MUSA CRITERIA- DIAGNOSIS OF ADENOMYOSIS BY ULTRASOUND
- Dr. Reena Sherene
- 4 days ago
- 2 min read
MUSA DIAGNOSTIC CRITERIA
asymmetrical thickening (a), cysts (b), hyperechoic islands (c), fan-shaped shadowing (d), echogenic subendometrial lines and buds (e), translesional vascularity (f), irregular junctional zone (g) and interrupted junctional zone (h).
The MUSA (Morphological Uterus Sonographic Assessment) criteria provide a standardized system for describing and reporting ultrasound features of the uterine myometrium, primarily used to diagnose adenomyosis.
The criteria classify ultrasound findings into Direct (indicate ectopic tissue) and Indirect (secondary uterine changes) signs.
Direct Signs (Ectopic Endometrial Tissue)
These signs directly indicate the presence of endometrial tissue inside the muscular wall of the uterus.
Myometrial cysts: Small, circular, fluid-filled pockets within the myometrium.
Hyperechogenic islands: Bright white spots within the muscle wall that are not associated with fibroids.
Echogenic subendometrial lines and buds: Bright lines extending outward from the inner lining of the uterus (the endometrium) into the muscle.
Indirect Signs (Secondary Uterine Changes)
These signs reflect changes in the uterus caused by the presence of the adenomyosis.
Globular uterus: The uterus takes on a rounded, symmetrical "ball-like" shape rather than its normal pear shape.
Asymmetrical myometrial thickening: One side (usually the posterior or anterior wall) of the uterine muscle is noticeably thicker than the other.
Fan-shaped shadowing: Striated, fan-shaped shadows radiating outward from the endometrium.
Translesional vascularity: Blood flow crossing through the lesion, observable via Color Doppler.
Irregular or interrupted junctional zone: The boundary line between the inner endometrium and the outer myometrium appears blurred, broken, or difficult to trace.
Clinical Application
To confirm a diagnosis, experts generally look for at least one direct sign or a combination of altered indirect signs in the junctional zone.
EXAMINATION OF THE MYOMETRIUM
Uterine measurement, shape and external contour
The junctional zone (JZ)
Description of myometrial pathology
Vascularization of the myometrium and myometrial lesions
Examination of the myometrium in general clinical practice
REFERENCE:
Van den Bosch, T., Dueholm, M., Leone, F.P.G., Valentin, L., Rasmussen, C.K., Votino, A., Van Schoubroeck, D., Landolfo, C., Installé, A.J.F., Guerriero, S., Exacoustos, C., Gordts, S., Benacerraf, B., D'Hooghe, T., De Moor, B., Brölmann, H., Goldstein, S., Epstein, E., Bourne, T. and Timmerman, D. (2015), Terms, definitions and measurements to describe sonographic features of myometrium and uterine masses: a consensus opinion from the Morphological Uterus Sonographic Assessment (MUSA) group. Ultrasound Obstet Gynecol, 46: 284-298. https://doi.org/10.1002/uog.14806
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