1. Transvaginal ultrasound
Gynecology Mini-Lectures for Students
Transvaginal ultrasound

2. Transvaginal Ultrasound
Technique

3. WRONG right Anatomy: Key Points
The uterus does NOT stand straight up in the coronal plane
It flops either forwards or backwards to lay on the bladder or on the rectum
Anteverted/retroverted
right

4. Anatomy: Key Points The vaginal fornices are very stretchy fornices
Source: Lentz: Comprehensive Gynecology, 6th ed Mosby. Figure 7-12.
In this image, the surgeons hand is INSIDE her vagina. See how much the anterior fornix can be stretched to perform bimanual massage of the uterus
Source: aafp.org

5. Anatomy: Key Points
The transvaginal ultrasound probe is placed in the anterior or posterior fornix. This allows the probe to push up against the side of the cervix.
Retroverted uterus. Probe in posterior fornix.
Anteverted uterus. Probe in anterior fornix.

6. Understanding ultrasound images
This is how you obtain a sagittal image of the uterus
PROBE

7. Understanding ultrasound images
PROBE
Rotate probe 90 degrees to obtain a transverse image

8. Understanding ultrasound images
vagina
PROBE
As you can see from this image, it is impossible to obtain a “head-on” or “coronal” view of the uterus using normal transvaginal ultrasound. The probe would have to be outside the vagina.

9. Understanding ultrasound images
The “head-on” or “coronal” view of the uterus can only be obtained by creating a 3D reconstruction of the sagittal and transverse images

10. Transvaginal Ultrasound
Advantages

11. Advantages
It is difficult to see the pelvic organs from a trans-abdominal perspective
Pubic bone creates shadows
There is a long distance between probe and organs
Source:

12. Advantages Transvaginal probe is right next to uterus
Probe has higher frequency=better image resolution, lower penetration
Source:

13. Transvaginal vs abdominal
cervix
fundus
bladder
endometrium
uterus
vagina
These images are from the same patient. Notice the greater image resolution with transvaginal imaging. You can better delineate the endometrium, internal os, and character of the myometrium.

14. Transvaginal Ultrasound
Procedure

15. Procedure Patient should empty her bladder
Patient lays in lithotomy position
Gel placed on ultrasound probe
Improves transmission of ultrasound waves
Sterile probe cover placed on probe
Gel placed over probe cover
Patient or sonographer inserts probe
Images obtained

16. Procedure
The components of a typical gynecologic sonographic examination include:
Uterine size, shape, and orientation
Evaluation of endometrium, myometrium, and cervix
Identification and morphology of ovaries, if possible
Assessment of the uterus and adnexa for masses, cysts, hydrosalpinges, fluid collections
Evaluation of the cul-de-sac for free fluid or masses
Normal fallopian tubes usually cannot be seen during pelvic sonography
Source: UpToDate, “Ultrasound examination in obstetrics and gynecology.”

17. Color flow
Doppler color flow mapping uses different colors to depict the direction of flow on a real-time color image
Useful to determine:
Presence of flow
Rule out ovarian torsion
Vascularity of a mass
Characterize the mass
Vascularity of the endometrium/myometrium
Distinguish benign versus malignant conditions

18. Color flow
Mass in endometrium. Color flow reveals multiple vessels=fibroid
Ovary with normal blood flow
Retained products of conception, demonstrated by increased flow to endometrium
Ovarian torsion (no flow)

19. Transvaginal Ultrasound
Indications

20. Indications
Gynecologic ultrasound examination has multiple uses, including but not limited to:
Evaluation of the menstrual cycle (endometrial thickness, follicular development)
Monitoring natural or stimulated follicular development during infertility therapy
Localization of an intrauterine device
Evaluation of abnormal uterine bleeding
Assessment of a pelvic mass (eg, adenomyosis, fibroid, cancer, cysts)
Evaluation for sequelae of pelvic infection (eg, abscess, hydrosalpinx)
Evaluation of congenital uterine anomalies
Screening for malignancy
Source: UpToDate, “Ultrasound examination in obstetrics and gynecology.”