.

Q. 20:-What is the explanation behind this? How do members account for this?? WE have to remember that the postmenopausal ovaries are not as quiescent as initially thought. As such small simple adnexal cysts measuring as large as 3 cm have been reported in up to 15% of postmenopausal women most of these spontaneously regress on serial sonographic examinations. These simple cysts seen early in menopause most likely represent an occasional ovulatory event or an atretic follicle .However any anechoic cystic lesion in a postmenopausal ovary should generally be referred to as a cyst,

Q 21:-Can you observe normal cyst in the age of 70-80 yrs of age?? In late menopause although ovulation is rare smaller cysts less than or equal to 1 cm have been reported in up to 21% of women. TVS will detect these cysts more readily than. What about TAS?? TAS for ovarian imaging will yield poorer result for obesity & because of the higher resolution of the higher frequency transvaginal probe. These simple appearing cysts measuring less than 1 cm in maximal diameter do not need further follow up and whether or not they are described in the final report can be left to the discretion of the interpreting physician.


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