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GYN ultrasound

17 studies9 challenges

Describe the uterus, the endometrium and each adnexa before naming anything. Every image opens with how to read it; switch to Practice when you are ready to be tested.

Transvaginal ultrasound of an ovary with many small dark follicles at its edge, with calipers marking the ovaryTransvaginal

GYN ultrasound · Ovaries

Ovary with peripheral follicles

Diagnosis

Polycystic ovarian morphology

The plane, and which way is up

Transvaginal in two planes, the ovary measured in three dimensions for its volume, the follicles counted around its periphery.

Look for, in order

  1. Volume (length by width by height by 0.523).
  2. Follicle number: count the antral follicles of 2 to 9 mm.
  3. The stroma: is it increased and bright, with the follicles pushed to the edge?
  4. A dominant follicle or a corpus luteum, which tells you the cycle phase.

What normal looks like

Polycystic morphology is 20 or more follicles per ovary or a volume of 10 mL or more on a modern probe; it is one Rotterdam criterion, not a diagnosis, and is common in normal adolescents.

Trap. Ultrasound is not used to diagnose PCOS within 8 years of menarche, because a multifollicular ovary is normal then.

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

Findings

  • Multiple small peripheral follicles
  • Ovarian volume measured by calipers

What it means for the patient

The current thresholds (follicle number per ovary and ovarian volume) depend on the transducer frequency, which is why the guideline specifies the technology rather than a single number. The count is of follicles 2 to 9 mm, not the cysts of everyday language.

Framework: International PCOS Network, International evidence-based guideline for the assessment and management of polycystic ovary syndrome (2023).

OBGynSpace Tutor

It coaches the description; it does not read the image for you and will not name the diagnosis before you commit.