Ultrasound in gynaecology

1. Ultrasound in gynaecology Dr Shruthi A G Senior Resident Dept of OBG YMCH

2. Ultrasound use in gynaecology has become a standard and valuable tool for the clinician in many aspects of daily practice • Ease of use and relatively low cost • Adjunct to clinical practice for everyday decision making

3. Ultrasound brings light into the female pelvis visualizing the uterus and adnexa • This imaging modality can help in diagnosis and management of many uterine and ovarian or adnexal disorders • Clinical information is obtained about morphology, hormonal status, sensation, pelvic organ mobility and vascular anatomy • Most of the pelvic masses can be characterised by B-mode and Doppler ultrasound.

4. Noninvasive procedure utilizes high frequency sound waves. Soft tissue imaging possible. No ionizing radiation. • 2 modes: • Transabdominal • Trasvaginal TAB- requires distended bladder, • Best used for large masses like fibroid / ovarian T. TVS – Does not require full bladder • Avoids the difficulties due to obesity • Better image

5. List of indications American Institute of Ultrasound in Medicine(AIUM) • Pelvic pain • Menstual abnormalities: • Dysmenorrhea • Menorrhagia • Metrorrhagia • Menometrorrhagia • Delayed menses or precocious puberty • Postmenopausal bleeding

6. Follow up of previously detected abnormality • Evaluation and /or monitoring of infertile patients • Abnormal pelvic examination • Evaluation of congenital anomalies • Excessive bleeding,pain or fever after delivery • Early pregnancy failures or pregnancy of uncertain outcome including ectopic pregnancies • Localization of a IUCD • Screening for malignancy in patients with increased risk • Further characterization of a pelvic abnormality detected on another imaging study

7. Normal findings UTERUS • It is important to note the timing of a woman’s cycle for the proper interpretation of the normal and its variants • Note if the woman is premenopausal or post menopausal • Can be Performed transabdominally , which requires atleast a partialy distended bladder that displaces the small bowel and gaseous intestines from th area being viewed • Or more precisely transvaginally with the bladder emptied • Rarely both modalities are used in cases of a large uterus or a large pelvic mass

8. Uterine size: • Length- long axis from fundus to cervix; 5-8cms • Depth- anteropoeterior measurement perpendicular to length; 1.5-3cms • Width- coronal view; 2.5-5cms. • Volume: length*depth*width*0.53= normal is <100cm3 • Postmenopausal uterus is smaller than the premenopausal uterus and endometrium has maximum thickness of <5mm

9. Endometrium • Depends on the timing of the menstrual cycle; • 1-4 mm thick during menstruation • Folicular phase: 8-15mm, trilaminar appearance- two proliferating bands &a central canal echo. • Secretory phase: thickness remains same but the proliferating bands and the central echo blend to form a single hyperechoic band. • Myometrium • Hypoechogenic & homogenous • Cervix

10. Ovary • Moderately echogenic, well demarcated • Location : just above the iliac vesselsand lateral to the edge of the broad ligament • Other sites: pod, lower abdomen • Folicular phase: a group of antral follicles(Mid proliferative phase) 4-8 antral follicles, 3-5mm • Ovulation : one dominant follicle maximum of 18-24mm, rest of the follicles reaches maximum to 10mm. • Corpus luteum- more solid, echogenic, disappears within a day or two of menstruation

11. Uterine abnormalities FIBROIDS • Most common uterine pathology • Uterine contour irregularity and enlargement • Hypoechoic or heterogenous uterine mass • Degenerative changes: irregular, anechoic areas in cystic degeneration; bright and highly echogenic area in calcified degeneration • Location • Pedunculatedmyomas- Mimic adnexal masses, vascular bridge connecting the mass to the uterus • Submucous fibroid: SIS with excellent ultrasound technique

12. Adenomyosis • A condition where the endometrial glands and stroma are present deep in the myometrium with surrounding myometrial hypertrophy • Usg findings: • Rainy pattern of acoustic shadowing • Normal vessels • Enlarged uterus(AP diameter) • Asymmetry • Myometrial cysts: cystic spaces ranging from 2-7 mm located within the myometrium

13. More common diagnostic feature • Diffuse heterogenous echo texture of myometrium • Asymmetric thickening of either the anterior or posterior wall of the uterus • Subendometrial myometrial cysts- causes endometrial myometrial junction to be poorly defined • Subendometrial echogenic linear striations • Globular enlarged uterus without a definitive mass.

14. Endometrial pathology • Submucous leiomyoma • Endometrial polyp • SIS

15. Saline infusion sonography • Saline infusion sonography : (Sonohysterography) • 20-40ml of salin, it is performed within first 10day of menstrual cycle. • Complications are minimal • Single dose of doxycycline 20mg • Contraindication: Pregnancy, active pelvic infection

16. Post menopausal bleeding • A thin stripe of <4 mm on TVS can exclude endometrial disease • Localization of IUCD • TVS can detect both the proximal and distal ends of the vertical arm • 3D TVS using multiplanar views has proven to superior.

17. Ovarian/ adnexal abnormalities • Safe, quick, inexpensive and in skilled hands a reliable method to help distinguish between most benign and malignant condition sof the adnexa • Morphological characteristic swhich increase the risk of malignancy • Solid components ( excrescences or papillary projections) • Irregularities • Decreased resistance index • Neovascularization • Ascitis • Doppler ultrasound gives a better information about neovascularization

18. Ectopic pregnancy • βHCG ≥ 1500 without a intra uterine sac, ectopic pregnancy should be suspected. • Intrauterine gestation sac is seen by TVS with βHCG levels between 1000-2000mIU/ml • Most telling usg finding: • a live embryo n the adnexa followed by a tubal ring ( doughnut or bagel sign ) with or without haemorrhage • Intrauterine pseudo sac along with complex adnexal mass • Free fluid in the POD and thickened endometrium with no viable intra uterine pregnancy • Rule out early gestation and heterotrophic pregnancy.

19. Pelvic pain • Ovarian torsion • Endometriosis • Pelvic inflammatory disease/tubo-ovarian abscess • TVS and Doppler helps in sorting out the differential diagnosis

20. Ovarian torsion • Is a surgical emergency • USG features: • enlarged ovary that appears oedematous • Heterogenousechotexture • Small cystic areas towards the periphery • Some free fluid • comparision with the morphological appearance and the blood flow patterns by Doppler.

21. Endometriosis • Most common eitiology of chronic pelvic pain • Endometriotic cysts : • Multilocular • Low level internal echoes • Hyperechoic • Thickened cyst wall • TVS is poor in detecting the presence of adhesions and mild endometriotic implants • In deep infiltrating disease where it involves the POD, hypoechoic linear thickening or nodules/masses is seen; POD can also be obliterated with or without free fluid

22. Pelvic inflammatory disease • Can cause acute or chronic pelvic pain • Hydrosalphinx is seen by USG as tubular adnexal structure with septations or nodules in its wall

23. Therapeutic application : • Oocyte retrieval in IVF • Draining of chocolate cyst • draining of pelvic abscess • In evacuation of molar pregnancy • Transcervial cannulation and sperm injection into fallopian tube • Retrieval of missing IUCD • Injection of methotrexate into an ectopic sac. • Focused ultrasound therapy

24. ROLE OF DOPPLER

25. DOPPLER EFFECT • Observed changes in the frequency of transmitted waves when relative motion exists between the source and an observer • Frequency of waves increases when source and observer move closer and vice versa

26. PRINCIPLES • Sound is a form of mechanical energy that travels through media as pressure waves generated when an object vibrates • Audible sound frequency ranges from 20Hz to 20 kHz • Frequency range of obstetric transducer is 2-5 MHz • To produce vibrations at the rate of millions of cycles per second, special materials with piezoelectric properties are used

27. DOPPLER SIGNAL PROCESSING

28. DOPPLER ULTRASOUND IN GYNECOLOGY • OVARIAN MASS • To differentiate between benign and malignant ovarian tumours • Neovascularization causes decrease in impedance to flow in malignant lesions • High level of colour content and high blood velocity indicates malignancy • Vascularization of solid nodules is predictive

29. 2) OVARIAN TORSION Abnormal flow pattern in affected ovary : - Reduced overall vascularity - Greater impedance in supplying vessels - Absence of blood flow - Whirlpool sign: vessels spiralling round each other or ovary (clockwise or counterclock wise wrapping of vessels in the twisted vascular pedicle)

30. 3) INFERTILITY • Some studies have demonstrated relationship between perifollicular vascularity and pregnancy rates, (higher if embryo from highly vascularized follicle)- controversial • Loss of subendometrial blood flow is indicative of tubal blockage PERIFOLLICULAR VASCULARITY

31. 4) ENDOMETRIAL CANCER • Vascularity of endometrium (low impedance in myometrial and endometrial vessels) along with thickness • Greater depth of myometrial invasion by tumour associated with greater vascularity and lower impedance • Other characteristics are: - Higher colour score - greater number of feeding vessels

32. 5) TROPHOBLASTIC DISEASE Non invasive mole: - High velocity and low resistance flow in uterine arterial circulation - Less intra tumoral flow in trophoblastic tissue Invasive mole and choriocarcinoma: - Increase in uterine vascularity - Increase in tumour vascularity

33. Doppler has been used to differentiate between adenomyosis and fibroid uterus Adenomyosis: Diffuse hypervascularity throughout the lesion Fibroid : Typical peripheral flow

34. ARTERIOVENOUS MALFORMATION • Multiple communication between arterial and venous system without an intervening capillary network • Can be iatrogenic secondary to dilatation and curettage and caesarean • Vascular tangle of blood vessels with high velocity low resistance flow

35. PSEUDOANEURYSM • Can occur as a complication secondary to dilation and curettage • Appears as blood filled cystic structure with swirling arterial flow • Also called Yin Yang sign

36. BIOSAFETY • Ultrasound beams transmit energy into tissue so possibility of hazard has to be considered • Likely mechanisms for harmful effects: - Tissue heating as ultrasound energy is absorbed - Cavitation: Gas bubbles in the tissue react under the influence of pressure fluctuations

37. There is a considerable amount of literature on the safety of diagnostic ultrasound • There are several organizations that actively scrutinize the literature and monitor the safety of ultrasound • Such as : British Medical Ultrasound Society • World Federation for Ultrasound in Medicine and Biology (WFUMB)

38. Approach now is to use the ALARA principle (As Low as Reasonably Achievable) • More caution has to be used with pulsed doppler especially during early pregnancy • Many systems now display the output in terms of Thermal Index (TI) and Mechanical Index (MI)

39. GUIDELINES FOR SAFE USE • Use the lowest possible transmit power which will give a diagnostic result (TI and MI <1) • Use minimum scan time possible • Check that transducer ceases to transmit when the image is frozen

40. THANK YOU