GYN ultrasound

The plane, and which way is up

Transvaginal, each adnexa found by following the tube laterally from the cornu or by the ovary's relation to the iliac vessels; the ovary is identified by its follicles.

Look for, in order

1. Is the mass ovarian (the ovary cannot be seen separately) or extra-ovarian (the ovary is seen beside it)?
2. Describe it, do not name it: unilocular or multilocular, cystic or solid or mixed, the wall, the septa, any papillary projections, the echogenicity of the fluid (clear, ground-glass, fat with hair), acoustic shadowing, and flow on Doppler.
3. Size in three planes; free fluid; the other side.
4. Then apply a rule (the IOTA simple rules or O-RADS) to sort benign from suspicious.

What normal looks like

A simple cyst under 5 cm in a premenopausal woman is a functional cyst and needs no follow-up. Ground-glass fluid means an endometrioma; fat, hair and a bright plug mean a dermoid; a tubular structure with incomplete septa is a hydrosalpinx.

Trap. A haemorrhagic corpus luteum can look solid and worrying for a few weeks; the clot has no flow and the mass shrinks on the repeat scan.

Describe it in this order

1. The plane and the approach
2. Uterus: size, position, outline, myometrium
3. Endometrium: thickness, echogenicity, outline, cavity contents
4. Cervix
5. Right adnexa, then left: ovary seen, any mass described not named
6. Pouch of Douglas: free fluid
7. Then, and only then, the impression