A sonographic classification of adenomyosis: interobserver reproducibility in the evaluation of type and degree of the myometrial involvement

Objective: To study the interobserver reproducibility of our new ultrasonographic mapping system to define the type and extension of uterine adenomyosis.

Design: Interobserver study involving two observers with different medical backgrounds and gynecological ultrasound experience.

Setting: University hospital.

Patients: Seventy consecutive women who underwent transvaginal ultrasound for suspected endometriosis, pelvic pain, heavy menstrual bleeding, and infertility.

Intervention: Two operators (observers A and B), who were blinded, independently reviewed the ultrasound videos offline, assessing the type of adenomyosis and the severity of the disease. Diagnosis of adenomyosis was made when typical ultrasonographic features of the disease were observed at the examination. Adenomyosis was defined as diffuse, focal, and adenomyoma according to the ultrasonographic characteristics. The severity of adenomyosis was described using a new schematic scoring system that describes the extension of the disease considering all possible ultrasound adenomyosis features.

Main outcome measures: Reproducibility of the new mapping system for adenomyosis and rate agreement between two operators.

Results: Multiple rate agreements to classify the different features and the score of adenomyosis (diffuse, focal adenomyoma, and focal or diffuse alteration of junctional zone) ranged from substantial to almost perfect (Cohen κ = 0.658 - 1) except for adenomyoma score 4 (one or more adenomyomas with the largest diameter >40 mm) in which interobserver agreement was moderate (κ = 0.479).

Conclusion: Our new scoring system for uterine adenomyosis is reproducible and could be useful in clinical practice. The standardization of the transvaginal approach and of the sonographer training represent a crucial point for a correct diagnosis of myometrial disease.