Endometrium in the myometrium: an asymmetric globular uterus, a thickened, irregular junctional zone, myometrial cysts and fan-shaped shadowing — MUSA features on ultrasound, junctional zone thickness on MRI.
Orient first
- On ultrasound the MUSA consensus lists direct features (myometrial cysts, islands, buds) and indirect features (asymmetry, fan-shaped shadowing, translesional vascularity).
- On MRI a junctional zone ≥ 12 mm or focal thickening supports adenomyosis (verify thresholds).
- It coexists with endometriosis and fibroids.
Acquire the study
- Transvaginal probe; sagittal and transverse planes; 3D coronal view of the junctional zone where available.
The manoeuvre
- Uterine shape: globular, asymmetric anterior vs posterior wall thickness in mm.
- Myometrial cysts and hyperechoic islands.
- Fan-shaped (venetian blind) acoustic shadowing.
- Colour Doppler: translesional vessels crossing the lesion (unlike the peripheral flow around fibroids).
What confirms it
- Direct features (myometrial cysts, islands, T2-bright foci in a thickened junctional zone).
What licenses you to exclude it
- A regular, thin junctional zone without direct features makes adenomyosis unlikely.
The classic misread
- Calling a contraction adenomyosis — it changes over minutes.